Imitation Kangaroo Robot Flexible Jump Institutions Kinetic Analysis

The kangaroo has the characters of moving fast, stable, little landing area and low consume. So the study of the kangaroo hopping robot can be used in outer space explore, military affairs, antiterrorism activity, etc. Making the compliance hopping model according with the kangaroos' kinematics and doing research to model's dynamics have become the pre-requisite and key problem for making the hopping kangaroo robot.First of all, on the base of referring dozens of references of bionic robotics' motion stability home and abroad, this paper summarized the basic theory of the research on the hopping robot. The whole process of the spring and two-mass model of hopping kangaroo robot was analyzed. The one-legged hopping model's problems about turning over and impact were considered. We also make it clear that which type of the hopping robot is better.Next, the one-legged model of a hopping kangaroo robot, which includes joints leg and conpliance foot, is designed based on kangaroos' structure and hopping characteristics. Kinematics and dynamics equations of the model during the stance phase and the flight phase are established by the lagrange method. Calculation and analysis were done, the curves of kinematics and dynamics were obtained using Matlab 6.5. Computer simulation shows that the take-off time becomes longer and takes 2/3 of the whole process;the vertical ground reaction force achieves max when the length of the compliant foot contacting with ground reaches max;the inputting ankle torque is about 6~8 bigger than that of the hip. The research will be the foundations for the machine design and the accurate control of the hopping kangaroo robot.The flexible cantilever model denoting the kangaroo's foot was established. The cantilever's small distortion and large distortion because of the ankle force or torque were studied. The location of ankle joint and the formula to conclude the maximal ground force were obtained using elliptic integral method, and the simulation was carried out, which shows the validity of the method.Finally, the spring-mass model including power was analyzed. The nondimensional transaction was carried to the dynamics equation of the model. Theexpression of calculating the optimal landing angel was deduced so as to low the lossof energy.The research of this paper will be the foundations for the machine design and the further research of the kangaroo hopping robot, and the datum will be important for the next research.