Research On Bionic Biped Robot Based On Biomechanical Principle Of Ankle Push-Off

Humanoid robots refer to intelligent robots that are similar in appearance and function to humans,and have a certain degree of movement,perception,learning,and emotional communication.This is a highly difficult research direction that integrates mechatronics,computer science,artificial intelligence,sensing and drive technology and other disciplines.It is also one of the challenging problems in the current research on bionic robotics.The research of humanoid robots not only has broad application prospects in education,medical care,special operations and other fields,but also can promote the development of bionics,artificial intelligence,computer science,material science and other related disciplines.Therefore,it has important research value and profound scientific significance.With the unceasing improvement of the research level,the performance in terms of walking speed and energy efficiency of biped robots have been improved,there is still a big gap between its comprehensive performance and the efficient and dynamic walking of human beings,which also limits its further application.Human beings can achieve different walking gaits with low energy consumption,and can still maintain stability in the case of large external interference,thus providing a natural learning blueprint for improving the comprehensive performance of biped robots.The output power of the ankle push-off accounts for more than 80% of the total power consumed by the body's center of mass(Co M)during walking.At present,most robots are mainly use hip and knee joints as power sources.Therefore,the output of hip and joints is higher,and the output power of the ankle joint is lower.As a result,the important role of ankle joint has not been studied deeply in biped robots.Aiming at the key problem that the current biped robot does not make full use of the ankle push-off to achieve efficient walking gait,an electric hybrid planar biped robot with ankle push-off function is developed,and the ankle push-off torque is studied using MATLAB/Simulink.With the influence of the timing of push-off on the walking speed and energy efficiency of the biped robot,the control system of the biped robot was built and its ankle push-off performance was tested.Based on the genetic algorithm,the optimal speed and energy efficiency of the biped robot were obtained.The parameters of the ankle push-off torque curve.The main findings are as follows:(1)The structure design and control system construction of the biped robot.Based on the biomechanics of the human ankle joint,an electric hybrid planar biped robot with ankle push-off function is designed,and an auxiliary platform and the corresponding joint servo control system are built.The hip joint and the knee joint adopts the motor drivie mode,and the ankle joint adopts a double-acting cylinder drive mode.The joint servo control system mainly uses the data acquisition card to realize data collection and control command transmission between the control layer,drive layer,actuator layer and sensing layer.(2)Simulation analysis of ankle push-off of the biped robot.The influence of step length and ankle push-off combination(the torque and timing of ankle push-off)on the walking speed and energy efficiency of the biped robot was studied using MATLAB/Simulink.The results show that in the case of the fixed push-off height and the inter-leg angles(that is step length)of 40°,50° and 60°,the walking speed of the robot increases with the increase of the ankle push-off torque.With the increase of ankle push-off torque,the trend of energy consumption is relatively stable.In order to obtain a highly economical walking gait,the torque and the height of ankle push-off need to cooperate with each other.The simulation results show that when the step length is 50°,the ankle push-off torque is 30 N·m,the ankle push-off height is 20 cm,the economic efficiency of the simulated biped robot gait is the highest and has good human-like dynamic characteristics.(3)Analysis of the effectiveness of control system and movement coordination of the biped robot.The control program of the biped robot was built using MATLAB/Simulink and real-time communication was realized in the external mode.The trajectory of the hip and knee joints of the biped robot was planned using the trajectory generation method with a linear function with parabolic transition.The finite state machine was established to control the movement of ankle joint.The solenoid valve control commands of the cylinders that control the ankle joint motion under three push-off angles were obtained.The motion coordination of the bipedal robot was debugged and the results show that the biped robot can effectively track the planned trajectory and the ankle joints have obvious push-off actions.(4)The walking testing of physical prototype of the biped robot using ankle push-off.The auxiliary platform of the electric hybrid planar biped robot was built.The lifting device was installed to facilitate the landing and debugging of the robot,and the robot dynamics model and the control system block diagram of the entire biped robot were established.The communication interruption during the debugging process,the unstable structure of the auxiliary arm,and the difficulty of the plantar module to feedback the foot-ground contact signal were solved.Finally,the suitable ankle push-off combination was obtained so that the electric hybrid planar biped robot can walk normally.The joint motion of the biped robot and the power curve of the ankle joint during push-off phase were analyzed.(5)The optimization analysis of the torque curve of ankle push-off on the bionic biped robot.The controller model of the biped robot was built in MATLAB/Simulink.Based on genetic algorithm,with walking distance and energy consumption as objective functions,the optimal torque curve of ankle push-off parameters were obtained.When the parameter combinations are P=[8,2,8,15°,53°] and P=[4,8,6,15°,55°],the walking distance of the biped robot is the longest 38.68 m,and the energy consumption is the lowest 0.7.A comparative analysispush-off torque and ankle push-off power were explored under different walking speeds.In addition,the influence of the amount and timing of ankle push-off on the walking speed and energy efficiency of humanoid biped robots were studied.