Self calibrating actuator position control system

摘要

An actuator position sensor employs a photo interrupter with an optical density gradient segment that has additional maximum and minimum density segments preceding the gradient segment. These preceding segments are sensed and sampled by a calibration circuit, preferably prior to each operation of the actuator, to generate high and low reference calibration values which are applied to a signal scaling circuit along with the gradient output signal. The scaling circuit is then able to generate a position output signal scaled between these reference values that is linearly proportional to the actuator position.