An Operator-based Nonlinear Vibration Control System Using a Flexible Arm with Shape Memory Alloy
An Operator-based Nonlinear Vibration Control System Using a Flexible Arm with Shape Memory Alloy
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DOI：
10.1007/s11633-018-1149-4
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发表时间：
2020-02-01
影响因子：
4.3
通讯作者：
Noge, Yuichi
中科院分区：
文献类型：
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作者：
Matsumori, Hiroki;Deng, Ming-Cong;Noge, Yuichi
在过去，工业和机器人领域使用的手臂被设计成通过增加其质量和刚度来避免振动。武器的重量已经趋于减少，以提高操作速度，并降低其生产成本。由于重量减轻使臂失去刚度，因此更容易振动，因此需要振动抑制控制来实现上述目的。顺便说一句，各种智能材料在致动器中的使用已经增长。特别地，形状记忆合金（SMA）被广泛地应用，并且具有若干优点：重量轻、由温度变化引起的大位移、以及大的力质量比。然而，SMA致动器在其自身的温度和由温度获得的位移之间具有滞后非线性。SMA致动器的滞后行为影响其控制性能。在先前的研究中，已经提出了一个基于操作员的控制系统，包括一个滞后补偿器。以柔性臂的振动为被控对象，一端固定，另一端自由。仿真和实验结果证实了滞环补偿器的有效性。然而，先前设计的系统的反馈信号呈指数增长。这一现象的存在，使该系统难以长期使用。另外，SMA致动器产生并辐射热量，因为通过SMA致动器的电流提供热量，并且在SMA致动器上产生应变。随着SMA致动器的长时间使用，SMA致动器周围的环境温度通过热的辐射而变化。存在这样的风险，即作为干扰处理的环境温度变化影响SMA致动器的温度和应变。在本研究中，提出一种基于操作员的控制系统的设计方法，考虑到系统的长期使用。该方法考虑了SMA驱动器的迟滞特性和驱动器周围的温度变化。仿真和实验验证了该方法的有效性。
In the past, arms used in the fields of industry and robotics have been designed not to vibrate by increasing their mass and stiffness. The weight of arms has tended to be reduced to improve speed of operation, and decrease the cost of their production. Since the weight saving makes the arms lose their stiffness and therefore vibrate more easily, the vibration suppression control is needed for realizing the above purpose. Incidentally, the use of various smart materials in actuators has grown. In particular, a shape memory alloy (SMA) is applied widely and has several advantages: light weight, large displacement by temperature change, and large force to mass ratio. However, the SMA actuators possess hysteresis nonlinearity between their own temperature and displacement obtained by the temperature. The hysteretic behavior of the SMA actuators affects their control performance. In previous research, an operator-based control system including a hysteresis compensator has been proposed. The vibration of a flexible arm is dealt with as the controlled object; one end of the arm is clamped and the other end is free. The effectiveness of the hysteresis compensator has been confirmed by simulations and experiments. Nevertheless, the feedback signal of the previous designed system has increased exponentially. It is difficult to use the system in the long-term because of the phenomenon. Additionally, the SMA actuator generates and radiates heat because electric current passing through the SMA actuator provides heat, and strain on the SMA actuator is generated. With long-time use of the SMA actuator, the environmental temperature around the SMA actuator varies through radiation of the heat. There exists a risk that the ambient temperature change dealt with as disturbance affects the temperature and strain of the SMA actuator. In this research, a design method of the operator-based control system is proposed considering the long-term use of the system. In the method, the hysteresis characteristics of the SMA actuator and the temperature change around the actuator are considered. The effectiveness of the proposed method is verified by simulations and experiments.