Stiffness Control of Deformable Robots Using Finite Element Modeling
Stiffness Control of Deformable Robots Using Finite Element Modeling
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DOI：
10.1109/lra.2019.2890897
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发表时间：
2019-04-01
影响因子：
5.2
通讯作者：
Duriez, Christian
中科院分区：
文献类型：
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作者：
Koehler, Margaret;Okamura, Allison M.;Duriez, Christian
由于可变形材料建模的复杂性和无限自由度，刚体机器人控制的丰富背景一直没有转移到软机器人身上。因此，为软机器人和软触觉接口开发的大多数基于模型的控制技术都是特定于特定设备的。在本文中，我们发展了一种适用于任意机器人几何形状和多种驱动类型的软机器人刚度控制的通用方法。扩展了以前使用有限元模型进行位置控制的工作，我们确定了执行器柔度和执行器柔度之间的关系，包括固有的装置柔度，并利用这一关系来确定期望的末端执行器刚度的适当受控执行器刚度。这种刚度控制作为阻抗控制的第一部分，可用于补偿可变形装置的自然刚度，并控制机器人与环境或用户的交互。我们验证了可变形机器人上的刚度投影，并将该刚度投影包含在触觉控制回路中，以呈现虚拟夹具。
Due to the complexity of modeling deformable materials and infinite degrees of freedom, the rich background of rigid robot control has not been transferred to soft robots. Thus, most model-based control techniques developed for soft robots and soft haptic interfaces are specific to the particular device. In this letter, we develop a general method for stiffness control of soft robots suitable for arbitrary robot geometry and many types of actuation. Extending previous work that uses finite element modeling for position control, we determine the relationship between endeffector and actuator compliance, including the inherent device compliance, and use this to determine the appropriate controlled actuator stiffness for a desired stiffness of the end-effector. Such stiffness control, as the first component of impedance control, can be used to compensate for the natural stiffness of the deformable device and to control the robot's interaction with the environment or a user. We validate the stiffness projection on a deformable robot and include this stiffness projection in a haptic control loop to render a virtual fixture.