Taking inspiration from the natural gait transition mechanism of quadrupeds, devising a good gait transition strategy is important for quadruped robots to achieve energy-efficient locomotion on various terrains and velocities. While previous studies have recognized that gait patterns linked to velocities impact two key factors, the Cost of Transport (CoT) and the stability of robot locomotion, only a limited number of studies have effectively combined these factors to design a mechanism that ensures both efficiency and stability in quadruped robot locomotion. In this paper, we propose a multi-gait selection and transition strategy to achieve stable and efficient locomotion across different terrains. Our strategy starts by establishing a gait mapping considering both CoT and locomotion stability to guide the gait selection process during locomotion. Then, we achieve gait switching in time by introducing affine transformations for gait parameters and a designed finite state machine to build the switching order. Comprehensive experiments have been conducted on using our strategy with changing terrains and velocities, and the results indicate that our proposed strategy outperforms baseline methods in achieving simultaneous efficiency in locomotion by considering CoT and stability.

翻译：受四足动物自然步态转换机制的启发，设计良好的步态转换策略对于四足机器人在不同地形和速度下实现节能运动至关重要。虽然先前研究已认识到与速度相关的步态模式会影响运输成本（CoT）和机器人运动稳定性这两个关键因素，但仅有有限的研究有效结合了这些因素来设计一种能同时确保四足机器人运动效率与稳定性的机制。本文提出一种多步态选择与转换策略，以实现跨不同地形的稳定高效运动。我们的策略首先建立一个同时考虑CoT与运动稳定性的步态映射，用以指导运动过程中的步态选择。随后，通过引入步态参数的仿射变换及设计的有限状态机来构建转换顺序，从而实现时序上的步态切换。我们在变化地形与速度条件下使用本策略进行了全面实验，结果表明，通过综合考虑CoT与稳定性，所提出的策略在实现运动效率方面优于基线方法。