Contact Force Optimization to Enhance Fault-tolerant Motion Stability of a Hexapod Robot

This paper presents a novel method for optimizing the contact force of a hexapod robot to enhance its dynamic motion stability when one of its legs fails. The proposed approach aims to improve the Force Angle Stability Margin (FASM) and adapt the foot trajectory through contact force optimization to achieve safe and stable motion on various terrains. The foot force optimization approach is designed to optimize the FASM, a factor rarely considered in existing contact force optimization methods. By formulating the problem of enhancing the motion stability of the hexapod robot as a Quadratic Programming (QP) optimization problem, this approach can effectively address this issue. Simulations of a hexapod robot using a fault-tolerant gait, along with real field experiments, were conducted to validate the effectiveness and feasibility of the contact force optimization approach. The results demonstrate that this approach can be used to design a motion controller for a hexapod robot with a significantly improved motion stability. In summary, the proposed contact force optimization method offers a promising solution for enhancing the motion stability of hexapod robots with single leg failures and has the potential to significantly advance the development of fault-tolerant hexapod robots for various applications.