基于Hybrid方法的大型冗余驱动机构控制策略研究

A large electro-hydraulic shaking table based on the Hybrid control strategy is theoretically studied and experimentally verifed, which is the typical device of the large redundant control mechanisms that is widely used in vibration mechanics tests. In order to improve the expected signal tracking accuracy and to extend the system frequency bandwidth, a nonlinear simulation model of the larger redundant control mechanism is established, a transfer function of the servo system based on the parameter model is adaptively identified, a stable inverse model of the estimated nominimum phase system transfer function is designed to realize the feed-forward compensation control，an improved internal model control is proposed to reduce the influences of the tracking accuracy caused by estimated and designed modeling error, in which some important theories such as hydraulic transmission, system identification, zero phase error tracking control, internal model control, etc, are studied in the project. In order to further improve the tracking accuracy, the convergence rate and stability of an adaptive control is also investigated in the large redundant control mechanisms. A hybrid control method is proposed by combing advantages of servo control, feed-forward offline compensation and online adaptive control, and a bumpless transfer controller is designed，especially, the stablily of the bumpless transfer controller is studied due to catastrophic behavior casued by the controller during transfer period. Hence, the proposed Hybrid control strategy can further improve the expected reference signals tracking accuracy. The achievements of the project can provide theoretical support for developmenting the large redundant control mechanisms.

本项目以振动力学试验中的大型冗余驱动机构的典型装置-电液振动台为研究对象，开展基于Hybrid方法的大型冗余驱动机构控制策略研究。针对电液振动台系统频宽较低、参考信号跟踪精度较差问题，综合运用液压传动、系统辨识、零相差跟踪、内模控制等理论，建立大型冗余驱动机构的非线性仿真模型，研究自适应辨识算法并辨识基于参数模型的伺服系统传递函数，设计非最小相位系统的稳定逆模型并实现前馈补偿控制，提出改进的内模控制以降低模型偏差对跟踪精度的影响；研究自适应控制算法在大型冗余驱动机构中的收敛速度及稳定性，提出基于伺服系统、前馈逆模型补偿控制和自适应控制相结合的Hybrid控制策略，设计Hybrid的无缝切换控制器，解决切换过程中可能发生的突变行为对系统稳定性造成的影响，实现稳定可靠的Hybrid控制，提高参考信号跟踪精度，为大型冗余驱动机构控制系统的研究提供重要的基础理论支持。

项目建立了大型冗余驱动电液振动台液压系统非线性仿真模型，研究了伺服系统的传递函数辨识算法，辨识了电液振动台位置闭环和加速度闭环的传递函数，设计了逆模型和内模控制器；研究了LMS自适应控制算法，分析了其稳定性和收敛速度问题，进一步提出了基于模型偏差补偿的Hybrid复合控制方法，研究了无缝切换控制的稳定性，验证了切换时存在的突变行为对自适应控制方法的影响；研制了六自由度八执行器冗余驱动的大型电液振动台及其实时控制系统，开发了基于xPC快速原型控制系统，研制了控制系统硬件，完成了软件的编程及大型冗余驱动机构伺服系统的整体调试，实现了大型冗余驱动机构的平稳运动；在前馈逆模型补偿控制基础上，对基于参数逆模型的前馈逆模型补偿控制和提出的Hybrid控制策略的可行性以及自适应控制和无缝切换控制器稳定性进行了实验验证。研究成果发表SCI论文9篇，EI论文1篇，申请发明专利4件，已授权2件。该项目研究成果突破了前馈逆模型和自适应控制在电液伺服系统中应用的关键技术，为进一步研究开发大型超冗余电液系统提供了重要的理论依据和科学支撑，具有较高的学术水平和推广应用价值。