公开(公告)号：WO1981002347A1

公开(公告)日：1981-08-20

申请号：PCT/GB1981000021

申请日：1981-02-16

申请人： ZEUS INT TRADING CO LTD ,  SINGH H ,  BILLINGSLEY J

发明人： ZEUS INT TRADING CO LTD

IPC分类号： G05B19/18

CPC分类号： G05B19/23 ,  G05B19/4142 ,  G05B2219/34215 ,  G05B2219/37152

摘要： Control of a d.c. motor (14), which may drive for example a 'daisy' print-wheel, is achieved using a micro-computer (18). A movel algorithm which uses the micro-computer in an unconventional way permits the construction of a system with a minimum of additional circuitry and with a very fast response time. A striped disc (10) coupled to the motor (14) and sensed photo-electrically (A, B, H) provides position status information. An 8-bit status byte is produced, with 4 bits (a, b, a', b') representing present and past position status and indicative of clockwise, anticlockwise or no movement. The 8-bit status byte is used as a pointer into a look-up table of addresses of action routines. A loop of only four instructions can perform the input and decode functions. As the target position is approached the motor is switched to slow mode operation in which the motor decelerates for a fixed interval and then accelerates until the next incremental move is made.