Sensor less Wash Fluid Detection in Automotive Application

摘要

The proposed paper describes the hardware and software method used for detection of wash fluid level in water tank used in automotive; thereby eliminating the need for sensor (Reed type switch mounted on washer bottle) for low wash fluid detection. Wash motor is used for water spray on windscreen during wash and wipe operation. The proposed system makes use of hardware circuit used to drive the wash motor usually of DC (Direct current) type and a feedback circuitry to read back the current consumed by motor during particular wash operation. This hardware system is coupled with software algorithm such that during IGNITION ON instance wash motor will be turned on such as to get motor current readings to determine amount of load operated by motor which is related to wash fluid inside the washer bottle. Motor operation is optimized so as to avoid water spray causing nuisance to user. It also eliminates the cost of the sensor, wiring harness and related signal conditioning circuitry used for sensor data processing. The proposed invention does not suffer from mundane sensor faults such as short to battery / ground, sensor open wire output, variation due to vibration and wear/tear.