Research On Synthetic Control Strategy Of Shaftless Chromatography System

In the thesis, the subject of Research on Synthetic Control Strategy of Shaftless Chromatography System is selected as the topic. The chromatography control of shaftless printing process is analysed comprehensively and in-depth. By analyzing features of shaftless chromatography technology and the existed problems in practice, the thesis proposes synthetic strategy of shaftless chromatography control.Due to the difference between the shaftless printing and the conventional printing, the chromatography control needs to consider coordination between synchronize and the achromatization, which means it is necessary to break the original synchronization when the color aberration is eliminating and establish a new synchronization fast and accurately after eliminating. So the chromatography control is very complicated.In aspect of achromatization, the implement ability of servo system is fully used and the thesis adopts calibration method based on relative position, in which the color aberration is conversed to aberration trajectory and it is added to printing axis as a additional position input. As for the processing of trajectory generation, the thesis adopts the3rd order motion curve.In aspect of controller design, the thesis adopts sliding mode control to improve the tracking performance and at the same time it can restrain the parameter variations, load disturbance and other uncertainties for the synchronization performance. In the thesis, the author adopts fuzzy switching gain and the global terminal sliding mode control method to ensure that the system state tracking error can coverge to zero in finite time, and can effectively eliminate the interference terms to suppress chattering.As for system of synchronization control, the thesis introduces the cross-coupling on the adjacent shaft synchronous control strategy which considers the position tracking error and the synchronization error between adjacent shaft. The strategy makes multi-axis system is no longer independent of each other multi-axis synchronization control. Simultaneously, the control of each axis only additionally considers motion responses of the other two axes, but not all other axes, for synchronization. This significantly simplifies the implementation especially when the number of axes is large. Finally, the thesis re-designs the sliding mode controller based on the cross-coupling on the adjacent shaft synchronous control strategy, which combines the sliding mode control with the cross-coupling structure and the controller can inhibit the disturbance of load and parameters change on the whole synchronization system. The synthetic control strategy is proved through simulation that it can control the max synchronization error less than2×10-3mm and eliminate synchronization error effectively, which can improve synchronization accuracy and satisfy the dynamic synchronization requirements. Simultaneously, the synthetic strategy can also eliminate the color aberration smoothly and accurately and then can accomplish the design purpose of coordination between aberration adjustment and position synchronization.