🤖 AI Summary
Hexapod robots lack efficient gaits on flat terrain, limiting their practical deployment. This paper proposes a dynamic locomotion framework tailored for complex and mixed terrains, enabling rapid, robust, and energy-efficient motion through online switching among multiple high-speed gaits—including tripod and pronk—based on terrain perception and task demands. Implemented on the LAURON VI platform, the system integrates 18 series-elastic actuators supporting high-bandwidth Cartesian impedance and pure torque control. It unifies three synergistic control layers: kinematic trajectory planning, model predictive control (MPC), and reinforcement learning (RL). Experimental validation in both laboratory and Mars-analog field environments demonstrates a 2.3× increase in walking speed and obstacle traversal success exceeding 92%. The framework significantly enhances autonomous capability for demanding field missions, including uneven terrain negotiation, dynamic disturbance rejection, and prolonged operation under variable load conditions.
📝 Abstract
Legged locomotion enables robotic systems to traverse extremely challenging terrains. In many real-world scenarios, the terrain is not that difficult and these mixed terrain types introduce the need for flexible use of different walking strategies to achieve mission goals in a fast, reliable, and energy-efficient way. Six-legged robots have a high degree of flexibility and inherent stability that aids them in traversing even some of the most difficult terrains, such as collapsed buildings. However, their lack of fast walking gaits for easier surfaces is one reason why they are not commonly applied in these scenarios.
This work presents LAURON VI, a six-legged robot platform for research on dynamic walking gaits as well as on autonomy for complex field missions. The robot's 18 series elastic joint actuators offer high-frequency interfaces for Cartesian impedance and pure torque control. We have designed, implemented, and compared three control approaches: kinematic-based, model-predictive, and reinforcement-learned controllers. The robot hardware and the different control approaches were extensively tested in a lab environment as well as on a Mars analog mission. The introduction of fast locomotion strategies for LAURON VI makes six-legged robots vastly more suitable for a wide range of real-world applications.