A new asymptotic tracking approach for robot manipulators with actuator saturation

Author(s):  
Yuxin Su ◽  
J. Swevers
Robotica ◽  
2018 ◽  
Vol 37 (3) ◽  
pp. 405-427 ◽  
Author(s):  
Seyed Mohammad Ahmadi ◽  
Mohammad Mehdi Fateh

SUMMARYAchieving the asymptotic tracking control of electrically driven robot manipulators is a challenging problem due to approximation/modelling error arising from parametric and non-parametric uncertainty. Thanks to the specific property of Taylor series systems as they are universal approximators, this research outlines two robust control schemes using an adaptive Taylor series system for robot manipulators, including actuators' dynamics. First, an indirect adaptive controller is designed such as to approximate an uncertain continuous function by using a Taylor series system in the proposed control law. Second, a direct adaptive scheme is established to employ the Taylor series system as a controller. In both controllers, not only a robustifying term is constructed using the estimation of the upper bound of approximation/modelling error, but the closed-loop stability, as well as the asymptotic convergence of joint-space tracking error and its time derivative, is ensured. Due to the design of the Taylor series system in the tracking error space, our technique clearly has an advantage over fuzzy and neural network-based control methods in terms of the small number of tuning parameters and inputs. The proposed methods are simple, model free in decentralized forms, no need for uncertainty bounding functions and perfectly capable of dealing with parametric and non-parametric uncertainty and measurement noise. Finally, simulation results are introduced to confirm the efficiency of the proposed control methods.


Author(s):  
Huihui Tian ◽  
Yuxin Su

This paper proposes a sliding mode based repetitive learning control method for high-precision tracking of robot manipulators with actuator saturation. Advantages of the proposed control include the absence of model parameter in the control law formulation and the ability to remove the possibility of actuator failure due to excessive torque input levels. Lyapunov's direct method is employed to prove semiglobal asymptotic tracking. Simulation results on a three degree-of-freedom (3DOF) robot illustrate the effectiveness and improved performance of the proposed scheme.


1998 ◽  
Vol 122 (2) ◽  
pp. 369-374 ◽  
Author(s):  
Weiguang Niu ◽  
Masayoshi Tomizuka

This paper deals with asymptotic tracking for linear systems with actuator saturation in the presence of disturbances. Both reference inputs and disturbances are assumed to belong to a class which may be regarded as the zero-input responses of linear systems. The controller includes an anti-windup term which reduces the degradation in the system performance due to saturation. The stability of the overall system is established based on the Lyapunov stability theory. Both state and output feedback solutions are given. The proposed scheme is evaluated for a two axis motion control system by simulation. [S0022-0434(00)01002-9]


Sign in / Sign up

Export Citation Format

Share Document