Sliding Mode Observer-Based ABS Offers Advantages for HD Truck Applications

This paper presents a method of trailer yaw stabilization for a tractor-trailer by automatic differential braking of trailer rear wheels. It is implemented as part of an ABS based upon a sliding mode observer (SMO). The trailer rear wheel brakes are alternately applied according to a control law derived from measurements of trailer yaw (relative to the tractor axis). The SMO provides an additional control function that prevents wheel lock. Brakes are applied in response to a control signal that is generated from measurements of trailer yaw. The SMO-based ABS regulates braking to prevent wheel lock and to simultaneously optimize yaw control.