Elery Toby, Rezazadeh Siavash, Nesler Christopher, Gregg Robert D
T. Elery is with the Departments of Bioengineering and Mechanical Engineering, University of Texas at Dallas, Richardson, TX 75080 USA. S. Rezazadeh is with the Department of Mechanical Engineering, University of Denver, Denver, CO, 80208 USA. C. Nesler and R. D. Gregg are with the Department of Electrical Engineering and Computer Science; Robotics Institute, University of Michigan, Ann Arbor, MI, 48109 USA.
IEEE Trans Robot. 2020 Dec;36(6):1649-1668. doi: 10.1109/TRO.2020.3005533. Epub 2020 Jul 13.
We present the design of a powered knee-ankle prosthetic leg, which implements high-torque actuators with low-reduction transmissions. The transmission coupled with a high-torque and low-speed motor creates an actuator with low mechanical impedance and high backdrivability. This style of actuation presents several possible benefits over modern actuation styles in emerging robotic prosthetic legs, which include free-swinging knee motion, compliance with the ground, negligible unmodeled actuator dynamics, less acoustic noise, and power regeneration. Benchtop tests establish that both joints can be backdriven by small torques (~1-3 Nm) and confirm the small reflected inertia. Impedance control tests prove that the intrinsic impedance and unmodeled dynamics of the actuator are sufficiently small to control joint impedance without torque feedback or lengthy tuning trials. Walking experiments validate performance under the designed loading conditions with minimal tuning. Lastly, the regenerative abilities, low friction, and small reflected inertia of the presented actuators reduced power consumption and acoustic noise compared to state-of-art powered legs.
我们展示了一种电动膝踝假肢腿的设计，该设计采用了带有低减速传动装置的高扭矩执行器。与高扭矩低速电机相结合的传动装置创造了一种具有低机械阻抗和高反向驱动能力的执行器。这种驱动方式相对于新兴机器人假肢腿中的现代驱动方式具有几个潜在优势，包括膝关节自由摆动、与地面的顺应性、可忽略不计的未建模执行器动力学、较少的声学噪声以及能量再生。台式测试表明，两个关节都可以由小扭矩（约1 - 3牛米）反向驱动，并证实了较小的反射惯性。阻抗控制测试证明，执行器的固有阻抗和未建模动力学足够小，无需扭矩反馈或长时间的调谐试验就能控制关节阻抗。行走实验验证了在设计负载条件下的性能，只需进行最小限度的调谐。最后，与现有电动腿相比，所展示的执行器的再生能力、低摩擦力和小反射惯性降低了功耗和声学噪声。
