Fuzzy Skyhook Surface Sliding Mode Control for Semi-active Suspension system

Sliding Mode Control, Skyhook Damper, Fuzzy Logic Control, Semi-Active Suspension System

Description

A skyhook surface sliding mode control method was proposed and applied to the control on the semi-active vehicle suspension system for its ride comfort enhancement. A two degree of freedom dynamic model of a vehicle semi-active suspension system was given, which focused on the passenger’s ride comfort perform-ance. A simulation with the given initial conditions has been devised in MATLAB/SIMULINK. The simula-tion results were showing that there was an enhanced level of ride comfort for the vehicle semi-active sus-pension system with the skyhook surface sliding mode controller.

• MATLAB release: MATLAB 7.7 (R2008b)

[Koldo]

There is a fundamental problem with this Simulink scheme: there is an algebraic loop since the value of "ecc" is being computed through a derivative block. This makes the simulation result sensitive to the selected integration step-size. To fix this issue just compute the value of this signal directly from the state variables of the plant. It is easy and solves the problem. I did it and everything works perfectly for any integration step-size!

[Olexander Zhytenko]