Task space trajectory tracking for quadruped robots plays a crucial role on achieving dexterous maneuvers in unstructured environments. To fulfill the control objective, the robot should apply forces through the contact of the legs with the supporting surface, while maintaining its stability and controllability. In order to ensure the operation of the robot under these conditions, one has to account for the possibility of unstable contact of the legs that arises when the robot operates on partially or globally slippery terrains. In this work, we propose an adaptive trajectory tracking controller for quadruped robots, which involves two prioritized layers of adaptation for avoiding possible slippage of one or multiple legs. The adaptive framework is evaluated through simulations and validated through experiments.

翻译：四足机器人的任务空间轨迹跟踪在非结构化环境中实现灵巧操作起着关键作用。为了实现控制目标，机器人应通过腿与支撑表面的接触施加力，同时保持其稳定性和可控性。为了确保机器人在这些条件下的操作，必须考虑腿部可能不稳定接触的可能性，尤其是当机器人在部分或全局湿滑地形上操作时。在本研究中，我们提出了一种四足机器人的自适应轨迹跟踪控制器，其中涉及两个自适应优先级层，以避免可能发生的一个或多个腿的滑动。我们通过模拟评估了自适应框架，并通过实验证实了其有效性。