Adjustable Electromechanical Wedge Brakes With Reduced Energy Consumption

Abstract

An Electromechanical Wedge Brake (EWB) has an inherent self-reinforcing capability that translates into reduced actuation forces and subsequently into reduced energy requirements. However, to avoid jamming the brake, there is a need for a dedicated means of adjusting the effective wedge angle in order to modulate the braking forces and to accommodate changing pad friction conditions. Earlier prototypes had one actively controlled moveable wedge with a fixed wedge angle. In this paper, two new designs are considered and compared with the conventional EWB design. The first one uses pre-defined wedge shapes in a self-adjusting design with one movable wedge. The second uses an externally adjustable wedge and an actively movable wedge with similarly pre-defined wedge shapes. These designs can be employed to further reduce the required actuator forces beyond what is possible with the conventional design. The benefits of these self-adjusting and externally adjustable EWB designs are demonstrated using dynamic model simulations for a typical hard braking event.