| Mini/Micro LED have advantages such as high brightness,low power consumption,ultra-high resolution,and color saturation,which are key technologies driving the development of display technology towards miniaturization of display chip volume,high-definition display image quality,strong display contrast,and intelligent display applications.Mass transfer can accurately and quickly transfer millions or even tens of millions of micron LED chips to the driver circuit board,making it a top priority for achieving mass production of Mini/Micro LEDs.n this paper,the ultra-precision fast motion positioning platform with a large number of transfer core components is taken as the research object,and the following research work is completed from the perspective of high-precision motion control and response performance improvement:This paper introduces the configuration and performance index of the fast motion positioning platform for mass transfer at home and abroad.A fast motion positioning platform for needle-type mass transfer equipment is designed,and its structure and working principle are introduced.Aiming at the fast motion positioning platform of core component ’H’ configuration,a mathematical model of Permanent magnet linear synchronous motor based on d-q coordinate is constructed.The rationality of the structure is verified by statics and modal analysis.Aiming at the problem of synchronization control accuracy of ’H’ type motion positioning platform under external disturbance,the internal and external input disturbance error sources affecting the synchronization performance of linear motor are analyzed,and a position-velocity doubleloop cross-coupled sliding mode synchronization control algorithm is proposed.A dual-motor synchronization error coupling model is constructed by using the cross-coupling algorithm.Combined with the control response characteristics of the position loop and the speed loop,a double-loop cross-coupling sliding mode synchronization control strategy is proposed.The corresponding control simulation system is built.The simulation results show that the synchronization control performance of this scheme is improved by 51.95% and 41.91% respectively compared with the unit set loop cross coupled Sliding mode control algorithm and the single speed loop cross coupled Sliding mode control algorithm.To effectively improve the complex curve trajectory tracking performance of planar interpolation motion of ’H’ motion positioning platform,the contour tracking error models of linear trajectory and circular trajectory based on numerical difference method are established,and the equivalent contour error compensation model of any curve trajectory is summarized.A second-order equivalent sliding mode contour error compensation control algorithm for arbitrary curve equivalent contour error is designed.The contour error observer,XY motion platform singleaxis direct drive motion controller and XY dual-axis motion platform contour error second-order sliding mode controller are designed,and the Lyapunov stability analysis is carried out.Based on this,a contour control simulation system is built.The simulation results show that compared with the traditional PID contour error compensation method,the contour error compensation control performance of this scheme is improved by 49.08 %.Finally,based on the ultra-precision fast motion positioning platform prototype developed by the research group,the control system is built,the control algorithm is transplanted and the host computer operating system is developed.The synchronization control performance and trajectory tracking performance of the platform are verified.The experimental results show that the platform control system can achieve synchronization control with a maximum synchronization error of 9μm and contour control with a steady-state contour error of less than 7μm.The performance meets the accuracy design requirements of the huge transfer of Mini/Micro LED chips. |
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