Journal articles: 'Linear control systems Reliability'

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Jírová, Radka, Lubomír Pešík, and Robert Grega. "An Original Vibrodiagnostic Device to Control Linear Rolling Conveyor Reliability." Journal of Marine Science and Engineering 10, no. 3 (March 21, 2022): 445. http://dx.doi.org/10.3390/jmse10030445.

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On the basis of an analysis of the number of goods that are transported and handled in maritime transport, the ports for cargo ships may be considered as places with concentrated emissions. Reducing the emissions in ports can be achieved by shortening the stay times of cargo ships. The time that ships spend in ports may be reduced to the time that is required for the effective handling of the goods. One of the solutions for effective handling is using equipment with linear rolling systems. To prevent the idle time of cargo ships and the unnecessary increment of emissions in ports because of the possible failure of the linear rolling systems, their reliability and failure prediction are greatly required. Unfortunately, the common diagnostic systems of linear rolling systems in transportation practice still fail in particular cases of great external loads. Therefore, an original solution of the diagnostic system was designed on the basis of a load-free diagnostic part with a vibration sensor that is integrated into a carriage of the linear rolling system. A functional sample of the diagnostics was produced, and the vibrations that were measured on a loaded carriage and on the diagnostic part were compared in laboratory conditions under significant external loads. Encouraging results were reached by a time-domain analysis of the measured data. On the diagnostic part, the damage appeared clearly, while, on the loaded carriage, there were no observable signs of damage.

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Eryilmaz, Serkan, and Timur Aksoy. "Reliability of linear (n, f, k) systems with weighted components." Journal of Systems Science and Systems Engineering 19, no. 3 (May 25, 2010): 277–84. http://dx.doi.org/10.1007/s11518-010-5131-0.

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Tyncherov, Kamil T., Vyacheslav Sh Mukhametshin, Victor A. Krasnobaev, and Maria V. Selivanova. "Error Control Coding Algorithms in High Reliability Telemetry Systems." Symmetry 14, no. 7 (July 1, 2022): 1363. http://dx.doi.org/10.3390/sym14071363.

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In the oil and gas industry, in the process of drilling support (geosteering) and well telemetry, there is a problem of transmitting reliable information via wireless communication channels. The quality of such communication, as a rule, suffers due to the presence of errors caused by interference. As the depth of the well increases, the problem becomes more extensive. In order to solve the problem, it is proposed to choose noise-resistant coding in the system of residual classes. This system parallelizes the execution of arithmetic operations, has corrective abilities and organically adapts to the neural network basis of intelligent field management. At the same time, there are constraining factors for the mass application of the RNS; for example, difficulties in implementing non-modular procedures, forward and reverse coding, and some difficulties in identifying and correcting errors. That is why the task of improving the RNS seems relevant not only for oil and gas complexes, but also for any digital signal processing applications focused on intelligent neural network management on the basis of non-positional computing. The material of the article is limited to the study of the noise immunity of linear codes of the deduction system and the development of algorithms for detecting and correcting errors.

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Huo, Zhi Hong, Yuan Zheng, and Chang Xu. "Robust Reliability Design for Networked Control Systems Based on State Observers." Applied Mechanics and Materials 44-47 (December 2010): 1867–671. http://dx.doi.org/10.4028/www.scientific.net/amm.44-47.1867.

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Networked control systems with network-induced delay, packet loss and parameters uncertainty is modeled in this paper, consider the sensors that can’t send information to controller and the actuators that can’t receive information calculated and sent by the controller, the integrity design of the networked control system with sensors failures and actuators failures is analyzed based on robust fault-tolerant control theory. Parametric expression of controller is given based on feasible solution of linear matrix inequality. After detailed theoretical analysis, the simulation results is provided, which further demonstrated the proposed scheme.

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Radu, Alin, and Irina F. Lazar. "Reliability of controlled linear systems under Gaussian and non-Gaussian loads." International Journal of Dynamics and Control 7, no. 4 (July 16, 2019): 1489–500. http://dx.doi.org/10.1007/s40435-019-00562-5.

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Guo, Shu-Xiang. "An efficient reliability method for probabilistic H-infinity robust control of uncertain linear dynamic systems." Journal of Vibration and Control 21, no. 15 (January 24, 2014): 2946–58. http://dx.doi.org/10.1177/1077546313518957.

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Kwon, Wookyong, and Jaemin Baek. "Novel Summation-Type Triggering Condition on Event-Based Memory Output Feedback Control for Networked Control Systems." Electronics 9, no. 5 (May 8, 2020): 779. http://dx.doi.org/10.3390/electronics9050779.

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Networked control systems are widely spread, which is composed of numerous sensor and control nodes through communication channel. In this paper, an event-triggered H ∞ memory output feedback control (EMOFC) is investigated for networked control linear systems in discrete form. The memory control employing memorized past information is exploited to enhance the triggering intervals under event-triggered condition. Moreover, novel summation type event-triggering condition is newly proposed by utilizing buffer memory element. Based upon memory control and novel triggering conditions, the control design methodology is constructed for transformed input-delay model in forms of linear matrix inequalities (LMIs) adopting generalized free-weighting matrix summation inequality. As a result, the proposed scheme shows off the reduction of average signal transmission frequency and reliability while covering standard condition. Throughout numerical examples, the effectiveness is shown and the effect of memory element is analyzed.

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Zhu, Qixin, Kaihong Lu, and Yonghong Zhu. "H∞ Guaranteed Cost Fault-Tolerant Control of Double-Fault Networked Control Systems: Piecewise Delay Method." Mathematical Problems in Engineering 2019 (January 3, 2019): 1–19. http://dx.doi.org/10.1155/2019/6348727.

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The term double-fault networked control system means that sensor faults and actuator faults may occur simultaneously in networked control systems. The issues of modelling and an H∞ guaranteed cost fault-tolerant control in a piecewise delay method for double-fault networked control systems are investigated. The time-varying properties of sensor faults and actuator faults are modelled as two time-varying and bounded parameters. Based on the linear matrix inequality (LMI) approach, an H∞ guaranteed cost fault-tolerant controller in a piecewise delay method is proposed to guarantee the reliability and stability for the double-fault networked control systems. Simulations are included to demonstrate the theoretical results of the proposed method.

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Huo, Zhi Hong, Yuan Zheng, and Bo Qu. "Robust Reliability Design for Networked Control Systems Based on Information Scheduling." Advanced Materials Research 179-180 (January 2011): 43–48. http://dx.doi.org/10.4028/www.scientific.net/amr.179-180.43.

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This document explains and demonstrates how to prepare your camera-ready manuscript for Trans Tech Publications. The best is to read these instructions and follow the outline of this text. The text area for your manuscript must be 17 cm wide and 25 cm high (6.7 and 9.8 inches, resp.). Do not place any text outside this area. Use good quality, white paper of approximately 21 x 29 cm or 8 x 11 inches (please do not change the document setting from A4 to letter). Your manuscript will be reduced by approximately 20% by the publisher. Please keep this in mind when designing your figures and tables etc.Networked Control Systems (NCS) are systems with at least one loop closed through data networks. The existence of real-time network in the feedback control loop makes it more complex to analyze and design the NCS. In this paper, the networked control systems with network-induced delay, parameters uncertainty and packet loss which are induced by the limited bandwidth of communication networks is modeled, consider the sensors that can’t send information to controller and the actuators that can’t receive information calculated and sent by the controller, the integrity design of the networked control system with sensors failures and actuators failures is analyzed based on information scheduling and robust fault-tolerant control theory. Sufficient conditions, based on Lyapunov function method, are established in terms of linear matrix inequalities (LMIs). When these LMIs are feasible, the explicit expression of the controller can also be characterized. After detailed theoretical analysis, the simulation results is provided, which further demonstrated the proposed scheme.

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Jia, Qingxian, Huayi Li, Xueqin Chen, and Yingchun Zhang. "Observer-based reaction wheel fault reconstruction for spacecraft attitude control systems." Aircraft Engineering and Aerospace Technology 91, no. 10 (November 4, 2019): 1268–77. http://dx.doi.org/10.1108/aeat-07-2018-0203.

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Purpose The purpose of this paper is to achieve fault reconstruction for reaction wheels in spacecraft attitude control systems (ACSs) subject to space disturbance torques. Design/methodology/approach Considering the influence of rotating reaction wheels on spacecraft attitude dynamics, a novel non-linear learning observer is suggested to robustly reconstruct the loss of reaction wheel effectiveness faults, and its stability is proven using Lyapunov’s indirect method. Further, an extension of the proposed approach to bias faults reconstruction for reaction wheels in spacecraft ACSs is performed. Findings The numerical example and simulation demonstrate the effectiveness of the proposed fault-reconstructing methods. Practical implications This paper includes implications for the development of reliability and survivability of on-orbit spacecrafts. Originality/value This paper proposes a novel non-linear learning observer-based reaction wheels fault reconstruction for spacecraft ACSs.

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Eliwa, M. S., Medhat EL-Damcese, A. H. El-Bassiouny, Abhishek Tyag, and M. El-Morshedy. "The Weibull Distribution: Reliability Characterization Based on Linear and Circular Consecutive Systems." Statistics, Optimization & Information Computing 9, no. 4 (September 24, 2021): 974–83. http://dx.doi.org/10.19139/soic-2310-5070-1132.

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Linear and circular consecutive models play a vital role to study the mechanical systems emerging in various fields including survival analysis, reliability theory, biological disciplines, and other lifetime sciences. As a result, analysis of reliability properties of consecutive k − out − of − n : F systems has gained a lot of attention in recent years from a theoretical and practical point of view. In the present article, we have studied some important stochastic and aging properties of residual lifetime of consecutive k − out − of − n : F systems under the condition n − k + 1, k ≤ n and all components of the system are working at time t. The mean residual lifetime (MRL) and its hazard rate function are proposed for the linear consecutive k − out − of − n : F (lin/con/k/n:F) and circular consecutive k − out − of − n : F (cir/con/k/n:F) systems. Furthermore, several mathematical properties of the proposed MRL are examined. Finally, the Weibull distribution with two parameters is used as an example to explain the theoretical results.

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Efimov, S. N., V. A. Terskov, P. V. Galushin, and K. V. Yarkov. "Reliability Model of Multiprocessor Hardware-Software Complexes of Real-Time Control Systems with Multi-Version Software." Herald of the Bauman Moscow State Technical University. Series Instrument Engineering, no. 4 (137) (December 2021): 41–58. http://dx.doi.org/10.18698/0236-3933-2021-4-41-58.

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Reliability is a critical parameter of real-time control systems. In practice, the reliability of hardware and software complexes included in such systems, is ensured by creating redundancy of hardware components and a multi-version approach to software development. But the redundant reservation of hardware devices and too many versions of software can lead to unjustified growth in the cost of creating and operating the projected control system. A rational approach to the design requires the creation of a model, which allows evaluating the reliability of different hardware and software complex configurations at the design stage. We proposed a mathematical reliability model of hardware and software complexes of real-time control systems, built with the use of mathematical apparatus of the queueing theory, which is a system of differential equations for the probability of finding states in the system, in which one or another component of the hardware and software complex is faulty. From the system of differential equations, the system of linear algebraic equations for probabilities of states in a steady-state mode was obtained. An analytical solution of this system is given, which allows us to evaluate the reliability of multiprocessor hardware-software complexes with multi-version software without significant expenditure of computational resources. Possibilities of using the results obtained to optimize the reliability of multiprocessor hardware-software complexes with multi-version software are presented and directions for further research are proposed

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Luo, Yuwei, Varun Gupta, and Mladen Kolar. "Dynamic Regret Minimization for Control of Non-stationary Linear Dynamical Systems." Proceedings of the ACM on Measurement and Analysis of Computing Systems 6, no. 1 (February 24, 2022): 1–72. http://dx.doi.org/10.1145/3508029.

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We consider the problem of controlling a Linear Quadratic Regulator (LQR) system over a finite horizon T with fixed and known cost matrices Q,R, but unknown and non-stationary dynamics A_t, B_t. The sequence of dynamics matrices can be arbitrary, but with a total variation, V_T, assumed to be o(T) and unknown to the controller. Under the assumption that a sequence of stabilizing, but potentially sub-optimal controllers is available for all t, we present an algorithm that achieves the optimal dynamic regret of O(V_T^2/5 T^3/5 ). With piecewise constant dynamics, our algorithm achieves the optimal regret of O(sqrtST ) where S is the number of switches. The crux of our algorithm is an adaptive non-stationarity detection strategy, which builds on an approach recently developed for contextual Multi-armed Bandit problems. We also argue that non-adaptive forgetting (e.g., restarting or using sliding window learning with a static window size) may not be regret optimal for the LQR problem, even when the window size is optimally tuned with the knowledge of $V_T$. The main technical challenge in the analysis of our algorithm is to prove that the ordinary least squares (OLS) estimator has a small bias when the parameter to be estimated is non-stationary. Our analysis also highlights that the key motif driving the regret is that the LQR problem is in spirit a bandit problem with linear feedback and locally quadratic cost. This motif is more universal than the LQR problem itself, and therefore we believe our results should find wider application.

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Peng, Lijuan, Jian Wang, Guicheng Yu, Zuoxue Wang, Aijun Yin, and Hongji Ren. "Active Vibration Control of PID Based on Receptance Method." Journal of Sensors 2020 (August 14, 2020): 1–8. http://dx.doi.org/10.1155/2020/8811448.

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Active vibration control approaches have been widely applied on improving reliability of robotic systems. For linear vibratory systems, the vibration features can be altered by modifying poles and zeros. To realize the arbitrary assignment of the closed-loop system poles and zeros of a linear vibratory system, in this paper, an active PID input feedback vibration control method is proposed based on the receptance method. The establishment and verification of the proposed method are demonstrated. The assignable poles during feedback control are calculated and attached with importance to expand the application of the integral control. Numerical simulations are conducted to verify the validity of the proposed method in terms of the assignment of closed-loop poles, zeros, and both. The results indicate that the proposed method can be used to realize the active vibration control of closed-loop system and obtain the desired damping ratio, modal frequency, and dynamic response.

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GUROV, SERGEY V., and LEV V. UTKIN. "FUZZY RELIABILITY OF GRACEFULLY DEGRADING SYSTEMS WITH THE COMPOSITE SOFTWARE." International Journal of Reliability, Quality and Safety Engineering 03, no. 02 (June 1996): 153–65. http://dx.doi.org/10.1142/s0218539396000119.

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In this paper, we focus on the transient and steady-state reliability behavior of a computer system whose software component as a program executes an infinite loop to provide control function and consists of several subprograms sequentially executed during iterations of the loop. The performance degradation of the system is due to the hardware failure occurrence. For reducing a large number of the system performance levels, we assume that the system success and failure are characterized by the fuzzy success and failure states with the defined membership functions. The system failure behavior is fully characterized in the context of probability measures. All random variables, such as times to hardware failures and mission times of subprograms, are arbitrarily distributed. In fact, we solve two problems: (1) reliability analysing under condition of many states and (2) reducing the state reliability measures to fuzzy success and failure reliability characteristics. The systems of integral and linear equations are used to obtain the unsteady and steady-state reliability characteristics, respectively. A numerical example is provided to illustrate and analyze the results.

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Smallwood, David. "Minimum Input Trace for Multiple Input Multiple Output Linear Systems." Journal of the IEST 56, no. 2 (October 1, 2013): 57–67. http://dx.doi.org/10.17764/jiet.56.2.41344333010617q6.

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Specification of the cross spectra for a multiple-input/multiple-output (MIMO) vibration test is challenging. This paper presents a method for tests where the specifications of the output (the control points) autospectra are available. The autospectra of the outputs are specified and cross spectra between the outputs are derived that will minimize the trace of the autospectra of the inputs (the drive signals) with the constraint that the input spectral density matrix is positive definite. The hypothesis is that nature likes a minimum energy solution.

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Geng, Hua, and Geng Yang. "Linear and Nonlinear Schemes Applied to Pitch Control of Wind Turbines." Scientific World Journal 2014 (2014): 1–9. http://dx.doi.org/10.1155/2014/406382.

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Linear controllers have been employed in industrial applications for many years, but sometimes they are noneffective on the system with nonlinear characteristics. This paper discusses the structure, performance, implementation cost, advantages, and disadvantages of different linear and nonlinear schemes applied to the pitch control of the wind energy conversion systems (WECSs). The linear controller has the simplest structure and is easily understood by the engineers and thus is widely accepted by the industry. In contrast, nonlinear schemes are more complicated, but they can provide better performance. Although nonlinear algorithms can be implemented in a powerful digital processor nowadays, they need time to be accepted by the industry and their reliability needs to be verified in the commercial products. More information about the system nonlinear feature is helpful to simplify the controller design. However, nonlinear schemes independent of the system model are more robust to the uncertainties or deviations of the system parameters.

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Żugaj, Marcin, Przemysław Bibik, and Marcin Figat. "An Unmanned Aircraft Model for Control System Reconfiguration Analysis and Synthesis." Transactions on Aerospace Research 2017, no. 2 (June 1, 2017): 97–116. http://dx.doi.org/10.2478/tar-2017-0018.

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Abstract Reliability of unmanned aircraft is a decisive factor for conducting air tasks in a controlled airspace. One of the means of improving unmanned aircraft reliability is reconfiguration of the control system, which will allow to maintain control over the aircraft despite an occurring failure. The control system is reconfigured by using still operational control surfaces to compensate for failure consequences and to control the damaged aircraft. Development of effective reconfiguration algorithms involves utilization of a non-linear model of unmanned aircraft dynamics, in which each control surface deflection can be controlled independently. The paper describes a non-linear model of a small unmanned aircraft with decoupled control surfaces. The paper discusses aircraft flight dynamics equations and estimated equations for controllability derivatives for each control surface, the results of comparison tests of the model and actual aircraft as well as the structure of the simulation model. The developed unmanned aircraft model may be used in development and in optimization of control algorithms for aircraft with damaged control systems as well as to test the impact of failures on dynamic properties of the aircraft.

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Parulekar, Y. M., G. R. Reddy, K. K. Vaze, and K. Muthumani. "Passive Control of Seismic Response of Piping Systems." Journal of Pressure Vessel Technology 128, no. 3 (August 30, 2005): 364–69. http://dx.doi.org/10.1115/1.2217969.

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Passive energy dissipating devices, such as elastoplastic dampers (EPDs) can be used for eliminating snubbers and reducing the response of piping systems subjected to seismic loads. Cantilever and three-dimensional piping systems were tested with and without EPD on shaker table. Using a finite element model of the piping systems, linear and nonlinear time-history analysis is carried out using Newmark’s time integration technique. Equivalent linearization technique, such as Caughey method, is used to evaluate the equivalent damping of the piping systems supported on elastoplastic damper. An iterative response spectrum method is used for evaluating response of the piping system using this equivalent damping. The analytical maximum response displacement obtained at the elastoplastic damper support for the two piping systems is compared with experimental values and time history analysis values. It has been concluded that the iterative response spectrum technique using Caughey equivalent damping is simple and results in reasonably acceptable response of the piping systems supported on EPD.

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Park, Jungjoon, Sinwoo Jeong, and Honghee Yoo. "Dynamic Modeling of a Front-Loading Type Washing Machine and Model Reliability Investigation." Machines 9, no. 11 (November 15, 2021): 289. http://dx.doi.org/10.3390/machines9110289.

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A linear dynamic model of a front-loading type washing machine was developed in this study. The machine was conceptualized with three moving rigid bodies, revolute joints, springs, and dampers along with prescribed rotational drum motion. Kane’s method was employed for deriving the equations of motion of the idealized washing machine. Since the modal and transient characteristics can be conveniently investigated with a linear dynamic model, the linear model can be effectively used for the design of an FL type washing machine. Despite the convenience, however, the reliability of the linear dynamic model is often restricted to a certain range of system parameters. Parameters relevant to the reliability of the linear dynamic model were identified and the parameters’ ranges that could guarantee the reliability of the proposed linear dynamic model were numerically investigated in this study.

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Rahman, Mahmudur, Muhammad Mahbubur Rashid, Asan G. A. Muthalif, and Banna Kasemi. "Evaluation of Different Control Policies of Semi-Active MR Fluid Damper of a Quarter-Car Model." Applied Mechanics and Materials 165 (April 2012): 310–15. http://dx.doi.org/10.4028/www.scientific.net/amm.165.310.

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Proportional Integral Derivative and clipped-optimal control strategy controllers are studied to control the response of Quarter-car suspension profile. A Semi-active device is used for this purpose because it carries valuable result which maintains the reliability of passive control methods and includes the advantage of the adjustable parameter characteristics of active systems. Semi-active devices like Magnetorheological fluids dampers are very effective to control vibration, which use MR fluids to produce controllable damping force and provide both the reliability of passive systems and the facility of active control systems with small power supply. The quarter car model is used here can be described as a nonlinear two degrees of freedom system which is subject to excitation from different road profile. For the best possible reduction of vibration in suspension systems, various Magnetorheological damper models are studied which Bouc-wen model, Neuro-fuzzy model and Bingham model. The performances of these models are evaluated to select a best model. The quarter-car model is executed using step input with two most common and effective control algorithm in vehicle suspension control which are linear quadratic regulator control, and Proportional Integral Derivative control algorithm. The main objective of this study is to evaluate performances of these control algorithms.

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Cortes-Vega, David, Hussain Alazki, and Jose Luis Rullan-Lara. "Current Sensorless MPPT Control for PV Systems Based on Robust Observer." Applied Sciences 12, no. 9 (April 26, 2022): 4360. http://dx.doi.org/10.3390/app12094360.

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Photovoltaic (PV) systems are among the most used alternatives for electrical power generation from renewable sources. To ensure that PV systems make the most of the available solar energy, maximum power point tracking (MPPT) schemes must be implemented, which usually require voltage and current sensors to track the PV power. This paper presents the design of a robust observer using the Attractive Ellipsoid Method to achieve a precise estimation of PV current under parametric uncertainty and output perturbations. The application of such an observer enables the PV generation system to operate in a current sensorless mode, which reduces the overall cost of the system and enhances its reliability. The convergence of the observer is guaranteed by solving an optimization problem which generates the optimal gains using Linear Matrix Inequalities (LMI). To prove the effectiveness of the proposed sensorless scheme, simulations are performed in Matlab under test profiles based on the EN50530 standard and parameter uncertainty conditions, obtaining an accurate estimation which is used for MPPT operation.

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Cortes-Vega, David, Hussain Alazki, and Jose Luis Rullan-Lara. "Current Sensorless MPPT Control for PV Systems Based on Robust Observer." Applied Sciences 12, no. 9 (April 26, 2022): 4360. http://dx.doi.org/10.3390/app12094360.

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Photovoltaic (PV) systems are among the most used alternatives for electrical power generation from renewable sources. To ensure that PV systems make the most of the available solar energy, maximum power point tracking (MPPT) schemes must be implemented, which usually require voltage and current sensors to track the PV power. This paper presents the design of a robust observer using the Attractive Ellipsoid Method to achieve a precise estimation of PV current under parametric uncertainty and output perturbations. The application of such an observer enables the PV generation system to operate in a current sensorless mode, which reduces the overall cost of the system and enhances its reliability. The convergence of the observer is guaranteed by solving an optimization problem which generates the optimal gains using Linear Matrix Inequalities (LMI). To prove the effectiveness of the proposed sensorless scheme, simulations are performed in Matlab under test profiles based on the EN50530 standard and parameter uncertainty conditions, obtaining an accurate estimation which is used for MPPT operation.

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Yu, Lijuan, Jie Huang, Wei Luo, Shuyuan Chang, Huilu Sun, and Hailong Tian. "Sliding-Mode Control for PMLSM Position Control—A Review." Actuators 12, no. 1 (January 7, 2023): 31. http://dx.doi.org/10.3390/act12010031.

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Owing to the competitive advantages of fast response speed, large pushing force, high reliability, and high precision, the permanent magnet linear synchronous motor (PMLSM) has played an increasingly vital role in various high-speed and high-precision control systems. However, PMLSM exhibits nonlinear behavior in actual operation, and position tracking precision is negatively affected by friction, load changes, and other external disturbances. To meet the growing demand and solve the position tracking control problem for the PMLSM, the control system is critical. Sliding-mode control (SMC) has been used extensively in nonlinear control systems due to its superior performance characterized by simplicity, good dynamic response and insensitivity to parameter perturbation and external disturbances, and has been implemented in PMLSMs to track practical position. The objective of this article is to classify, scrutinize and review the major sliding-mode control approaches for position control of PMLSM. The three different conventional SMC methods, namely the boundary layer approach, the reaching law approach and the disturbance observer-based SMC, are discussed in detail. The four advanced forms of SMC, namely terminal SMC, super-twisting SMC, adaptive SMC and intelligent SMC, are also presented. A comparison of these approaches is given, in which the advantages and disadvantages of each approach are presented; additionally, they are presented in table form in order to facilitate reading. It is anticipated that this work will serve as a reference and provide important insight into position control of PMLSM systems.

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Bahatskyi, Valentin, and Aleksey Bahatskyi. "ERRORS CONVERSION ON TRANSFER FUNCTIONS OF MEASUREMENT AND CONTROL." Journal of Automation and Information sciences 4 (July 1, 2021): 92–104. http://dx.doi.org/10.34229/1028-0979-2021-4-9.

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Currently, the measurement of electrical and non-electrical quantities is performed using analog-to-digital conversion channels, which consist of analog signal conditioning circuits and analog-to-digital converters (ADC) of electrical quantities into a digital code. The paper considers the case when the defining errors of the measurement and control channel are systematic errors of the ADC. The reliability of measurements is assessed by their errors, and the reliability of control - by the likelihood of correct operation of the control device. In our opinion, evaluating the reliability of such similar processes as measurement and control using different criteria seems illogical. The aim of the work is to study the effect of systematic errors of an analog-to-digital converter on the errors of parameter control depending on the type of conformity functions and the width of the control window, as well as the choice of the resolution of the ADC for various control tasks. The paper analyzes the transfer functions of measurement and control. It is shown that they are formed using step functions. It is proposed to use not a step function as a control transfer function, but other functions of conformity to the norm, for example, a linear function or functions of higher orders. In this case, the control result is assessed not according to the criterion of the probability of correct operation, but using the control error. Analyzed from the point of view of reconfiguring the errors of the line, parabolic and state parabolic functions of the norms for the development of changes windows in control. A recommendation has been given for the selection of functions for the conformity of standards and for the distribution of analog-to-digital conversions for industrial control enterprises.

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Ma, Lifeng, Zidong Wang, Hongli Dong, and Guoliang Wei. "Variance-Constrained Multiobjective Control and Filtering for Nonlinear Stochastic Systems: A Survey." Abstract and Applied Analysis 2013 (2013): 1–13. http://dx.doi.org/10.1155/2013/724018.

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The multiobjective control and filtering problems for nonlinear stochastic systems with variance constraints are surveyed. First, the concepts of nonlinear stochastic systems are recalled along with the introduction of some recent advances. Then, the covariance control theory, which serves as a practical method for multi-objective control design as well as a foundation for linear system theory, is reviewed comprehensively. The multiple design requirements frequently applied in engineering practice for the use of evaluating system performances are introduced, including robustness, reliability, and dissipativity. Several design techniques suitable for the multi-objective variance-constrained control and filtering problems for nonlinear stochastic systems are discussed. In particular, as a special case for the multi-objective design problems, the mixedH2/H∞control and filtering problems are reviewed in great detail. Subsequently, some latest results on the variance-constrained multi-objective control and filtering problems for the nonlinear stochastic systems are summarized. Finally, conclusions are drawn, and several possible future research directions are pointed out.

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Hong, G. S., H. A. Zhu, C. L. Teo, and A. N. Poo. "Robust Control of Robotic Manipulators with Model-Based Precompensation and SMC Postcompensation." Proceedings of the Institution of Mechanical Engineers, Part I: Journal of Systems and Control Engineering 207, no. 2 (May 1993): 97–103. http://dx.doi.org/10.1243/pime_proc_1993_207_323_02.

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Robust and reliable control of robotic manipulators is studied. A model-based precompensation configuration is first used to decouple and linearize the highly complicated electromechanical dynamics of robotic manipulators. Then a linear state-feedback control law is used for closed-loop control. Finally, simplified SMC is adopted to postcompensate for the resulting error dynamics of the closed-loop control system. It is shown that the intentionally introduced control redundancy will not only ensure global high performance for the resulting system, but will also provide the system with built-in high reliability.

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Mosconi, Denis, Adriano Almeida Gonçalves Siqueira, and Everthon Silva Fonseca. "Optimal control of a planar robot manipulator based on the Linear Quadratic Inverse-Dynamics design." Journal of Mechatronics Engineering 2, no. 2 (July 30, 2019): 2. http://dx.doi.org/10.21439/jme.v2i2.25.

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To ensure the correct positioning of the end-effector of robot manipulators is one of the most important objectives of the robotic systems control. Lack of reliability in tracking the reference trajectory, as well as in the desired final positioning compromises the quality of the task to be performed, even causing accidents. The purpose of this work was to propose an optimal controller with an inner loop based on the dynamic model of the manipulator and a feedback loop based on the Linear Quadratic Regulator, in order to ensure that the end effector is in the right place, at the right time. The controller was compared to the conventional PID, presenting better performance, both in the transient response, eliminating overshoot, and steady-state, eliminating the stationary error.

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Lindstedt, Paweł, and Karol Golak. "Examination of Operational Dependability Demonstrated by Turbine Reactive Engines." Journal of Konbin 14-15, no. 1 (January 1, 2010): 61–76. http://dx.doi.org/10.2478/v10040-008-0165-9.

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Examination of Operational Dependability Demonstrated by Turbine Reactive Engines The paper presents course and results of operational examination carried out for engines with particular consideration of land-based tests. It has been suggested that available, already recorded signals from the automatic and control systems can serve as a basis for assessment of the engine operability. The recorded signals can be analyzed in various manners, including the method that is based on the phase trajectory superposed with the Lyapunov function. It has been shown that analysis of signal interrelations presents substantial advantages, where the movement of the phase trajectory vector over the time period is subject to analysis and is related to successive values of the Lyapunov function that is calculated for subsequent moments of time (possibility to analyze both linear and non-linear systems, simultaneous analysis of three signals: operational, environment and feed), therefore the proposed method prevails over other approaches to analysis of signals. The final part of the paper deals with analysis of signals obtained from recorded waveforms from the automation and control systems of the K-15 engine.

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Jiao, Zongxia, Yuan Cao, Liang Yan, Xinglu Li, Lu Zhang, and Yang Li. "Advancing Motivation Feedforward Control of Permanent Magnetic Linear Oscillating Synchronous Motor for High Tracking Precision." Actuators 10, no. 6 (June 10, 2021): 128. http://dx.doi.org/10.3390/act10060128.

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Linear motors have promising application to industrial manufacture because of their direct motion and thrust output. A permanent magnetic linear oscillating synchronous motor (PMLOSM) provides reciprocating motion which can drive a piston pump directly having advantages of high frequency, high reliability, and easy commercial manufacture. Hence, researching the tracking performance of PMLOSM is of great importance to realizing its popularization and application. Traditional PI control cannot fulfill the requirement of high tracking precision, and PMLOSM performance has high phase lag because of high control stiffness. In this paper, an advancing motivation feedforward control (AMFC), which is a combination of advancing motivation signal and PI control signal, is proposed to obtain high tracking precision of PMLOSM. The PMLOSM inserted with AMFC can provide accurate trajectory tracking at a high frequency. Compared with single PI control, AMFC can reduce the phase lag from −18 to −2.7 degrees, which shows great promotion of the tracking precision of PMLOSM. In addition, AMFC will promote the application of PMLOSM to other working conditions needing high frequency reciprocating tracking performance and give PMLOSM greater future prospects.

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Soliman, Hisham M., Farag A. El-Sheikhi, Ehab H. E. Bayoumi, and Michele De Santis. "Ellipsoidal Design of Robust Stabilization for Markov Jump Power Systems under Normal and Contingency Conditions." Energies 15, no. 19 (October 2, 2022): 7249. http://dx.doi.org/10.3390/en15197249.

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The essential prerequisites for secure customer service are power system stability and reliability. This work shows how to construct a robust switching control for studying power system load changes using an invariant ellipsoid method. Furthermore, the suggested control ensures stability when the system is subjected to random stochastic external disturbances, and functions randomly in two conditions: normal and contingency. The extreme (least) reliability state is chosen as the most severe scenario (corresponding to a transmission line outage). As a two-state Markov random chain, the transition probabilities are utilized to simulate the switching between normal and contingency modes (or processes). To characterize the dynamics of the studied system, a stochastic mathematical model is developed. The effect of stochastic disturbances and random normal/contingency operations is taken into account during the design stage. For a stochastic power system, a novel excitation control is designed. The attractive ellipsoid approach and linear matrix inequalities (LMIs) optimization are used to build the best two-controller gains. Therefore, the proposed modeling/design technique can be employed for the power system under load changes, stochastic topological changes, and random disturbances. Finally, the system’s random dynamics simulation indicates the effectiveness of the designed control law.

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Flores, Thommas Kevin Sales, Juan Moises Mauricio Villanueva, and Heber Pimentel Gomes. "Fuzzy Pressure Control: A Novel Approach to Optimizing Energy Efficiency in Series-Parallel Pumping Systems." Automation 4, no. 1 (January 18, 2023): 11–28. http://dx.doi.org/10.3390/automation4010002.

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Automation and control systems are constantly evolving, using artificial intelligence techniques to implement new forms of control, such as fuzzy control, with advantages over classic control strategies, especially in non-linear systems. Water supply networks are complex systems with different operating configurations, uninterrupted operation requirements, equalization capacity and pressure control in the supply networks, and high reliability. In this sense, this work aims to develop a fuzzy pressure control system for a supply system with three possible operating configurations: a single motor pump, two motor pumps in series, or two motor pumps in parallel. For each configuration, an energy efficiency analysis was carried out according to the demand profile established in this case study. In order to validate the proposed methodology, an experimental water supply system was used, located in the Laboratory of Energy Efficiency and Hydraulics in Sanitation at the Federal University of Paraiba (LENHS/UFPB).

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Wang, Lei, Tao Shen, and Chen Chen. "Multimodel Modeling and Predictive Control for Direct-Drive Wind Turbine with Permanent Magnet Synchronous Generator." Abstract and Applied Analysis 2015 (2015): 1–11. http://dx.doi.org/10.1155/2015/296436.

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The safety and reliability of the wind turbines wholly depend on the completeness and reliability of the control system which is an important problem for the validity of the wind energy conversion systems (WECSs). A method based on multimodel modeling and predictive control is proposed for the optimal operation of direct-drive wind turbine with permanent magnet synchronous generator in this paper. In this strategy, wind turbine with direct-drive permanent magnet synchronous generator is modeled and a backpropagation artificial neural network is designed to estimate the wind speed loaded into the turbine model in real time through the estimated turbine shaft speed and mechanical power. The nonlinear wind turbine system is presented by multiple linear models. The desired trajectory of the nonlinear system is decomposed to be suitable for the reference trajectory of multiple models that are presented by the linear models of the nonlinear system, which simplifies the nonlinear optimization problems and decreases the calculation difficulty. Then a multivariable control strategy based on model predictive control techniques for the control of variable-speed variable-pitch wind turbines is proposed. Finally, simulation results are given to illustrate the effectiveness of the proposed strategy, and the conclusion that multiple model predictive controller (MMPC) has better control performance than the PI control method is obtained.

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Serna-Suárez, Iván David. "A Convex Approximation for Optimal DER Scheduling on Unbal-anced Power Distribution Networks." DYNA 86, no. 208 (January 1, 2019): 281–91. http://dx.doi.org/10.15446/dyna.v86n208.72886.

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The increase of solar photovoltaic penetration poses several challenges for distribution network operation, mainly because such high penetration might cause reliability problems like protection malfunctioning, accelerated decay of voltage regulators and voltage violations. Some control strategies avoid such drawbacks at the cost of not fully exploiting the available energy. Existing solutions based on mathematical programming solve a 3-phase ACOPF to optimally exploit the available energy, however, this might increase all reliability problems above if done carelessly. As a solution to optimally exploit DERs (like local photovoltaic and storage systems) without compromising the network reliability, this paper presents a novel algorithm to solve the 3-phase ACOPF as a sequence of convex Quadratically Constrained Quadratic Programs. Results show that this solution has a lower voltage unbalance and computation time than its non-linear counterpart, furthermore, it converges to a primal feasible point for the non-linear formulation without major sacrifices on optimal DER active power injections.

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Amin, Arslan Ahmed, and Khalid Mahmood-ul-Hasan. "Robust active fault-tolerant control for internal combustion gas engine for air–fuel ratio control with statistical regression-based observer model." Measurement and Control 52, no. 9-10 (January 9, 2019): 1179–94. http://dx.doi.org/10.1177/0020294018823031.

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Fault-tolerant control systems are utilized in safety and critical applications to achieve greater reliability and availability for continued operation despite faults in the system components. These systems can be utilized in the process plants to avoid costly production loss due to abnormal and unscheduled tripping of the machines. In this paper, advanced fault-tolerant control systems of active type are proposed for air–fuel ratio control of internal combustion gas engine in a process plant to achieve greater reliability and availability to avoid a shutdown of the gas engine. Gas engines are extensively used equipment in the process industry and proper air–fuel ratio control in the fuel system of these engines is quite important to achieve greater engine efficiency, fuel energy savings and environmental protection. Active fault-tolerant control system is proposed in this paper in which linear regression–based observer model is used in the fault detection and isolation unit for fault detection, isolation and reconfiguration. Fuel actuator is introduced in the fuel supply line and proportional feedback controller is implemented to maintain the air–fuel ratio in faulty conditions. Redundancy in the sensors and fuel actuator is proposed to avoid engine shutdown in case of simultaneous faults in more than one sensor and to avoid a single point of failure due to fault in the single actuator. Noise is introduced in the sensor measurements to determine the robustness of proposed active fault-tolerant control system in noisy and faulty conditions. Results show that the proposed system remains stable, maintaining air–fuel ratio well in faulty conditions and is robust to noise.

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Aggogeri, Francesco, and Nicola Pellegrini. "Design and Experimental Validation of a Shape Memory Alloy Actuator for Linear Motors." Applied Mechanics and Materials 783 (August 2015): 69–75. http://dx.doi.org/10.4028/www.scientific.net/amm.783.69.

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This paper presents an innovative mechanical actuator using a shape memory alloy (SMA) with a cooling system based on combined thermoelectric effect and forced air cooling systems. The main advantages of using SMAs include the reduction of the system weight, the ease and reliability in application, and a simple control strategy. This study focuses on the development of the system highlighting the mathematical model of the actuator, and an experimental prototype was implemented. Several experiments are used to validate the model and to identify best SMA actuator configuration parameters. Experiments were used to evaluate the actuator closed-loop performance, stability, and robustness properties.

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Wang, Ruochen, Renkai Ding, and Long Chen. "Application of hybrid electromagnetic suspension in vibration energy regeneration and active control." Journal of Vibration and Control 24, no. 1 (March 15, 2016): 223–33. http://dx.doi.org/10.1177/1077546316637726.

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To improve the reliability of active electromagnetic suspension and reduce energy consumption, a hybrid electromagnetic suspension that consists of linear motor and passive damper in parallel is proposed in this paper. First, a dynamic model is established and passive energy regeneration and active control systems are built. Thereafter, energy regeneration, ride comfort, and driving safety are taken as control objects. The effect of damping values on different control objects are studied, and the best values are determined. Passive suspension is taken for comparison, and comparative simulation analysis is conducted. Finally, a bench test of 1/4 suspension is performed to verify the accuracy of the simulation results.

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Riaz, Saleem, Hui Lin, and Muhammad Pervez Akhter. "Design and Implementation of an Accelerated Error Convergence Criterion for Norm Optimal Iterative Learning Controller." Electronics 9, no. 11 (October 23, 2020): 1766. http://dx.doi.org/10.3390/electronics9111766.

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Designing an optimal iterative learning control is a huge challenge for linear and nonlinear dynamic systems. For such complex systems, standard Norm optimal iterative learning control (NOILC) is an important consideration. This paper presents a novel NOILC error convergence technique for a discrete-time method. The primary effort of the controller is to converge the error efficiently and quickly in an optimally successful way. A new iterative learning algorithm based on feedback based on reliability against input disruption was proposed in this paper. The illustration of the simulations authenticates the process suggested. The numerical example simulated on MATLAB@2019 and the mollified results affirm the validation of the designed algorithm.

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Wu, Fen, and Suat E. Yildizoglu. "Distributed Parameter-Dependent Modeling and Control of Flexible Structures." Journal of Dynamic Systems, Measurement, and Control 127, no. 2 (June 21, 2004): 230–39. http://dx.doi.org/10.1115/1.1898240.

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In this paper, distributed parameter-dependent modeling and control approaches are proposed for flexible structures. The distributed model is motivated from distributed control design, which is advantageous in reducing control implementation cost and increasing control system reliability. This modeling approach mainly relies on a central finite difference scheme to capture the distributed nature of the flexible system. Based on the proposed distributed model, a sufficient synthesis condition for the design of a distributed output-feedback controller is presented using induced L2 norm as the performance criterion. The controller synthesis condition is formulated as linear matrix inequalities, which are convex optimization problems and can be solved efficiently using interior-point algorithms. The distributed controller inherits the same structure as the plant, which results in a localized control architecture and a simple implementation scheme. These modeling and control approaches are demonstrated on a non-uniform cantilever beam problem through simulation studies.

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Chen, Zengqiang, Yongshuai Wang, Mingwei Sun, and Qinglin Sun. "Convergence and stability analysis of active disturbance rejection control for first-order nonlinear dynamic systems." Transactions of the Institute of Measurement and Control 41, no. 7 (September 18, 2018): 2064–76. http://dx.doi.org/10.1177/0142331218794812.

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To quantitatively investigate the correlation between parameters, disturbance and stability of the linear active disturbance rejection control (LADRC) technique, this paper provides a perspective of first-order nonlinear dynamic systems, and obtains the stable region of LADRC and reduced-order LADRC according to the Lyapunov function and the Markus–Yamabe theorem, along with mathematical proofs for global stability and asymptotic regulation. To be specific, regardless of whether plant dynamics are exactly known or unknown, the control bandwidth can be chosen arbitrarily from the obtained feasible region as long as the derivative of the disturbance satisfies a Lipschitz condition, or some knowledge of the boundary is available. Moreover, simulations are presented to testify the reliability of the results for different disturbances that are probably known or unknown when designing the extended state observer. The results show the validity and feasibility of this analysis.

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Taghirad, H. D., and P. R. Be´langer. "Modeling and Parameter Identification of Harmonic Drive Systems." Journal of Dynamic Systems, Measurement, and Control 120, no. 4 (December 1, 1998): 439–44. http://dx.doi.org/10.1115/1.2801484.

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The unique performance features of harmonic drives, such as high gear ratios and high torque capacities in a compact geometry, justify their widespread industrial application. However, harmonic drive can exhibit surprisingly more complex dynamic behavior than conventional gear transmission. In this paper a systematic way to capture and rationalize the dynamic behavior of the harmonic drive systems is developed. Simple and accurate models for compliance, hysteresis, and friction are proposed, and the model parameters are estimated using least-squares approximation for linear and nonlinear regression models. A statistical measure of variation is defined, by which the reliability of the estimated parameter for different operating condition, as well as the accuracy and integrity of the proposed model is quantified. By these means, it is shown that a linear stiffness model best captures the behavior of the system when combined with a good model for hysteresis. Moreover, the frictional losses of harmonic drive are modeled at both low and high velocities. The model performance is assessed by comparing simulations with the experimental results on two different harmonic drives. Finally, the significance of individual components of the nonlinear model is assessed by a parameter sensitivity study using simulations.

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Snell, S. A., and P. W. Stout. "Flight Control Law Using Nonlinear Dynamic Inversion Combined With Quantitative Feedback Theory." Journal of Dynamic Systems, Measurement, and Control 120, no. 2 (June 1, 1998): 208–15. http://dx.doi.org/10.1115/1.2802411.

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A method of designing control laws for uncertain nonlinear systems is presented. Dynamic inversion is used to partially linearize the dynamics and then a nonlinear version of quantitative feedback theory (QFT) is applied to the resulting system which assures robustness to plant uncertainty. The design yields good performance with low bandwidth. An application to the design of flight control laws for a high performance aircraft is presented. The control laws demonstrate good performance by accurately following large angle of attack commands at flight speeds ranging from 53 to 150 m/s. Robustness is verified by including ±20 percent variations in pitching moment derivatives. The reduced bandwidth compared to a fixed-gain, linear design, leads to greatly reduced actuator transients, which should give improved reliability and longer life for the actuators and associated structure.

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43

Fu, Hongfei, Hongxing Rui, Jiansong Zhang, and Hui Guo. "A Priori Error Estimate of Splitting Positive Definite Mixed Finite Element Method for Parabolic Optimal Control Problems." Numerical Mathematics: Theory, Methods and Applications 9, no. 2 (May 2016): 215–38. http://dx.doi.org/10.4208/nmtma.2016.m1409.

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AbstractIn this paper, we propose a splitting positive definite mixed finite element method for the approximation of convex optimal control problems governed by linear parabolic equations, where the primal state variable y and its flux σ are approximated simultaneously. By using the first order necessary and sufficient optimality conditions for the optimization problem, we derive another pair of adjoint state variables z and ω, and also a variational inequality for the control variable u is derived. As we can see the two resulting systems for the unknown state variable y and its flux σ are splitting, and both symmetric and positive definite. Besides, the corresponding adjoint states z and ω are also decoupled, and they both lead to symmetric and positive definite linear systems. We give some a priori error estimates for the discretization of the states, adjoint states and control, where Ladyzhenkaya-Babuska-Brezzi consistency condition is not necessary for the approximation of the state variable y and its flux σ. Finally, numerical experiments are given to show the efficiency and reliability of the splitting positive definite mixed finite element method.

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Trapanese, Marco, Valeria Boscaino, Giovanni Cipriani, Domenico Curto, Vincenzo Di Dio, and Vincenzo Franzitta. "A Permanent Magnet Linear Generator for the Enhancement of the Reliability of a Wave Energy Conversion System." IEEE Transactions on Industrial Electronics 66, no. 6 (June 2019): 4934–44. http://dx.doi.org/10.1109/tie.2018.2838076.

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Da, Qiang, Dexin Li, Xiaolei Zhang, Weiling Guo, Dongyu He, Yanfei Huang, and Gengchao He. "Research on Performance Evaluation Method of Rice Thresher Based on Neural Network." Actuators 11, no. 9 (September 8, 2022): 257. http://dx.doi.org/10.3390/act11090257.

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Because the threshing device of a combine harvester determines the harvesting level and threshing separation performance of a combine harvester, the analysis and study of the threshing device of a combine harvester is key to improving its performance. Based on the threshing device of a half-feed combine harvester, the simulation model of a discrete element threshing device is established in this paper. With the threshing drum rotation speed, feed volume, and concave sieve vibration frequency as the variable factors, the BP neural network model and linear regression equation model established for the loss rate and impurity content for two kinds of threshing performance indicators, respectively, and through the discrete element threshing performance test, two kinds of methods of threshing performance prediction are analyzed. The results show that the neural network and linear regression can be used for the threshing performance indicators, however, the BP neural network prediction effect has a better prediction precision, better reliability, and the trained neural network can be used in the general case of the threshing performance indicators. This provides a new idea for improving the threshing performance of a combine harvester.

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Li, Huayi, Qingxian Jia, Rui Ma, and Xueqin Chen. "Observer-based robust actuator fault isolation and identification for microsatellite attitude control systems." Aircraft Engineering and Aerospace Technology 93, no. 7 (August 14, 2021): 1145–55. http://dx.doi.org/10.1108/aeat-10-2020-0224.

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Purpose The purpose of this paper is to accomplish robust actuator fault isolation and identification for microsatellite attitude control systems (ACSs) subject to a series of space disturbance torques and gyro drifts. Design/methodology/approach For the satellite attitude dynamics with Lipschitz constraint, a multi-objective nonlinear unknown input observer (NUIO) is explored to accomplish robust actuator fault isolation based on a synthesis of Hinf techniques and regional pole assignment technique. Subsequently, a novel disturbance-decoupling learning observer (D2LO) is proposed to identify the isolated actuator fault accurately. Additionally, the design of the NUIO and the D2LO are reformulated into convex optimization problems involving linear matrix inequalities (LMIs), which can be readily solved using standard LMI tools. Findings The simulation studies on a microsatellite example are performed to prove the effectiveness and applicability of the proposed robust actuator fault isolation and identification methodologies. Practical implications This research includes implications for the enhancement of reliability and safety of on-orbit microsatellites. Originality/value This study proposes novel NUIO-based robust fault isolation and D2LO-based robust fault identification methodologies for spacecraft ACSs subject to a series of space disturbance torques and gyro drifts.

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Feng, Xiang-Qian, Xiao-Dong Pang, and Cui-Ping Wei. "Distance-Based Consistency Measure and Priority Weights of Best-Worst Multi-Criteria Decision Making Method." International Journal of Uncertainty, Fuzziness and Knowledge-Based Systems 28, no. 05 (September 30, 2020): 853–78. http://dx.doi.org/10.1142/s0218488520500373.

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Best-Worst method (BWM) is a new multi-criteria decision-making method based on pairwise comparisons, but only the comparisons concerning the best and the worst alternatives or criteria. This method shows some significant advantages in the simplicity with a less requirement of comparison data and reliability with better consistency. This paper proposes a new consistency measure method based on the distance of the vectors of reference comparisons in BWM because the difference of the preference in two vectors directly affects the reliability of results. Through the establishment of the threshold of consistency ratio, we supplement the definition of satisfactory consistency of the comparisons in BWM. With comparisons satisfying the acceptable consistency, we use linear programming models to find all possible priority weights between the preferences given by decision maker and derive interval weights. For comparisons with unacceptable consistency, another approach is presented to find the interval weights meeting the consistent requirement. At last, several examples are used to illustrate the details of process.

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Suprantiningrum, Suprantiningrum, and Aurora Diskayani Lukas. "Sistem Informasi Akuntansi Manajemen, Pengendalian Manajemen terhadap Kinerja Manajerial dengan Variabel Moderating Teknologi Informasi." Owner 5, no. 1 (February 3, 2021): 174–85. http://dx.doi.org/10.33395/owner.v5i1.368.

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The success of garment companies in increasing business competition is influenced by good managerial performance. Managers to achieve optimal performance in planning, control and decision making need the support of management accounting information systems, management control systems and information technology. This study aims to determine the effect of management accounting information systems and management control systems on managerial performance, the effect of management accounting information systems and management control systems on managerial performance with information technology as a moderating variable. The research object is the manager of a garment company in the city of Semarang with a population of 200, sampling using probability sampling, the sample used is 67 managers, determining the number of samples using the Slovin formula. The data used are primary data, data collection using a questionnaire with 5 Likert scale. The data analysis used in this research is validity test, reliability test, multiple linear regression and interaction regression. The results showed that the management accounting information system had a significant positive effect on managerial performance. The management control system has a significant positive effect on managerial performance. Information technology is a moderating variable on the effect of management accounting information systems and management control systems on managerial performance, meaning that information technology strengthens the influence of management accounting information systems and management control systems on managerial performance in garment companies in the city of Semarang.

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Mohammadi, Nader, and Mehrdad Nasirshoaibi. "Optimization of vibrational absorber rested on linear structures under arbitrary vibrations." International Journal of Engineering & Technology 4, no. 3 (August 8, 2015): 446. http://dx.doi.org/10.14419/ijet.v4i3.4784.

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Vibrational absorber is one of the common approaches for vibration control in structures. In this article, optimization criteria for mechanical systems under arbitrary vibrations is presented based on a multi-purpose method whose objective function vector collects the efficiency of arbitrary reliability and indexes of structure costs. The criterion is different from conventional criteria and standards used to design structures subjected to arbitrary vibrations and is based on minimizing the changes in displacement or response acceleration of the main structure, regardless of the required function for the failure. In this study, multi-purpose optimization approach to the design of vibrational an absorber is investigated to control non-uniform structural vibrations stimulating mechanical a mechanical structure based on an arbitrary acceleration process. It is performed based on bee optimization algorithm. In the following, a numerical example is shown for a simple vibrational absorber by this way. It shows the results of cost increase for decreased possibility of deconstruction, and therefore, allows appropriate decision making and selection based on need and cost.

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Heidari Gharehbolagh, Hadi, Ashkan Hafezalkotob, Ahmad Makui, and Sadigh Raissi. "A cooperative game approach to uncertain decentralized logistic systems subject to network reliability considerations." Kybernetes 46, no. 8 (September 4, 2017): 1452–68. http://dx.doi.org/10.1108/k-02-2017-0043.

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Purpose Maximum-flow of an uncertain multi-owner network has become very important recently. This study aims to evaluate the maximum flow on a cooperated logistic system in the presence of uncertainties, raised by travel time, capacity, cost and failures. Design/methodology/approach To consider different uncertainties and to promote network efficiency, the proposed model is enriched with a cooperative game methodology and a reliability method. A scenario-based method covers optimistic, pessimistic and most likely estimates time, cost and capacity of each route as well as applies a prior failure pattern for breakdown of any resource. Findings A linear optimization model, which is enriched with target reliability estimation, is presented. Results on a water distribution network indicate more revenue performance for players. Carrying out sensitivity analysis shows the importance of the model parameters. Originality/value Modeling maximum-flow problem in the presence of many sources of uncertainty with the aim of a cooperative game is the main contribution of the present study. Also, a novel method based on the reliability theory is applied to close the chasm on evaluating the real maximum flow in a shared decentralized network which suffers from risky conditions on arcs and nodes.

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Journal articles on the topic 'Linear control systems Reliability'

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