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Abstract: We investigate motion synchronization of dual-cylinder pneumatic servo systems and develop an adaptive robust synchronization controller. The proposed controller incorporates the cross-coupling technology into the integrated direct/indirect adaptive robust control (DIARC) architecture by feeding back the coupled position errors, which are formed by the trajectory tracking errors of two cylinders and the synchronization error between them. The controller employs an online recursive least squares estimation algorithm to obtain accurate estimates of model parameters for reducing the extent of parametric uncertainties, and uses a robust control law to attenuate the effects of parameter estimation errors, unmodeled dynamics, and disturbances. Therefore, asymptotic convergence to zero of both trajectory tracking and synchronization errors can be guaranteed. Experimental results verify the effectiveness of the proposed controller.

基于交叉耦合方法的双轴气动伺服系统自适应鲁棒同步控制研究

研究目的：多轴气动伺服系统因具有功率-质量比大、清洁、价格低、结构简单、易维护等优点，在机器人、工业自动化、医疗机械等领域具有广泛应用前景。但是，该系统具有很多不利于精确控制的缺点，如强非线性、参数时变性、模型不确定性等。本文针对双缸气动伺服系统，从建立系统模型入手，探寻同时实现单气缸高精度轨迹跟踪控制和双气缸高精度位置同步的控制策略，旨在为这项技术的工业实用化奠定基础。
创新要点：提出了一种基于交叉耦合方法的自适应鲁棒气动同步控制策略，既保证了多气缸精确同步，又实现了系统中每一气缸的高精度运动轨迹跟踪控制。
方法提亮：将交叉耦合思想与直接/间接集成自适应鲁棒控制结合起来，提出一种基于交叉耦合方法的自适应鲁棒气动同步控制策略。将同步误差直接反馈至每个轴控制器的输入端而非输出端，利用交叉耦合方法将同步误差和轨迹跟踪误差组成耦合误差，基于该新误差变量设计自适应鲁棒控制器。控制器由在线最小二乘参数估计和基于反步法设计的非线性鲁棒控制器组成，前者用于减小模型中的参数不确定性，后者用于抑制参数估计误差、未建模动态和干扰的影响，使得单缸的轨迹跟踪误差和多缸间的同步误差同时收敛，既保证多气缸精确同步又不影响系统中每一气缸的轨迹跟踪控制精度。
重要结论：实验结果表明，该控制器能实现很高的同步位置控制精度，对干扰具有较强的鲁棒性。
运动同步；气动伺服系统；交叉耦合；自适应鲁棒控制

[1]Carneiro, J.F., de Almeida, F.G., 2006. Reduced-order thermodynamic models for servo-pneumatic actuator chambers. Proc. Inst. Mech. Eng. Part I: J. Syst. Contr. Eng., 220(4):301-314.

[2]Chen, C., Liu, L., Cheng, C., et al., 2008. Fuzzy controller design for synchronous motion in a dual-cylinder electro-hydraulic system. Contr. Eng. Pract., 16(6):658-673.

[3]Chen, C.Y., 2007. Synchronous motion of two-cylinder electrohydraulic system with unbalanced loading and uncertainties. Proc. Inst. Mech. Eng. Part I: J. Syst. Contr. Eng., 221(7):937-955.

[4]Hsieh, M., Tung, C., Yao, W., et al., 2007. Servo design of a vertical axis drive using dual linear motors for high speed electric discharge machining. Int. J. Mach. Tools Manuf., 47(3-4):546-554.

[5]Jang, J.S., Kim, Y.B., Lee, I.Y., et al., 2004. Design of a synchronous position controller with a pneumatic cylinder driving system. SICE Annual Conf., p.2943-2947.

[6]Koren, Y., 1980. Cross-coupled biaxial computer controls for manufacturing systems. J. Dynam. Syst. Meas. Contr., 102(4):265-272.

[7]Meng, D., Tao, G., Chen, J., et al., 2011. Modeling of a pneumatic system for high-accuracy position control. Proc. Int. Conf. on Fluid Power and Mechatronics, p.505-510.

[8]Meng, D., Tao, G., Zhu, X., 2013. Integrated direct/indirect adaptive robust motion trajectory tracking control of pneumatic cylinders. Int. J. Contr., 86(9):1620-1633.

[9]Shan, J., Liu, H., Nowotny, S., 2005. Synchronized trajectory-tracking control multiple 3-DOF experimental helicopters. IEE Proc.-Contr. Theory Appl., 152(6):683-692.

[10]Shibata, S., Yamamoto, T., Jindai, M., 2006. A synchronous mutual position control for vertical pneumatic servo system. JSME Int. J. Ser. C, 49(1):197-204.

[11]Su, Y., Sun, D., Ren, L., et al., 2006. Integration of saturated PI synchronous control and PD feedback for control of parallel manipulators. IEEE Trans. Robot., 22(1):202-207.

[12]Sun, D., 2003. Position synchronization of multiple motion axis with adaptive coupling control. Automatica, 39(6):997-1005.

[13]Sun, D., Mills, K., 2002. Adaptive synchronized control of coordination of multi-robot assembly tasks. IEEE Trans. Robot. Autom., 18(4):498-510.

[14]Sun, D., Lu, R., Mills, J.K., et al., 2006. Synchronous tracking control of parallel manipulators using cross-coupling approach. Int. J. Robot. Res., 25(11):1137-1147.

[15]Sun, D., Shao, X., Feng, G., 2007. A model-free cross-coupled control for position synchronization of multi-axis motions: theory and experiments. IEEE Trans. Contr. Syst. Technol., 15(2):306-314.

[16]Sun, D., Wang, C., Feng, G., 2009. A synchronization approach to trajectory tracking of multiple mobile robots while maintaining time-varying formations. IEEE Trans. Robot., 25(5):1074-1086.

[17]Xiao, Y., Zhu, K., 2006. Optimal synchronization control of high-performance motion systems. IEEE Trans. Ind. Electron., 53(4):1160-1169.

[18]Xiao, Y., Zhu, K., Liaw, H., 2005. Generalized synchronization control of multi-axis motion systems. Contr. Eng. Pract., 13(7):809-819.

[19]Zhu, X., Cao, J., Tao, G., et al., 2009. Synchronization strategy research of pneumatic servo system based on separate control of meter-in and meter-out. IEEE/ASME Int. Conf. on Advanced Intelligent Mechatronics, p.24-29.