Design And Experiment Of Frog-inspired Soft Jumping Robot Driven By Combustion

The jumping robot has the potential to perform tasks in complex terrain with its excellent barrier-crossing ability,and has a broad application prospect.Jumping is one of the typical forms of frog movement on land,and it is important to analyze the mechanism of frog jumping and develop a frog-like jumping robot.Most of the current frog-like jumping robots use electric motors or pneumatic muscles to directly drive jumping or store energy for jumping motion,which leads to a complex structure and large mass of the robot,making it difficult to achieve a design that is close to the size of the frog and can jump flexibly.In this paper,a high energy density combustion soft body actuator is selected as the driving method to design a continuous jumping frog-like soft body jumping robot with strong motion capability.This paper firstly analyzes the physiological structure and jumping gait mechanism of the frog,simplifies the structural model of the frog based on the combustion and explosion drive method,analyzes the jumping center of mass trajectory based on the SLIP model,and conducts Python simulation.Based on this simplified model,the structural design of the frog-like soft body jumping robot was carried out,including the design of the forelimb linkage joint applied to the forelimb of the robot,the hindlimb with the soft body actuator as the main body of the combustion explosion drive,the gas dosing transmission device,and the model of the whole machine.The forelimb linkage joint imitates the forelimb of the frog and plays the role of adjusting the jumping angle and landing cushion of the robot.As the "muscle" of the robot,the soft actuator is the energy supply unit for the jumping motion,and the expansion of the hind limb during the combustion explosion drive pushes the hind limb to extend and transmit the combustion explosion drive force to the ground.The kinematics and dynamics of the designed frog-like soft jumping robot were analyzed,mainly the position,velocity,and acceleration changes of the center of mass,forelimbs and hindlimbs of the robot during the jumping phase,soaring phase and landing phase.The kinetic equations of the robot were established based on the La Grange model,and the validity of the established kinetic model was verified by using Adams dynamics simulation software.The kinetic equations were then used to analyze the motion parameters such as jump direction,velocity,and angular velocity under different initial postures.The soft body actuator,which provides energy to the robot,is calculated based on the Yeah intrinsic model,and the process of combustion and explosion deformation of the soft body actuator is simulated in the Ansys simulation software.To achieve the goals of stable continuous jumping and obstacle crossing of the robot during the jumping process.The improved particle swarm optimization trajectory planning algorithm is used to calculate the jump height and jump distance required for this jumping over the obstacle in the offline situation with the goal of weight optimization.Finally,a frog-like soft body jumping robot system was built,and the effects of the air volume and jumping angle of the linear soft body actuator on the jumping performance of the robot were carried out under this structure,and the applicability of the jumping over obstacles algorithm was verified.The single jumping distance of the robot is 140 cm and the height is 60 cm,and the robot can achieve continuous jumping and barrier crossing.