Twisting Algorithm with Integral Sliding Surface for Positioning of Single-Rod Electrohydraulic Actuator: An LMI Approach

Abstract

Electrohydraulic actuators are extensively used in many industrial applications. This paper presents a robust position controller of single-rod electrohydraulic actuators. The design methodology is based on the twisting algorithm (TA) with an integral sliding surface. The TA is one of the most promising high-order sliding-mode control algorithms. However, implementations of the TA usually require a derivative of the system’s states making the implementations difficult. In this paper, by using an integral sliding surface, the implementation does not require any derivative. The integration also enhances steady state performance when approximating the discontinuous control signal with a continuous one to reduce the chattering. In addition, by formulating the stability conditions in Linear Matrix Inequality (LMI) forms, the parameters of the controller are readily solved. Experiments on a real-life electrohydraulic actuator were conducted to illustrate the success and effectiveness of the proposed controller.