Hydraulic servo shaking table is an essential testing facility to simulate the actual vibration situation in real time. As a parallel mechanism, multiaxis hydraulic servo shaking table shows strong coupling characteristic among different degrees of freedom. When the multiaxis hydraulic shaking table moves to one direction, some unnecessary related motions will appear in other directions, which seriously affect the control performance. An effective approach to decouple motions in command direction and in unnecessary related directions is an urgent need for a higher precision control performance. In this work, the coupling phenomena and reasons of the multiaxis hydraulic servo table are analyzed based on dynamic model of a multiaxis hydraulic servo shaking table. In this regard, multiaxis hydraulic servo shaking table with strong coupling within the physical space is transformed into a set of single-input single-output systems that are independent of each other in the modal space. A decoupling control strategy is proposed in modal space to restrain the coupling motions. Simulation and experimental results show that the proposed control strategy can effectively improve the control performance and the decoupling effect.

中文翻译：

---

基于动态模型的多轴液压伺服振动台解耦控制

液压伺服振动台是实时模拟实际振动情况的必备测试设备。多轴液压伺服振动台作为一种并联机构，在不同自由度之间表现出很强的耦合特性。当多轴液压振动台向一个方向运动时，其他方向会出现一些不必要的相关运动，严重影响控制性能。对指令方向和不必要的相关方向上的运动进行解耦的有效方法是对更高精度控制性能的迫切需要。本文基于多轴液压伺服振动台的动力学模型，分析了多轴液压伺服台的耦合现象及产生的原因。在这方面，将物理空间内强耦合的多轴液压伺服振动台转化为模态空间中一组相互独立的单输入单输出系统。在模态空间提出了一种解耦控制策略来抑制耦合运动。仿真和实验结果表明，所提出的控制策略能够有效提高控制性能和解耦效果。