| 摘要 |
A motor control system for a high accuracy incremental motion system such as a paper feed system in a high speed printer. The system utilizes a stepping motor (10) which is driven in one of two modes, depending upon its position. During most of the movement from one position to another, the motor is driven as a DC brushless motor. This is accomplished by commutating the phases of the motor so that they are energized around the peaks of their torque curves. The motor is driven in a closed loop fashion, with velocity commands being generated by a velocity profile generator (25) incorporating a microprocessor (24). Both position and velocity feedback are utilized. Since the motor (10) is driven as a DC brushless motor, traditional control theory methods (e.g., Root locus, Bode, etc.) can be employed. As the motor nears the final desired position, the system switches so that the motor is energized as a step motor. This energization is applied when the motor is less than one motor step from its final position, and causes the motor to be drawn to a null point and held in position. Velocity feedback is provided to damp the motor so as to further decrease positioning time. |
