Performance analysis of wheel slip reset controller in brake systems

The aim of the wheel slip controllers is to provide certain degree of slip on each wheel independently, maximizing the friction between the tire and road, avoiding simultaneously its lock and so it implements a braking control strategy to generate independent brake forces at each wheel. On the other hand, reset control is able to overcome fundamental limitations of linear and time invariant controllers, and thus a reset controller, a standard linear controller that, at some instants, resets to zero its internal states, may be designed to simultaneously improve speed of response and robustness. In this way an efficient solution can be enhanced by the application of reset controllers to brake systems. In a recent work presented by the authors is defined a wheel slip reset controller, based on a PI+CI controller, versatile and with a simple design, that simultaneously presents improved performance, decreasing the braking distance in several road conditions while maintaining as far as possible appropriate driving characteristics of the vehicle, and also is robust against technological limitations such as model uncertainties, actuator saturation and time delay in communications. This paper presents some ideas about the analysis and tuning of this wheel slip PI+CI reset controller.