Robust adaptive control and observer for a robot with pneumatic actuators

Robotica ◽  
2002 ◽  
Vol 20 (2) ◽  
pp. 167-173 ◽  
Author(s):  
F. Errahimi ◽  
H. Cherrid ◽  
N. K. M'Sirdi ◽  
H. Abarkane
Keyword(s):  
Adaptive Control ◽  
Sliding Mode ◽  
Upper Bounds ◽  
Robust Adaptive Control ◽  
Physical Parameters ◽  
Convergence Conditions ◽  
Pneumatic Actuators ◽  
Precise Knowledge ◽  
Robot Leg ◽  
Robust Adaptive

In this paper, the robust adaptive control and observer are considered for a pneumatic robot leg. This approach does not require a precise knowledge of the robot model physical parameters, only the adaptive upper bounds on the norm of the matrices model are used, which with the sliding mode guarantee the robustness of system. Convergence conditions and simulation results for the adaptive control and observer are presented.

Nonlinear robust adaptive control of an airplane with structural damage

2020 ◽  
Vol 234 (14) ◽  
pp. 2076-2088
Author(s):  
Davood Asadi ◽  
Karim Ahmadi
Keyword(s):  
Adaptive Control ◽  
Structural Damage ◽  
Control Algorithm ◽  
Transport Model ◽  
Sliding Mode ◽  
Robust Adaptive Control ◽  
Damage Effect ◽  
Wing Damage ◽  
Robust Adaptive ◽  
Nonlinear Robust

This article investigates the design of a novel nonlinear robust adaptive control architecture to stabilize and control an airplane in the presence of left-wing damage. Damage effect is modeled by considering the sudden mass and inertia changes, center of gravity, and aerodynamic variations. The novel nonlinear control algorithm applies a state predictor as well as the error between the real damaged dynamics and a virtual model based on the nominal aircraft dynamics in the control loop of the adaptive strategy. The projection operator is used for the purpose of robustness of the adaptive control algorithm. The stability of the proposed nonlinear robust adaptive controller is demonstrated applying the Lyapunov stability theory. The performance of the proposed controller is compared with two previous successful algorithms, which are implemented on the Generic Transport Model airplane to accommodate wing damage. Numerical simulations demonstrate the effectiveness and advantages of the proposed robust adaptive algorithm regarding two other algorithms of adaptive sliding mode and L 1 adaptive control.

Robust sliding model control-based adaptive tracker for a class of nonlinear systems with input nonlinearities and uncertainties

2020 ◽  
pp. 014233122097611
Author(s):  
Jiunn-Shiou Fang ◽  
Jason Sheng-Hong Tsai ◽  
Jun-Juh Yan ◽  
Shu-Mei Guo
Keyword(s):  
Adaptive Control ◽  
Nonlinear Systems ◽  
Sliding Mode ◽  
Sufficient Conditions ◽  
Upper Bounds ◽  
Controlled System ◽  
Control Laws ◽  
Model Control ◽  
Simulation Results ◽  
Robust Adaptive

A robust adaptive tracker is newly proposed for a class of nonlinear systems with input nonlinearities and uncertainties. Because the upper bounds of input nonlinearities and uncertainties are difficult to be acquired, the adaptive control integrated with sliding mode control (SMC) and radial basis function neural network (RBFNN) are utilized to cope with these undesired problems and effectively complete the robust tracker design. The main contributions are concluded as follows: (1) new sufficient conditions are obtained such that the proposed adaptive control laws can avoid overestimation; (2) A smooth [Formula: see text] function is introduced to eliminate the undesired chattering phenomenon in the traditional SMC systems; (3) A robust tracker is proposed such that the controlled system outputs can robustly track the pre-specified trajectories directly, even when subjected to unknown input nonlinearities and uncertainties. Finally, the numerical simulation results are illustrated to verify the proposed approach.

scholarly journals Robust Adaptive Control for Coordinated Constrained Multiple Flexible Joint Manipulators with Hysteresis Loop

2018 ◽  
Vol 2018 ◽  
pp. 1-9 ◽  
Author(s):  
Shurong Li ◽  
Zhulong Shao ◽  
Pandeng Xu ◽  
Huaiqiang Yin
Keyword(s):  
Adaptive Control ◽  
Hysteresis Loop ◽  
Sliding Mode ◽  
External Disturbance ◽  
Robust Adaptive Control ◽  
Loop Model ◽  
Parameter Uncertainties ◽  
Constraint Force ◽  
Flexible Joint ◽  
Robust Adaptive

This paper focuses on the position/force tracking control problem for constrained multiple flexible joint manipulators system with nonlinear input of hysteresis loop. Firstly, the dynamic model is given in the task space and the input of hysteresis loop model is approximated by a differential equation. Secondly, considering the disturbance with unknown bounds, a robust adaptive control strategy based on the sliding mode which consists of constraint force error and position error is designed. The proposed approach can not only compensate the model error, external disturbance, and flexible parameter uncertainties, but also drive the closed-loop system variables to reach the sliding model surface. Then it can be proved that both position and constraint force errors can be guaranteed to converge to zero. Finally, the simulation results can verify the effectiveness of the proposed method.

Part 1: robust adaptive control of quadrotor with disturbance observer

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Nigar Ahmed ◽  
Abid Raza ◽  
Rameez Khan
Keyword(s):  
Adaptive Control ◽  
Disturbance Observer ◽  
Control Method ◽  
Sliding Mode ◽  
External Disturbance ◽  
Robust Adaptive Control ◽  
External Disturbances ◽  
Content Type ◽  
Control Objective ◽  
Robust Adaptive

Purpose The aim of this paper is to design a nonlinear disturbance observer-based control (DOBC) method obtained by patching a control method developed using a robust adaptive technique and a DO. Design/methodology/approach For designing a DOBC, initially a class of nonlinear system is considered with an external disturbance. First, a DO is designed to estimate the external disturbances. This estimate is combined with the controller to reject the disturbances and obtain the desired control objective. For designing a controller, the robust sliding mode control theory is used. Furthermore, instead of using a constant switching gain, an adaptive gain tuning criterion is designed using Lyapunov candidate function. To investigate the stability and effectiveness of the developed DOBC, stability analysis and simulation study are presented. Findings The major findings of this paper include the criteria of designing the robust adaptive control parameters and investigating the disturbance rejection when robust adaptive control based DOBC is developed. Practical implications In practice, the flight of quadrotor is affected by different kind of external disturbances, thus leading to the change in dynamics. Hence, it is necessary to design DOBCs based on robust adaptive controllers such that the quadrotor model adapts to the change in dynamics, as well as nullify the effect of disturbances. Originality/value Designing DOBCs based on robust control method is a common practice; however, the robust adaptive control method is rarely developed. This paper contributes in the domain of DOBC based on robust adaptive control methods such that the behavior of controller varies with the change in dynamics occurring due to external disturbances.

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