According to the analysis of control task and control object, this paper introduces the control method of four servo electric cylinders by using domestic Xinjie XDM series motion control PLC. The method is simple, easy to program and high reliability.
1. Control task
The control system design requirements of the test diagnosis platform are as follows:
(1) According to the instructions of the on-site installation and adjustment personnel, the operator sends out the action command of the servo electric cylinder, and the four servo electric cylinders act independently within the total stroke range and stop reliably at the limit position of the stroke;
(2) The control box shall have the travel display and action indication functions of each electric cylinder, and shall be easy to operate and move.
2. Analysis of control objects
The test diagnosis platform is shown in Figure 1.
3. Scheme design of control system
According to the analysis of control task and controlled object, the control system should provide a friendly man-machine interface, which can complete the semi closed loop position control of four servo electric cylinders. The operation mode has the functions of jog continuous operation, jog step inching and electronic handwheel mode, servo motor start / stop S-shaped acceleration and deceleration, motor enable and brake control, etc.
Because it is driven by AC servo position control system, according to l7s series standard I / O servo driver terminal input position operation mode wiring, the upper control system needs programmable development motion controller with PTO (pulse train output), motion control card or PLC, and HMI touch screen which can communicate with the controller or control card.
3.1 control system based on four axis motion control PLC
The whole control system includes power supply, Xinjie th765 series HMI touch operation display screen, Xinjie xdm-32t-c four axis motion control PLC, electronic hand wheel, l7s series standard I / O servo driver, etc. HMI touch operation display, motion control PLC and l7s servo driver constitute the monitoring system through the serial communication network MODBUS-RTU protocol. The system structure is shown in Figure 2.
3.2 human machine interface design
Xinjie th765 series HMI touch operation display screen can quickly configure human-machine interface through touchwin editing software to realize multiple interfaces, as shown in Figure 3, including operation and position display interface, servo driver status interface, alarm and history record interface, etc.
AP inclined platform integrated control system is adopted. As shown in Figure 4, the operation platform is mainly divided into HMI touch screen and electronic hand wheel. The left side of the electronic hand wheel is the axis selection knob, which is divided into five gears – off, x1, Y1, X2, Y2; the right side of the electronic hand wheel is the magnification selection knob, which is divided into three gears – x1, X10, X100. When it is placed in the off gear, the manual metal encoder is invalid; when it is placed in the corresponding shaft, the electronic handwheel manual metal encoder can operate clockwise and counterclockwise, and the corresponding shaft can move forward and backward.
The domestic Xinjie XDM series motion control PLC introduced in this paper integrates motion control function and ordinary PLC function. It can support up to 10 axis pulse output and realize two axis linkage. It not only supports ordinary motion control commands, such as arc, linear interpolation, etc., but also supports plane conversion commands. It can carry out two axis linkage conversion of X-Y, Y-Z, x-z, etc., which is simple and reliable, It has a certain reference value to realize multi axis motion control.
Editor in charge: yyx