Research On Gait And Leg Control Method For High Speed Running Quadruped Robot

China has a vast territory,covers an area of 9.6 million square kilometers,most of which are mountainous,gully,sand and other complex terrain.Due to the limitations of traditional wheeled and tracked mobile tools,transportation,exploration,investigation,patrol and other tasks need to be completed by workers on foot in complex environment.In the movement process of bionic quadruped robot,it only needs some discrete support points to realize the walking and climbing in complex environment.Its flexibility is much higher than that of traditional mobile robot.After installing manipulator and other operating equipment,it can complete complex and dangerous work instead of human,and has incomparable advantages.Moving speed is an important performance index of quadruped robot.High speed and stable walking can greatly improve the efficiency of the robot,and in some specific tasks,"high speed" is the key to successfully complete the task.After hundreds of millions of years of evolution,there are many powerful quadruped mammals in the biological world,such as cheetah,horse and so on.The most effective way to realize the fast running of robot is to use the power of nature to study the bionics of animals with strong running ability in the biological world,analyze the gait selection criteria under different speeds,and design simple and effective gait control strategy,which is the key to realize the fast running of robot.The robot's excellent top control strategy also needs the bottom control to support it.Leg swing and force servo control are particularly important in high-speed running,and a little carelessness will lead to the failure of running.As one of the key disturbances,the dynamics of the robot's own legs will greatly improve the control effect of the motion if it can be compensated.To realize the running gait control of robot and improve the leg motion control performance of high-speed quadruped robot,this paper focuses on the following work:(1)This paper analyzes the gait of mammals,starting from the study of high-speed running gait,simplifies the dynamics model of mammals,deduces the dynamics model of double flying phase Bound gait and Rotary gallop gait,and analyzes the principle of running motion.This paper introduces the leg mechanical structure and driving elements of highspeed quadruped robot,and deduces kinematics and statics in the polar coordinate system.(2)Based on the analysis of gait dynamics and the "three-way" control idea of SLIP model,the running control strategy of double flying phase Bound gait gait is designed.The D-SLIP model with two touchdown legs is obtained by optimizing the SLIP model.The dynamic characteristics of the D-SLIP model are analyzed,and the motion control strategy of the D-SLIP model is designed.The D-SLIP model is applied to the gait motion control as the unilateral leg mechanism model of rotational gallop gait.Four groups of ADAMS virtual prototypes including SLIP model,D-SLIP model,double flying phase Bound gait,Rotary gallop gait and MATLAB / Simulink control system are built to verify the control strategy.(3)This paper analyzes the motion characteristics of the leg mechanical structure and deduces the leg dynamics.Combined with the forward and inverse kinematics and statics of the robot leg,the implementation method of force-based impedance control in the highspeed running robot leg is designed,the control block diagram based on force-based impedance is built,and the specific control process is described.Finally,the dynamics compensation is introduced into the robot leg based force impedance control system to optimize the robot leg control system and improve the control accuracy.The robot leg can play the role of "spring leg",buffer the collision in the running movement,and store and release the energy of the motion system.(4)The existing high-speed robot prototype,control system and running platform are introduced.The experiment of swing leg,bounce-drop are carried out.The experimental results show that the robot prototype has good motion control performance.Finally,the double flying phase Bound gait control method is introduced to carry out the running control experiment with high-speed gait.The experimental results show that the performance of high-speed robot is excellent,and the running control method is correct and feasible.