The Terrestrial Locomotion Comparation Of Insects With Full Legs And With Legs Amputation

Animals have strong ability to adapt to the environment. They also can adjust locomotion behavior quickly to achieve rapid and stable movement when they are disabled. We observed that insects still can achieve a stable movement by adjusting the motion gait and the ground reaction forces(GRFs) of each leg when they lost one or two legs. The research of comparation of insects with full legs and with legs amputation can provide the design methods and bascical theory for robots when their feet are disabled. High-speed video camera was used to record the locomotion behavior of disabled stinkbugs. Animal reaction force measurement system which was invented ourselves was used to measure locomotion mechanics counterforce of each foot and record locomotion behavior of disabled grasshoppers.We analyzed locomotion gait of stinkbugs with all legs, one leg amputation and two legs amputation, respectively. We analyzed the gait parameters of disabled stinkbugs, such as location point of each foot, the gait sequence as well as its phase shift, the trajectory of each foot, period, velocity, single foot span and length of a typical step. Insects could move stablely with two units-gait when they are sound; they could also move relatively stablely with three units-gait when their one leg was amputated; however, they could't move stablely with four units-gait when their two legs were amputated.We analyzed GRFs of grasshoppers with all legs, one leg amputation and two legs amputation, respectively. We analyzed the GRFs parameters of disabled grasshoppers. The GRFs of two fore legs were the least and the GRFs of two middle legs were the largest when the insects were healthy. The disabled insects could reach a new stable movement gait by redistributing the GRFs of each leg.Since the insects should maintain the stability and efficiency movement gait, the parameter data of motion behavior and the GRFs of 12 kinds of disabled states are different. In order to achieve a new balance, all the healthy legs coordinate the location point and movement gait, as well as the GRFs.