Journal articles: 'Mechanically Actuated System'

1

Kamadan, Abdullah, Gullu Kiziltas, and Volkan Patoglu. "A Systematic Design Selection Methodology for System-Optimal Compliant Actuation." Robotica 37, no. 4 (November 29, 2018): 656–74. http://dx.doi.org/10.1017/s0263574718001248.

Full text

Abstract:

SummaryThis work presents a systematic design selection methodology that utilizes a co-design strategy for system-level optimization of compliantly actuated robots that are known for their advantages over robotic systems driven by rigid actuators. The introduced methodology facilitates a decision-making strategy that is instrumental in making selections among system-optimal robot designs actuated by various degrees of variable or fixed compliance. While the simultaneous co-design method that is utilized throughout guarantees systems performing at their full potential, a homotopy technique is used to maintain integrity via generation of a continuum of robot designs actuated with varying degrees of variable and fixed compliance. Fairness of the selection methodology is ensured via utilization of common underlying (variable) compliant actuation principle and dynamical task requirements throughout the generated system designs. The direct consequence of the developed methodology is that it allows robot designers make informed selections among a variety of systems which are guaranteed to perform at their best. Applicability of the introduced methodology has been validated using a case study for system-optimal design of an active knee prosthesis that is driven by a mechanically adjustable compliance and controllable equilibrium position actuator (MACCEPA) under a periodic/real-life dynamical task.

APA, Harvard, Vancouver, ISO, and other styles

2

Wester, Brock A., Swaminathan Rajaraman, James D. Ross, Michelle C. LaPlaca, and Mark G. Allen. "Development and characterization of a packaged mechanically actuated microtweezer system." Sensors and Actuators A: Physical 167, no. 2 (June 2011): 502–11. http://dx.doi.org/10.1016/j.sna.2011.01.005.

Full text

APA, Harvard, Vancouver, ISO, and other styles

3

Muralidharan, Vivek, Abhijith Balakrishnan, Vinit Ketan Vardhan, Nikita Meena, and Y. Suresh Kumar. "Design of Mechanically Actuated Aerodynamic Braking System on a Formula Student Race Car." Journal of The Institution of Engineers (India): Series C 99, no. 2 (May 9, 2017): 247–53. http://dx.doi.org/10.1007/s40032-017-0354-1.

Full text

APA, Harvard, Vancouver, ISO, and other styles

4

Hancock, David, Mark Shannon, Bertrand Beaumont, Pierre Dumortier, Frederic Durodie, Volodymyr Kyrytsya, Fabrice Louche, Robert McKinley, and Keith Nicholls. "Design of a mechanically actuated RF grounding system for the ITER ICRH antenna." Fusion Engineering and Design 88, no. 9-10 (October 2013): 2100–2104. http://dx.doi.org/10.1016/j.fusengdes.2013.02.089.

Full text

APA, Harvard, Vancouver, ISO, and other styles

5

Grund, T., C. Megnin, J. Barth, and M. Kohl. "Batch Fabrication of Shape Memory Actuated Polymer Microvalves by Transfer Bonding Techniques." Journal of Microelectronics and Electronic Packaging 6, no. 4 (October 1, 2009): 219–27. http://dx.doi.org/10.4071/1551-4897-6.4.219.

Full text

Abstract:

Polymer based microvalves offer outstanding properties for biomedical and life science applications. They can be produced cost efficiently by batch fabrication methods. Further, by adapting the polymer material, custom-tailored properties of the valve are possible. For mechanically active microvalves, actuation with smart materials like shape memory alloys is highly attractive due to their high work output per volume and favorable scaling behavior. For the integration of such smart materials, fabrication process incompatibilities between the actuator material and the polymer target system need to be avoided. This can be achieved by novel transfer bonding technologies being optimized for batch fabrication. These technologies are demonstrated for polymer microvalves actuated by a shape memory alloy but they can also be applied to other functional materials and structures.

APA, Harvard, Vancouver, ISO, and other styles

6

Csencsics, Ernst, Markus Thier, Reinhard Hainisch, and Georg Schitter. "System and Control Design of a Voice Coil Actuated Mechanically Decoupling Two-Body Vibration Isolation System." IEEE/ASME Transactions on Mechatronics 23, no. 1 (February 2018): 321–30. http://dx.doi.org/10.1109/tmech.2017.2771440.

Full text

APA, Harvard, Vancouver, ISO, and other styles

7

Almeida, Alexsandro C. S., Tarlei A. Botrel, Steven R. Raine, Antonio P. de Camargo, Marinaldo F. Pinto, and Conan A. Salvador. "Irrigation controller mechanically actuated by soil-water tension: II - Field evaluations." Revista Brasileira de Engenharia Agrícola e Ambiental 21, no. 5 (May 2017): 298–303. http://dx.doi.org/10.1590/1807-1929/agriambi.v21n5p298-303.

Full text

Abstract:

ABSTRACT In this study, a field evaluation of the performance of an irrigation controller mechanically actuated by soil-water tension (SWT) was performed. The controller employs a tensiometer used as a sensor of SWT to directly control a mechanically actuated hydraulic valve. Six controllers were installed in an orchard to control the irrigation for six rows of plants over 64 days. Each controller controlled the irrigation of one lateral drip line. The drip irrigation system was gravity-fed from a water source placed 7 m above the soil surface. The SWT and the pressure in each lateral line were measured to evaluate the performance of the controllers. All the controllers tested in the field autonomously initiated and terminated the irrigation during the evaluation. Irrigation events were initiated when values close to the set soil-tension values were reached and were terminated at lower soil-tension values. As the SWT in the root zone was maintained close to the setup threshold plus 20% tolerance for at least 90% of the evaluation period, the performance of the controllers was considered satisfactory. The proposed controller was shown to be functional and was operated effectively for an SWT range of up to 30 kPa, which is commonly encountered under high-frequency irrigation conditions.

APA, Harvard, Vancouver, ISO, and other styles

8

Kagadi, Matin, Girish Tembhare, Vinaay Patil, and Sujay Shelke. "Optimization of Self Activating Bi-Metallic Valve Using Thermo – Structural Coupled FEA." Advanced Materials Research 622-623 (December 2012): 147–51. http://dx.doi.org/10.4028/www.scientific.net/amr.622-623.147.

Full text

Abstract:

Besides relying on electronically actuated valves, there is a need to have a mechanically actuated valve and a warning system as second layer of safety in-case of electronic malfunction. The specific process for which optimization is carried out, is the process of nitrous oxide generation from ammonium nitrate. The key challenge in the process was maintaining temperatures below 200°C, as above this temperature ammonium nitrate becomes explosive and hence safety risks are involved. The secondary objective was to maintain temperatures above 170°C, as below this temperature the reaction does not proceed. In this paper we have tried to fulfill these objectives by employing a bi-metallic valve and a warning system having bi-metallic strip which will bend at higher temperatures, thus serving our primary purpose of self-actuation. However the key constraint in determining the dimensions of the valve and the warning system is a desirable deflection of bi-metallic strip. To optimize these parameters we have employed non-linear FEA and thermo-structural coupled FEA, and this paper reflects on the process employed in achieving the same.

APA, Harvard, Vancouver, ISO, and other styles

9

Wen, Haiying, Ming Cong, and Guifei Wang. "Experimental verification of workspace and mouth-opening movement of a redundantly actuated humanoid chewing robot." Industrial Robot: An International Journal 42, no. 5 (August 17, 2015): 406–15. http://dx.doi.org/10.1108/ir-04-2015-0069.

Full text

Abstract:

Purpose – This paper aims to verify the workspace and movement performance of a redundantly actuated humanoid chewing robot. Design/methodology/approach – A redundantly actuated humanoid chewing robot with 6-PUS linkages and two higher kinematic pairs (HKPs) is introduced. The design of HKPs is specified by mimicking the temporomandibular joint (TMJ) structure obtained through a computed tomography scan of the mastication system. The border movement, mouth-opening trajectory and velocity of subjects’ lower incisor point are measured by using the mandibular kinesiograph. Based on the kinematics, the envelope of the workspace is analyzed. The workspace and mouth-opening movement experiments are carried out. The border movement of the lower incisor point is measured. The mouth-opening trajectory is planned and tested on the chewing robot. Findings – Comparing with measurement results of border movement and mouth-opening movement of human, it is shown that the humanoid chewing robot can meet the workspace requirements and is able to perform mouth-opening movement like human-beings. Practical implications – The chewing robot is designed to reproduce human jaw movements and application in test of dental components and materials or evaluation of food textural properties. Originality/value – The chewing robot is inspired by the mastication system which itself is mechanically redundant because of the TMJ and more muscles than required. The novel spatial redundantly actuated chewing robot is the first of this kind with two HKPs to mimic the human TMJ and is a higher fidelity mechanism.

APA, Harvard, Vancouver, ISO, and other styles

10

Khalifeh, Nour El-Hoda, Rudy Youssef, Farah Fadel, Roy Khalil, Elie Shammas, Naseem Daher, Imad H. Elhajj, Thomas Irrenhauser, Michael N. Niedermeier, and Christian Poss. "Sensorless localization of a minimally-actuated robotic system for automated pallet de-strapping." Assembly Automation 41, no. 6 (October 18, 2021): 681–96. http://dx.doi.org/10.1108/aa-04-2021-0039.

Full text

Abstract:

Purpose The purpose of this paper is to detail the design and prototyping of a smart automation solution for de-strapping plastic bonding straps on shipping pallets, which are loaded with multiple containers secured by a top-cover as they move on a conveyor belt. Design/methodology/approach The adopted design methodology to have the system perform its function entails using the least number of sensors and actuators to arrive at an economic solution from a system design viewpoint. Two prototypes of the robotic structure are designed and built, one in a research laboratory and another in an industrial plant, to perform localized cutting and grabbing of the plastic straps, with the help of a custom-designed passive localizing structure. The proposed structure is engineered to locate the plastic straps using one degree of freedom (DOF) only. An additional strap removal mechanism is designed to collect the straps and prevent them from interfering with the conveyor. Findings The functionality of the system is validated by performing full-process tests on the developed prototypes in a laboratory setting and under real-life operating conditions at BMW Group facilities. Testing showed that the proposed localization system meets the specified requirements and can be generalized and adapted to other industrial processes with similar requirements. Practical implications The proposed automated system for de-strapping pallets can be deployed in assembly or manufacturing facilities that receive parts in standard shipping pallets that are used worldwide. Originality/value To the best of the authors’ knowledge, this is the first mechanically smart system that is used for the automated removal of straps from shipping pallets used in assembly facilities. The two main novelties of the proposed design are the robustness of the strap localization without the need for computer vision and a large number of DOF, and the critical placement and choice of the cutting and gripping tools to minimize the number of needed actuators.

APA, Harvard, Vancouver, ISO, and other styles

11

Budde, Leon, Sontje Ihler, Svenja Spindeldreier, Tobias Lücking, Tim Meyer, Eberhard Bodenschatz, and Wolfram-Hubertus Zimmermann. "A Six Degree of Freedom Extrusion Bioprinter." Current Directions in Biomedical Engineering 8, no. 2 (August 1, 2022): 137–40. http://dx.doi.org/10.1515/cdbme-2022-1036.

Full text

Abstract:

Abstract Motivated by a high demand, the research interest in personalized artificial tissues is steadily increasing. Combining knowledge of additive manufacturing and tissue engineering, the research field of 3D bioprinting emerged. This work presents a six-degree-of-freedom mechanically actuated extrusion bioprinter within a sterile working environment. The system is based on an off-the-shelf robot arm and a custom modular printhead end-effector. Advanced dexterity is achieved by the six degrees of freedom, enabling printing on non-planar surfaces. The printhead is designed for co-axial extrusion of three fluids but can easily be adapted for different number of fluids or different extrusion flows. The custom controller of the system is implemented within the Robot Operating System (ROS) framework and plans the trajectory based on a path given in a custom GCode dialect. Since the robot is clean-room-certified, can be sterilized using hydrogen peroxide steam, and is placed within a sterile hood, the setup enables working under sterile conditions.

APA, Harvard, Vancouver, ISO, and other styles

12

Rahman, Md Mozasser, and Ryojun Ikeura. "Impedance characteristic of the human arm during passive movements." IAES International Journal of Artificial Intelligence (IJ-AI) 12, no. 1 (March 1, 2023): 34. http://dx.doi.org/10.11591/ijai.v12.i1.pp34-40.

Full text

Abstract:

This paper describes the impedance characteristics of the human arm during passive movement. The arm was moved in the desired trajectory. The motion was actuated by a 1-degree-of-freedom robot system. Trajectories used in the experiment were minimum jerk (the rate of change of acceleration) trajectories, which were found during a human and human cooperative task and optimum for muscle movement. As the muscle is mechanically analogous to a spring-damper system, a second-order equation was considered as the model for arm dynamics. In the model, inertia, stiffness, and damping factor were considered. The impedance parameters were estimated from the position and torque data obtained from the experiment and based on the “Estimation of Parametric Model”. It was found that the inertia is almost constant over the operational time. The damping factor and stiffness were high at the starting position and became near zero after 0.4 seconds.

APA, Harvard, Vancouver, ISO, and other styles

13

Padmanaban, Nitish, Robert Konrad, Tal Stramer, Emily A. Cooper, and Gordon Wetzstein. "Optimizing virtual reality for all users through gaze-contingent and adaptive focus displays." Proceedings of the National Academy of Sciences 114, no. 9 (February 13, 2017): 2183–88. http://dx.doi.org/10.1073/pnas.1617251114.

Full text

Abstract:

From the desktop to the laptop to the mobile device, personal computing platforms evolve over time. Moving forward, wearable computing is widely expected to be integral to consumer electronics and beyond. The primary interface between a wearable computer and a user is often a near-eye display. However, current generation near-eye displays suffer from multiple limitations: they are unable to provide fully natural visual cues and comfortable viewing experiences for all users. At their core, many of the issues with near-eye displays are caused by limitations in conventional optics. Current displays cannot reproduce the changes in focus that accompany natural vision, and they cannot support users with uncorrected refractive errors. With two prototype near-eye displays, we show how these issues can be overcome using display modes that adapt to the user via computational optics. By using focus-tunable lenses, mechanically actuated displays, and mobile gaze-tracking technology, these displays can be tailored to correct common refractive errors and provide natural focus cues by dynamically updating the system based on where a user looks in a virtual scene. Indeed, the opportunities afforded by recent advances in computational optics open up the possibility of creating a computing platform in which some users may experience better quality vision in the virtual world than in the real one.

APA, Harvard, Vancouver, ISO, and other styles

14

Bazeille, Stéphane, Jesus Ortiz, Francesco Rovida, Marco Camurri, Anis Meguenani, Darwin G. Caldwell, and Claudio Semini. "Active camera stabilization to enhance the vision of agile legged robots." Robotica 35, no. 4 (November 17, 2015): 942–60. http://dx.doi.org/10.1017/s0263574715000909.

Full text

Abstract:

SUMMARYLegged robots have the potential to navigate in more challenging terrains than wheeled robots. Unfortunately, their control is more demanding, because they have to deal with the common tasks of mapping and path planning as well as more specific issues of legged locomotion, like balancing and foothold planning. In this paper, we present the integration and the development of a stabilized vision system on the fully torque-controlled hydraulically actuated quadruped robot (HyQ). The active head added onto the robot is composed of a fast pan and tilt unit (PTU) and a high-resolution wide angle stereo camera. The PTU enables camera gaze shifting to a specific area in the environment (both to extend and refine the map) or to track an object while navigating. Moreover, as the quadruped locomotion induces strong regular vibrations, impacts or slippages on rough terrain, we took advantage of the PTU to mechanically compensate for the robot's motions. In this paper, we demonstrate the influence of legged locomotion on the quality of the visual data stream by providing a detailed study of HyQ's motions, which are compared against a rough terrain wheeled robot of the same size. Our proposed Inertial Measurement Unit (IMU)-based controller allows us to decouple the camera from the robot motions. We show through experiments that, by stabilizing the image feedback, we can improve the onboard vision-based processes of tracking and mapping. In particular, during the outdoor tests on the quadruped robot, the use of our camera stabilization system improved the accuracy on the 3D maps by 25%, with a decrease of 50% of mapping failures.

APA, Harvard, Vancouver, ISO, and other styles

15

Fitz-Coy, Norman, Vivek Nagabhushan, and Michael T. Hale. "Benefits and Challenges of Over-Actuated Excitation Systems." Shock and Vibration 17, no. 3 (2010): 285–303. http://dx.doi.org/10.1155/2010/435740.

Full text

Abstract:

This paper provides a comprehensive discussion on the benefits and technical challenges of controlling over-determined and over-actuated excitation systems ranging from 1-DOF to 6-DOF. The primary challenges of over-actuated systems result from the physical constraints imposed when the number of exciters exceeds the number of mechanical degree-of-freedom. This issue is less critical for electro-dynamic exciters which tend to be more compliant than servo-hydraulic exciters. To facilitate the technical challenges discussion, generalized methods for determining the drive output commands and the actuator input transform is presented. To further provide insights into the problem, over-actuated 1-DOF and 6-DOF examples are provided. Results are presented to support the discussions.

APA, Harvard, Vancouver, ISO, and other styles

16

Sunar, M., and O. Keles. "Magnetostrictive Actuator Modeling and Placement." Advanced Materials Research 83-86 (December 2009): 281–88. http://dx.doi.org/10.4028/www.scientific.net/amr.83-86.281.

Full text

Abstract:

Quasi-static equations are presented for a magnetostrictive medium where mechanical and magnetic fields interact with each other. Finite element method is used in conjunction with the Hamilton's principle to deduce equations for the dynamic behavior of the magnetostrictive material. These equations form the basis for the magnetostrictive material to be utilized as a sensor or as an actuator. When used as an actuator, the material can provide enough power to actuate mechanical systems for vibration control. In this work, a cantilever beam with a magnetostrictive actuator is taken to demonstrate the modeling and use of the magnetostrictive actuator in attenuating structural vibrations. The position of the actuator is changed to observe its effect on the response of the system. This is important because it is a well-known fact that the actuator location has impact, sometimes big, on its performance.

APA, Harvard, Vancouver, ISO, and other styles

17

Garcia Velarde, Miguel Angel, Wilberth Melchor Alcocer Rosado, Andres Blanco Ortega, Arturo Abúndez, Claudia Cortés, and Jorge Colin. "LOWER LIMB ASSISTANCE SYSTEMS: A STATE OF THE ART." Latin American Applied Research - An international journal 52, no. 2 (March 25, 2022): 89–99. http://dx.doi.org/10.52292/j.laar.2022.626.

Full text

Abstract:

In this paper, we present a state of the art regarding lower limb assistance systems. That is, exoskeletons, exosuits, actuated orthoses and smart walkers intended to assist users with or without walking difficulties in such task. We focus on those systems headed towards motion intention prediction, especially those that implement myosignals in order to control the system. However, there are some using cortical or encephaloelectric signals. We make clear the importance of developing this technology for the sake of userâ€™s health, when regarding people with reduced motor capacity. After the reviewed systems, we bring forward our own system intended to assist hemiplegic/hemiparetic patients walking by predicting motion intention. The main differentiator of our design shall be energy saving as it is being designed to actuate the hip only during swing phase. Thus, hypothetically allowing the system to save 40% energy, compared to the same system actuated during the whole walking cycle.

APA, Harvard, Vancouver, ISO, and other styles

18

Le, T. T. "Stability Analysis of a Proximate Time Optimal Controlled Electrostatic Suspension System Using Piezo Actuator via Lyapunov Functional Approach." Mathematical Problems in Engineering 2020 (January 22, 2020): 1–14. http://dx.doi.org/10.1155/2020/9516476.

Full text

Abstract:

An electrostatic suspension of silicon wafer using proximate time optimal control has been successfully developed. In this system, the movable electrodes which are supplied by constant voltage and actuated by the piezoelectric (PZT) actuator are used instead of stationary electrodes like previous systems. The changing of the gap length between movable electrodes and the suspended object will create varying capacitances that can control the electrostatic forces. To overcome the problem of actuator saturation of the piezo actuator, a proximate time optimal control is used to stabilize the system. The system stability is theoretically investigated using Lyapunov’s function. The constant voltage supplying to the electrode is an important parameter, and it is also determined. The paper presents series of the simulation and experimental results that prove completely suspension of 4-inch silicon wafer without any mechanical contact.

APA, Harvard, Vancouver, ISO, and other styles

19

AFONIN, Sergey M. "The Condition for Absolute Stability of an Electroelastic Actuator Control System for Nanomechatronics." Elektrichestvo 10, no. 10 (2020): 52–58. http://dx.doi.org/10.24160/0013-5380-2020-10-52-58.

Full text

Abstract:

An electroelastic actuator for nanomechatronics is used in nanotechnology, adaptive optics, microsurgery, microelectronics, and biomedicine to actuate or control mechanisms, systems based on the electroelastic effect, and to convert electrical signals into mechanical displacements and forces. In nanomechatronic systems, a piezoactuator is used in scanning microscopy, laser systems, in astronomy for precision alignment, for compensation of temperature, gravitational deformations and atmospheric turbulence, focusing, and stabilizing the image. In this study, a condition for absolute stability of an electroelastic actuator control system for nanomechatronics under deterministic and random inputs is obtained. A number of equilibrium positions in an electroelastic actuator mechatronic control system are found, the totality of which is represented by a straight line segment. The electroelastic actuator’s deformation control system dead band relative width is determined for the actuator’s symmetric and asymmetric hysteresis characteristics. Under deterministic inputs and with fulfilling the condition for the derivative of the nonlinear hysteresis actuator deformation characteristic, the set of equilibrium positions of the electroelastic actuator control system for nanomechatronics is absolutely stable. Under random inputs, the system absolute stability with respect to the mathematical expectations of the electroelastic actuator mechatronic control system equilibrium positions has been determined subject to fulfilling the condition on the derivative of the actuator hysteresis characteristic.

APA, Harvard, Vancouver, ISO, and other styles

20

Galhano, Alexandra M. S. F., and J. A. Tenreiro Machado. "Kinematic Robustness of Manipulating Systems." Journal of Advanced Computational Intelligence and Intelligent Informatics 6, no. 2 (June 20, 2002): 93–98. http://dx.doi.org/10.20965/jaciii.2002.p0093.

Full text

Abstract:

Present day mechanical manipulators have poor performances when compared with the human arm. In fact, joint-driven manipulators are not efficient due to the high actuator requirements imposed by the transients of the operational tasks. Muscle-actuated arms are superior because the anatomic levers adapt the manipulating exigencies to the driving linear actuators. The kinematic analysis of these systems highlights its main properties and constitutes a step towards the design of new mechanical biological-like. robotic structures adopting linear actuators replacing the standard rotational joint-driving motor systems.

APA, Harvard, Vancouver, ISO, and other styles

21

Mou, Shann-Chyi. "Structure Design and Stepping Characteristics Analysis of the Biaxial Piezoelectric Actuated Stage Using a Thin-Disc Piezoelectric Actuator." Advances in Mechanical Engineering 6 (January 1, 2014): 121497. http://dx.doi.org/10.1155/2014/121497.

Full text

Abstract:

In this paper, a novel thin-disc piezoelectric actuator, 4-9-9-14 piezoelectric actuator, is used to construct and drive the micro/nanometer level biaxial piezoelectric actuated stage. The 4-9-9-14 piezoelectric actuator offers a better balanced capability of forward rotation and reverse rotation than the conventional edge-driving piezoelectric actuator. The biaxial piezoelectric actuated stage structure comprises a base, a V-shaped guide rail, an optical scale measurement system, a preload adjusting structure, and a load-carrying stage. The movement signals of the piezoelectric actuated stage are read and analyzed by means of NI PCI-6115 data acquisition card and LabVIEW software operating in conjunction with a linear optical scale. The new consideration of tuning Ton time is used in place of the traditional method of changing the magnitude of driving voltage to control the stepping distance of the stage. A combined driving signal is based on the sum of a continuous driving signal for Ton time and a DC signal for Ton time; the combined driving signal is continuously output in this manner to form a continuous driving pulse chain. Under a constant driving voltage, the displacement of the stage increases with Ton time and the displacement of the stage decreases with Ton time.

APA, Harvard, Vancouver, ISO, and other styles

22

Biswal, Deepak Ranjan, and Pramod Kumar Parida. "Modelling and Finite Element Based Analysis of a Five Fingered Underactuated Robotic Hand." International Journal for Research in Applied Science and Engineering Technology 10, no. 9 (September 30, 2022): 100–108. http://dx.doi.org/10.22214/ijraset.2022.46579.

Full text

Abstract:

Abstract: Imparting the dexterity and autonomous competence to a robotic system is a significant burden in humanoid robotics, especially in the fields of industrial manufacturing, prosthetics, orthopedic rehabilitation, etc. Operating a humanoid hand requires a very innovative actuator and transmission system. The under-actuated concepts are proving to be a possible means of achieving extremely dexterous robotic hands without the need for diverse mechanical design. The main characteristics of an under-actuated robotic hand are that fewer actuators are required to operate it than the degrees of freedom. The under-actuated equivalent hand is significantly less expensive than the fully-actuated equivalent hand and remarkably reduces the complexity of the control system. The existing work dealt with the modeling and finite element-based analysis of an anthropomorphic underactuated robotic hand using five fingers including the thumb and palm with dexterity and with a total of twenty-one degrees of freedom.

APA, Harvard, Vancouver, ISO, and other styles

23

Fu, Qiang, Songyuan Zhang, Shuxiang Guo, and Jian Guo. "Performance Evaluation of a Magnetically Actuated Capsule Microrobotic System for Medical Applications." Micromachines 9, no. 12 (December 4, 2018): 641. http://dx.doi.org/10.3390/mi9120641.

Full text

Abstract:

The paper aims to propose a magnetic actuated capsule microrobotic system, which is composed of a magnetically actuated microrobot with a screw jet mechanism, a driving system, and a positioning system. The magnetically actuated microrobot embedded an O-ring magnet as an actuator has potential for achieving a particular task, such as medical diagnose or drug delivery. The driving system composes of a three axes Helmholtz coils to generate a rotational magnetic field for controlling the magnetically actuated microrobot to realize the basic motion in pipe, e.g., forward/backward motion and upward/downward motion. The positioning system is used to detect the pose of the magnetically actuated microrobot in pipe. We will discuss the shape of the Helmholtz coils and the magnetic field around the O-ring magnet to obtain an optimal performance of the magnetically actuated microrobot. The experimental result indicated that the microrobot with screw jet motion has a flexible movement in pipe by adjusting the rotational magnetic field plane and the magnetic field changing frequency.

APA, Harvard, Vancouver, ISO, and other styles

24

Kochersberger, Kevin B., Osgar John Ohanian, Troy Probst, and Paul A. Gelhausen. "Design and flight test of the generic micro-aerial vehicle (GenMAV) utilizing piezoelectric conformal flight control actuation." Journal of Intelligent Material Systems and Structures 28, no. 19 (April 5, 2017): 2793–809. http://dx.doi.org/10.1177/1045389x17698590.

Full text

Abstract:

A novel morphing control surface design employing piezoelectric macro-fiber composite actuators is compared to a servo-actuated system. The comprehensive comparison including aerodynamics, size, weight, power, bandwidth, and reliability has been extended to include flight test comparisons. Three flight vehicles were designed, built, and evaluated: a servo-controlled generic micro-aerial vehicle aircraft and two conformal actuator controlled versions based on thick and thin wing designs. Flight agility and control response of the morphing-actuated and servo-actuated configurations were quantified through state measurement during identical automated maneuvers. The morphing actuation scheme demonstrated control bandwidth that was an order of magnitude greater than for the servo-actuated system, but showed a 12% decrease in roll rate when compared to the servo-actuated baseline aircraft. The flight vehicles allowed system-level comparisons of conventional and morphing control, where conformal actuation occupied less volume, consumed equivalent power as micro servos and provided effective control power for maneuvering.

APA, Harvard, Vancouver, ISO, and other styles

25

Qu, Haibo, Yuefa Fang, and Sheng Guo. "Structural synthesis of a class of 3-DOF wrist mechanisms with redundantly-actuated closed-loop units." Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science 230, no. 2 (February 17, 2015): 276–90. http://dx.doi.org/10.1177/0954406215573039.

Full text

Abstract:

In this paper, a new method is proposed for the structural synthesis of a class of redundantly-actuated parallel wrists (RaPWs) with three rotational degrees of freedom of the moving platform and symmetrical structures based on screw theory. First, the new procedure for structural synthesis of RaPWs with closed-loop actuated unit is proposed and the constraint system of the moving platform of RaPWs is analyzed. Then, considering the inclusion relation between the primary constraint system and the limb constraint system, the type of kinematic limb is determined. The synthesis of type-1 and type-2 kinematic limbs is dealt with based on the obtained closed-loop actuated unit and open-loop sub-limb. Next, the RaPWs are synthesized and a number of new RaPWs have been identified. Finally, the condition for proper actuator selections of RaPWs is revealed, and one example is used to perform the validation.

APA, Harvard, Vancouver, ISO, and other styles

26

Miller, Jay, and Nathan Wicks. "Vacuum-Actuated Bending for Grasping." Robotics 7, no. 4 (November 16, 2018): 73. http://dx.doi.org/10.3390/robotics7040073.

Full text

Abstract:

Soft robotic devices typically are actuated with the application of a positive pressure (compared to ambient pressure), but some exciting work has been done with negative pressure application, with advantages for safety and robustness. Here, we present a negative pressure bending actuator inspired by previous work by Yang et al., fabricated using rapid prototyping techniques and elastomeric polymers. We describe the mechanical behavior of the system from a cellular solids perspective, showing the steps needed for the analysis and characterization of future similar systems. We find good agreement between experimentally measured values of displacement and force generated in atmospheric pressure conditions.

APA, Harvard, Vancouver, ISO, and other styles

27

Naderi, Mehdi, and Ali Khaki Sedigh. "Actuator selection for over-actuated systems using the actuator effectiveness index." International Journal of Dynamics and Control 8, no. 3 (January 28, 2020): 991–98. http://dx.doi.org/10.1007/s40435-020-00610-5.

Full text

APA, Harvard, Vancouver, ISO, and other styles

28

Lin, Chao, Zhonglei Shen, Jiang Yu, Pingyang Li, and Dehong Huo. "Modelling and Analysis of Characteristics of a Piezoelectric-Actuated Micro-/Nano Compliant Platform Using Bond Graph Approach." Micromachines 9, no. 10 (September 29, 2018): 498. http://dx.doi.org/10.3390/mi9100498.

Full text

Abstract:

The piezoelectric-actuated flexure-based compliant platform is commonly adopted in many fields of micro and nanotechnology. In this paper, bond graph modeling, and kinematic and dynamic characteristics of a piezoelectric-actuated micro-/nano compliant platform system are investigated. During modeling, the bond graph model of the piezoelectric actuator (PZT) is derived by considering both the electrical domain and the mechanical domain. Considering the compliances of flexure hinges and elastic linkages, as well as the input ends, the bond graph model for the bridge-type displacement amplification mechanism in the compliant platform is established by combining pseudo-rigid-body (PRB) model theory and elastic beam theory. Based on the interactions between the PZT subsystem and compliant platform subsystem, the kinematic performance of the proposed compliant platform system is evaluated through both computer simulations and experimental tests. Furthermore, the frequency responses, dynamic responses and load capacity of the compliant platform system are studied. This paper explores a new modeling method for a piezoelectric-actuated compliant platform system, which can provide an effective solution when analyzing the micro-/nano system.

APA, Harvard, Vancouver, ISO, and other styles

29

Luecke, Greg R., and John F. Gardner. "Local joint control in cooperating manipulator systems - force distribution and global stability." Robotica 11, no. 2 (March 1993): 111–18. http://dx.doi.org/10.1017/s0263574700019214.

Full text

Abstract:

SUMMARYAlmost all industrial robot applications in use today are controlled using a control law that is simple and computationally efficient, local joint error feedback. When two or more open chain manipulators cooperate to manipulate the same object - such as in mechanical grippers, walking machines, and cooperating manipulator systems - closed kinematic chain, redundantly actuated mechanisms are formed. Control approaches for this type of system focus on the more computationally intensive computed torque or inverse plant control laws, due to the concern over instability caused by the unspecified distribution of control forces in the redundant actuator space, and due to the constrained motion caused by the closed kinematic chains.

APA, Harvard, Vancouver, ISO, and other styles

30

Li, Yunfeng, Federico Marcassa, Roberto Horowitz, Roberto Oboe, and Robert Evans. "Track-Following Control With Active Vibration Damping of a PZT-Actuated Suspension Dual-Stage Servo System." Journal of Dynamic Systems, Measurement, and Control 128, no. 3 (November 1, 2005): 568–76. http://dx.doi.org/10.1115/1.2229257.

Full text

Abstract:

In this paper we discuss the controller design of a PZT-actuated suspension dual-stage servo system in hard disk drives. The proposed control structure includes an active vibration damping control loop and a track-following control loop. The vibration damping control loop, which runs at a faster rate than the track-following control loop, utilizes a PZT element on a PZT-actuated suspension as a vibration sensor to damp the resonance modes of the voice coil motor (VCM) and the PZT actuator. The vibration damping controller is designed using Kalman filter based state feedback control techniques. A simple dual-stage track-following controller is designed, based on the damped actuator model, using the sensitivity function decoupling design method. Simulation and experimental results are presented to demonstrate the benefits of this control scheme in expanding servo control bandwidth and suppressing airflow excited structural vibrations.

APA, Harvard, Vancouver, ISO, and other styles

31

Hussain, Imran, Wei Xia, Dongpo Zhao, Peng Huang, and Zhiwei Zhu. "Multi-Physical Design and Resonant Controller Based Trajectory Tracking of the Electromagnetically Driven Fast Tool Servo." Actuators 9, no. 2 (April 12, 2020): 28. http://dx.doi.org/10.3390/act9020028.

Full text

Abstract:

In this paper, a voice coil motor (VCM) actuated fast tool servo (FTS) system is developed for diamond turning. To guide motions of the VCM actuator, a crossed double parallelogram flexure mechanism is selected featuring totally symmetric structure with high lateral stiffness. To facilitate the determination of the multi-physical parameters, analytical models of both electromagnetic and mechanical systems are developed. The designed FTS with balanced stroke and natural frequency is then verified through the finite element analysis. Finally, the prototype of the VCM actuated FTS is fabricated and experimentally demonstrated to achieve a stroke of ±59.02 μm and a first natural frequency of 253 Hz. By constructing a closed-loop control using proportional–integral–derivative (PID) controller with the internal-model based resonant controller, the error for tracking a harmonic trajectory with ±10 μm amplitude and 120 Hz frequency is obtained to be ±0.2 μm, demonstrating the capability of the FTS for high accuracy trajectory tracking.

APA, Harvard, Vancouver, ISO, and other styles

32

Habibi, Hossein, and William O’Connor. "Wave-based planar motion and vibration control of under-actuated mass-spring arrays." Journal of Low Frequency Noise, Vibration and Active Control 37, no. 2 (June 2018): 269–78. http://dx.doi.org/10.1177/1461348418780026.

Full text

Abstract:

This paper considers the problem of position control and active vibration damping of a planar, array (or grid) of masses and springs, by a single actuator, attached to one corner of the array, which is required to translate and rotate the entire system from rest to rest, through target linear and angular displacements, simultaneously. An obvious challenge is that the system has many degrees of freedom, with many undamped vibration modes, and is clearly highly under-actuated. The control technique is a development of “wave-based control,” whereby rapid and effective control of the entire system is achieved, robustly, using measurements made only at the actuator, of the actuator’s own motion and of the forces between the actuator and the attached flexible system. No detailed system model or system identification is needed. The actuator need not be ideal. The array does not have to be uniform, in its geometry or in the mass and spring values. The control strategy is simple to implement. The 2D array is of interest in itself as a benchmark control challenge, but it can also be considered a model of various lumped structures, or a discretisation of distributed systems.

APA, Harvard, Vancouver, ISO, and other styles

33

Guan, Le, Jia Li Gao, Qi Liu, Bin Li, and Jin Kui Chu. "System-Level Simulation and Fabrication of On-Chip Fatigue Bending Test Structure for Micro-Scale Polysilicon Films." Key Engineering Materials 562-565 (July 2013): 930–34. http://dx.doi.org/10.4028/www.scientific.net/kem.562-565.930.

Full text

Abstract:

Two kind of on-chip integrated fatigue bending test structures are designed through system-level simulation method based on macromodels to measure the fracture strength and fatigue mechanical properties of polysilicon thin films. The first on-chip fatigue test structure is actuated by V-beam thermal actuator, and the other test structure actuated by electrostatic comb. The static and dynamic analysis was performed by Coventorware Architect module using self-bulid reduced order model described with the MAST hardware language and some other commercial parts from Coventorware parts library. The structural dimension parameters are determined and optimized according to system-level simulation and the computing result has shown that the self-build macromodels and the on-chip integrated test system are efficient and reliable. Two kinds of polysilicon on-chip fatigue bending test structure were fabricated with two-layer polysilicon surface micromachining process in Institute of Microelectronics, Peking University.

APA, Harvard, Vancouver, ISO, and other styles

34

Kadotani, Masato, Takakazu Kitagawa, Satoshi Katto, Tomoko Hirayama, Takashi Matsuoka, Hiroshi Yabe, and Katsumi Sasaki. "Development of Pneumatic Servo Bearing Actuator for Nanometer Positioning." International Journal of Automation Technology 3, no. 3 (May 5, 2009): 249–56. http://dx.doi.org/10.20965/ijat.2009.p0249.

Full text

Abstract:

The ‘pneumatic servo bearing actuator (PSBA)’ that consists of an aerostatic bearing and a servo valve was proposed and developed for ultraprecise positioning. In the actuator, pressurized air controlled by the servo valve moves an actuated spool ultra-precisely. Even under open-loop control, the PSBA provided accurate replication and positioning resolution on a nanometer order. Applying simple positioning feedback and parallel observation that estimates the disturbance into the system increased the actuator stiffness to be almost infinite and promoted a sharp step response without drift and hysteresis, and thus the minimum positioning resolution of prototype PSBA was about 1 nm.

APA, Harvard, Vancouver, ISO, and other styles

35

Wu, Min, and Hai Pu. "Stable Control of Under-Actuated Mechanical System Acrobot." Advanced Materials Research 971-973 (June 2014): 727–30. http://dx.doi.org/10.4028/www.scientific.net/amr.971-973.727.

Full text

Abstract:

The mechanical system with one control input and two degrees of freedom is one kind of simple under-drive system, As a typical of two-DOF underactuated mechanical systems , Two-link underactuated mechanical arms is a system scholars always research of.This paper mainly take the two link underactuated mechanical arms-Acrobot which motivate in the vertical plane as object to discusses the asymptotic stability of control

APA, Harvard, Vancouver, ISO, and other styles

36

Vargas-Chable, Pedro, Margarita Tecpoyotl-Torres, Gerardo Vera-Dimas, Volodymyr Grimalsky, and José Mireles García. "Novel Electrothermal Microgrippers based on a Rotary Actuator System." Micromachines 13, no. 12 (December 10, 2022): 2189. http://dx.doi.org/10.3390/mi13122189.

Full text

Abstract:

Microgrippers are devices that have found applications in various fields of research and industry. They are driven by various actuation methods. In this article, an electrothermal rotary actuator recently proposed in the literature is explored to obtain a novel microgripper design (Model 1). In addition, the use of the rotary actuator as part of the chevron actuated microgrippers (Model 2) is also discussed. The theoretical analysis of the rotary actuator is supported by an equivalent U-shaped-like microactuator. The small error values validate the approximation used. Numerical modeling is performed with ANSYSTM (Student version 2022, ANSYS, PA, USA). A comparison of theoretical and numerical results provides acceptable error values. The total inter-jaw displacement values obtained for models 1 and 2 are 12.28 μm and 21.2 μm, respectively, and the reaction force is 8.96 μN and 34.2 μN, respectively. The performance parameters of both microgrippers could make their use feasible for different nanoapplications. Model 2 can be used when higher force and displacement are required.

APA, Harvard, Vancouver, ISO, and other styles

37

Yi-Wei Tung, Wayne, Michael McKinley, Minerva V Pillai, Jason Reid, and Homayoon Kazerooni. "Design of a Minimally Actuated Medical Exoskeleton With Mechanical Swing-Phase Gait Generation and Sit-Stand Assistance." Mechanical Engineering 136, no. 09 (September 1, 2014): S18—S21. http://dx.doi.org/10.1115/1.2014-sep-7.

Full text

Abstract:

This article describes the design of Austin exoskeleton – a minimally actuated medical exoskeleton with mechanical swing-phase gait generation and sit-stand assistance. The Austin exoskeleton is an accessible lightweight system that enables individuals with paraplegia to walk. The gait generation hardware of the Austin exoskeleton suit consists of three major components: hip actuation, a hip-knee coupler, and a controllable locking knee. Users operate the exoskeleton with a simple wireless user interface consisting of two push buttons that are installed on the handle of the stability aid. Electrical components are located on the back of the exoskeleton. A single actuator per leg and a mechanical hip-knee coupler power the knee during swing phase and provide assistance for sitting and standing. The suit’s design embeds gait generation into hardware, decreasing controller complexity. By using a bio-inspired coupling mechanism, the Austin system is able to power both the hip and knee joints using a single hip actuator.

APA, Harvard, Vancouver, ISO, and other styles

38

Malvezzi, Monica, Zubair Iqbal, Maria Cristina Valigi, Maria Pozzi, Domenico Prattichizzo, and Gionata Salvietti. "Design of Multiple Wearable Robotic Extra Fingers for Human Hand Augmentation." Robotics 8, no. 4 (December 11, 2019): 102. http://dx.doi.org/10.3390/robotics8040102.

Full text

Abstract:

Augmenting the human hand with robotic extra fingers is a cutting-edge research topic and has many potential applications, in particular as a compensatory and rehabilitation tool for patients with upper limb impairments. Devices composed of two extra fingers are preferred with respect to single finger devices when reliable grasps, resistance to external disturbances, and higher payloads are required. Underactuation and compliance are design choices that can reduce the device complexity and weight, maintaining the adaptability to different grasped objects. When only one motor is adopted to actuate multiple fingers, a differential mechanism is necessary to decouple finger movements and distribute forces. In this paper, the main features of a wearable device composed of two robotic extra fingers are described and analyzed in terms of kinematics, statics, and mechanical resistance. Each finger is composed of modular phalanges and is actuated with a single tendon. Interphalangeal joints include a passive elastic element that allows restoring the initial reference configuration when the tendon is released. The stiffness of each passive element can be customized in the manufacturing process and can be chosen according to a desired closure movement of the fingers. Another key aspect of the device is the differential system connecting the actuator to the fingers.

APA, Harvard, Vancouver, ISO, and other styles

39

Ahmad, Belal, Hugo Chambon, Pierre Tissier, and Aude Bolopion. "Laser Actuated Microgripper Using Optimized Chevron-Shaped Actuator." Micromachines 12, no. 12 (November 30, 2021): 1487. http://dx.doi.org/10.3390/mi12121487.

Full text

Abstract:

In this paper, we propose a laser actuated microgripper that can be activated remotely for micromanipulation applications. The gripper is based on an optothermally actuated polymeric chevron-shaped structure coated with optimized metallic layers to enhance its optical absorbance. Gold is used as a metallic layer due to its good absorption of visible light. The thermal deformation of the chevron-shaped actuator with metallic layers is first modeled to identify the parameters affecting its behavior. Then, an optimal thickness of the metallic layers that allows the largest possible deformation is obtained and compared with simulation results. Next, microgrippers are fabricated using conventional photolithography and metal deposition techniques for further characterization. The experiments show that the microgripper can realize an opening of 40 µm, a response time of 60 ms, and a generated force in the order of hundreds of µN. Finally, a pick-and-place experiment of 120 µm microbeads is conducted to confirm the performance of the microgripper. The remote actuation and the simple fabrication and actuation of the proposed microgripper makes it a highly promising candidate to be utilized as a mobile microrobot for lab-on-chip applications.

APA, Harvard, Vancouver, ISO, and other styles

40

Chang, Edmond Chin-Ping. "Guidelines for Actuated Controllers in Coordinated Systems." Transportation Research Record: Journal of the Transportation Research Board 1554, no. 1 (January 1996): 61–73. http://dx.doi.org/10.1177/0361198196155400109.

Full text

Abstract:

Research sponsored by the Texas Department of Transportation, Efficient Utilization of Actuated Controllers in Coordinated Traffic Control Systems, was used to develop a set of reliable control strategies to allow users to improve the overall design and operation of actuated controllers in conventional coordinated systems. The recommended analysis procedure can help users generate the signal timing parameters for coordinated arterial or network operations. Actuated, coordinated traffic signal system implementation will maximize the available resources for effective coordinated operations during undersaturated conditions, demand variations, and near-saturation conditions. The recommended coordination strategies and implementation guidelines for using actuated controllers effectively on coordinated signal systems are summarized. The study will effectively assist users in selecting the proper controller-detector combinations and improving system detector locations. It will also aid users in optimizing actuated timing parameters in actuated control operation of arterial signal systems.

APA, Harvard, Vancouver, ISO, and other styles

41

Liu, Fengyu, Li Chen, Jian Yao, Chunhao Lee, Chi-kuan Kao, Farzad Samie, Ying Huang, and Chengliang Yin. "Design, modeling, and analysis of wedge-based actuator with application to clutch-to-clutch shift." Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering 232, no. 9 (September 26, 2017): 1149–66. http://dx.doi.org/10.1177/0954407017727178.

Full text

Abstract:

Clutch-to-clutch shift technology is a key enabler for fast and smooth gear shift process for multi gear transmissions. However, conventional hydraulic actuation systems for clutches have drawbacks of low efficiency, oil leakage and inadequate robustness. Electromechanical devices offer potential alternative actuators. In this paper, a novel motor driven wedge-based clutch actuator, featuring self-reinforcement, is proposed. The design concept and physical structure are thoroughly described. Dynamic models for the actuation system and vehicle powertrain are validated by experiments. Upshift and downshift processes at different engine throttle openings, clutch clearances and friction coefficients are discussed. The results show that, the self-reinforcement ratio is tested as 9.6; at the same time, the shift quality is comparable to that of the conventional hydraulic actuated clutch in automatic transmissions in terms of the shift duration (about 1 s) and vehicle jerk (<10 m/s3). Taking advantage of fast response of the actuation DC motor, the wedge-based actuator is robust dealing with uncertain clutch clearance and friction coefficient. Therefore, the wedge-based clutch actuator has potential to provide acceptable performance for clutch-to-clutch shift.

APA, Harvard, Vancouver, ISO, and other styles

42

Nguyen, Viet-Quoc, M. Syaifuddin, H. C. Park, D. Y. Byun, N. S. Goo, and K. J. Yoon. "Characteristics of an Insect-mimicking Flapping System Actuated by a Unimorph Piezoceramic Actuator." Journal of Intelligent Material Systems and Structures 19, no. 10 (December 21, 2007): 1185–93. http://dx.doi.org/10.1177/1045389x07084203.

Full text

APA, Harvard, Vancouver, ISO, and other styles

43

Kim, Won-Hyo, Joon Shik Park, Kyu Shik Shin, Kwang Bum Park, Woo Kyeong Seong, and Chan Woo Moon. "Simulation and Fabrication of Silicon Micro-Grippers Actuated by Piezoelectric Actuator." Materials Science Forum 475-479 (January 2005): 1885–88. http://dx.doi.org/10.4028/www.scientific.net/msf.475-479.1885.

Full text

Abstract:

The eight types of micro-grippers with silicon were simulated by ANSYS and fabricated by MEMS(Micro Electro Mechanical System) process. Each type of micro-grippers had a small difference in design shape such as beam width, gap between beams. In order to modify design shape, these micro-grippers were estimated and simulated in point of structure, actuation characteristics by changing design factors. Micro-grippers were composed of five parts which were piezoelectric actuation part, fixing part, rotation arms, the block and gripping jaws. The shape of gripping jaws was designed as the teeth of a saw to reduce adhesion force by decreasing the contact area. The 10.2 µm movement by piezoelectric actuator at 120 V generated the 142.8 µm gripping range of a micro-gripper in real measurement. In the case of simulation result, the gripping range of 162 µm was generated at the same condition. This gripping range was enough to handle small objects like micro-parts

APA, Harvard, Vancouver, ISO, and other styles

44

Leonardis, Daniele, Luca Tiseni, Domenico Chiaradia, and Antonio Frisoli. "A Twisted String, Flexure Hinges Approach for Design of a Wearable Haptic Thimble." Actuators 10, no. 9 (August 29, 2021): 211. http://dx.doi.org/10.3390/act10090211.

Full text

Abstract:

Wearable haptic devices in the shape of actuated thimbles are used to render the sense of touch in teleoperation and virtual reality scenarios. The design of similar devices has to comply with concurring requirements and constraints: lightweight and compactness, intensity and bandwidth of the rendered signals. Micro-sized motors require a mechanical reduction to increase the output force, at the cost of noise and vibrations introduced by conventional gear reducers. Here we propose a different actuation method, based on a miniaturized twisted string actuator and a flexure hinge transmission mechanism. The latter is required to transmit and transform the pulling force of the twist actuator to a pushing force of the plate in contact with the fingerpad. It achieves a lightweight and noiseless actuation in a compact mechanism. In this work, we present design guidelines of the proposed approach, optimization, and FEM analysis of the flexure hinge mechanism, implementation of the prototype, and experimental characterization of the twist actuator measuring frequency response and output force capabilities.

APA, Harvard, Vancouver, ISO, and other styles

45

Mahmoodi, Masih, Mohammad Kojouri Manesh, Mohammad Eghtesad, Mehrdad Farid, and Saeid Movahed. "Adaptive passivity-based control of a flexible-joint robot manipulator subject to collision." Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science 229, no. 5 (June 30, 2014): 840–49. http://dx.doi.org/10.1177/0954406214541633.

Full text

Abstract:

In this paper, passivity-based methods are used to perform tracking control of flexible robot manipulators subject to impact collision. The model taken for colliding system is an n-degree of freedom body moving in the manipulator’s workspace. Impulsive forces generated in the course of impact cause sudden changes in velocity/acceleration of the links of robot and the colliding system. On the other hand, under-actuated systems subject to impact are likely to have instabilities, or poor transient responses, due to excitation of some un-actuated states. The proposed adaptive passivity-based controller not only improves the post-impact transient response of the under-actuated system (e.g. flexible-joint robot), but also needs no force sensor to measure impulse force during the impact phase of robot motion. The main advantage of the proposed controller relative to model-based inverse-dynamic algorithms is its highly robust characteristics in dampening effects of oscillation right after impact collision for an under-actuated system. This can be done through the introduction of an energy-storage function which incorporates the effects of both actuated and un-actuated states of the system.

APA, Harvard, Vancouver, ISO, and other styles

46

Janani, R., Aparna, and Hari Hara Ganesh. "Sensor Assisted Braking System in Automobiles." Advanced Science, Engineering and Medicine 12, no. 11 (November 1, 2020): 1388–92. http://dx.doi.org/10.1166/asem.2020.2606.

Full text

Abstract:

One of the fastest growing industries in the world in terms of high demand as well in technological development is Automobile Industry. There have been a lot of technological concepts introduced in automotive industry to improve comfort, more efficiency, cost reduction and eco-friendly. From the past century, the braking system of vehicle hasn’t evolved much. Today from small to exotic vehicles use only two types braking system are Disc and Drum Brakes, and their mode of operation are the Hydraulic and pneumatic actuations respectively. The 60+ percentage of brake system used in automobile are hydraulic whereas the remaining is pneumatic brake system. They have separate booster getting input from the brake pedal to stop vehicle, and separate hose lining to all four wheel. In this Sensor assisted braking system, the booster, hosing and mechanical systems are removed and sensor acts as input and actuator actuate the brake system.

APA, Harvard, Vancouver, ISO, and other styles

47

Maheshwari, Nandan, Keith Gunura, and Fumiya Iida. "Trajectory Control Based on Discrete Full-Range Dynamics." Journal of Robotics and Mechatronics 24, no. 4 (August 20, 2012): 612–19. http://dx.doi.org/10.20965/jrm.2012.p0612.

Full text

Abstract:

There has been an increasing interest in the use of mechanical dynamics, (e.g., passive, elastic, and viscous dynamics) for energy efficient and agile control of robotic systems. Despite the impressive demonstrations of behavioural performance, the mechanical dynamics of this class of robotic systems is still very limited as compared to those of biological systems. For example, passive dynamic walkers are not capable of generating joint torques to compensate for disturbances from complex environments. In order to tackle such a discrepancy between biological and artificial systems, we present the concept and design of an adaptive clutch mechanism that discretely covers the full-range of dynamics. As a result, the system is capable of a large variety of joint operations, including dynamic switching among passive, actuated and rigid modes. The main innovation of this paper is the framework and algorithm developed for controlling the trajectory of such joint. We present different control strategies that exploit passive dynamics. Simulation results demonstrate a significant improvement in motion control with respect to the speed of motion and energy efficiency. The actuator is implemented in a simple pendulum platform to quantitatively evaluate this novel approach.

APA, Harvard, Vancouver, ISO, and other styles

48

Vermes, Bruno, and Tibor Czigany. "Non-Conventional Deformations: Materials and Actuation." Materials 13, no. 6 (March 18, 2020): 1383. http://dx.doi.org/10.3390/ma13061383.

Full text

Abstract:

This paper reviews materials and structures displaying non-conventional deformations as a response to different actuations (e.g., electricity, heat and mechanical loading). Due to the various kinds of actuation and targeted irregular deformation modes, the approaches in the literature show great diversity. Methods are systematized and tabulated based on the nature of actuation. Electrically and mechanically actuated shape changing concepts are discussed individually for their significance, while systems actuated by heat, pressure, light and chemicals are condensed in a shared section presenting examples and main research trends. Besides scientific research results, this paper features examples of real-world applicability of shape changing materials, highlighting their industrial value.

APA, Harvard, Vancouver, ISO, and other styles

49

Zhou, Weijun, Yongxin Wu, Haiqiang Hu, Yanjun Li, and Yu Wang. "Port-Hamiltonian Modeling and IDA-PBC Control of an IPMC-Actuated Flexible Beam." Actuators 10, no. 9 (September 14, 2021): 236. http://dx.doi.org/10.3390/act10090236.

Full text

Abstract:

In this paper, the infinite-dimensional port-Hamiltonian modelling and control problem of a flexible beam actuated using ionic polymer metal composite (IPMC) actuators is investigated. The port-Hamiltonian framework is used to propose an interconnected control model of the mechanical flexible beam and the IPMC actuator. The mechanical flexible dynamic is modelled as a Timoshenko beam, and the electric dynamics of the IPMCs are considered in the model. Furthermore, a passivity-based control-strategy is used to obtain the desired configuration of the proposed interconnected system, and the closed-loop stability is analyzed using the early lumped approach. Lastly, numerical simulations and experimental results are presented to validate the proposed model and the effectiveness of the proposed control law.

APA, Harvard, Vancouver, ISO, and other styles

50

Fang, Jiwen, Jia Wang, Chong Li, Wei Zhong, and Zhili Long. "A Compound Control Based on the Piezo-Actuated Stage with Bouc–Wen Model." Micromachines 10, no. 12 (December 7, 2019): 861. http://dx.doi.org/10.3390/mi10120861.

Full text

Abstract:

The piezoelectric actuator (PA) is one of the most commonly used actuators in a micro-positioning stage. But its hysteresis non-linearity can cause error in the piezo-actuated stage. A modified Bouc–Wen model is presented in this paper to describe the hysteresis non-linearity of the piezo-actuated stage. This model can be divided into two categories according to the input frequency: rate-independent type and rate-dependent type. A particle swarm optimization method (PSO) is employed to identify these parameters of the Bouc–Wen hysteresis model. An inverse model feedforward compensator is established based on the modified Bouc–Wen model. The fuzzy proportional-integral-derivative (PID) controller combined with the feedforward compensator is implemented to the piezo-actuated stage. The experimental results indicate that the proposed control strategy can compensate for the hysteresis phenomenon.

APA, Harvard, Vancouver, ISO, and other styles

Journal articles on the topic 'Mechanically Actuated System'

Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles