Enhancing the Braking Performance of a Vehicle Through the Proper Control of the Active Suspension System

This paper investigates the problem of the vehicle's braking performance and a control method is proposed that can reduce the stopping time and distance, through the proper control of the active suspension system. Specifically, a Linear Quadratic Controller is utilized, that regulates the vehicle's frame pitch angle during the braking process for establishing a correct balance between the front and rear axles. Moreover, a fuzzy-logic system is introduced, which penalizes the effort of the actuators aiming to the reduction of the consumed power. The proposed control method of the active suspension system is energized only in an emergency condition, which is identified through the travel of the braking pedal pushed by the driver. Under normal conditions, the active suspension returns to the regular operation, that is the improvement of the passengers' comfort by means of rejecting the vehicle's disturbances induced by road's irregularities. The effectiveness of the proposed emergency control technique of the active suspension system is verified through a simulation model, by using the MATLAB/Simulink software, in comparison to a passive, semi-active and an active suspension, as in the literature. Selective simulation results for various road conditions are presented to demonstrate the operating improvements.