A Multifunctional Self-calibrated Sensor For Brake Fluid Condition Monitoring

A multifunctional self-calibrated sensor is proposed for on-line monitoring of liquid level and water content of brake fluid using capacitive method. The sensor is characterized by self-calibration ability to influence factors including temperature, water content (to liquid level sensing) and variety of brake fluid without calibration arithmetic supported by database as in conventional intelligent sensor systems. By using mutual calibrated output functions and taking new brake fluid as on-line reference, the sensor is well self-calibrated to the influence factors. The prototype sensor is developed and tested. The effectiveness of sensor is conformed by experimental results.