In this paper, we propose standing and stepping control with switching rules based on angular momentum around the ankle for planar bipedal robots. A theoretical analysis under some approximation and mass distribution conditions shows that the proposed standing control maximizes stable regions. We can then classify the state of robots into the following three categories: (1) stabilizable via ankle torque; (2) unstabilizable only via ankle torque and stabilizable via ankle torque and trunk posture control; and (3) unstabilizable via ankle torque and trunk posture control. This criterion enables switching rules to appropriately switch robot control to balance control via ankle torque, balance control via ankle torque and trunk posture control, or stepping control. The proposed method is applicable to robots without feet. Simulation results demonstrate that the proposed method appropriately switches control according to the amplitudes of disturbances and maintains the balance of robots with and without feet.

中文翻译：

---

基于绕踝角动量的双足机器人站立和跨步切换规则控制

在本文中，我们提出了基于脚踝周围角动量的切换规则的站立和步进控制，用于平面双足机器人。在一些近似和质量分布条件下的理论分析表明，所提出的站立控制最大化稳定区域。然后我们可以将机器人的状态分为以下三类：（1）通过脚踝扭矩稳定；(2) 仅通过脚踝扭矩不稳定，通过脚踝扭矩和躯干姿势控制稳定；(3) 通过脚踝扭矩和躯干姿势控制不稳定。该标准使切换规则能够将机器人控制适当地切换为通过脚踝扭矩的平衡控制、通过脚踝扭矩和躯干姿势控制的平衡控制或步进控制。所提出的方法适用于没有脚的机器人。