Robust active disturbance rejection control for modular fluidic soft actuators

Abstract

Delicate dynamic control of soft actuators is a challenging task due to their strongly nonlinearities. This article focuses on the dynamic control of the modular fluidic soft actuators governed by pneumatic proportional valves. Since it is difficult to accurately describe the complex coupling relationships among the chambers of the soft actuators, the dynamic control of the soft actuators cannot be implemented by using advanced control algorithms based on precise model in usual. To improve the manipulability and extend the application scenarios, we design a robust active disturbance rejection control method based on linear extended state observer, which only requires an approximate model of the soft actuators. Experimental results show that closed-loop stability and good tracking performance are achieved by the proposed method, meanwhile better disturbance rejection ability is guaranteed in comparison to the commonly used proportional-integral-differential control method.