Control of a Hexapod Robot Considering Terrain Interaction

Abstract

Bioinspired walking hexapod robots are a relatively young branch of robotics. Despite the high degree of flexibility and adaptability derived from their redundant design, open-source implementations do not fully utilize this potential. This paper proposes an exhaustive description of a hexapod robot-specific control architecture based on open-source code that allows for complete control over a robot’s speed, body orientation, and walk gait type. Furthermore, terrain interaction is deeply investigated, leading to the development of a terrain-adapting control algorithm that allows the robot to react swiftly to the terrain shape and asperities, such as non-linearities and non-continuity within the workspace. For this purpose, a dynamic model derived from interpreting the hexapod movement is presented and validated through a Matlab SimMechanicsTM simulation. Furthermore, a feedback control system is developed, which is able to recognize leg–terrain touch and react accordingly to ensure movement stability. Finally, the results from an experimental campaign based on the PhantomX AX Metal Hexapod Mark II robotic platform by Trossen RoboticsTM are reported.

Keywords

• hexapod robot
• terrain interaction
• locomotion control
• dynamic model