The drive motors used in electric vehicles have torque curves unlike those in internal combustion engines. Electric drive motors can produce enough torque to overpower conventional vehicle braking systems. Therefore an electrical malfunction could cause unintended acceleration that pressing the brake pedal could not overcome. Dartmouth researchers have invented a safety device – Sudden Acceleration Motor Vehicle Shutdown Device using a hydraulic brake pressure detector to address this problem.
Notably, this device could prevent most unintended acceleration accidents in many types of vehicles, including production vehicles. Accidents preventable by the device include those where accelerators jam and those where drivers mistake accelerator pedals for brake pedals. The device is particularly desirable in vehicles, such as farm tractors or cars with high-torque electric motors, where brakes may be too weak to overcome engine power.
This device is a simple electro-mechanical device that can sense the abnormally high brake system pressure that would result from a panic braking situation and activate a latching switch to shut down the drive system. The device would remain in the activated position, disabling the vehicle until the device was reset.
Initial deployment is in electric racing vehicles with high-torque motors, nonstandard controls and uncertified electronics, where the device’s independence from vehicles electronics is particularly desirable. However, as stated above, the device may be used in a variety of other vehicles.
The Sudden Acceleration Shutdown Device is claimed in a U.S. Provisional Patent Application by Dartmouth College. The College is seeking an industrial partner interested in its further development and commercialization, particularly through prototyping and testing.
Last Updated: 1/7/13