平面型リニアパルスモータの位置決め制御システム

Abstract

Fundamental positioning characteristics of a dual-axis Sawyer linear motor are described. The Sawyer motor is capable of high positional accuracy. An electronic control unit of the motor whose velocity is proportional to the excitation frequency is producted in our laboratory. The positioning system is constructed using two Sawyer motors, an air bearings suspension unit and an electronic control unit. The stable motion of the motor is confirmed on the open loop operation. The adjustable operating conditions are the live load is 1Kg, the maximun acceleration is 1.2G, the maximun velocity is 350mmls. The travel time of the motor is 180ms for distance at 50mm. Absolute positional accuracy is improved within ±5μm, on microstep operating conditions of dividing for 508μm of 1 pitch into 508 steps. The following two conclusions are obtained. An accelerating-slewing-decelerating control is effective for reduction in the travel time required. Also, microstep operation is effective for improving the resolution of position.