Energy Consumption Characteristics Of Plantar Bionic Legs Based On Squirrel Jumping

Foot mammals show strong adaptability,can adapt to a variety of complex unstructured environment,and have great advantages in speed,flexibility,stability,control difficulty and so on.It has become a hot research object in the field of bionic robot.Due to its own motion characteristics,jumping robot can easily cross obstacles several times its own size,and has super ability to cross obstacles.It is an effective research object to solve many problems in the application of bionic robot.The hind leg of grey squirrel was selected as the bionic sample,and the curve of joint angle changing with jumping time was fitted based on its joint biological parameters.According to its physiological structure,the hind leg model was simplified and the equivalent analysis model was established.The cycle jumping process of bionic jumping leg is divided into several stages,and the gait model of continuous cycle is established.The mapping relationship between hind leg model and slip model and three-dimensional croe model of bionic jumping hind leg are established.The kinematics equation and Jacobian matrix of the model are established.The simulation verification is carried out according to the curve of hip joint displacement and speed changing with time.The symmetrical jumping gait of the bionic squirrel robot is analyzed,and the sole with rotational toe joint is simplified.The difference of the centroid position of different models in jumping is compared.The constraint conditions of the hind legs in the clearance and continuity of take-off and landing are analyzed,and the constraint equations of the friction and reaction of the sole take-off and landing are determined.The energy consumption formula of the swing phase and support phase of the bionic squirrel's hind leg is given.The energy consumption correlation curve of the cycle jump process is generated by calculation and MATLAB image processing,and the reasons affecting the energy consumption are analyzed and the best parameters are obtained.The research model of driving joint is established and the dynamic model is listed.By optimizing the output trajectory of driving leg end to compound cycloid trajectory,the energy consumption ratio model based on driving elastic joint is obtained.Select the driving motor and the target bar for local simulation,find the best stiffness coefficient through the output performance of acceleration and deceleration stage,compare with the theoretical optimal stiffness coefficient calculated previously,judge that the proposed theoretical model is in line with the expected conjecture,get the improvement degree of the energy consumption of the elastic system on the driving joint,and finally modify the stiffness coefficient value.Adams is used to simulate and analyze the whole hind leg,and the stiffness coefficient of toe joint with the lowest energy consumption is found through data processing.The change of the center of mass of the simulation model in the process of jumping is verified,and the regulating effect of the rotational toe joint on the jumping gait is obtained through the trajectory of the hind leg and the trajectory of the center of mass of the sole.Based on the energy consumption model in Chapter 3,the secondary simulation is carried out to study the change of energy consumption under the conditions of variable stiffness coefficient and variable take-off speed,respectively The optimal parameters affecting the energy consumption are determined.