scholarly journals Fuzzy Backstepping Torque Control Of Passive Torque Simulator With Algebraic Parameters Adaptation

2015 ◽  
Vol 66 (4) ◽  
pp. 203-213
Author(s):  
Nasim Ullah ◽  
Shaoping Wang ◽  
Xingjian Wang
Keyword(s):  
Adaptive Control ◽  
Closed Loop ◽  
Control Method ◽  
Estimation Error ◽  
Loop System ◽  
Torque Control ◽  
Closed Loop System ◽  
Adaptation Algorithm ◽  
Saturation Function ◽  
Load Simulator

Abstract This work presents fuzzy backstepping control techniques applied to the load simulator for good tracking performance in presence of extra torque, and nonlinear friction effects. Assuming that the parameters of the system are uncertain and bounded, Algebraic parameters adaptation algorithm is used to adopt the unknown parameters. The effect of transient fuzzy estimation error on parameters adaptation algorithm is analyzed and the fuzzy estimation error is further compensated using saturation function based adaptive control law working in parallel with the actual system to improve the transient performance of closed loop system. The saturation function based adaptive control term is large in the transient time and settles to an optimal lower value in the steady state for which the closed loop system remains stable. The simulation results verify the validity of the proposed control method applied to the complex aerodynamics passive load simulator.

Fuzzy fault-tolerant containment control for multi-agent systems with unknown nonlinear dynamics

2021 ◽  
pp. 014233122110430
Author(s):  
Malika Sader ◽  
Fuyong Wang ◽  
Zhongxin Liu ◽  
Zengqiang Chen
Keyword(s):  
Closed Loop ◽  
Control Method ◽  
Fault Tolerant ◽  
Nonlinear Function ◽  
Loop System ◽  
Multi Agent Systems ◽  
Closed Loop System ◽  
Containment Control ◽  
Agent Systems ◽  
Multi Agent

This paper studies the containment control problem for a class of nonlinear multi-agent systems (MASs) with actuator faults (AFs) and external disturbance under switching communication topologies. To address this problem, a new fuzzy fault-tolerant containment control method is developed via utilizing adaptive mechanisms. Furthermore, a sufficient condition is obtained to guarantee the stability of the considered closed-loop system by the dwell time technique combined with Lyapunov stability theory. Unlike the traditional method to estimate the weight matrix, the fuzzy logic system is used to estimate the norm of weight vectors. Thus, the difficulty that the unknown nonlinear function cannot be compensated for when the actuator produces outage or stuck fault is solved. Compared with the existing controllers for nonlinear MASs, the proposed controller is more suitable for the considered problem under the influence of AFs that are detrimental to the operation of each agent system. Besides which, the closed-loop system is proven to be stable by using the developed controller, and all followers converge asymptotically to the convex hull formed by the leaders. Finally, an example based on a reduced-order aircraft model is presented to verify the effectiveness of the designed control scheme.

scholarly journals Adaptive Stabilization Control for a Class of Complex Nonlinear Systems Based on T-S Fuzzy Bilinear Model

2015 ◽  
Vol 2015 ◽  
pp. 1-11 ◽  
Author(s):  
Jinsheng Xing ◽  
Naizheng Shi
Keyword(s):  
Adaptive Control ◽  
Nonlinear Systems ◽  
Complex Systems ◽  
Closed Loop ◽  
Loop System ◽  
Asymptotically Stable ◽  
Bilinear Model ◽  
Closed Loop System ◽  
Fuzzy Modelling ◽  
Control Scheme

This paper proposes a stable adaptive fuzzy control scheme for a class of nonlinear systems with multiple inputs. The multiple inputs T-S fuzzy bilinear model is established to represent the unknown complex systems. A parallel distributed compensation (PDC) method is utilized to design the fuzzy controller without considering the error due to fuzzy modelling and the sufficient conditions of the closed-loop system stability with respect to decay rateαare derived by linear matrix inequalities (LMIs). Then the errors caused by fuzzy modelling are considered and the method of adaptive control is used to reduce the effect of the modelling errors, and dynamic performance of the closed-loop system is improved. By Lyapunov stability criterion, the resulting closed-loop system is proved to be asymptotically stable. The main contribution is to deal with the differences between the T-S fuzzy bilinear model and the real system; a global asymptotically stable adaptive control scheme is presented for real complex systems. Finally, illustrative examples are provided to demonstrate the effectiveness of the results proposed in this paper.

Mode Decoupling Controller for Feedback Model Updating

2004 ◽  
Author(s):  
Hunsang Jung ◽  
Youngjin Park ◽  
K. C. Park
Keyword(s):  
Closed Loop ◽  
Model Updating ◽  
Control Method ◽  
Loop System ◽  
Mode Shapes ◽  
Closed Loop System ◽  
Sensitivity Matrix ◽  
Data Set ◽  
Conventional Methods ◽  
The Stability

A novel concept of feedback loop design for modal test and model updating is proposed. This method uses the closed-loop frequency information for parameter modifications to overcome the problems associated with the conventional methods employing the modal sensitivity matrix. To obtain new modal information from the closed-loop system, controllers should be effective in changing modal data while guaranteeing the stability of the closed-loop system. The present paper proposes a mode-decoupling controller that can alter a target mode while guaranteeing the stability of the closed-loop, and that can be constructed by using the measured open-loop, mode shapes. A simulation based on time domain input/output data is performed to evaluate the feasibility of the proposed control method, which is subsequently corroborated via experiments. Experimental data obtained on a beam via the proposed mode-decoupling controller have been applied to estimate thicknesses of a beam. The results show that the proposed approach outperforms conventional methods with a far less number of data set for the estimation of system parameters.

An Approach to Telerobotic Manipulations

1997 ◽  
Vol 119 (3) ◽  
pp. 431-438 ◽  
Author(s):  
H. Kazerooni ◽  
C. L. Moore
Keyword(s):  
Closed Loop ◽  
Control Method ◽  
Sufficient Conditions ◽  
Human Robot Interaction ◽  
Loop System ◽  
Robotic Manipulation ◽  
Closed Loop System ◽  
Robot Interaction ◽  
Minimum Number ◽  
The Stability

This article introduces three areas of study: 1 telefunctioning; 2 a control method for producing telefunctioning; and 3 an analysis of human-robot interaction when telefunctioning governs the system behavior. Telefunctioning facilitates the maneuvering of loads by creating a perpetual sense of the load dynamics for the operator. Telefunctioning is defined as a robotic manipulation method in which the dynamic behaviors of the slave robot and the master robot are functions of each other; these functions are the designer’s choice and depend on the application. (In a subclass of telefunctioning currently referred to as telepresence, these functions are specified as “unity” so that the master and slave variables (e.g., position, velocity) are dynamically equal.) To produce telefunctioning, this work determines a minimum number of functions relating the robots’ variables, and then develops a control architecture which guarantees that the defined functions govern the dynamic behavior of the closed-loop system. The stability of the closed-loop system (i.e., master robot, slave robot, human, and the load being manipulated) is analyzed and sufficient conditions for stability are derived.

Passivity-Based Stabilization of Underactuated Mechanical Systems

2013 ◽  
Vol 421 ◽  
pp. 16-22
Author(s):  
Shan Shan Wu ◽  
Wei Huo
Keyword(s):  
Closed Loop ◽  
Control Method ◽  
Controller Design ◽  
Design Method ◽  
Mechanical Systems ◽  
Matching Condition ◽  
Loop System ◽  
Closed Loop System ◽  
Underactuated Mechanical Systems ◽  
Stabilization Control

A new stabilization control method for underactuated linear mechanical systems is presented in this paper. By proper setting the desired closed-loop system, the matching condition for controller design is reduced to one equation and an adjustable parameter (damping coefficient) is introduced to the controller. Stability of the closed-loop system is proved based on passivity. As an application example, stabilization control of 2-DOF Pendubot is studied. The system is linearized at its equilibrium point and the proposed controller design method is applied to the linearized system. The procedure of solving matching condition and design controller for the Pendubot is provided. The simulation results verify feasibility of the proposed method.

Adaptive control of missile attitude based on BP–ADRC

2020 ◽  
Vol 92 (10) ◽  
pp. 1475-1481
Author(s):  
Haiyan Qiao ◽  
Hao Meng ◽  
Wei Ke ◽  
Quanxi Gao ◽  
Shaobo Wang
Keyword(s):  
Neural Network ◽  
Adaptive Control ◽  
Control System ◽  
Bp Neural Network ◽  
Closed Loop ◽  
Control Method ◽  
Extended State ◽  
Dynamics Model ◽  
Closed Loop System ◽  
Content Type

Purpose To improve the robustness of missile control system and reduce the error, a missile attitude adaptive control method based on active disturbance rejection control technology (ADRC) and BP neural network is innovatively proposed. Design/methodology/approach ADRC improves the performance of the missile control system by estimating and eliminating the total disturbance of the system. BP neural network adjusts the parameters of ADRC controller according to the state of the system to realize adaptive control. Based on the control system and missile dynamics model, the convergence analysis of the extended state observer and the stability analysis of the closed-loop system after embedding BP neural network are given. Findings The simulation results show that the adaptive control method can adjust the coefficient of error feedback rate according to the system input, output and error change rate, which accelerates the response speed of missile attitude angle and reduces the attitude angle error. Practical implications BP–ADRC further improves the robustness and environmental adaptability of the missile control system. The BP–ADRC control method proposed in this paper is proved feasible. Originality/value Different from the traditional ADRC, the BP–ADRC feedback signal proposed in this paper uses the output signal and its rate of the closed-loop system instead of the system state quantity estimated by extended state observer (ESO). This innovative method combined with BP neural network can make the system output meet the requirements when ESO has errors in the estimation of missile dynamics model.

H ∞ -Based Robust Torque Control of Harmonic Drive Systems

1998 ◽  
Vol 123 (3) ◽  
pp. 338-345 ◽  
Author(s):  
H. D. Taghirad ◽  
P. R. Be´langer
Keyword(s):  
Closed Loop ◽  
Loop System ◽  
Torque Control ◽  
Free Motion ◽  
Friction Compensation ◽  
Harmonic Drive ◽  
Constrained Motion ◽  
Closed Loop System ◽  
Experimental Frequency ◽  
Low Frequencies

In this paper, the torque control of a harmonic drive system for constrained-motion and free-motion applications is examined in detail. A nominal model for the system is obtained in each case from experimental frequency responses of the system, and the deviation of the system from the model is encapsulated by a multiplicative uncertainty. Robust torque controllers are designed using this information in an H∞-framework, and implemented on two different setups. From time and frequency domain experiments, it is shown that the closed-loop system retains robust stability, while improving the tracking performance exceptionally well. To further improve the performance of the system for free-motion case, a feedforward friction-compensation algorithm is implemented in addition to the robust torque control. It is shown that friction-compensation will shrink the model uncertainty at low frequencies and hence, the performance of the closed-loop system will be improved at those frequencies.

Adaptive Control of a Smart Projectile Fin With Unknown High-Frequency Gain by Piezoelectric Actuation

2007 ◽  
Author(s):  
Venkat Mudupu ◽  
Sahjendra Singh ◽  
Woosoon Yim
Keyword(s):  
Adaptive Control ◽  
Control System ◽  
High Frequency ◽  
Closed Loop ◽  
Aerodynamic Force ◽  
Angular Rate ◽  
Loop System ◽  
Reference Trajectory ◽  
Piezoelectric Bimorph ◽  
Closed Loop System

This paper delves into adaptive control of a smart projectile fin with unknown high frequency gain using a piezoelectric bimorph. The hollow projectile smart fin is actuated using a cantilevered piezoelectric bimorph that is completely enclosed within the fin. The model of the smart fin system includes the aerodynamic moment which is a function of the angle of attack of the projectile. The rotation angle of the fin is controlled by deforming the piezoelectric bimorph which is hinged at the tip of the rigid fin. It is assumed that fin parameters as well as the high frequency gain of the model are unknown. Moreover, the model includes an unknown bounded time varying aerodynamic disturbance. An adaptive control system using the Nussbaum gain is designed. The structure of the control system is independent of the dimension of the flexible fin model. This is important because the fin model has large number of flexible modes. For the design of the control law, a linear combination of the fin angle and fin angular rate is chosen as the controlled output variable. In the closed loop system, all the signals are bounded and the fin angle tracks the reference trajectory. Simulation results are presented along with the experimental validation done using the subsonic wind tunnel at the University of Nevada, Las Vegas (UNLV). Both simulation and experimental results show that in the closed-loop system, the fin angle is precisely controlled in spite of the uncertainties in the fin parameters and the aerodynamic force.

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