公开(公告)号：US3798430A

公开(公告)日：1974-03-19

申请号：US3798430D

申请日：1973-02-27

Applicant: GIDDINGS & LEWIS

Inventor： SIMON J ,  BULLOCK T

IPC: G05B19/37 ,  G06F15/46 ,  G05B21/00

CPC classification number: G05B19/371 ,  G05B2219/41187 ,  G05B2219/41461 ,  G05B2219/42072 ,  G05B2219/42207

Abstract: Methods and apparatus for reducing following errors in the servo drives of positioning and velocity control systems wherein the commanded position is signaled and updated by increments Delta X during each successive equal time periods Delta T, -so as to cause the controlled member movable along any axis X to travel at a velocity Vx Delta X/ Delta T. The commanded position is updated by iterative computations at least once during each period Delta T, and the Delta X increments to be used for such updating are numerically signaled and can be changed as frequently as once during each period Delta T. In order to create a feed forward signal for application to the servo in a sense additive to the position command signal, the digitally signaled number Delta X is converted into a corresponding analog signal. In the preferred arrangement, this conversion is accomplished by a counter which is preset to the number Delta X at regularly recurring instants and arranged to count down whenever the number held in the counter is other than zero. A decoder responsive to a predetermined count, for example zero, not only terminates the counting action until the next presetting but also produces a constant frequency, variable duty cycle squarewave having an average or dc. value proportional to the number Delta X and which serves as an accurate feed forward input to the servo.

Abstract translation: 用于减少定位和速度控制系统的伺服驱动器中的跟随误差的方法和装置，其中在每个连续的相等时间段DELTA T中，命令位置由增量DELTA X发出信号并更新，以使得受控构件沿着任何轴线移动 X以速度Vx = DELTA X / DELTA T行进。命令位置通过在每个周期DELTA T期间至少一次的迭代计算来更新，并且用于这种更新的DELTA X增量被数字信号通知并且可以被改变为 频繁地在每个时段DELTA T期间一次。为了产生用于在位置指令信号的加法中施加到伺服的前馈信号，数字信号的数字DELTA X被转换成相应的模拟信号。 在优选的布置中，这种转换是通过在定期循环的时刻被预设为数字DELTA X的计数器来实现的，并且每当计数器中保持的数字不为零时被布置为递减计数。 响应于预定计数（例如为零）的解码器不仅终止计数动作直到下一个预设，而且产生具有平均值或直流的恒定频率，可变占空比方波。 值与数字DELTA X成比例，并且其作为伺服的精确前馈输入。