Electronic wedge brake passes initial road tests

The electronic wedge brake (EWB) developed by Siemens VDO is already in use in several prototype vehicles. In the opinion of experts, the behavior of the wedge brake — particularly its dynamic release behavior, which is important for driving dynamics controls — is markedly superior to that of a hydraulic brake. The braking effect of the wedge brake is provided by means of a wedge, which is pressed between the brake caliper and the brake disk by means of an electric motor (see the May 2006 issue of Elektronik Automotive). This motor is activated by FlexRay, a real-time data bus, with the redundancy of the system ensuring that it is fail safe. The main aim of the next development step is to modularize and further reduce the size of the mechanical components. According to Siemens VDO, once it becomes ready for series production by the end of the decade, the wedge brake could be used in every vehicle category, i.e., from small cars to trucks.