Shen Gang, Li Xiang, Zhu Zhencai, Tang Yu, Zhu Weidong, Liu Shanzeng
School of Mechatronic Engineering, China University of Mining and Technology, Xuzhou 221116, China; Jiangsu Key Laboratory of Mine Mechanical and Electrical Equipment, China University of Mining and Technology, Xuzhou 221116, China.
School of Mechatronic Engineering, China University of Mining and Technology, Xuzhou 221116, China; Jiangsu Key Laboratory of Mine Mechanical and Electrical Equipment, China University of Mining and Technology, Xuzhou 221116, China.
ISA Trans. 2017 Sep;70:322-337. doi: 10.1016/j.isatra.2017.07.018. Epub 2017 Jul 25.
An electro-hydraulic shaking table (EHST) is an essential experimental facility to simulate in real-time actual vibration situations. An adaptive controller combined with off-line compensators is proposed to improve the acceleration frequency bandwidth and tracking accuracy of a six-degree-of-freedom (6-DOF) EHST. A servo controller has been employed to implement acceleration closed-loop and coordinate control of the 6-DOF EHST. A recursive extended least-squares algorithm is employed to identify acceleration closed-loop transfer functions and a zero-phase-error tracking controller is used to design off-line inverse model compensators using the identified transfer functions. However, the off-line compensators cannot compensate in real-time varying dynamics of the 6-DOF EHST; so an online adaptive controller with a least-mean-squares (LMS) algorithm based on a delay compensator is employed. The proposed controller combines advantages of the off-line compensators and the online adaptive controller, which guarantees both a fast rate of convergence of the LMS algorithm and high-fidelity acceleration tracking accuracy of the 6-DOF EHST. Some experimental studies have been conducted on a 6-DOF EHST and experimental results show that acceleration tracking control performances, including the rate of convergence of the LMS algorithm and acceleration tracking accuracy, have been improved compared to a conventional three-variable controller and adaptive controllers.
电动液压振动台（EHST）是实时模拟实际振动情况的重要实验设备。提出了一种结合离线补偿器的自适应控制器，以提高六自由度（6-DOF）电动液压振动台的加速度频率带宽和跟踪精度。采用伺服控制器实现6-DOF电动液压振动台的加速度闭环和坐标控制。采用递归扩展最小二乘算法识别加速度闭环传递函数，并使用零相位误差跟踪控制器根据识别出的传递函数设计离线逆模型补偿器。然而，离线补偿器无法实时补偿6-DOF电动液压振动台变化的动力学特性；因此，采用了一种基于延迟补偿器的具有最小均方（LMS）算法的在线自适应控制器。所提出的控制器结合了离线补偿器和在线自适应控制器的优点，既保证了LMS算法的快速收敛速度，又保证了6-DOF电动液压振动台的高保真加速度跟踪精度。在6-DOF电动液压振动台上进行了一些实验研究，实验结果表明，与传统的三变量控制器和自适应控制器相比，加速度跟踪控制性能，包括LMS算法的收敛速度和加速度跟踪精度，都得到了提高。
