Optimal Force Distribution for Compliance Control of Multi-legged Walking Robots

다각 보행로보트의 순응 제어를 위한 힘의 최적 분배

Force and compliance control has been used in the control of legged walking vehicles to achieve superior terrain adaptability on rough terrains. The compliance control requires distribution of the vehicle load over the supporting legs. However, the constraint equations for ground reaction forces of supporting legs are generally underdetermined, allowing an infinite number of solutions. Thus, it is possible to apply an optimization criteria in solving the force setpoint problem. It has been observed that the previous force setpoint optimization methods sometimes cause a system stability problem and/or the load distribution among supporting legs is not well balanced due to a memory effect on the solution trajectory, This paper presents an iterative force setpoint method to solve this problem using an interpolation technique. By simulation it was shown that an excessive load unbalance among supporting legs and the memory effect in the force trajectory are alleviated much with the proposed method.