"Look Ma, no hands": Optical Sensors Take Over Wiper Controls

An optically-based, moisture-activated system developed by TRW (Cleveland, OH) controls automotive windshield wipers, detecting how hard the rain or snow is falling and determining how fast to run the wiper motor.

The system incorporates infrared emitters and detectors arranged in a four-emitter-by-two-detector array. This configuration creates a large target area that estimates true rain intensity while minimizing the number of components. When the system experiences an interruption to its infrared signal, such as moisture striking the windshield, the advanced analog processing detects the occurrence of a true rain event•rather than stray signals, such as sunlight•and activates the wiper motor at the appropriate speed.

According to TRW Automotive Electronics vice president and general manager Heinz Pfannschmidt, the sensor is more economical and robust, as well as 90% faster to install at the vehicle manufacturing plant than previous versions.

The company has five contracts worldwide for the wiper system. The unit is already in volume production on luxury and family vehicles for customers in the US and Asia. The company will be launching a new rain sensor system this year for mid-range vehicles and minivans.

Edited by Kristin Lewotsky