A new approach for modelling and control of two-wheel anti-lock brake systems

Abstract

Anti-lock brake system is designed to actively improve the vehicle safety during hard braking. In this article, optimization-based braking pressure control laws for the front and rear wheels are analytically designed based on a non-linear two-axle vehicle model. The integral feedback technique is also appended to the design method to increase the robustness of the controller in the presence of modelling uncertainties. In order to achieve the maximum braking force for each wheel at any time during braking, a new reference wheel slip model is presented to be tracked by the controller. In this model, the variations of tyre normal load and tyre/road condition are considered in finding the optimum slip of each wheel. The derived control laws are evaluated and their main features are discussed. Finally, the effectiveness of the proposed controller in tracking the new reference model is investigated and the obtained results are compared with the prevalent research results. The simulation studies demonstrate that the designed controller can successfully cope with the strong non-linearity and uncertainty existing in a vehicle dynamics model. Also, the vehicle stopping distance is remarkably reduced by the proposed approach.