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ISA Transactions

Abdelkarim Ammar, Amor Bourek, Abdelhamid Benakcha
This paper presents a nonlinear Direct Torque Control (DTC) strategy with Space Vector Modulation (SVM) for an induction motor. A nonlinear input-output feedback linearization (IOFL) is implemented to achieve a decoupled torque and flux control and the SVM is employed to reduce high torque and flux ripples. Furthermore, the control scheme performance is improved by inserting a super twisting speed controller in the outer loop and a load torque observer to enhance the speed regulation. The combining of dual nonlinear strategies ensures a good dynamic and robustness against parameters variation and disturbance...
January 17, 2017: ISA Transactions
Yi Long, Zhijiang Du, Lin Cong, Weidong Wang, Zhiming Zhang, Wei Dong
This paper presents an active disturbance rejection control (ADRC) based strategy, which is applied to track the human gait trajectory for a lower limb rehabilitation exoskeleton. The desired human gait trajectory is derived from the Clinical Gait Analysis (CGA). In ADRC, the total external disturbance can be estimated by the extended state observer (ESO) and canceled by the designed control law. The observer bandwidth and the controller bandwidth are determined by the practical principles. We simulated the proposed methodology in MATLAB...
January 17, 2017: ISA Transactions
Chengwen Wang, Long Quan, Shijie Zhang, Hongjun Meng, Yuan Lan
Hydraulic servomechanism is the typical mechanical/hydraulic double-dynamics coupling system with the high stiffness control and mismatched uncertainties input problems, which hinder direct applications of many advanced control approaches in the hydraulic servo fields. In this paper, by introducing the singular value perturbation theory, the original double-dynamics coupling model of the hydraulic servomechanism was reduced to a integral chain system. So that, the popular ADRC (active disturbance rejection control) technology could be directly applied to the reduced system...
January 17, 2017: ISA Transactions
Xiangyang Zhou, Beilei Zhao, Wei Liu, Haixiao Yue, Ruixia Yu, Yulong Zhao
A compound scheme is proposed to compensate the effect of nonlinear friction disturbance on the control precision of a three-axis inertially stabilized platform (ISP) for aerial remote sensing applications. The scheme consists of friction parameters identification and adaptive compensation. A LuGre model-based ISP friction model is first developed. Then, a comprehensive experimental scheme is proposed to obtain the static friction parameters. Further, the dynamic parameters are identified by experiments and dynamic optimization...
January 13, 2017: ISA Transactions
Ramón Ramírez-Villalobos, Luis T Aguilar, Luis N Coria
In this paper, a sensorless speed tracking control is proposed for a surface-mount permanent magnet synchronous motor by using a nonlinear H∞-controller via stator currents measurements for feedback. An output feedback nonlinear H∞-controller was designed such that the undisturbed system is uniformly asymptotically stable around the desired speed reference, while also the effects of external vanishing and non-vanishing disturbances, noise, and input backlash were attenuated locally. The rotor position was calculated from the causal dynamic output feedback compensator and from the desired speed reference...
January 13, 2017: ISA Transactions
Dan Li, Xiaoguang Hu
Because of the high availability requirements from weapon equipment, an in-depth study has been conducted on the real-time fault-tolerance of the widely applied Compact PCI (CPCI) bus measurement and control system. A redundancy design method that uses heartbeat detection to connect the primary and alternate devices has been developed. To address the low successful execution rate and relatively large waste of time slices in the primary version of the task software, an improved algorithm for real-time fault-tolerant scheduling is proposed based on the Basic Checking available time Elimination idle time (BCE) algorithm, applying a single-neuron self-adaptive proportion sum differential (PSD) controller...
January 12, 2017: ISA Transactions
Xiao-Wei Jiang, Xian-He Zhang, Zhi-Hong Guan, Li Yu, Huai-Cheng Yan
This paper investigates the problem of optimal tracking performance of networked control systems (NCSs) with quantization and packet-dropouts. The system under consideration is linear time-invariant (LTI), multi-input multi-output (MIMO), where an H2 norm of error signal between the reference input and the system output is used as the tracking performance index. The impacts of packet-dropouts in the communication channel and the quantized input and output are studied. The goal is to obtain the minimal error in tracking a random signal, by searching through all possible stabilizing two-parameter controllers...
January 11, 2017: ISA Transactions
Yuechao Ma, Pingjing Yang, Yifang Yan, Qingling Zhang
This paper investigates the problem of robust observer-based passive control for uncertain singular time-delay system subject to actuator saturation. A polytopic approach is used to describe the saturation behavior. First, by constructing Lyapunov-Krasovskii functional, a less conservative sufficient condition is obtained which guarantees that the closed-loop system is regular, impulse free, stable and robust strictly passive. Then, with this condition, the design method of state feedback controller and the observer are given by solving linear matrix inequalities...
January 10, 2017: ISA Transactions
Housheng Su, Yuan Qiu, Lei Wang
This paper investigates the problem of leader-following output consensus of a linear discrete-time multi-agent system with input saturation and external disturbances. Low-gain state feedback technique and output regulation theory are used to deal with the output consensus of multi-agent systems with input saturation and external disturbances. Both the cases with identical and non-identical disturbances are discussed in the multi-agent systems. For the case of identical external disturbance, the output consensus can be attained when the directed graph has no loop and there exists at least one directed path from the leader to every follower agent...
January 9, 2017: ISA Transactions
Jianming Miao, Shaoping Wang, Zhiping Zhao, Yuan Li, Mileta M Tomovic
This paper ̇α investigates the problem of spatial curvilinear path following control of underactuated autonomous underwater vehicles (AUVs) with multiple uncertainties. Firstly, in order to design the appropriate controller, path following error dynamics model is constructed in a moving Serret-Frenet frame, and the five degrees of freedom (DOFs) dynamic model with multiple uncertainties is established. Secondly, the proposed control law is separated into kinematic controller and dynamic controller via back-stepping technique...
January 5, 2017: ISA Transactions
Yadong Zhao, Weidong Zhang
To investigate the energy consumption involved in a sampled-data consensus process, the problem of guaranteed cost consensus for sampled-data linear multi-agent systems is considered. By using an input delay approach, an equivalent system is constructed to convert the guaranteed cost consensus problem to a guaranteed cost stabilization problem. A sufficient condition for guaranteed cost consensus is given in terms of linear matrix inequalities (LMIs), based on a refined time-dependent Lyapunov functional analysis...
December 23, 2016: ISA Transactions
Fei Ye, Weidong Zhang, Linlin Ou
An analytical H2 controller design approach of homogeneous multi-agent systems with time delays is presented to improve consensus performance. Firstly, a closed-loop multi-input multi-output framework in frequency domain is introduced, and a consensus tracking condition is given. Secondly, the decomposition method is utilized to simplify the analysis of internal stability and H2 performance index of the whole system to a set of independent optimization problems. Finally, the H2 optimal controller can be computed from all the stabilizing controllers...
December 21, 2016: ISA Transactions
Yunkai Wu, Bin Jiang, Ningyun Lu, Hao Yang, Yang Zhou
This paper deals with the problem of incipient fault diagnosis for a class of Lipschitz nonlinear systems with sensor biases and explores further results of total measurable fault information residual (ToMFIR). Firstly, state and output transformations are introduced to transform the original system into two subsystems. The first subsystem is subject to system disturbances and free from sensor faults, while the second subsystem contains sensor faults but without any system disturbances. Sensor faults in the second subsystem are then formed as actuator faults by using a pseudo-actuator based approach...
December 16, 2016: ISA Transactions
Mahdi Kazemi, Mohammad Mehdi Arefi
In this paper, an online identification algorithm is presented for nonlinear systems in the presence of output colored noise. The proposed method is based on extended recursive least squares (ERLS) algorithm, where the identified system is in polynomial Wiener form. To this end, an unknown intermediate signal is estimated by using an inner iterative algorithm. The iterative recursive algorithm adaptively modifies the vector of parameters of the presented Wiener model when the system parameters vary. In addition, to increase the robustness of the proposed method against variations, a robust RLS algorithm is applied to the model...
December 15, 2016: ISA Transactions
Liang Sun, Wei Huo, Zongxia Jiao
This paper studies relative pose control for a rigid spacecraft with parametric uncertainties approaching to an unknown tumbling target in disturbed space environment. State feedback controllers for relative translation and relative rotation are designed in an adaptive nonlinear robust control framework. The element-wise and norm-wise adaptive laws are utilized to compensate the parametric uncertainties of chaser and target spacecraft, respectively. External disturbances acting on two spacecraft are treated as a lumped and bounded perturbation input for system...
December 15, 2016: ISA Transactions
Helem Sabina Sánchez, Fabrizio Padula, Antonio Visioli, Ramon Vilanova
In this paper a set of optimally balanced tuning rules for fractional-order proportional-integral-derivative controllers is proposed. The control problem of minimizing at once the integrated absolute error for both the set-point and the load disturbance responses is addressed. The control problem is stated as a multi-objective optimization problem where a first-order-plus-dead-time process model subject to a robustness, maximum sensitivity based, constraint has been considered. A set of Pareto optimal solutions is obtained for different normalized dead times and then the optimal balance between the competing objectives is obtained by choosing the Nash solution among the Pareto-optimal ones...
December 14, 2016: ISA Transactions
Omid Naghash Almasi, Vahid Fereshtehpoor, Mohammad Hassan Khooban, Frede Blaabjerg
In this paper, a new modified fuzzy Two-Level Control Scheme (TLCS) is proposed to control a non-inverting buck-boost converter. Each level of fuzzy TLCS consists of a tuned fuzzy PI controller. In addition, a Takagi-Sugeno-Kang (TSK) fuzzy switch proposed to transfer the fuzzy PI controllers to each other in the control system. The major difficulty in designing fuzzy TLCS which degrades its performance is emerging unwanted drastic oscillations in the converter output voltage during replacing the controllers...
December 12, 2016: ISA Transactions
Songsong Cheng, Yiheng Wei, Yuquan Chen, Shu Liang, Yong Wang
This paper presents a fractional order modified least square algorithm(FOMLMS), which involves an iteration order switch strategy. A FOMLMS scheme whose iteration order can be extended into α∈(0,2) is investigated. The performance of FOMLMS with the iteration order in different interval (0<α<1or1<α<2) is separately analyzed. It turns out that, both of a larger iteration order (0<α<2) and iteration step size can always result in a faster response speed and convergence speed. Therefore, in order to obtain a satisfying convergence speed without sacrificing other performance, a hybrid switch law of iteration order is naturally developed...
December 12, 2016: ISA Transactions
Haoqian Huang, Xiyuan Chen, Bo Zhang, Jian Wang
The underwater navigation system, mainly consisting of MEMS inertial sensors, is a key technology for the wide application of underwater gliders and plays an important role in achieving high accuracy navigation and positioning for a long time of period. However, the navigation errors will accumulate over time because of the inherent errors of inertial sensors, especially for MEMS grade IMU (Inertial Measurement Unit) generally used in gliders. The dead reckoning module is added to compensate the errors. In the complicated underwater environment, the performance of MEMS sensors is degraded sharply and the errors will become much larger...
December 11, 2016: ISA Transactions
Xiulan Song, Fu Miaomiao
In this paper, we use the control Lyapunov function (CLF) technique to present an optimized visual servo control method for constrained eye-in-hand robot visual servoing systems. With the knowledge of camera intrinsic parameters and depth of target changes, visual servo control laws (i.e. translation speed) with adjustable parameters are derived by image point features and some known CLF of the visual servoing system. The Fibonacci method is employed to online compute the optimal value of those adjustable parameters, which yields an optimized control law to satisfy constraints of the visual servoing system...
December 7, 2016: ISA Transactions
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