Combined use of ground learning model and active compliance to the motion control of walking robotic legs

The foot force/position adjustment method, the hybrid ground-learning model and active compliance force control method (or hybrid GLAC method), is introduced. The proposed method combines the active compliance force control with a ground-learning model for controlling the leg motion of the robot. The ground model reflects the relationship between the leg-end force and the sinkage. To verify the control quality of the proposed method together with the active compliance (AC) control and ground learning model control, experiments based on a robotic leg have been carried out on hard and soft terrain, respectively. The results show that the proposed method can ensure the actual leg-end force to follow closely the changing of reference forces both on hard and soft terrain. Therefore, by using the hybrid GLAC control, the error of the actual forces relative to the reference forces can be reduced more quickly than by using the AC method alone.