| With the rapid development of modern industry,the detection of mobile phone LCD cover plate has gradually realized automation.Due to the fast detection speed and multiple functions of the mobile phone LCD cover plate detection device,vibration and response delay of the detection device are easily caused during the detection operation.Motion control is the key component of mobile phone LCD cover plate detection device,and its performance affects the accuracy and efficiency of the detection device.As the mobile phone LCD cover plate detection device is affected by its own characteristics,the problems of weak real-time performance,poor stability and low accuracy of its motion control system need to be solved urgently.Therefore,this topic studies the motion control system of mobile phone LCD cover plate detection device through digital technology.In this thesis,Luoyang Gingko Technology Co.,Ltd.undertakes the small size single platform mobile phone LCD cover plate detection device as the research object,based on the analysis of its functional requirements and mechanical characteristics,and a motion control system scheme based on embedded is proposed.Used the stability control theory,combined with the calculation amount of trapezoidal and S-shaped acceleration and deceleration methods and the complexity of the control process,a modified trapezoidal acceleration and deceleration speed planning algorithm was proposed by introducing the correction coefficient to set the running stage time,which effectively reduced the amount of data processing tasks and improved the stability of the single-axis high-speed operation.Used on the principle of linear interpolation and the principle of linkage speed control,through analyzing the errors caused by the linkage relationship between two axes in the process of linear interpolation,a two-axis linkage linear control algorithm was proposed to determine the feed of each axis in the process of interpolation,so as to improve the positioning accuracy of the two-axis linkage control detection platform.Based on Advanced RISC Machine(ARM)and Field Programmable Gate Array(FPGA),the overall scheme of motion control system was designed,including communication module,data processing module and drive control module design,among them,ARM was used as the main controller to complete the communication interaction and data processing of the upper computer,and the FPGA was used as the slave controller to complete the interface driving and signal control,which improved the system integration and simplified the system control logic.Based on C language and Verilog HDL,the system software was designed,and the embedded real-time multi-thread operating system(Real Time-Thread,RT-Thread)platform was built through ARM,and the full preemption mechanism of RT-Thread priority was used to realize communication interaction,motion control,interrupt processing and other multi-task real-time processing functions;the FPGA implemented functions such as output pulse,encoder detection,and I/O control.ARM and FPGA work in concert to realize the system multi-task control,so as to improve the system positioning accuracy.Experiments showed that the motion control system can multi-task real-time control of axes and I/Os.The modified trapezoidal acceleration and deceleration speed planning algorithm were applied to a single axis,and the repeated positioning accuracy is 0.129 mm.The running curve is consistent with that of the control algorithm,which improves the smoothness of the axis.The detection platform was tested and verified by the two-axis linkage linear control algorithm,and the position of the LCD cover plate was realized.The test positioning accuracy is 0.149 mm,which meets the system control indicators. |
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