Reducing Braking Distance by Control of Semi-Active Suspension

TLDR: In this paper, the authors presented a control algorithm for semi-active suspension to reduce the braking distance of passenger cars, which is based on a switching control logic for ABS-controlled full braking.

Abstract: This thesis presents a control algorith for semi-active suspension to reduce the braking distance of passenger cars. Active shock absorbers are controlled and used to influence the vertical dynamics during ABS-controlled full braking. The core of the approach presented in this paper is based on a switching control logic. The control algorithm is implemented in a compact class passenger car. Test drives on a real road, using a braking machine for reproducibility reasons, have been executed. It could be shown that it is possible to reduce the braking distance by affecting on the vertical dynamics of a passenger car in general. This is the first experimental result of this kind published ever. The amount of reduction depends on the height profile of the testing track chosen and on the initial velocity. On a road with an unevenness comparable to one on a typical German Autobahn an average reduction of 1-2 %, compared to the best passive damping, was achieved.