Enhanced human-machine interface in braking

Antilock brake system (ABS) technology with powerful electronic components has shown superior braking performance to conventional vehicles on test tracks. On real highways, however, the performance of the ABS-equipped car has been disappointing. The poor braking performance with ABS has resulted from the questionable design of the human-machine interface for the brake system. The goal of this study is to design brake systems that provide more intuitive brake control and proper braking-performance information for the driver. In this study automotive brake systems are modeled as a type of master-slave telemanipulator. Human force-displacement interaction at the brake pedal has a strong effect on braking performance. As a preliminary study in brake-system design, the characteristics of human leg motion and its underlying motor-control scheme are studied through experiments and simulations, and a model of braking motion by the driver's leg is developed. This paper proposes novel brake systems based on two new aspects. First, the mechanical impedance characteristics of the leg action of the driver are taken into consideration in designing the brake systems. Second, the brake systems provide the driver with kinesthetic feedback of braking conditions or performance. The effectiveness of the proposed designs in a combined driver-vehicle system is investigated using driving simulation.