Active safety diagnosis of brake-by-wire systems with unscented Kalman filter

Abstract

Electric vehicle with brake-by-wire system may perform active safety control while keeping the vehicle lithe and nimble. Active safety diagnosis of the brake-by-wire system may find braking component that is on the brink of ceasing effectiveness. The diagnosis relies on using a diagnostic observer to continuously monitor the disk-pad friction coefficient and the tire forces; safety flaw is announced if any observed value violates the safety requirements. This paper presents a design of the diagnostic observer with the unscented Kalman filter. The unscented Kalman filter enforces the parameter observations more adaptive for dealing with the nonlinear vehicle-tire dynamics. The diagnostic observer is verified for active safety diagnosis of a vehicle under many operation conditions; simulation results show that the design is efficacious.