Design Of System And Research About Highly Fast Dynamic Gait Planning For Electrically Actuated Quadruped Robots

Leg-footed robot is one of the hot topics in the field of mobile robot.At present,the mainstream driving methods for leg-legged robots are hydraulic and motor.Compared with hydraulic,the quadruped robot driven by motor has the advantages of fast torque response,portability,energy saving and low noise,which has better commercial application value.In recent years,with the rapid development of artificial intelligence and bionics,the control system of legged robot needs to have a high control frequency when it is running in high speed gait,so it is of great significance for the system to have reliable real-time performance.Domestic legged robots have made good achievements,but legged robots run as fast as animals,which has been the goal pursued by researchers.In order to realize high speed running like animals,the application of bionic foot trajectory and high speed moving gait algorithm of leg-legged robot still needs further research.Based on the experimental platform of the electrically driven quadruped robot that the research group is building as the research object,this paper builds the single-legged and four-legged robot models in the open source dynamics software WEBOTS,studies the quadruped robot with high speed motion and bionic characteristics,and carries out the simulation experiment verification and result analysis.In order to achieve the goal of high-speed movement of quadruped bionic robot,this paper studies the electric quadruped robot from three aspects of high real-time control system,bionic foot trajectory and high-speed dynamic step planning.The main research contents are as follows:(1)The mechanical design of the leg of the robot is briefly introduced,and the kinematics and dynamics of the one-legged and four-legged robots are deduced and analyzed.The leg design accords with the characteristics of low inertia and lightness.On the basis of measuring torque with current loop,the leg adopts the collimating drive actuation mode,and realizes the current control of the motor under high bandwidth through the reducer with low transmission ratio.(2)The single-leg control system of the electrically driven quadruped robot is designed,including hardware and software systems.The hardware system takes the embedded IPC as the master station and three joint servo controller as the slave station.The system architecture based on EtherCAT communication adopts QNX system,which enables the electrically driven one-legged robot to complete complex hard real-time tasks.The experimental results show that this control system has an efficient and real-time communication mode and can be extended to the quadruped robot system.(3)A simulation model was established for the single leg of the electrically driven quadruped robot.Based on the compliant control of the virtual model,a high-speed bionic trajectory curve of the foot was planned to meet the requirements of the subject.Verification and analysis of the simulation results show that this method improves the flexibility of the single leg and completes the research on the stability of the forward jump of the single leg.The optimization of the trajectory curve of the bionic foot improves the bionic characteristics when moving at high speed.(4)Based on the bionic foot trajectory proposed in this paper,two kinds of high-speed moving gait control methods are designed.Under the premise of single-leg forward jumping compliant control,two feasible control methods are proposed:high-speed diagonal trot gait control method and galloping running control method.Based on the VMC and QP algorithm,the galloping gait realizes the high speed running performance of the robot.By planning and controlling the ground off state variables and optimizing the trajectory curve of the bionic foot,the quadruped robot has high speed motion performance and good stability of the body.