Vibration suppression of the series elastic actuator (SEA) used for robotic compliant grinding is significant for guaranteeing force control accuracy and stability, which is important for material removal accuracy and surface quality improvement. This paper establishes a multi-feedforward control system to achieve vibration suppression for the SEA. The hybrid optimized input shaper (HOIS), instruction reconstructor, and nonlinear friction compensation model are seamlessly integrated into the multi-feedforward control method. Combination optimization principles are employed to formulate the HOIS, ensuring selectable performances on vibration suppression, response speed, and model stability when addressing the residual vibration caused by elastic elements. Base on the inherent delay characteristics of the shaper, a head/tail compression and intermediate shift instruction reconstruction (CSIR) method is introduced to address the tracking error induced by the time-delay of the shaper. Additionally, the friction compensator is established based on the Stribeck model and integrated into the feedforward control system to mitigate the vibration caused by the low-speed viscous friction. The effectiveness of the proposed method is verified by experimental tests. Results show that the HOIS has rich optional performance and can effectively suppress vibration. The tracking error caused by the shaper is effectively mitigated through the reconstruction of instructions. Grinding tests on curved parts are conducted on the robotic grinding system with SEA used as the force-control system. Compared with the benchmark method, the developed reconstructed hybrid optimized input shaper reduces the average force tracking error, the average absolute grinding depth error, and average roughness by 26.6 %, 22.5 %, and 21.5 % respectively. At the natural frequency of the grinding system, the amplitude of the frequency spectrum with the developed multi-feedforward method decreases by 48.13 %.

中文翻译：

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基于重构混合优化输入整形器的机器人磨削用串联弹性执行机构振动抑制


用于机器人柔顺磨削的系列弹性执行器（SEA）的振动抑制对于保证力控制的精度和稳定性具有重要意义，这对于材料去除精度和表面质量的改善具有重要意义。本文建立了多前馈控制系统来实现SEA的振动抑制。混合优化输入整形器 (HOIS)、指令重构器和非线性摩擦补偿模型无缝集成到多前馈控制方法中。采用组合优化原理制定HOIS，确保在解决弹性元件引起的残余振动时，在振动抑制、响应速度和模型稳定性方面具有可选择的性能。基于整形器固有的延迟特性，引入头/尾压缩和中间移位指令重构(CSIR)方法来解决整形器时延引起的跟踪误差。此外，基于Stribeck模型建立摩擦补偿器，并将其集成到前馈控制系统中，以减轻低速粘性摩擦引起的振动。通过实验测试验证了所提方法的有效性。结果表明HOIS具有丰富的可选性能，能够有效抑制振动。通过指令重构，有效减轻了整形器带来的跟踪误差。在以SEA为力控系统的机器人磨削系统上进行了曲面零件的磨削试验。 与基准方法相比，所开发的重构混合优化输入整形器将平均力跟踪误差、平均绝对磨削深度误差和平均粗糙度分别降低了26.6%、22.5%和21.5%。在磨削系统的固有频率下，采用所开发的多前馈方法的频谱幅度降低了48.13%。