METHOD AND APPARATUS FOR A CONTACLESS ELECTROMECHANICAL ACTUATOR WITH COUPLED ELECTRONIC MOTOR COMMUTATION AND OUTPUT POSITION SENSORS

摘要

An electromechanical actuator includes a brushless motor driving an output shaft through a torque-amplifying geartrain. An integrated motor commutation senso r includes an annular, two-pole magnet rotating with the motor and two ratiometric Hall- effect sensors at right angles around the magnet. The sensor signals are utilized by a process or to compute motor angle over 360 degrees rotation. An integrated output position sensor includes a second annular magnet rotating with the output shaft, and a second pair of Hall-effect sensors providing signals to the processor for computation of output shaft absolute position. The commutation magnet angle is predicted from the output shaft position, and compared to the motor's sensed rotational angle. The difference is used to correct the outpu t shaft sensed angle with improved accuracy proportional to the gear ratio. The processor also provides logic signals to control motor winding current and provide closed-loop contr ol of actuator position.