Phase control of oscillators for moving body in narrow passage
Phase control of oscillators for moving body in narrow passage
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DOI：
10.1299/mej.14-00545
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发表时间：
2015-03
影响因子：
4.4
通讯作者：
A. Yamano;A. Shintani;Tomohiro Ito;C. Nakagawa
中科院分区：
文献类型：
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作者：
A. Yamano;A. Shintani;Tomohiro Ito;C. Nakagawa
开发了一种用于狭窄通道流动的柔性仿生鱼机器人。使用形状记忆合金（SMA）执行器实现了移动体的小型化。然而，SMA 执行器过热会导致相变饱和，并可能导致翅片振动幅度减小。为了避免这个问题，引入了一种利用自激振荡器的新驱动方法。该方法适合利用自感产生振荡并保持 SMA 温度恒定，并且只需要调整一个参数。我们通过实验和数值模拟证实了所提出的防止过热驱动方法的有效性。仿真证明该方法能够保持运动体推力恒定。对于类鱼运动体，需要多个执行器来实现更高自由度的行为，并且这些执行器输出的相位也需要同步以产生类鱼行为，即行波。另一方面，在所提出的驱动方法中，执行器系统模拟自激振动系统。因此，有必要为由执行器组成的振荡器设计耦合输入以同步振荡器输出。为了实现这一目标，从执行器模型获得了相模型，该模型由热导率模型和使用相还原分析的磁滞模型组成。基于该相位模型设计了所提出的连接方法的耦合输入，并检查了耦合执行器的相位差与连接增益之间的关系。最后，我们利用它实现了相位控制。
A flexible biomimetic fish-like robot for use in a flow in narrow passage was developed. Downsizing of the moving body was achieved using shape memory alloy (SMA) actuators. However, overheating an SMA actuator causes phase–transition saturation, and may cause a decrease in the fin vibration amplitude. In order to avoid this problem, a new driving method that utilized a self-excited oscillator was introduced. This proposed method is suited for generating oscillation with keeping temperature in SMA constant by using self-sensing, and needs to adjust only one parameter. We confirmed the effectiveness of the proposed driving method against overheating based on experiments and numerical simulations. Simulation proved that this method can keep thrust force of the moving body constant. For the fish-like moving body, multiple actuators are needed to realize higher degree of freedom behavior, and the phases of these actuator outputs also are needed to be synchronized to generate fish-like behavior, i.e., traveling wave. On the other hand, in the proposed driving method, the actuator system simulates a self-excited vibration system. Therefore, it was necessary to design the coupled inputs for oscillators composed by actuators to synchronize the oscillator outputs. To achieve this, a phase model was obtained from an actuator model, which consists of a thermal conductivity model and hysteresis model using a phase reduction analysis. Coupled inputs for proposed connecting method were designed based on this phase model, and the relationship between the phase difference of the coupled actuators and the connection gains was examined. Finally, we realized phase control using this.