A switching traction control strategy based on tire force feedback

The paper presents a novel concept of switching traction control (or ABS) strategy which does not rely on wheel slip information. The core of the strategy includes a driven wheel speed control loop and a reference vehicle model in the wheel speed target path. The reference model is fed by a bidirectional sawtooth-like tire force input signal, in order to keep the longitudinal tire force close to its maximum value. The switching criterion for transition between adhesion and slipping region of the tire static curve is based on comparing the applied wheel force with the tire force that can be obtained by estimation or direct measurement. The proposed 4WD traction control strategy is verified by means of computer simulations and partly by experiment.