Research On Jumping Robot Based On Skeletal Structure Of The Frog

The research on biomimetic jumping robot is a forward positional task in robot field, jumping robots can be widely applied in interstellar probe, antiterrorism and resource exploration. Compared to walking robots and wheeled robots, jumping robots own excellent feature ability on adjust to different ground and getting across cannel and obstacle. Therefore, it is very important for the research of jumping robots. Because frog’s jumping movement has the characteristic of strong burst and long distance, this paper selects frog as study target to do research on frog-like jumping robot.Firstly, this paper studies the characteristics of the frog’s biological musculoskeletal structure and the jumping performance to establish the model of the musculoskeletal structure that can describe the characteristics of frog biological movement completely. According to the different factors those affect the frog jumping movement, the paper simplify frog’s complex joint and skeleton structure to four different jumping structure models. By using ADAMS simulation software to analyze comparatively the ground reaction force, speed and displacement of the center of mass and joint’s torque of the four models, the optimum structure model of the comprehensive index is determined that can provide a reference of the design of the robot.Secondly, based on the optimal structure model, the whole mechanical structure of the frog-inspired hopping robot is designed. The robot’s forelimb is simplified as one active shoulder joint and one passive elbow joint for the function of supporting and stance adjusting, and the steering gears are used to control joints. The hind limb has hip, knee, ankle and tarsometatarsal joints. Because of high power density, the pneumatic muscles are chosen as drives between each joint. High-speed on-off valve is adopted to control pneumatic muscles, effectively reducing the weight of the robot. The layout of the robot’s structure is reasonable and the quality of the robot mainly concentrates on the hind limb and torso, and this is helpful to improve the efficiency of energy conversion.Third, the paper analyzes the kinematics of the robot in the jumping process with D-H matrix and establish the kinematics equations of the take-off phase and flight phase to get the analytical solutions of the direct and inverse kinematics equations of the forelimb and hind limb. Base on the analytical solutions, the paper analyzes the working space of the bottom of the robotic limbs in the flight phase by using MATLAB software.Finally, the paper sets up an experimental platform for frog-inspired hopping robot. The platform is used to finish the experiment of the take-off adjustment and the physical prototype robot. According to the analysis and comparison of the dates of the experiment and theoretical analysis. The physical prototype experiment dates verify the rationality of the simplified model of frog skeletal structure, the design of the robot’s structure and the correctness of the theoretical analysis method.