Development of pre-crash safety system

A large number of means for active safety and passive safety have been studied for road traffic safety, and various safety systems have been commercialized. It has now become important to link active safety with passive safety to enhance overall safety. Therefore, a pre-crash safety system has been developed that helps to reduce crash injuries by determining the likelihood of a crash in advance, and activating active safety systems and passive safety systems at an earlier stage. This paper describes the configuration, functions, and effects of this pre-crash safety system. The newly developed system consists of a pre-crash sensor, a pre-crash seat belt, and pre-crash brake assist. The pre-crash sensor is composed of a millimeter-wave radar that detects forward obstacles and a pre-crash safety computer that helps to determine in advance whether a crash is unavoidable, based on location, speed and course of an obstacle. The pre-crash seat belt, which employs a mechanism to retract the seat belt by a motor, helps to reduce crash injuries through earlier restraint of front occupants. The pre-crash brake assist helps to reduce the crash speed by quickly generating a large brake force in response to the driver's brake pedal operation even when sudden braking is not being performed. For the covering abstract see ITRD E825082.