Dissertations / Theses: 'Heavy vehicles'

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Felixson, Henrik. "Vehicle Ahead Property Estimation in Heavy Duty Vehicles." Thesis, Linköpings universitet, Reglerteknik, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-108341.

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Rombach, Markus. "Vehicle Speed Estimation for Articulated Heavy-Duty Vehicles." Thesis, Linköpings universitet, Reglerteknik, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-152428.

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Common trends in the vehicle industry are semiautonomous functions and autonomous solutions. This new type of functionality sets high requirements on the knowledge about the state of the vehicle. A precise vehicle speed is important for many functions, and one example is the positioning system which often is reliant on an accurate speed estimation. This thesis investigates how an IMU (Inertial Measurement Unit), consisting of a gyroscope and an accelerometer, can support the vehicle speed estimation from wheel speed sensors. The IMU was for this purpose mounted on a wheelloader. To investigate the speed estimation EKFs (Extended Kalman Filters) with different vehicle and sensor models are implemented. Furthermore all filters are extended to Kalman smoothers. First an analysis of the sensors was performed. The EKFs were then developed and verified using a simulation model developed by Volvo Construction Equipment. The filters were also implemented on the wheel loader and tested on data collected from real world scenarios.

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Iqbal, Ammar Tanange Rakesh Virk Shafqat. "Vehicle fault prediction analysis : a health prediction tool for heavy vehicles /." Göteborg : IT-universitetet, Chalmers tekniska högskola och Göteborgs universitet, 2006. http://www.ituniv.se/w/index.php?option=com_itu_thesis&Itemid=319.

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Gustafsson, Tobias. "In-Vehicle Execution Environment for Diagnostic Scripts on Heavy Commercial Vehicles." Thesis, KTH, Maskinkonstruktion (Inst.), 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-192155.

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Today the importance and complexity of vehicle diagnostics are increasing and more systems uses remote diagnostics. Remote diagnostics involves an off-board server that uses a wireless connection to access the diagnostic services inside a vehicle on a remote location. Problems occur because of the remote connections limitations in speed and reliability. This can be solved by executing tasks on an Electrical Control Unit (ECU) inside the vehicle. However, implementing new software in an ECU is time consuming and expensive. An in-vehicle execution environment for diagnostic scripts can make it possible to send these tasks from the off-board systems and execute them on-board the vehicle. This thesis investigates that possibility. A set of requirements for an in-vehicle execution environment are identified together with important decisions that affects them. Restricting the diagnostic services to only passive scripts reduces the requirements. Using a higher abstraction level in the scripts to send diagnostic commands makes it easier to develop scripts, but requires more software to be implemented on the ECU. The choice of script engine is also important and a survey and evaluation of different script engines is performed. Python, Lua, mRuby and ChaiScript are compared and Lua is selected for an implementation used in a case study where the results are validated. This case study shows that the requirements are sufficient to create an in-vehicle execution environment that can execute advanced diagnostic tasks. An in-vehicle script executes more than eight times faster than the same task on the off-board system and decreases the amount of data in the remote communication. Development of a script is more than 20 times faster compared to the development of ECU system software. Before this in-vehicle execution environment can be used on a population of vehicles, investigations needs to be done regarding the requirements for the off- board systems and how the development and usage of scripts should be organized.
Idag ökar vikten och komplexiteten hos fordonsdiagnostik och fler system använder fjärrdiagnostik. Fjärrdiagnostik innebär att en server använder en trådlös anslutning för att komma åt de diagnostiska tjänsterna i ett fordon på en avlägsen plats. Problem uppstår på grund av begränsningar i hastighet och tillförlitlighet hos fjärranslutningarna. Detta kan lösas genom att köra uppgifter i fordonet. Men att göra ny programvara i ett fordon är tidskrävande och dyrt. En exekveringsmiljö för diagnostiska skript kan göra det möjligt att skicka dessa uppgifter från de externa systemen och köra dem ombord på fordonet. I den här avhandling undersöks denna möjlighet. En uppsättning krav för en exekveringsmiljö för diagnostiska skript har identi- fieras. Att begränsa de diagnostiska tjänsterna till endast passiva skript minskar kraven. Med hjälp av en högre abstraktionsnivå för att skicka diagnostiska kommandon blir det lättare att utveckla skript, men detta kräver att mer programvara är implementerad i fordonet. Valet av skriptmotorn är också viktigt och en undersökning och utvärdering av olika skriptmotorer har utförs. Python, Lua, mRuby och ChaiScript har jämförts och Lua valts för en implementering som används i en fallstudie där resultaten har validerats. Denna fallstudie visar att kraven är tillräckliga för att skapa en exekveringsmiljö som kan utföra avancerade diagnostiska uppgifter. Ett skript som körs i fordonet körs mer än åtta gånger snabbare än samma uppgift på som körs på de externa systemet och minskar också mängden data i fjärrkommunikationen. Utveckling av ett skript är mer än 20 gånger snabbare jämfört med utvecklingen av systemprogramvaran i fordonet. Innan en exekveringsmiljö kan användas på en population av fordon måste undersökningar göras om kraven för de externa system som ska hantera skripten och hur utvecklingen och användningen av skript ska organiseras.

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Möller, Anders. "Software Component Technologies for Heavy Vehicles." Licentiate thesis, Mälardalen University, Department of Computer Science and Electronics, 2005. http://urn.kb.se/resolve?urn=urn:nbn:se:mdh:diva-34.

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Control-systems for heavy vehicles have advanced from an area where Industrial Requirements on Component Technologies for Embedded Systemsmainly mechanic and hydraulic solutions were used, to a highly computerised domain using distributed embedded real-time computer systems. To cope with the increasing level of end-customer demands on advanced features and functions in future vehicle systems, sophisticated development techniques are needed. The development techniques must support software in numerous configurations and facilitate development of systems with requirements on advanced functionality, timeliness, and safety-criticality. In order to meet these requirements, we propose the use of component-based software engineering. However, the software component-technologies available on the market have not yet been generally accepted by the vehicular industry. In order to better understand why this is the case, we have conduced a survey - identifying the industrial requirements that are deemed decisive for introducing a component technology. We have used these requirements to evaluate a number of existing component technologies, and one of our conclusions is that none of the studied technologies is a perfect match for the industrial requirements. In addition, we have implemented and evaluated the novel component model SaveCCM, which has been designed for safety-critical automotive applications. Our evaluation indicates that SaveCCM is a promising technology which has the potential to fulfil the industrial requirements. However, tools are still immature and incomplete. In the final part of this work, we propose the use of monitored software components, as a general approach for engineering of embedded systems. In our approach, a component's execution is continuously monitored and experience regarding the behaviour is accumulated. As more and more experience is collected the confidence in the component grows.

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Hellström, Erik. "Look-ahead Control of Heavy Vehicles." Doctoral thesis, Linköpings universitet, Fordonssystem, 2010. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-54922.

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Trucks are responsible for the major part of inland freight and so, they are a backbone of the modern economy but they are also a large consumer of energy. In this context, a dominating vehicle is a truck with heavy load on a long trip. The aim with look-ahead control is to reduce the energy consumption of heavy vehicles by utilizing information about future conditions focusing on the road topography ahead of the vehicle. The possible gains with look-ahead control are evaluated by performing experiments with a truck on highway. A real-time control system based on receding horizon control (RHC) is set up where the optimization problem is solved repeatedly on-line for a certain horizon ahead of the vehicle. The experimental results show that significant reductions of the fuel consumption are achieved, and that the controller structure, where the algorithm calculates set points fed to lower level controllers, has satisfactory robustness to perform well on-board in a real environment. Moreover, the controller behavior has the preferred property of being intuitive, and the behavior is perceived as comfortable and natural by participating drivers and passengers. A well-behaved and efficient algorithm is developed, based on dynamic programing, for the mixed-integer nonlinear minimum-fuel problem. A modeling framework is formulated where special attention is given to properly include gear shifting with physical models. Fuel equivalents are used to reformulate the problem into a tractable form and to construct a residual cost enabling the use of a shorter horizon ahead of the vehicle. Analysis of errors due to discretization of the continuous dynamics and due to interpolation shows that an energy formulation is beneficial for reducing both error sources. The result is an algorithm giving accurate solutions with low computational effort for use in an on-board controller for a fuel-optimal velocity profile and gear selection. The prevailing approach for the look-ahead problem is RHC where main topics are the approximation of the residual cost and the choice of the horizon length. These two topics are given a thorough investigation independent of the method of solving the optimal control problem in each time step. The basis for the fuel equivalents and the residual cost is formed from physical intuition as well as mathematical interpretations in terms of the Lagrange multipliers used in optimization theory. Measures for suboptimality are introduced that enables choosing horizon length with the appropriate compromise between fuel consumption and trip time. Control of a hybrid electric powertrain is put in the framework together with control of velocity and gear. For an efficient solution of the minimum-fuel problem in this case, more fuel equivalence factors and an energy formulation are employed. An application is demonstrated in a design study where it is shown how the optimal trade-off between size and capacity of the electrical system depends on road characteristics, and also that a modestly sized electrical system achieves most of the gain. The contributions develop algorithms, create associated design tools, and carry out experiments. Altogether, a feasible framework is achieved that pave the way for on-board fuel-optimal look-ahead control.

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Kitching, Kevin John. "Semi-active damping of heavy vehicles." Thesis, University of Cambridge, 1997. https://www.repository.cam.ac.uk/handle/1810/265419.

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This thesis is concerned with the use of semi-active suspensions in heavy vehicles to improve ride and reduce road damage. An introduction into the subject is given in chapter 1 and a review of the relevant literature is presented at the beginning of each main chapter. The development and modelling of a prototype, continuously variable semi-active damper for heavy vehicles is described in chapter 2. A proportional valve is used to generate the variable damping coefficient and the detrimental effects of the oil flow forces acting on the valve spool are studied. The force tracking performance of the damper is then examined for simple input conditions and the compliance of the hydraulic fluid is found to have a strong influence upon the response of the damper. The different vehicle and road models used in the thesis are described in chapter 3. In chapter 4, the performance of the prototype damper is investigated under realistic operating condition using a Hardware-in-the-Loop (HiL) test rig, with a single wheel station vehicle model. The prototype damper displays a phase lag of approximately 20ms between the demanded and achieved damping force. The semi-active suspension is found to be most effective in reducing the body accelerations relative to an optimum non-linear passive suspension. A theoretical investigation into the reduction of road damage through the use of active and semi-active suspensions is described in chapter 5. The relative performance of four linear state feedback control strategies is examined. The potential for reducing road damage by using a controller which directly regulates various measures of road damage is also studied. Significant improvements are predicted for the three controllers which assume the road inputs to the vehicle are correlated. However, these benefits are shown to diminish as the vehicle speed is reduced. It is concluded that the control of the dynamic tyre forces is an effective means by which to regulate road damage. Theoretical predictions of the benefits from wheelbase preview control are measured experimentally in chapter 6, using the prototype semi-active damper in a half-car HiL rig with a planar two axled heavy vehicle model. The benefits of preview control using the prototype semi-active damper are found to be less than theoretically possible due to the phase lag between the demanded and achieved damping force of the prototype damper. The final section of chapter 6 shows that the performance of the prototype damper can be improved further by having a theoretical simulation running ahead of the HiL vehicle. The theoretical simulation is used to predict the demanded damper force for the HiL vehicle and thereby compensate for the phase lag in the prototype damper. Conclusions and recommendations for further work are presented in chapter 7.

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Garcia, Hector, and Emma Smith. "Wheel Induced Vibrations on Heavy Vehicles." Thesis, KTH, Skolan för teknikvetenskap (SCI), 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-153927.

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Some of the most significant comfort disturbances in heavy vehicles can often be related to the wheels. In those cases, the vibration of the vehicle is excited by for example force variations within the tire, ovality of the tire or imbalance in the wheel. The disturbances are dependent on vehicle speed and are often perceived as most unpleasant at cruising speed on a motorway, at around 90 km/h. Truck manufacturers want to increase the robustness against this type of disturbance, since this results in an improved operator comfort. But it also makes it possible to lower the requirements on the suppliers of tires and rims, and thereby there is a financial gain for both customer and manufacturer. The aim with this project is to increase the understanding of wheel induced vibrations. In order to achieve this a literature survey has been performed on the subject. Furthermore, the phenomenon has been studied analytically by using a quarter car model which includes a brush tire model. The model is scripted in MATLAB. Simulations have been performed to analyse the effect on the chassis when forces excited by mass imbalance and radial run out are introduced. When looking at the second harmonic radial run out imperfection the unsprung mass, i.e the wheel, starts to bounce during the settling time. Also when comparing two different weights of a mass imbalance the power increase of the vibration in the sprung mass is much larger than the power increase of the unsprung mass at the specific frequency. This implies that the excitation frequency, the wheel rotation frequency in this case, is a harmonic repetition of the sprung mass undamped natural frequency. To avoid this phenomenon the undamped natural frequency of the sprung mass must change either by adding a damper or by changing the weight or the spring stiffness. The simulation is run with a damper although without it the power increase would be much larger.

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Ohlsén, Rikard, and Erik Sten. "Optimal Platooning of Heavy-Duty Vehicles." Thesis, Linköpings universitet, Fordonssystem, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-149599.

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The vehicle and transport industry have a constant strive towards reduced fuelconsumption and for HDVs are there numerous of different approaches. Twoapproaches that have been proven to reduce fuel consumption in previous workare look-ahead control (LAC) and platooning. LAC uses knowledge about the fu-ture road topography to optimize the vehicles velocity. Platooning is when HDVsdrive relatively close to each other in order to reduce air drag. Platooning vehi-cles can also optimize their velocity based on the preceding vehicles trajectory,known as adaptive look-ahead control (ALAC).Utilizing LAC/ALAC can enable a pulse-and-glide (PnG) strategy, where thevehicle engages neutral gear and freewheels e.g. in a downhill. Thereby reducesthe fuel consumption. So, the main purpose of this thesis was to study how pla-tooning vehicles and the control strategy known as pulse-and-glide (PnG) inter-act when pursuing lower fuel consumption. Therefore, a vehicle model, a pla-toon model and optimization-based controllers (LAC/ALAC) were designed anddeveloped. For the optimization-based controllers was dynamic programming(DP) chosen as optimization solver.The results shows that the combination of these approaches has a great poten-tial to enable substantial fuel reduction, both for individual vehicles and for theentire platoon. The most suitable strategy, in terms of fuel consumption, for theplatoon as a whole is closely related to the one for individual vehicles. The strate-gies resulting in the largest fuel reduction for a single vehicle does also give thelargest total fuel reduction for the platoon as a whole. According to the results,a lead vehicle should utilize both LAC and PnG. The other platooning vehiclesshould employ ALAC in order to also utilize PnG meanwhile keeping a shortintermediate distance.According to the results the greatest potential fuel reduction is achieved forthe downhill segment. For the last vehicle in the platoon it is as high as 42 %, com-pared to the nominal case (a single vehicle using conventional cruise control andnot shifting gears). The potential fuel reduction for the flat and uphill segmentsare similar to each other, 22 % and 20 % respectively. For all three segments PnGaccounts for roughly 1-3 percentage points of the entire platoons fuel reduction.In reality the road topography is constantly varying, so it is also promising thatthe fuel efficiency is improved for all types of road segments

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Hård, Patrik. "Heavy vehicles: Load variation and scatter." Thesis, KTH, Skolan för industriell teknik och management (ITM), 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-279493.

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This master thesis studies accelerations recorded and stored onboard Scania trucks. From these accelerations, a general load (𝐹 = 𝑚 ∗ 𝑎) description is deduced. In the next step, an abstract number, ‘pseudo-damage’, representing the load’s fatigue damage potential is calculated. Method At workshop visits, data stored on-board is ‘read out’ and stored in a database. Read-outs from Scania test vehicles are used to study how accumulated pseudo-damage evolves with mileage and test cycles. Pseudo-damage intensity (damage per km or test cycle) variation in carefully controlled vehicle operation, i.e. test track vehicle testing, suggests a threshold between random scatter and variation caused by describable load-influencing factors (vehicle specification, road quality, etc). Influence of wheel configuration – two or three axles – on accelerations and pseudo-damage is studied as an example of vehicle specification influence. Result Test track operation produces considerably higher pseudo-damage intensities than operation on public roads. A ‘normal’ pseudo-damage distribution is shown on title page. But when the vehicle’s operation is split in two distinctly different modes, the distribution displays two peaks instead. RSD, relative standard deviation of pseudo-damage intensity, is used to quantify scatter and variation. Available data indicates that RSD below 0,3 can be regarded as purely random scatter. RSD values above this threshold suggests that traceable, maybe intentional, variation of loadinfluencing factors is present. A pilot study of axle configuration’s influence on loads (pseudo-damage calculated from acceleration matrices) produces inconclusive results, the available database (number of trucks) is too small. Conclusions and recommendations On-board storage of acceleration data provides a general ‘fatigue load’ indication. Resolution is sufficient for meaningful load variation studies. Regular, closer-spaced read-outs would facilitate more detailed studies of test vehicles’ operation.
Mastersarbetet studerar accelerationer, uppmätta och lagrade hos Scanias fordon. Från dessa accelerationer är begreppet ‘pseudo-skada’ beräknat. Pseudo-skada representerar en lasts utmattnings skada potential. Metod Vid verkstadsbesök sparas den data som finns lagrad ombord på lastbilen till en databas. Med utläsningar från testfordonen studeras hur den ackumulerade pseudo-skadan beror på miltal och antal körda test cykler. Genom analys utav variationen i pseudo-skada intensitet (skada per km eller test cykel) från en välkontrollerad fordonsdrift, exempelvis test utförda på test banan, fås ett tröskelvärde mellan slumpmässiga variationer och variationer som beror på förklarliga belastningspåverkande faktorer (fordon specifikation, väg kvalité, etc.) Som ett exempel på influens från olika fordon specifikationer, studeras beroendet mellan pseudoskada och hjulkonfiguration. Fordon med antingen två eller tre hjulaxlar är studerade. Resultat Vid framförande av fordon på testbanan genereras högre pseudo-skada intensitet än när fordonet framförs på allmänna vägar. Figuren på titelsidan visar den normala fördelningen utav pseudo-skada. När fordonsdriften är uppdelad i två distinkta körsätt visar istället fördelningen upp två stycken pikar. Relativ standard avvikelse, RSD, av pseudo-skada intensiteten är beräknad för att kvantifiera slumpmässig och betydelsefull variation. Tillgänglig data visar att ett RSD under 0,3 är att se som slumpmässig variation. RSD värden över detta tröskelvärde visar på existens utav spårbara variationer från belastningspåverkande faktorer. Resultaten från förstudien av beroendet mellan hjulkonfiguration och pseudo-skada är inte slutgiltiga. Den analyserade datamängden är för liten. Slutsatser och rekommendationer De lagrade accelerationerna ger en generell indikation om ‘utmattningslasten‘. Upplösningen är tillräcklig för att kunna studera de meningsfulla lastvariationerna. Regelbundna utläsningar, i ett tätare intervall, skulle främja mer detaljerade studier utav fordonsdriften.

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Miller, Jonathan Israel. "Advanced braking systems for heavy vehicles." Thesis, University of Cambridge, 2010. https://www.repository.cam.ac.uk/handle/1810/244231.

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This dissertation describes research into the use of advanced emergency braking hardware and wheel slip control algorithms on pneumatically braked heavy goods vehicles. Anti-lock braking systems (ABS) on commercial heavy vehicles use inefficient control approaches that work on cycles of exceeding the limits of tyre-road adhesion. Long pipe lengths and slow pneumatic brake valves create time delays that limit the speed of response. The result is poor emergency stopping performance. An alternative approach to conventional ABS is wheel slip control, which optimises slip during braking. Mathematical models were made of the pneumatics and dynamics of a heavy vehicle brake that featured a high-speed actuator placed directly on the brake chamber. The results were used to inform the specifications for a second generation, made-for-purpose actuator. Designing the second generation actuator involved balancing the conflicting requirements for the magnetic circuit subsystem and the mechanical performance. The resulting prototype actuator produced pneumatic response times an order of magnitude smaller than conventional ABS hardware. A wheel slip control algorithm was derived for pneumatically-braked heavy vehicles. The algorithm was based on sliding mode theory, and was robust to sensor noise and road conditions. A braking force observer based on sliding mode theory, a nonlinear least squares surface identification algorithm, and a recursive least squares brake gain estimator were formulated to support the sliding mode controller. The state and parameter estimation algorithms were evaluated in vehicle simulations and with full-scale test data. The sliding mode controller was combined with the second generation actuator in vehicle simulations to compare its performance to an alternative actuator with piloted piston valves proposed for a separate project, and to conventional ABS hardware and control algorithms. The second generation actuator produced 8.2% shorter stops and used 70% less compressed air than the alternative actuator. The second generation actuator also produced up to 25% shorter stops and used up to 70% less air relative to conventional ABS.

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Oliveira, Rui. "Motion Planning for Heavy-Duty Vehicles." Licentiate thesis, KTH, Reglerteknik, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-252537.

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Autonomous driving is a disrupting technology that is expected to reshape transportation systems. The benefits of autonomous vehicles include, but are not limited to, safer transportation, increased economic growth, and broader access to mobility services. Industry and academia are currently researching a variety of topics related to autonomous driving, however, the focus seems to be on passenger vehicles. As a consequence, heavy-duty vehicles, which are a significant share of transportation systems, are overlooked, and the challenges associated with these vehicles are neglected. This thesis studies motion planning algorithms for heavy-duty vehicles. Motion planning is a fundamental part of autonomous vehicles, it is tasked with finding the correct sequence of actions that take the vehicle towards its goal. This work focuses on particular aspects that distinguish heavy-duty vehicles from passenger vehicles, and that call for novel developments within motion planning algorithms. We start by addressing the problem of finding shortest paths for a vehicle in obstacle-free environments. This problem has been studied since the fifties, but the addressed vehicle models are often simplistic. We propose a novel algorithm that is able to plan paths respecting complex vehicle actuator constraints associated with the slow dynamics of heavy vehicles. Using the previous method, we tackle the motion planning problem in environments populated with obstacles. Lattice-based motion planners, a popular choice for this type of scenario, come with drawbacks related to the sub-optimality of solution paths, and the discretization of the goal state. We propose a novel path optimization method, which is able to significantly reduce both problems. The resulting optimized paths contain less oscillatory behavior and arrive precisely at arbitrary non-discretized goal states. We then study the problem of bus driving in urban environments. It is shown how this type of driving is fundamentally different than that of other vehicles, due to the chassis configuration with large overhangs. To successfully maneuver buses, distinct driving objectives need to be used in planning algorithms. Moreover, a novel environment classification scheme must be introduced. The result is a motion planning algorithm that is able to mimic professional bus driver behavior, resulting in safer driving and increased vehicle maneuverability.

QC 20190603

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Nennelli, Anjali Devi. "Simulation of heavy-duty hybrid electric vehicles." Morgantown, W. Va. : [West Virginia University Libraries], 2001. http://etd.wvu.edu/templates/showETD.cfm?recnum=2259.

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Thesis (M.S.)--West Virginia University, 2001.
Title from document title page. Document formatted into pages; contains xvi, 112 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 85-87).

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George, Rodney Martin, and rod george@arrb com au. "Towards performance-based route selection guidelines for heavy vehicles (the dynamics of heavy vehicles over rough roads)." Swinburne University of Technology, 2003. http://adt.lib.swin.edu.au./public/adt-VSWT20060629.100558.

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With an increasing number of transport operators seeking permits to operate nonstandard or purpose-built vehicle types, information is required to assist road authorities to determine which vehicle types could operate on the road network without compromising the safety of other road users. A project was created by ARRB TR to develop guidelines for determining route access for heavy vehicles. This project was developed in conjunction with the state road authorities, the National Road Transport Commission and the transport industry to obtain an understanding of the road space requirements for a range of common vehicle types. This project is the subject of this thesis. Two series of field experiments were conducted with six common heavy vehicle types on public roads west of Parkes NSW. Information collected during these full-scale experiments was used to increase the knowledge of the dynamic behaviour of these vehicles and to develop model route access guidelines. Data obtained from these field experiments also provided information to validate computer models and simulation outputs. This thesis showed that: 1) There was experimental evidence to demonstrate that vehicle lateral movement is excited by differences in vehicle wheelpath profiles (point-by-point pavement crossfall), which make a contribution to trailing fidelity (swept width), offtracking and swept path; 2) Vehicle type and speed are prime influences on the lateral movement of the rear trailer and therefore an important input into the model route access guidelines. Notwithstanding the practical and safety implications of applying different speed limits for various vehicle types, speed is a prime contributor to vehicle lateral movement and should be considered when determining route access; 3) Limited lateral position information suggested that one driver of two vehicle types position the vehicles so that the tyres on the rear trailer track on the sealed pavement and not on the pavement shoulder; 4) Based on a statistical analysis of the data obtained from the small sample which only considered the average crossfall of each test section the relative importance of the key parameters was (highest to lowest), IRI, vehicle speed and vehicle type. It was shown that good estimates of lateral movement can be obtained using a double integration technique of the measured lateral acceleration, without applying compensation for the trailer roll or the pavement crossfall. It is recommended that route access guidelines be developed using the lateral performance of a larger sample of vehicles in each class of heavy vehicles operating over a larger range of road types. The route access guidelines should contain a matrix of information on vehicle type/length, pavement condition roughness/profile and lane width. This would provide operators and regulators with a desk-top assessment tool for determining route access.

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Smith, Jonathan Burke. "Optimum hybrid vehicle configurations for heavy duty applications." Morgantown, W. Va. : [West Virginia University Libraries], 2001. http://etd.wvu.edu/templates/showETD.cfm?recnum=1985.

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Thesis (M.S.)--West Virginia University, 2001.
Title from document title page. Document formatted into pages; contains viii, 109 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 71-72).

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Wallmyr, Markus. "Exploring Interaction Design Perspectives on Heavy Vehicles." Licentiate thesis, Mälardalens högskola, Inbyggda system, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:mdh:diva-34906.

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Interaction design is more crucial than ever as an ingredient in product development and digitalization. Its need is driven by a trend where software based functionality is becoming increasingly important in all types of product features, simultaneously as new technology moves the frontier where interaction between human and computer takes place. There is also a market demanding renewed experiences, more efficient, stimulating and fashionable, which enterprises seek to deliver to attract customers. Also[WM1] , as systems, for example vehicle systems, get increasingly information intense, the information exchange with the user becomes a factor for safe and successful operation, thus increasing the need for a proficient interaction design. This research investigates how interaction technologies, interaction design principles, and machine information systems can be used to provide user experiences and efficient interaction between the operator and industrial mobile machines; for example, agricultural machines and construction machines. The research combines software engineering and interaction design together with an industrial perspective. It does so by studies, both in literature and through field studies of operators, by design exploration and prototype realization. The thesis describes the design space for heavy vehicles through different perspectives. It outlines the principal dimensions of interaction design and the benefits of including design in product and services realization. It presents perspectives on the challenges for the different stakeholders involved, covering the operator of the machines, the software engineer and the designer. It depicts a method for gaining detailed insights into operator’s daily behavior, with minimal interference with their work. Furthermore, it introduces a tool for practitioners to explore interaction design using mixed reality and free head movements, and it investigates possible interfaces using augmented reality.
Interaktionsdesign är mer avgörande i produktutveckling och digitalisering än någonsin. Utvecklingen här drivs av en trend där mjukvarubaserad funktionalitet blir allt viktigare i alla typer av produkter samtidigt som ny teknik ökar designrymden för var samspelet mellan människa och dator kan äga rum. Användare efterfrågar förnyade upplevelser, mer effektiva, stimulerande och moderiktiga. Företag söker möta denna efterfrågan för att locka kunder och genera affärer. Dessutom, genom att system, exempelvis fordonssystem, blir allt mer informationsintensiva, blir sättet som informationsutbytet sker med användaren en allt viktigare faktor för säkerhet och funktionalitet. Sammantaget ökar behovet av en skickligt utförd interaktionsdesign. Den här avhandlingen undersöker hur interaktionstekniker, interaktionsdesignsprinciper och informationssystem kan användas för att leverera användarupplevelser och effektiv interaktion för operatörer av industriella mobila maskiner, exempelvis jordbruksmaskiner och anläggningsmaskiner. Forskningen kombinerar interaktionsdesign och mjukvaruutveckling i ett industriellt kontext. Forskningen har bedrivits genom studier, i litteratur och etnografiska studier av användare i fält, genom utforskande design och genom prototyprealisering. Avhandlingen beskriver designrymden för industrifordon från flera perspektiv. Dels från perspektiven av de grundläggande elementen inom interaktionsdesign, processerna för att skapa och forska inom interaktionsdesign samt fördelarna med designdriven produkt- och tjänste-förverkligande. Vidare tar den upp perspektiv utifrån situationen och utmaningarna för inblandade aktörer, såsom operatören av maskinen, mjukvaruutvecklaren och designern. Avhandlingen bidrar också med praktiska perspektiv, dels en metod för att få detaljerad inblick i operatörens dagliga beteende med minimal störning i sitt arbete, och dels ett verktyg för interaktionsdesigners att undersöker möjliga designs med virtuell förstärkt verklighet med hjälp av blandad virtuell verklighet och fria huvudrörelser.

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Holen, Peter. "On modally distributed damping in heavy vehicles." Doctoral thesis, Stockholm : School of engineering sciences, Royal Institute of Technology, 2006. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-4163.

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18

Sjölund, Rickard, and Nicklas Vedin. "Steering System Modelling for Heavy Duty Vehicles." Thesis, Linköpings universitet, Reglerteknik, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-119770.

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Future heavy duty vehicles will be designed and manufactured with improved Advanced Driver Assistance Systems, ADAS. When developing ADAS, an accurate model of the vehicle dynamics greatly simplifies the development process. One element integral to the vehicle lateral dynamics and development of ADAS is the steering system. This thesis aims to develop an accurate model of a heavy duty vehicle steering system suitable for simulations. The input to the system is an input torque at the steering wheel and the output is the wheel angle. Physical models of the system components are developed using bond graphs and known relations. Some components are modelled with non-linear inefficiencies and friction of different complexity. Unknown parameters and functions are identified from measurement data using system identification tools such as, for example, linear regression and non-linear grid search. The different subsystems are identified separately to the extent deemed possible. Different model designs are considered, validated, and compared. The advantages and disadvantages of different model choices are discussed. Finally, a non-linear state space model is selected for its high accuracy and efficiency. As this final model can be used to simulate a heavy duty vehicle steering system on a desktop computer faster than real time, it fulfills its purpose.

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Barden, Jason. "Active Aerodynamic Control of Heavy Goods Vehicles." Thesis, Cranfield University, 2013. http://dspace.lib.cranfield.ac.uk/handle/1826/9293.

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Most heavy goods vehicles in service today are fitted with add-on aerodynamic devices. The most common of which is the cab-mounted roof deflector. Such devices provide appreciable drag savings, however, they are often not optimised for the trailer. When a wind yaw angle is present, their savings also diminish as the yaw angle increases. The work conducted within this thesis investigated the possibility of using an adjustable deflector for active flow control. The optimum deflector height for a given trailer height was initially investigated using wind tunnel testing. The variation of this optimum with yaw angle and container separation was then investigated. From the results a 3D look-up table was generated. A control scheme was proposed that used the 3D look-up table requiring only three measurable inputs. The three inputs required were: the wind yaw angle, the container height and the container separation. A pressure differential located on the deflector was found to linearly relate to the wind yaw angle. This relationship allowed on-road measurement of the wind yaw angle and therefore enabled the development of a prototype controller. Extensive on-road testing and unsteady computational simulation were conducted. The results obtained indicated a mean yaw angle magnitude of around 5 perturbed by four fundamental low frequencies. These frequencies were identified in the runs conducted over the test period and an average frequency established. Higher frequency disturbances were attributed to the wakes of leading heavy goods vehicles and were filtered by a suitably chosen numerical filter. Finally, an estimation of the efficiency of the active device was made using a combination of simulation and full scale testing. From the results obtained, an optimised deflector generated an average drag reduction of 7.4%. An estimated additional drag reduction of 1.9% over the optimised deflector was predicted through use of an active system.

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Rimmer, Amy Juliet. "Autonomous reversing of multiply-articulated heavy vehicles." Thesis, University of Cambridge, 2015. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.708656.

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Sampson, David John Matthew. "Active roll control of articulated heavy vehicles." Thesis, University of Cambridge, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.621986.

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22

Birksjö, Marcus. "Event-based diagnostics in heavy-duty vehicles." Thesis, Linköpings universitet, Programvara och system, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-129589.

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The integration of small computer units in vehicles has made new and more complex functionalitypossible within the vehicle industry. To verify that the functionality is working and to troubleshoot it when a fault is detected requires a set of diagnostic services. Due to the increasing complexity of the functionality the diagnostic services need to extract more data to be able to diagnose the functionality. This causes an increased network load which soon threatens to become too high for some of the current networks. New ways to diagnose functionality in vehicles are therefore needed. The aim of this thesis was to investigate the need for an event-based service within the domain of vehicle diagnostics as well as presenting a recommendation of how sucha service should be designed. The thesis also aimed at eliciting obstacles and pitfalls connected with the implementation of the service in the current software architecture in heavy duty vehicles. An industrial case study was performed at the Swedish company Scania to elicit the potential need, problems and limitations with an event-based service for vehicle diagnostics. First a set of experts representing different domains within vehicle diagnostics were interviewed to investigate the need and potential of the service for different use cases. Requirements were elicited and compared with the service ResponseOnEvent defined inthe ISO standard 14229-1:2013. A decision was then made to diverge from the standard inorder to increase the number of fulfilled requirements and flexibility of the service. A new proprietary service was therefore created and evaluated through a proof of concept wherea prototype of the service was implemented in one client and one server control unit. A final recommendation was then given suggesting how to implement an event-based service and how to solve the found problems. The elicitation of the need for an event-based service resulted a confirmed need in three different domains and 23 different requirements which the service ResponseOnEvent was compared against. The service failed to meet all the requirements and therefore a proprietary service was designed. The prototype implementation of the proprietary service showed on multiple difficulties connected to the realization of an event-based service in the current architecture. One of the biggest was the fact that diagnostic services was assumed to always have a one-to-one relation between request and response, which an event-based service would not have. Different workarounds were discovered and assessed. Another problem was the linking between an event triggered response message and the triggercondition. It was concluded that some restrictions would have to be made to facilitatethe process of linking a response to its trigger condition. Non-determinism was another problem, since there were no guarantees that an event would not trigger too often causinga bus overload. In the final recommendation there are suggestions of how to solve these problems and some suggested areas for further research. The thesis confirms the need for a new way to diagnose vehicle functionality due to their increased complexity and the limited bandwidth of some of today’s in-vehicle networks. The event-based service ResponseOnEvent offers a good alternative but might lacksome key functionality. Therefore it might be valuable to consider a proprietary service instead. Due to its nature, an event-based service might require a restructuring of thesystem architecture and limitations in the hardware might limit the usability and flexibilityof the service. Keywords: event-based service, Response on Event, ECU, Vehicle Diagnostics, UDS,KWP.

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af, Klintberg Max. "Predictive Modeling of Emissions : Heavy Duty Vehicles." Thesis, Umeå universitet, Institutionen för matematik och matematisk statistik, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-124452.

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24

Åfeldt, Tom. "Adaptive Steering Behaviour for Heavy Duty Vehicles." Thesis, KTH, Reglerteknik, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-215134.

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Today the majority of the driver assistance systems are rule-basedcontrol systems that help the driver control the truck. But driversare looking for something more personal and exible that can controlthe truck in a human way with their own preferences. Machine learningand articial intelligence can help achieve this aim. In this studyArticial Neural Networks are used to model the driver steering behaviourin the Scania Lane Keeping Assist. Based on this, trajectoryplanning and steering wheel torque response are modelled to t thedriver preference. A model predictive controller can be used to maintainstate limitations and to weigh the two modelled driver preferencestogether. Due to the diculties in obtaining an internal plant modelfor the model predictive controller a variant of a PI-controller is addedfor integral action instead. The articial neural network also containsan online learning feature to further customize the t to the driverpreference over time.
Idag används till största del regelbaserade reglersystem förförarassistanssystem i lastbilar. Men lastbilschaufförer vill ha någotmer personligt och flexibelt, som kan styra lastbilen på ett mänskligtsätt med förarens egna preferenser. Maskininlärning och artificiell intelligenskan hjälpa till för att uppnå detta mål. I denna studie användsartificiella neurala nätverk för att modellera förarens styrbeteende genomScania Lane Keeping Assist. Med användning av detta modellerasförarens preferenser med avseende på placering på vägbanan och momentpåslag på ratten. En modell prediktiv kontroller kan användas föratt begränsa tillstånd och för att väga de två modellerade preferensernamot varann. Eftersom det var mycket svårt att ta fram den internaprocessmodellen som krävdes för regulatorn används istället en variantav en PI-kontroller för att styra lastbilen. De artificiella neuralanätverken kan också tillåtas att lära sig under körning för att anpassasig till förarens preferenser över tid.

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Nilsson, Arvid. "Fuel and ride comfort optimization in heavy vehicles." Thesis, Linköping University, Linköping University, Vehicular Systems, 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-53682.

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In modern heavy vehicles low fuel consumption as well as good ride comfort and driveability is desired. Assuming that the road altitude ahead of the vehicle is known the optimal control regarding fuel and time consumption can be calculated. However this results in a bang-singular-bang control which decreases the ride comfort by introducing high jerk levels and oscillations in acceleration as well as jerk originating from the dynamics in the driveline.

In this thesis several methods to supress these behaviours are presented. A qualitative study of the methods impact on ride comfort as well as fuel and time consumption is carried out. A driveline model is implemented in Simulink and used for the evaluations. The aim is not to find a optimal strategy but rather to suggest methods and evaluate these as far as can be done in simulation to enable for future test runs.

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Eriksson, Nils. "Estimation of Distance to empty for heavy vehicles." Thesis, Linköping University, Vehicular Systems, 2010. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-56905.

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The distance to empty (DTE) for a heavy vehicle is valuable information both forthe driver and the hauler company. The DTE is estimated as the ratio between the current fuel level and a representative mean fuel consumption. This means the fuel consumption is a prediction of the most likely future mean fuel consumption based on earlier data. It is calculated by applying a forgetting filter on the signal of the momentary fuel consumption in the engine. The filter parameter control how many values that contributes to the output. This is a balance between desired robustness and adaptability of the estimate.

Initially, a pre-stored value is used as an estimate of the mean fuel consumption. By this, the driver gets a first hint of the DTE value and the estimation of the DTE gets a good starting point. Stored values will adapt continuously with an online algorithm using vehicle data from previous runs. An alternative to showing the DTE is to present the time to empty when the vehicle speed is close to zero.

The accuracy of the proposed algorithm depends on the quality of the input signals. With the current input signals, it is possible to get a DTE estimate that, over a longer time period, decrease in the same pace as the distance meter increase. This is considered as a good validation measurement. If altitude data for the current route would be used, a more accurate DTE estimate could be obtained. The sample distance for this altitude data could however be set to a 1000 meter without affecting the estimate significantly.

Sträckan till tom tank för ett tungt fordon är värdefull information, både för den enskilde föraren och åkeriet. Förkortad som DTE (Distance to empty) kan detta värde estimeras som kvoten av den nuvarande bränslenivån i tanken och en genomsnittlig bränsleförbrukning.

Denna genomsnittliga bränsleförbrukning är en prediktion av den troligaste framtida snittförbrukningen baserad på tidigare värden. Detta görs genom att ett glömskefilter appliceras på signalen för den aktuella bränsleförbrukningen i motorn. Filterparametern avgör hur snabbt gamla värden på insignalen ska klinga av och när den anpassas så måste önskad stabilitet vägas mot önskad känslighet hos skattningen.

Initialt så används förlagrade värden som skattning för den genomsnittliga bränsleförbrukningen. Detta gör att föraren får en första aning om hur långt fordonet kan köras samt ger DTE estimeringen en bra utgångspunkt. Dessa lagrade värden uppdateras under drift med information från det aktuella fordonet. För att hanterade problem som kan uppstå vid låga hastigheter eller tomgång kan istället tiden till tom tank visas.

Resultatet av DTE skattningen beror på kvalitén på insignalerna. Med de nuvarande insignalerna fås en DTE skattning som över en längre tidsperiod minskar sitt värde i samma takt som avståndsmätaren ökar sitt, vilket är ett önskvärt uppförande.

Om höjddata för en den aktuella rutten skulle användas skulle DTE estimeringen kunna göras mer noggrant. Det skulle dock räcka med att använda höjdinformation var 1000:e meter och ändå få en tillräckligt noggrann skattning.

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27

Sahlholm, Per. "Distributed Road Grade Estimation for Heavy Duty Vehicles." Doctoral thesis, KTH, Reglerteknik, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-32054.

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An increasing need for goods and passenger transportation drives continued worldwide growth in traffic. As traffic increases environmental concerns, traffic safety, and cost efficiency become ever more important. Advancements in microelectronics open the possibility to address these issues through new advanced driver assistance systems. Applications such as predictive cruise control, automated gearbox control, predictive front lighting control, and hybrid vehicle state-of-charge control decrease the energy consumption of vehicles and increase the safety. These control systems can benefit significantly from preview road grade information. This information is currently obtained using specialized survey vehicles, and is not widely available. This thesis proposes new methods to obtain road grade information using on-board sensors. The task of creating road grade maps is addressed by the proposal of a framework where vehicles using a road network collect the necessary data for estimating the road grade. The estimation can then be carried out locally in the vehicle, or in the presence of a communication link to the infrastructure, centrally. In either case the accuracy of the map increases over time, and costly road surveys can be avoided. This thesis presents a new distributed method for creating accurate road grade maps for vehicle control applications. Standard heavy duty vehicles in normal operation are used to collect measurements. Estimates from multiple passes along a road segment are merged to form a road grade map, which improves each time a vehicle retraces a route. The design and implementation of the road grade estimator are described, and the performance is experimentally evaluated using real vehicles. Three different grade estimation methods, based on different assumption on the road grade signal, are proposed and compared. They all use data from sensors that are standard equipment in heavy duty vehicles. Measurements of the vehicle speed and the engine torque are combined with observations of the road altitude from a GPS receiver, using vehicle and road models. The operation of the estimators is adjusted during gearshifts, braking, and poor satellite coverage, to account for variations in sensor and model reliability. The estimated error covariances of the road grade estimates are used together with their absolute positions to update a stored road grade map. Highway driving trials show that the proposed estimators produce accurate road grade data. The estimation performance improves as the number of road segment traces increases. A vehicle equipped with the proposed system will rapidly develop a road grade map for its area of operation. Simulations show that collaborative generation of the third dimension for a pre-existing large area two-dimensional map is feasible. The experimental results indicate that road grade estimates from the proposed methods are accurate enough to be used in predictive vehicle control systems to enhance safety, efficiency, and driver comfort in heavy duty vehicles. The grade estimators may also be used for on-line validation of road grade information from other sources. This is important in on-board applications, since the envisioned control applications can degrade vehicle performance if inaccurate data are used.
QC 20110408

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28

Stone, Edwin James. "Semi-active anti-roll bars for heavy vehicles." Thesis, University of Cambridge, 2004. https://www.repository.cam.ac.uk/handle/1810/251941.

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29

Potter, Theodore Edmund Cooper. "Assessing the road damaging potential of heavy vehicles." Thesis, University of Cambridge, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.389885.

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30

Tang, Edvin, and Toni Zalem. "Unregulated Emissions from Heavy-Duty Engines and Vehicles." Thesis, KTH, Fordonsdynamik, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-163713.

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Road transport emission levels are at an all-time low and post Euro VI regulations are now up for discussion. A literature study of unregulated diesel emissions in Europe; CO2, N2O, NO2, CH4 and aldehydes has been made to determine the effects and importance of the emissions in today´s heavy-duty vehicles. This work aims to give better knowledge of the emissions with fundamental information about each emission’s formation, environmental effects, health effects, measuring methods, and reduction methods. Also examined is the possibility of limiting these emissions and what policies can be enforced in any future legislative directives. The greenhouse gas emissions, CO2, N2O and CH4, from road transport are getting a lot of attention since they are hugely responsible for an increase of the global temperature. CO2 will clearly be the focus of future regulations. It is the most abundant emission and is the main cause of global warming. Reduction is best achieved through more fuel efficient vehicles but regulations and political means will also be needed to lower CO2 levels in the atmosphere. The European Commission have therefore agreed in 2014 to come up with a plan to cut their CO2 emissions from road transport. The most important ozone depleting substance today and the most potent of the greenhouse gases is N2O which has a GWP of 298. It is mainly produced by aftertreatment systems and its formation is highly dependent on temperature. CH4 is a regulated emission for CNG but not for diesel where the levels are much lower. It has a GWP of 34 and is plays a big role in global warming. Although it is an important emission to examine, the levels of CH4 from diesel vehicles today are negligible. In modern diesel vehicles NO2 emissions come from platinum catalysed DOCs and DPFs. NO2 is used for DPF regeneration and causes respiratory problems as well as contributing heavily to ozone formation and smog pollution. By adopting a better urea dosing strategy and choosing DPF coating material with less platinum NO2 can be reduced. Aldehydes are found in low concentrations in diesel but more in alternative fuels such as ethanol, and are important to study because of their carcinogenic properties and large contribution smog pollution. Studies have shown that the most abundant forms of aldehydes are formaldehyde and acetaldehyde for almost all fuel types, and that they can be reduced with efficient catalysts and high quality fuel. Different measurement techniques are used to analyse each of these mentioned emissions but their low levels require more accurate instruments with greater level of detail for measuring the substances.

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Henderson, Leon Michael. "Improving emergency braking performance of heavy goods vehicles." Thesis, University of Cambridge, 2014. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.648714.

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Midgley, William John Baudinet. "Regenerative braking of urban delivery heavy goods vehicles." Thesis, University of Cambridge, 2013. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.607710.

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Amb, Joel, and Rikard McPherson. "Electrification of Heavy Transport Vehicles in Stockholm Sweden." Thesis, KTH, Maskinkonstruktion (Inst.), 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-298982.

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Sweden wants to reach its climate goals and one important step towards doing so is to lower road emissions. Today heavy transport constitutes 5% of all vehicles on the road in Sweden but are contributing to 25% of all CO2 road emissions. Therefore, electrification of heavy vehicle transport could contribute a lot towards reaching Sweden’s climate goals. The transition into heavy electric vehicles will however affect many different areas within the haulage market as well as Sweden’s electrical grid. For the scope of this report Stockholm is used as an example to calculate what is required to successfully transition the existing truck fleet into a fully electrical truck fleet. The report aims to answer seven questions that will give a clear indication on the feasibility and effects of a fully electrical truck fleet in Stockholm. The questions answered are: A) Will electrical vehicles be able to last the long-range transportation routes that the haulage market currently has? B) How many charging stations would be needed to supply these vehicles with electricity? C) Where will these charging station need to be placed? D) When will the trucks be charged? E) What is the charging time for a large truck, and will this severely impact the effectiveness of the hauling market? F) How much electricity will Sweden have to produce to supply the trucks with electricity? G) Can Sweden supply this electricity in a sustainable way? The methods used in this report are based on literature studies. Contemporary information about Stockholm’s haulage market as well as trends on the heavy electrical vehicle market will be analysed to conclude how feasible this transition is. In the results it is estimated that electrical trucks can last between 76-92% of all transportation routes depending on load weight and battery size. Between 3000 and 4300 charging stations would be needed in Stockholm to supply the trucks with electricity. The most likely charging scenario is believed to be mostly overnight combined with mid-routecharging when needed. This electricity will be distributed mainly over Östermalm, Järfälla, Årstaberg as well as Huddinge. The charging times for trucks range from 55 minutes to 2 hours 15 minutes depending on battery size and the power of the charging stations used. The total electricity demand for this transition is calculated to be around 300-600 GWh each year. The major problem Sweden faces is to supply this electricity in a sustainable way as there currently is no surplus in electricity production. In conclusion, the transition into a fully electrical truck fleet in Stockholm seems feasible. The technology required to successfully manage this transition exists today but has to be implemented by both Stockholm’s län and the private companies. The interest as well as trends in this sector provide further affirmation that this transition eventually will happen.
Sverige vill nå sina klimatmål och ett viktigt steg i detta är att sänka utsläppen från fordon. Idag står tunga lastbilar för 5% av alla fordon på vägen i Sverige men bidrar till 25% av koldioxidutsläppen. Detta är varför elektrifiering av tunga lastbilar kan bidra mycket till att Sverige ska nå sina uppsatta klimatmål. Elektrifieringen kommer dock att påverka flertalet olika områden inom transportsektorn samt Sveriges elnät. I denna rapport används Stockholm som exempel för att räkna ut vad som krävs för att framgångsrikt ersätta hela den nuvarande flottan av lastbilar till sin elektriska motpart. Rapporten svarar på sju frågor som ger en bred och tydlig bild på troligheten och effekterna av full elektrifieringen för tunga lastbilar. De sju frågorna lyder: A) Kommer elektriska lastbilar klara av de långa avstånden som krävs för transporterna? B) Hur många laddstationer kommer behövas för att förse alla fordon med elektricitet? C) Var behöver laddstationerna placeras? D) När kommer lastbilarna laddas? E) Hur lång tid tar det att ladda en tung lastbil med dagens teknik? Kommer detta påverka effektiviteten av transportsektorn? F) Hur mycket elektricitet behöver Sverige producera för att tillgodose lastbilarna med el? G) Kan Sverige producera krävd mängd el på ett hållbart sätt? Rapporten är baserad på litteraturforskning. Samtida information om Stockholms transportsektor samt trender i marknader för tunga elektriska lastbilar analyseras för att ta fram hur trolig denna övergång är. I resultatet estimeras det att elektriska lastbilar har räckvidden för att täcka 76-92% av de nuvarande transport rutterna beroende på lastvikt och batterikapacitet. Mellan 3000-4300 laddstationer behöver installeras i Stockholm för att tillgodose det nya behovet. Det mest troliga scenariot tros vara mestadels ”över natten”- laddning kombinerat med ”på vägen”- laddning vid behov. Det ökade behovet i elnätet kommer framförallt behöva fördelas över Östermalm, Järfälla, Årstaberg samt Huddinge då detta är var de största åkerierna har sina huvudkvarter. Laddningstiderna varierar mellan 55 minuter och 2 timmar 15 min beroende på laddarens spänning och storleken på lastbilens batterikapacitet. Den ökade konsumtionen av elektricitet beräknas uppgå till 300 till 600 GWh totalt per år. Stockholms största utmaningar för att på ett hållbart sätt tillgodose det nya behovet av elektricitet är både kapaciteten samt de tillfälliga topparna av elefterfrågan. Idag är efterfrågan redan lika stor som den totala tillgången på elektricitet som Stockholm kan producera. När efterfrågan ökar ytterligare kommer länet behöva utöka sin elproduktion överlag men även utveckla nätet för att klara av de nya topparna i den tillfälliga elefterfrågan. Om flertalet lastbilar börjar laddas samtidigt stiger den tillfälliga efterfrågan i taket och det rörliga elpriset följer efter. Sammanfattningsvis verkar det idag möjligt att göra övergången till elektriska tunga lastbilar. Tekniken finns redan idag men måste implementeras av både Stockholms län samt de privata företagen. Intresset samt trenderna inom elektrifiering ger oss ytterligare bekräftelse att övergången kommer till slut att ske.

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Hanowski, Richard J. "The Impact of Local/Short Haul Operations on Driver Fatigue." Diss., Virginia Tech, 2000. http://hdl.handle.net/10919/28416.

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Massie, Blower, and Campbell (1997) indicate that trucks that operate less than 50 miles from the vehicle's home base comprise 58% of the trucking industry. However, despite being the largest segment, research involving local/short haul (L/SH) operations has been scant. In fact, little is known about the general safety issues in L/SH operations. As a precursor to the present research, Hanowski, Wierwille, Gellatly, Early, and Dingus (1998) conducted a series of focus groups in which L/SH drivers provided their perspective on safety issues, including fatigue, in their industry. As a follow-up to the Hanowski et al. work, the effort presented here consisted of an on-road field study where L/SH trucks were instrumented with data collection equipment. Two L/SH trucking companies and 42 L/SH drivers participated in this research. To the author's knowledge, this is the first in-situ data collection effort of its kind with L/SH drivers. The analyses focused on determining if fatigue is an issue in L/SH operations. Of primary interest were critical incidents (near-crashes) where drivers were judged to be at fault. The results of the analyses indicated that fatigue was present immediately prior to driver involvement in at-fault critical incidents. Though it is difficult to determine why fatigue was present, the results seem to indicate that much of the fatigue that the drivers' experienced was brought with them to the job, rather than being caused by the job. There are four basic outputs of the Phase II research: (1) a description of the L/SH drivers who participated, (2) a description of critical incidents, (3) a determination if fatigue is an issue in L/SH trucking, and (4) the validation of the fatigue factors cited in Hanowski et al. (1998) using a proposed fatigue model. These four outputs culminate in a set of pragmatic guidelines to address fatigue and other safety issues in L/SH operations. Five guidelines are proposed that are directed at: (1) driver education with regard to on-the-job drowsiness/inattention, (2) driver education with regard to sleep hygiene, (3) driver training, particularly for novice L/SH truck drivers, (4) driver screening, and (5) public monitoring of L/SH driver performance.
Ph. D.

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35

Daley, James Joseph. "Development of a heavy duty vehicle chassis dynamometer test route." Morgantown, W. Va. : [West Virginia University Libraries], 1998. http://etd.wvu.edu/templates/showETD.cfm?recnum=251.

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Thesis (M.S.)--West Virginia University, 1998.
Title from document title page. Document formatted into pages; contains viii, 59 p. : ill. (some col.) Includes abstract. Includes bibliographical references (p. 57-58).

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Svantesson, Einar. "Transient thermal management simulations of complete heavy-duty vehicles." Thesis, KTH, Mekanik, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-266464.

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Transient vehicle thermal management simulations have the potential to be an important tool to ensure long component lifetimes in heavy-duty vehicles, as well as save development costs by reducing development time. Time-resolved computational fluid dynamics simulations of complete vehicles are however typically very computationally expensive, and approximation methods must be employed to keep computational costs and turn-around times at a reasonable level. In this thesis, two transient methods are used to simulate two important time-dependent scenarios for complete vehicles; hot shutdowns and long dynamic drive cycles. An approach using a time scaling between fluid solver and thermal solver is evaluated for a short drive cycle and heat soak. A quasi-transient method, utilizing limited steady-state computational fluid dynamics data repeatedly, is used for a long drive cycle. The simulation results are validated and compared with measurements from a climatic wind tunnel. The results indicate that the time-scaling approach is appropriate when boundary conditions are not changing rapidly. Heat-soak simulations show reasonable agreement between three cases with different thermal scale factors. The quasi-transient simulations suggest that complete vehicle simulations for durations of more than one hour are feasible. The quasi-transient results partly agree with measurements, although more component temperature measurements are required to fully validate the method.

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Khan, ABM Siddiqur Rahman. "Evaluating real-world idle emissions from heavy-duty vehicles." Morgantown, W. Va. : [West Virginia University Libraries], 2005. https://eidr.wvu.edu/etd/documentdata.eTD?documentid=4217.

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Thesis (M.S.)--West Virginia University, 2005.
Title from document title page. Document formatted into pages; contains xii, 58 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 55-58).

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38

Björklund, Mattias. "Online Detection of Evasive Maneuvers for Heavy Duty Vehicles." Thesis, KTH, Reglerteknik, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-98867.

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Abstract By the first of November 2013 there will be a new legislation introduced in the European Union to improve road safety, which is being developed by the United Nations Economic Commission for Europe. The new legislation will make it mandatory for all heavy-vehicles to have an Advanced Emergency Braking System (AEB system). This means that they need to be equipped with a system which has the capability of braking the vehicle if it is about to crash into the rear of a vehicle in front, provided that the driver does not make any action. This M aster’sthesis, which was initiated by Scania CV AB, covers the topic of making sure the AEB system never interferes with the drivers impending evasive maneuver. It presents three possible methods for identifying situations for when the drivers control should not be interfered. The requirement of a method, which has been provided by Scania CV AB, is that it should rely on minimal sensor input and require little computational resources. One of the three proposed methods meets these requirements well and has thus been further developed into an implementable on-board function. This method has been tested in simulation software as well as in an actual truck with promising results; the method correctly classified all the evasive maneuvers it was tested with. It can however be noted that there are situations which gets erroneously classified as an evasive maneuver, although none which have proved to be relevant since the AEB system is not operating in these situations.

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Pettersson, Niklas. "Modelling and control of auxiliary loads in heavy vehicles." Licentiate thesis, Stockholm : Automatic Control, Dept. of Signals, Sensors and Systems, Royal Institute of Technology (KTH), 2004. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-333.

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40

Schelin, Eva. "Road user charging for heavy goods vehicles - Implementation aspects." Licentiate thesis, Norrköping : Department of Science and technology, Linköpings universitet, 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-12052.

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Oliveira, Rui. "Planning and Motion Control in Autonomous Heavy-Duty Vehicles." Thesis, KTH, Reglerteknik, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-151022.

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Autonomous driving has been an important topic of research in recent years. In this thesis we study its application to Heavy Duty Vehicles, more specically, vehicles consisting of a truck and a trailer. An overview study is done on three fundamental steps of an autonomous driving system, planning, trajectory tracking and obstacle avoidance. In the planning part, we use RRT, and two other variants of the algorithm to nd trajectories in an unstructured environment, e.g., a mining site. A novel path optimization post-processing technique well suited for use with RRT solutions was also developed. For the trajectory tracking task several well-known controllers were tested, and their performance compared. An extension is proposed to one of the controllers in order to take into account the trailer. The performance evaluation was done on scaled truck systems in the Smart Mobility Lab at KTH. The obstacle avoidance is done with the aid of a simple, yet functional Model Predictive Controller. For this purpose, we developed dierent formulations of the optimization problem, corresponding to distinct optimization goals and vehicle models, in order to assess both the quality of the MPC, and of the assumed truck model. The outcome of this thesis is a fully autonomous system, able to plan and move in constrained environments, while avoiding unpredicted obstacles. It was implemented using a 1:32 scale remote controlled truck, commanded by a desktop computer.

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Park, Sanghoon. "Dynamics of heavy off-road vehicles on deformable ground." Thesis, University of Nottingham, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.405085.

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Morrison, G. "Combined emergency braking and cornering of articulated heavy vehicles." Thesis, University of Cambridge, 2016. https://www.repository.cam.ac.uk/handle/1810/283982.

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Roebuck, Richard Lee. "Application of semi-active suspension control to heavy vehicles." Thesis, University of Cambridge, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.619687.

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45

Winkler, Torsten, Zaaijer Rik de, and Christian Schwab. "Energy-efficient steering systems for heavy-duty commercial vehicles." Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2016. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-199785.

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Besides the braking system the steering system is one of the most important systems on vehicles. The reliability and the performance of a steering system decides on the controllability of the vehicle under normal conditions as well as emergency situations. In everyday use the characteristics, the connectivity to assistance systems and the energy efficiency of the steering system become more and more important to fulfill the increasing demands regarding fuel consumption, carbon dioxide emissions and comfort. To meet these demands, new steering systems must be implemented and new technologies have to be developed. This contribution compares different approaches regarding functionality and energy efficiency to give an indication which system is the most promising solution for future front axle steering systems as well as rear steered axles (tag- or pusher axle) on trucks.

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Velazquez, Abad Anthony. "Selection of low carbon technologies for heavy goods vehicles." Thesis, University of Southampton, 2016. https://eprints.soton.ac.uk/397268/.

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Profit margins in logistics are very tight and reducing fuel costs is critical to remain competitive. Customers and policy makers are becoming more sensitive towards climate change due to the links between fossil fuels and global warming. This research presents a framework to help decision makers to select the optimal heavy goods vehicles’ specification that minimises their carbon emissions cost-efficiently given their aversion to risk. The framework developed, uses a broad range of methodologies, techniques and tools including carbon emission lifecycle analysis; simulations; live trials; statistical analysis; metaheuristics and multicriteria decision analysis. An assessment of the waste-to-fuel opportunities of quick service restaurants showed that these could cover around 5% of the energy needs of UK commercial fleets and it was found that used cooking oil could reduce diesel emissions by over 85%. Among the range of scenarios built, the solution recommended by the framework indicated that all vehicles should fit spray reduction mudflaps, low rolling resistance tyres, automatic tyre monitoring systems and lightweight materials. While urban HGVs should also have automatic manual transmissions, regional and long-haul HGVs should include aerodynamic trailers and predictive cruise control instead. Compared to the do-nothing scenarios, the net present costs of urban, regional and long-haul vehicles can be reduced by 3%, 9.4% and 10.7% and their GHG emissions by 7%, 14.6% and 17.1%, respectively. This results in savings between £2.7M to £4.4M and 7,950 to 8,262 t CO2 eq. for the whole fleet of the industrial sponsor over 5 years. The lowest cost solution could save £5.8M and 27,684 t CO2 while carbon minimisation one could save over 30,000 tonnes and £2.9M, with current energy prices. The results suggest that diesel technology HGVs can still play a role in the decarbonisation of road haulage and that the uptake of low carbon technologies is highly influence by the risks aversion of the decision maker and duty cycle. The results demonstrate that the EU 2020 targets of delivering 10% savings from road transport by 2020 are perfectly feasible.

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Söderberg, Fredrik. "Route Planning for Heavy Vehicles on Real World Maps." Thesis, Uppsala universitet, Institutionen för informationsteknologi, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-411686.

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Fast route planning for a standard car is well explored, lots of research, and many algorithms exist. For trucks or other heavy vehicles, the available research and quick algorithm alternatives dwindle. This thesis focuses on available alternatives for trucks and other vehicles with attributes hindering them from traversing parts of the road network. Attributes like height are one among many, which can hinder a vehicle on its path. These attributes can vary greatly and is the reason why known solutions can’t be applied. Many well-known solutions rely partially on precalculated data regarding the shortest path for its performance. Precalculating for all possible combinations of attributes is not practical due to the number of possible configurations and the amount of computing needed for each one. The implemented solution is derived from multiple existing solutions and was evaluated on a graph representing Sweden’s road network. The solution is sufficiently fast to allow commercial use and allows changes to the road network with nightly updates. The solution is based on trying to predict which roads are more important when searching for the shortest path. With this knowledge, a search for the shortest path can be said to prioritize the before mentioned roads, which results in it finding its goal faster.
Snabb ruttplanering för en vanlig personbil är välutforskat med mycket tillgänglig forskning och många existerande algoritmer. För lastbilar och andra tunga fordon minskar den tillgängliga forskningen och alternativa algoritmer kraftigt. Den här avhandlingen fokuserar på alternativen som existerar för lastbilar, samt andra fordon som har egenskaper vilket blockerar dem från att framföras på delar av vägnätverket. Höjd är ett attribut bland flera som kan hindra ett fordon från att ta sig fram. Dessa egenskaper kan variera kraftigt och är orsaken till varför kända lösningar inte går att applicera. Många välkända lösningar förlitar sig på förberäknad data gällande snabbaste möjliga väg för sin prestanda. Att utföra dessa beräkningar för alla möjliga kombinationer av egenskaper är opraktiskt på grund av antalet möjliga konfigurationer och hur mycket som måste räknas ut för varje. Den implementerade lösningen är en kombination av flera existerande lösningar och utvärderades på en graf som representerar det svenska vägnätet. Lösningen är snabb nog för att tillåta bruk inom det kommersiella och den tillåter förändringar i vägnätet med nattliga uppdateringar. Lösningen bygger på att försöka förutsäga vilka vägar i ett vägnät som är viktigare än andra när det gäller att finna den snabbaste vägen. Med hjälp av det kan man sedan styra en sökning så att den prioriterar dessa vägar och därmed hitta sitt mål fortare.

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Evestedt, Niclas. "Sampling Based Motion Planning for Heavy Duty Autonomous Vehicles." Licentiate thesis, Linköpings universitet, Reglerteknik, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-132769.

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The automotive industry is undergoing a revolution where the more traditional mechanical values are replaced by an ever increasing number of Advanced Driver Assistance Systems (ADAS) where advanced algorithms and software development are taking a bigger role. Increased safety, reduced emissions and the possibility of completely new business models are driving the development and most automotive companies have started projects that aim towards fully autonomous vehicles. For industrial applications that provide a closed environment, such as mining facilities, harbors, agriculture and airports, full implementation of the technology is already available with increased productivity, reliability and reduced wear on equipment as a result. However, it also gives the opportunity to create a safer working environment when human drivers can be removed from dangerous working conditions. Regardless of the application an important part of any mobile autonomous system is the motion planning layer. In this thesis sampling-based motion planning algorithms are used to solve several non-holonomic and kinodynamic planning problems for car-like robotic vehicles in different application areas that all present different challenges. First we present an extension to the probabilistic sampling-based Closed-Loop Rapidly exploring Random Tree (CL-RRT) framework that significantly increases the probability of drawing a valid sample for platforms with second order differential constraints. When a tree extension is found infeasible a new acceleration profile that tries to brings the vehicle to a full stop before the collision occurs is calculated. A resimulation of the tree extension with the new acceleration profile is then performed. The framework is tested on a heavy-duty Scania G480 mining truck in a simple constructed scenario. Furthermore, we present two different driver assistance systems for the complicated task of reversing with a truck with a dolly-steered trailer. The first is a manual system where the user can easily construct a kinematically feasible path through a graphical user interface. The second is a fully automatic planner, based on the CL-RRT algorithm where only a start and goal position need to be provided. For both approaches, the internal angles of the trailer configuration are stabilized using a Linear Quadratic (LQ) controller and path following is achieved through a pure-pursuit control law. The systems are demonstrated on a small-scale test vehicle with good results. Finally, we look at the planning problem for an autonomous vehicle in an urban setting with dense traffic for two different time-critical maneuvers, namely, intersection merging and highway merging. In these situations, a social interplay between drivers is often necessary in order to perform a safe merge. To model this interaction a prediction engine is developed and used to predict the future evolution of the complete traffic scene given our own intended trajectory. Real-time capabilities are demonstrated through a series of simulations with varying traffic densities. It is shown, in simulation, that the proposed method is capable of safe merging in much denser traffic compared to a base-line method where a constant velocity model is used for predictions.

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Wallebäck, Peter. "Fuel Level Estimation for Heavy Vehicles using a Kalman Filter." Thesis, Linköping University, Department of Electrical Engineering, 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-15702.

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The object with this project is to develop a more accurate way to measure the level in the fuel tank in Scaniavehicles. The level should be displayed for the driver and a warning system be implemented to make the driveraware if the fuel level is too low. Furthermore a main goal is to develop an estimation of the distance that thevehicle could travel before refueling is needed.The fuel level estimation system is modeled using Matlab Simulink and simulated with measurement datacollected from real driving scenarios. After evaluating the system it is implemented in one of the electricalcontrol units located on a test vehicle which communicates with other systems. After implementation more testsare performed with the test vehicle to verify that the same functionality achieved during simulations is achievedusing the system implemented in a vehicle.The fuel level estimated with a KF (Kalman filter) that uses fuel consumption and level measurement results ingood performance. A more stable level estimate is achieved and a negative elevation of the estimate most of thetime, as a result of fuel use. Compared to the method Scania vehicles estimate their fuel level with today thenew level estimate is more steady and not that easily affected by fuel movements. The KF is more demanding interms of memory allocation, processor speed and inputs needed, which has to be considered when comparingboth methods. Another disadvantage with the KF is that it is dependent on the samples from the fuel levelsensor to get an initial estimate during startup.Furthermore the KF is easily expanded with more inputs that use information from other sensors on other parts of the vehicle.

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Axehill, Daniel, and Johan Sjöberg. "Adaptive Cruise Control for Heavy Vehicles : Hybrid Control and MPC." Thesis, Linköping University, Department of Electrical Engineering, 2003. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-1604.

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An Adaptive Cruise Controller (ACC) is an extension of an ordinary cruise controller. In addition to maintaining a desired set velocity, an ACC can also maintain a desired time gap to the vehicle ahead. For this end, both the engine andthe brakes are controlled.

The purpose with this thesis has been to develop control strategies for an ACC used in heavy vehicles. The focus of the work has been the methods used for switching between the use of engine and brake. Two different methods have been studied, a hybrid controller and an MPC-controller.

For the hybrid controller, the main contribution has been to use the influence of the surroundings on the acceleration of the truck. This consists of several parts such as wind drag, road slope and rolling resistance. The estimated influence of the surroundings is used as a switch point between the use of engine and brakes. Ideally, these switch points give bumpless actuator switches.

The interest in the MPC-controller as an alternative solution was to achieve automatic actuator switching, thus with no explicitly defined switch points. The MPC-controller is based on a model of the system including bounds on the control signals. Using this knowledge, the MPC-controller will choose the correct actuator for the current driving situation.

Results from simulations show that both methods solve the actuator switch problem. The advantages with the hybrid controller are that it is implementable in a truck with the hardware used today and that it is relatively simple to parameterise. A drawback is that explicit switch points between the uses of the different actuators have to be included. The advantages with the MPC-controller are that no explicit switch points have to be introduced and that constraints and time delays on signals in the system can be handled in a simple way. Among the drawbacks, it can be mentioned that the variant of MPC, used in this thesis, is too complex to implement in the control system currently used in trucks. One further important drawback is that MPC demands a mathematical model of the system.

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Dissertations / Theses on the topic 'Heavy vehicles'

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