Dual Fuzzy Sliding Mode Control of Collaborative Robot Based on Adaptive Algorithm

Abstract

The six-degree-of-freedom collaborative robot is a kind of nonlinear system with multiple inputs and multiple outputs, parameter uncertainty, external disturbance and unmodeled characteristics of the system. Changes in information and parameters adversely affect the operation of the robotic arm. Sliding mode variable structure control is very good enough to suppress the influence of external disturbance and internal disturbance on the stability of the system itself. Based on this, an adaptive fuzzy sliding mode controller based on exponential reaching law is designed in this paper, which adaptively estimates the uncertain upper bound of disturbance, and deduces the controller step by step, which can well eliminate the chattering problem of the control law. However, it did not solve the problem that the overall adjustment time of the control system was too long, and the performance of the control system on the control index of "rapidity" was not very good. Then a double fuzzy sliding mode control algorithm is designed, and the experiment proves that this scheme has higher tracking accuracy than the ordinary sliding mode control scheme. It greatly improves the robustness to external disturbances, system uncertain information and parameter changes.