An adaptive robust control scheme for robot manipulators with unknown backlash nonlinearity in gears

Abstract

This paper presents an adaptive robust control algorithm for the nonlinear dynamics of robot manipulators with unknown backlash in gears. The basic nonlinear model of a serial manipulator robot is used for the controller design, and this is combined with the nonlinear proposed dead zone model, based on the input and output torque. The main idea of providing this model is to achieve a dynamic model of the system considering the backlash of the robot joint gears, and having less complexity such that the developed controller does not need the inverse backlash model. The adaptive robust controller is developed, without using the inverse backlash model. The proposed controller is designed based on an unknown dead zone parameter and it guarantees the stability and path tracking of the robot trajectory with unknown dead zone parameter in the desired range. Numerical simulations are conducted to show the effectiveness of the proposed controller. Finally, the efficiency and capability of the proposed controller in dealing with the unknown backlash nonlinearities in gears of the manipulator are demonstrated by experimental results with a five-bar manipulator.

Adaptive sliding mode control for robotic manipulators with backlash

“…(2) The proposed control scheme ensures the motor reengage with the joint without collision after traverse the backlash gap. Unlike, 2,[12][13][14] in this paper, the speed of the motor and the joint are considered, the speed of the motor and the joint is almost same when they re-contact, so as to avoid the impact caused by the speed mismatch during re-engage. (3) Compared with Yang et al, 1,2 Xiang et al, 3 Ik Han and Lee, 12 DeBoon et al, 13 and Ahangarian Abhari et al, 14 the proposed control method has higher control accuracy.…”

Robust Control Based Stability Analysis and Trajectory Tracking of Triple Link Robot Manipulator

“…Other concern with structure like limped or distributed mass with inertia effect, actuator failure, speed constraint, degree of freedom, external factor etc. There are many control approaches like PID control [1], state feedback control, sliding, robust and adaptive control, Intelligent (Fuzzy and Neural) Control [2][3][4][5][6][7][8], LQR Control and optimal control [9]. As even single link manipulator is nonlinear in nature so conventional control technique is not suitable for the control of multilink manipulator as nonlinearities increasing in a drastic manner [10].…”

Self-tuning fuzzy nonsingular proportional-integral-derivative type fast terminal sliding mode control for robotic manipulator in the presence of backlash hysteresis

“…In Ahmed et al (2019), a robotic manipulator is controlled using an integration of high-order sliding mode and time delay estimation (TDE) techniques. An adaptive robust control scheme for robot manipulators with unknown backlash nonlinearity in gears is studied in Ahangarian Abhari et al (2019). Adaptive iterative learning control of a class of nonlinear time-delay systems with unknown backlash-like hysteresis input and control direction is synthesis in Wei et al (2017).…”