General interest press release
SIEMENS VDO'S ELECTRONIC WEDGE BRAKE BOASTS 15 PERCENT AVERAGE REDUCTION IN BRAKING DISTANCES DURING WINTER TESTING
Siemens VDO's Electronic Wedge Brake (EWB) has shown an average braking distance reduction of approximately 15 percent over vehicles equipped with conventional hydraulic brakes during recent driving tests on ice and snow. The automotive supplier achieved these results during intensive cold-weather testing in Arjeplog, Sweden, near the Arctic Circle. This confirms Siemens VDO's improved braking behavior data in a real-life winter driving environment, which was previously obtained in simulation models.
On pure ice, comparable with freezing rain conditions in Michigan, it takes an upper mid-range class vehicle with conventional hydraulic brakes, modern ABS and winter tires approximately 246 feet to come to a complete stop from a speed of 50 mph. Under similar testing conditions, Siemens VDO’s latest EWB prototype reached a standstill in 211 feet – almost two car lengths sooner than modern hydraulic brakes.
Siemens VDO's EWB marries high-performance electronics with a braking mechanism to take advantage of the wedge principle's self-reinforcing affect. During braking, an electric motor presses a wedge connected to a brake pad located between the brake caliper and the brake disk. The resulting friction of the wheel's rotation automatically strengthens the wedge effect, causing a very strong braking force to be produced with very little energy.
With the successful completion of winter testing, Siemens VDO now is reviewing its data to further develop and refine EWB hardware and software. The wedge-bearing mechanism will be driven by a single, highly responsive electric motor allowing a size reduction of the by-wire brake module by the time it is ready to go into series production as early as 2010.
The EWB’s improved performance on snow and ice suggests a greater potential if combined with advanced driver assistance systems. In future generations of automobiles, these systems would be integrated to help increase opportunities to avoid accidents by utilizing the extremely fast-responding, electronically controlled brake – although the EWB will not be able to defy the laws of physics.
Siemens VDO is a leading international automotive electronics and mechatronic supplier. The group is part of Siemens AG (NYSE:SI) and generated sales of $12.120 billion (€10.017 billion) in the 2006 business year (ending Sept. 30).
