最小运行时间最佳开关式控制器(英文)

Optimum Switching Controller for Minimum Time Motion Control

阐述了一种适用于机床工作台运动的DNC非线性控制器,该系统以一种最佳开关式控制器为基础,实现了工作台精确移位的最短时间优化控制,以工作台实测的机械特性为依据,采用计算辅助设计来确定最佳开关时间点,再用这些开关量来驱动一组在线的非线性闭环反馈控制器,使三个相互垂直的轴运动能精确定位,为得到快速响应,系统采用两个微处理器协调运行:一个主控制器实时控制三台步进电动机;一个副控制器采集三个轴的绝对座标并迅速将数值传送给主控制器,同时将座标数值按照用户要求以英寸或毫米或脉冲计数方式在一块液晶屏上显示出来,提供了系统硬件图和软件设计要点,并以一台三座标印刷电路板钻床为应用实例,给出了典型试验数据。

This paper dealt with the non—linear control of a DNC machine tool table. An optimum switching Controller was taken as a basis for the control system to accomplish Positional moves in minimum time. The optimum switching time was determined by a simple Computer Aided Design method based on the mesured physical characteristics of the machine table. Switching boundary data was used to derive an on-line nonlinear feedback controller to position three mutually orthogonal axes. To achieve the required speed of response,two parallel microprocessors were used for controller implementation.One processor, the MASTER, served for real—time control of the stepper motor actuator drives, the other, the SLAVE, was used to sample absolute positions, to pass data to the MASTER, to display position in a selected unit, inches, millimetres or pulses and to control a flat screen liquid crystal display. A host PC was supposed to create the setpoint data file from a CAD printed circuit board drill plot file. The data were loaded to the MASTER to define the desired table movement. The system was designed and implemented on an Electrocraft three axes drill table and shown to operate in minimun time.