Robust Dynamic Walking for a 3D Dual-SLIP Model under One-Step Unilateral Stiffness Perturbations: Towards Bipedal Locomotion over Compliant Terrain
Robust Dynamic Walking for a 3D Dual-SLIP Model under One-Step Unilateral Stiffness Perturbations: Towards Bipedal Locomotion over Compliant Terrain
复制标题
DOI：
10.48550/arxiv.2203.07471
复制
发表时间：
2022-03
期刊：
影响因子：
--
通讯作者：
Chrysostomos Karakasis;I. Poulakakis;P. Artemiadis
中科院分区：
文献类型：
--
作者：
Chrysostomos Karakasis;I. Poulakakis;P. Artemiadis
双足行走是人类最重要的特征之一，几十年来机器人一直试图模仿人类。虽然以前的控制方法已经实现了机器人在一些地形上行走，但需要一个框架，允许在广泛的柔性表面上稳定而稳健的运动。这项工作提出了一种新的生物力学启发的控制器，可以调节腿部的刚度，以支持在柔顺地形上稳健和动态的两足运动。首先，扩展了3D Dual-SLIP模型，首次支持在具有可变刚度和阻尼参数的柔性表面上的运动。然后，将所提出的控制器与线性二次型调节器（LQR）控制器在软地形上的鲁棒性进行了比较。结果表明，LQR控制器仅在200 kN/m的中等地面刚度水平下具有鲁棒性，而在较低的刚度水平下则失效。相反，所提出的控制器可以在低至30 kN/m的刚度水平下产生稳定的步态，这导致腿的垂直地面穿透深度超过其静止长度的10%。所提出的框架可以促进两足行走领域，通过生成稳定的行走轨迹，为广泛的柔性地形对两足动物和类人动物的控制有用，以及通过改进具有可调刚度的假肢装置控制器。
Bipedal walking is one of the most important hallmarks of human that robots have been trying to mimic for many decades. Although previous control methodologies have achieved robot walking on some terrains, there is a need for a framework allowing stable and robust locomotion over a wide range of compliant surfaces. This work proposes a novel biomechanics-inspired controller that adjusts the stiffness of the legs in support for robust and dynamic bipedal locomotion over compliant terrains. First, the 3D Dual-SLIP model is extended to support for the first time locomotion over compliant surfaces with variable stiffness and damping parameters. Then, the proposed controller is compared to a Linear-Quadratic Regulator (LQR) controller, in terms of robustness on stepping on soft terrain. The LQR controller is shown to be robust only up to a moderate ground stiffness level of 200 kN/m, while it fails in lower stiffness levels. On the contrary, the proposed controller can produce stable gait in stiffness levels as low as 30 kN/m, which results in a vertical ground penetration of the leg that is deeper than 10% of its rest length. The proposed framework could advance the field of bipedal walking, by generating stable walking trajectories for a wide range of compliant terrains useful for the control of bipeds and humanoids, as well as by improving controllers for prosthetic devices with tunable stiffness.