Adaptive speed controller using swing leg motion for 3-D limit-cycle-based bipedal gait
Adaptive speed controller using swing leg motion for 3-D limit-cycle-based bipedal gait
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DOI：
10.1007/s11071-016-2645-0
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发表时间：
2016-02
影响因子：
5.6
通讯作者：
Taisuke Kobayashi;T. Aoyama;Y. Hasegawa;K. Sekiyama;T. Fukuda
中科院分区：
文献类型：
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作者：
Taisuke Kobayashi;T. Aoyama;Y. Hasegawa;K. Sekiyama;T. Fukuda
本文提出了一种基于极限环的三维双足步态自适应速度控制器（ASC）。双足机器人基于极限环的步态具有很好的能效。然而，这些机器人的前进和侧向移动速度很难控制，因为它们是自主系统，它们的行为取决于每一步的初始状态。因此，在本研究中，我们设计了一个摆动腿的动作，以适当地调整每一步的初始状态。首先，通过注入摆腿的动量来控制前进速度，将一个能量平衡点从原点移动到达到参考前进速度的参考点。其次，侧身速度由左右腿的非对称触地位置控制，将每条腿的极限环分离为两个不同的极限环，这种分离导致侧身运动。由于所提出的ASC不依赖于步态模型的动力学特性，可以很容易地应用于任意基于极限环的步态。在两个步行示例的数值模拟中，从残差、阶跃响应和干扰抑制能力方面验证了所提出的ASC的性能。提出的ASC还实现了高能效的步态，这与分析结果一致。此外，拟议的ASC可以使机器人适应各种环境，包括上下斜坡或障碍物。
In this paper, we propose an adaptive speed controller (ASC) for a limit-cycle-based gait classified as a three-dimensional (3-D) bipedal gait. The limit-cycle-based gait of bipedal robots is excellent for energy efficiency. However, the forward and sideward moving speeds of these robots are difficult to control since they are autonomous systems and their behavior depends upon the initial states of every step. Therefore, in this study, we design a swing leg motion to appropriately adjust the initial states of every step. First, the forward speed is controlled by injecting the momentum of the swing leg, which shifts an energy equilibrium point from the original point to the reference point where the reference forward speed is achieved. Second, the sideward speed is controlled by asymmetric touchdown positions on the right and the left legs, which separate the limit cycle into two different limit cycles for each leg, and this separation leads to the sideward motion. The proposed ASC can be easily applied to an arbitrary limit-cycle-based gait because it is independent of the dynamics of the gait model. The performance of the proposed ASC was validated in terms of the residual error, step response, and disturbance rejection capabilities in numerical simulations for two examples of walking. The proposed ASC also achieved a highly energy-efficient gait, which was consistent with the analytical results. Further, the proposed ASC could adapt a robot to various environments that contained up and down slopes or an obstacle.