| 摘要 |
PURPOSE:To improve the precision of a positioning device which uses a DC motor by performing rough positioning by an encoder pulse and fine positioning by an encoder waveform. CONSTITUTION:An encoder pulse outputted from encoder circuit 8 is supplied to adding-subtracting counter 1 via optical encoder 6 connected direct to DC servomotor 5. Until the counter 1 to which an encoder pulse up to a target positioning point is set counts down to zero, motor 5 is controlled for rough positioning. Next, phases of mutually 90 deg. out-of-phase sine-wave signals from encoder 6 are selected and motor 5 is controlled to hold the voltage of the selected signal at the earth potential, thereby performing fine positioning. Thus, the fine positioning can be performed even when an optical encoder of relatively low resolution is in use. |
