The Design Of Electronic Control System For LCD Feeding Machine Based On PLC

As China taking growing share of flat panel display industry in the global market recent years,the enhancement of Equipment supporting capacity has become the key to the next healthy and sustainable development of the industry.Beijing TSTD Photoelectric Technology Co.Ltd reconstructed 4.5 generation(G4.5)LCD scribing and breaking line in accordance with the status quo of mainland China.The author participated in the project and designed the electrical control system of the feeding machine.The main contents of research are as follows:Research on hardware design was carried out.A feeding robot with three degrees of freedom was designed,the Q series PLC is used as the control core,along with orientation module,server driver and servo motor.Based on the AC servo control principle,the position control model of position,velocity and current(torque)three closed-loop AC servo systems with PI adjustment method is established according to the vector control strategy of id=0current control and the PWM modulation method based on SVPWM algorithm.The simulation results of Matlab/Simulink shows that the motor response and position tracking performance are good in the designed servo system model,meeting the requirements of robot positioning control.After setting the servo drive control parameters according to the servo system model,the robot in normal operation will complete the feeding process under the control of PLC built-in program.Research on software design was done.Using PLC structured programming tool GX Works2 to design the control program of the feeding machine control system,realized the function of manual&automatic feeding and control of the feeding process.Using LabVIEW development platform to design the monitoring screen of PC,achieved the online settings and reading for process parameters,and the manual and automatic feeding function of the feeding robot and the control of the feeding process were realized.The control program of servo motor was developed with the framework of the producer/consumer model,and communicate with the lower machine servo driver and provide the configuration parameters for the lower machine through the Modbus protocol,and realized real-time monitoring of the feeding machine.The result shows that,the man-machine interaction of feeding machine isconvenient and efficient.After the LCD feeding machine is manufactured,the positioning accuracy of the manipulator in the X-axis direction is tested,the result shows that the average positioning accuracy and repeat positioning accuracy of the robot in the X axis direction are 3.7um / mm and 0.7um respectively,meeting the requirements of position control.