The Graduate School of Engineering, Tokyo University of Agriculture and Technology, Tokyo 183-8538, Japan.
Sensors (Basel). 2023 Jan 18;23(3):1133. doi: 10.3390/s23031133.
The flexible arm easily vibrates due to its thin structural characteristics, which affect the operation accuracy, so reducing the vibration of the flexible arm is a significant issue. Smart materials are very widely used in the research topic of vibration suppression. Considering the hysteresis characteristic of the smart materials, based on previous simulation research, this paper proposes an experimental system design of nonlinear vibration control by using the interactive actuation from shape memory alloy (SMA) for a flexible arm. The experiment system was an interactive actuator-sensor-controller combination. The vibration suppression strategy was integrated with an operator-based vibration controller, a designed integral compensator and the designed -times feedback loop. In detail, a nonlinear vibration controller based on operator theory was designed to guarantee the robust stability of the flexible arm. An integral compensator based on an estimation mechanism was designed to optimally reduce the displacement of the flexible arm. Obtaining the desired tracking performance of the flexible arm was a further step, by increasing the -times feedback loop. From the three experimental cases, when the vibration controller was integrated with the designed integral compensator, the vibration displacement of the flexible arm was much reduced compared to that without the integral compensator. Increasing the number of -times feedback loops improves the tracking performance. The desired vibration control performance can be satisfied when n tends to infinity. The conventional PD controller stabilizes the vibration displacement after the 7th vibration waveform, while the vibration displacement approaches zero after the 4th vibration waveform using the proposed vibration control method, which is proved to be faster and more effective in controlling the flexible arm's vibration. The experimental cases verify the effectiveness of the proposed interactive actuation vibration control approach. It is observed from the experimental results that the vibration displacement of the flexible arm becomes almost zero within less time and with lower input power, compared with a traditional controller.
柔性臂由于其细薄的结构特点容易发生振动，这会影响操作精度，因此降低柔性臂的振动是一个重要问题。智能材料在抑制振动的研究课题中得到了非常广泛的应用。考虑到智能材料的滞后特性，基于之前的仿真研究，本文提出了一种基于形状记忆合金（SMA）的交互激励的柔性臂非线性振动控制实验系统设计。实验系统是一个交互执行器-传感器-控制器组合。振动抑制策略与基于算子的振动控制器、设计的积分补偿器和设计的 - 次反馈环相结合。具体来说，设计了一种基于算子理论的非线性振动控制器，以保证柔性臂的鲁棒稳定性。设计了基于估计机制的积分补偿器，以优化柔性臂的位移。通过增加 - 次反馈环，进一步获得柔性臂的期望跟踪性能。通过三个实验案例可以看出，当振动控制器与设计的积分补偿器集成时，柔性臂的振动位移比没有积分补偿器时要小得多。增加 - 次反馈环的数量可以提高跟踪性能。当 n 趋于无穷大时，可以满足期望的振动控制性能。传统的 PD 控制器在第 7 个振动波形后稳定振动位移，而采用所提出的振动控制方法，振动位移在第 4 个振动波形后接近零，证明其在控制柔性臂振动方面更快、更有效。实验案例验证了所提出的交互激励振动控制方法的有效性。从实验结果可以看出，与传统控制器相比，柔性臂的振动位移在更短的时间内和更低的输入功率下几乎为零。
