Walking mechanism and simulation of cattle-like robot on soft ground

The walking procedure of the cattle, Bostaurus, on a paddy field before spring plowing was captured with a high-speed video camera. The properties of the paddy soil used for tests and the geometrical configurations of the hooves of the cattle were examined. The geometrical configurations and motion postures of the cattle during walking on paddy field were analyzed, and the gait parameters were gained from the high-speed photographs. The changes of displacement, velocity, acceleration and force of the centre of mass (COM) of the cattle were analyzed. The changes of the joint angles and the orientations of all limbs were analyzed. It was shown that the changes of hip joint angle and shoulder joint angle were more remarkable, which provided the driving force for the body. The changes of the forelimb were more prominent compared with the hind-limb, moreover, the landing place of the hind-hooves were farther than the fore-hooves, which made the hind-limb have a larger movement space to prevent the interference between forelimb and hind-limb while the strides were increased. The movement of knee joint and elbow joint were very obvious after limb left the ground, the movements of hip joint and shoulder joint were steady to reduce the impact of the ground before limb touched down the ground. The results would provide some theoretical and practical references for biomimetic design for improving the reasonable motion of the walking robot on soft ground. This work may provide the basic theory in developing cattle-like robot in structural design. Besides, it provides an important reference to study the other bionic robots.