Practical use of robotic manipulators made from soft materials requires generating and executing complex motions. We present the first approach for generating trajectories of a thermally-actuated soft robotic manipulator. Based on simplified approximations of the soft arm and its antagonistic shape-memory alloy actuator coils, we justify a dynamics model of a discretized rigid manipulator with joint torques proportional to wire temperature. Then, we propose a method to calibrate this model from experimental data and demonstrate that the simulation aligns well with a hardware test. Finally, we use a direct collocation optimization with the robot's nonlinear dynamics to generate feasible state-input trajectories from a desired reference. Three experiments validate our approach for a single-segment robot in hardware: first using a hand-derived reference trajectory, then with two teach-and-repeat tests. The results show promise for both open-loop motion generation as well as for future applications with feedback.
翻译:用软材料制造的机器人操控器的实际使用需要生成和实施复杂的动作。 我们提出第一种生成热活性软机器人操纵器轨迹的方法。 根据软臂及其对立形状模拟合金活性线圈的简化近似值, 我们有理由使用离散的僵硬操纵器动态模型, 与电线温度成比例。 然后, 我们提出一种方法来根据实验数据校准这个模型, 并证明模拟与硬件测试完全吻合。 最后, 我们利用机器人的非线性动态直接对齐, 从一个理想的参照点生成可行的州- 投影轨迹。 三个实验证实了我们使用硬件中单项组合机器人的方法: 首先使用手导参考轨迹, 然后用两个教学和复位测试。 结果显示了对开球动作生成以及未来反馈应用的保证。