A chattering-free fuzzy hybrid sliding mode control of an electrohydraulic active suspension

Abstract

This paper introduces a new hybrid controller for position and force control of an electrohydraulic car active suspension. In most hybrid controllers, a switching function is normally used in order to take advantage of two separate controllers. Switching between the two controllers produces a chattering in the system, in addition to the chattering that may be inherent to the controller itself, which deteriorates the system performance. In this work, we resolved the switching limitations dilemma by transitioning from one controller to another through two low-pass filters. These filters are used with variable gains to improve the new hybrid position/force controller performance that we developed. The produced control signal is a structured combination, in which the signal coming from the position controller reduces the effect of road perturbations on passengers by bringing the car's vertical motion to zero. Simultaneously, the signal from the force controller tracks a reference force and thus reduces the force transmitted to passengers. To eliminate the chattering that is inherent to the sliding mode controller, we introduced an exponential reaching law function to the hybrid sliding mode controller. This exponential function also reduced the response time, consequently speeding up the system reaction to suppress perturbations. In addition to that, a recent sliding surface-based controller is applied to vary the filters' gains and obtain better performance. The frequency analysis is done to verify the controller performance. The proposed hybrid controller is also validated in real time on active suspension workbench and compared with a classical PID controller.

Real‐time hybrid control of electrohydraulic active suspension

“…This paper is an extension of our previous work , in which the simulation demonstrates that the hybrid controller can track a desired force while maintaining the position of the passenger seat near an initial value. This has motivated us to validate this hybrid controller on a hydraulic active suspension system and to test the effectiveness of the chattering suppression through an exponential reaching law integrated into the sliding mode control.…”

“…In Section 5.1, we will use the complete model in simulation to calculate the control law . The terms − a 0 ( x 1 rt − x 3 rt ) and d 0 ( x 1 rt − x 3 rt ) are added to the derivative in order to model virtual springs.…”

Robust Hybrid Position-Force Control for Robotic Surface Polishing

“…Discrete-time implementations of the above SMC make the system leave the ideal SM and oscillate with finite frequency and amplitude inside a band around / ¼ 0, which is called chattering [19]. Several approaches can be found in the literature [22,23] to theoretically avoid this drawback, as discussed below. However, it is interesting to remark that these approaches smooth the SMC behavior and, hence, they may bring issues like "drift."…”

Stability analysis of brain emotional intelligent controller with application to electrically driven robot manipulators

“…In the past decade, there has been an increasing trend towards intelligent control of non-linear systems [5,6]. To this end, many intelligent controllers including fuzzy systems [7,8] and neural networks [9,10] have been presented. The reason for these widespread applications of intelligent control can be attributed to the fact that they are model-free control approaches.…”