A sensorless safety power window control system in automotive application

The estimation of disturbance torque in the safety window system is important for people’s convenience. Mostly, this kind of system can estimate the torque of window traveling system using the output of a hall sensor. To set up a window torque estimation system, however, is normally complicate and expensive. In addition, the calculation process of a window torque from the hall sensor output has usually inaccuracy because of various noises. To tackle this inherent problems of the previous approaches, a new sensorless DC drive disturbance torque estimator based on the Kalman estimator is proposed. Aside from the existing methods which utilize a torque from the hall sensor output, the proposed algorithm detects the pinched condition using the a motor driving current. The suggested scheme is also able to produce more a reliable pinch alarm in stead of the previous method.