Active suspension control design for unmanned ground vehicles

Abstract

This paper presents the design of an active suspension control system for an unmanned ground vehicle (UGV). The purpose is to design an active suspension control for a low-speed (less than 1 m/s) off-road UGV in order to be able to move through rugged terrain with the least pitch and roll motion. Classical active suspension design methods cannot be used for minimizing pitch and roll angles, therefore a new approach is applied. The control design is based on the LQG method. The control system uses only pitch and roll angular rate signals, which ensures a simple and cheap control system, but any bias error on the gyro signals cause some problems in reconstructing angles. The control algorithm consists of an optimal state-feedback fed by an augmented observer for estimating the states and the bias error of the gyro sensors. The appropriate tuning of the observer is introduced, which eliminates the bias error problem and ensures the fast reconstruction of the states for the optimal state-feedback. In simulations, the active suspension control system shows high performance at minimizing pitch and roll angles.