Legged robots demand to keep the balance under required durations when performing standing and locomotion. It may be a challenge for legged robots to maintain balance during standing without actuation from ankle joints and involvement of support polygon plane to estimate the center of mass (CoM). In order to maintain the standing balance of legged robots under such a scenario, we propose a virtual suspension model control (VSMC) method which is concise and can get rid of updating model iterations on sophisticated dynamics. Furthermore, we optimize the range and propose the criteria for the virtual height of the CoM for quickly adjusting parameters and adapting to task characteristics. Simulation experiments on balance keeping are performed for single-leg robot vertical standing, quadruped robot diagonal standing and biped robot parallel standing cases, and the proposed method can achieve promising results within the approximative real setting condition that demonstrate the feasibility and strong anti-interference ability of the VSMC approach.

腿式机器人在站立和运动时要求保持平衡在规定的持续时间内。对于有腿的机器人来说，在站立过程中保持平衡而没有脚踝关节致动和支撑多边形平面的介入以估计质心（CoM）可能是一个挑战。为了在这种情况下保持腿式机器人的站立平衡，我们提出了一种虚拟悬浮模型控制（VSMC）方法，该方法简洁明了，可以摆脱在复杂动力学上更新模型迭代的问题。此外，我们优化范围并提出CoM虚拟高度的标准，以快速调整参数并适应任务特征。针对单腿机器人垂直站立进行了保持平衡的仿真实验，