Research On The Motion Of Quadruped Robot Based On Virtual Model Control Method

Legged robots have better obstacle striding ability than wheeled and crawler robots.With the potential value in military field and civilian applications,quadruped robots have become a hotspot research field all over the word.Better adaptability in rough terrain is the general trend of the future development of quadruped robots.In reasonable motion control method could not only ensure the smooth movement of the quadruped robot in the rough terrain but also improve the movement efficiency.Although there have been some breakthroughs in the field of motion control,but there are still problems that uncoordinated and low antiinterference ability when the robot walk on rugged terrain.Therefore,the quadruped robot based on the virtual model control method is research and analysis to further improve the terrain adaptability and stability of the robot in this article,the main research obtained are as follows:Structural design and kinematic analysis of quadruped robots.The size and mass distribution of each part of the robot are designed on the presumption of movement agility and smooth movement.The kinematics and inverse kinematics of the joint of the robot’s movements are analyzed.According to the control characteristics of the virtual model control method,the control scheme of the torque which drive joint is designed.The feasibility of the drive scheme is verified by building a drive controller model in matlab/simulink simulation environment.Quadruped robot foot trajectory planning.The movement mode of walk gait and trot gait and the characteristics of them are analyzed and introduced.The quadruped robot with trot gait movement is selected as the research object.The trajectory planning method of robots on flat and rough terrain is studied,the collision that may occur when the robot crosses is analyzed.In the simulation environment of matlab/simulink and Adams,the proposed foot trajectory planning and the fifth-order polynomial trajectory planning of the robot are compared and analyzed through the motion data of complex obstacle terrain,this foot trajectory planning method has better terrain adaptability is proved.Motion analysis and improvement based on virtual model control method.The application of the previous virtual model control method on quadruped robots is analyzed.On this basis,the whole control of the robot is divided into two parts: foot movement control and body motion state control.The foot motion control is achieved by virtual model control.However,in order to avoid the problem which is distribution of virtual force control the robot’s leg,control of the robot support phase selects the method of tracking the trajectory of the foot.The body motion state control of the robot is achieved by model predictive control.By analyzing the impact of the robot on the attitude change and making the body dynamics estimate,and model predictive control methods to adjust the state of the body.Finally,the movement performance of the control method has been improvd and before are compared by the simulation environment.Simulation analysis of the passability of quadruped robots in common terrain.In a simulation environment with matlab/simulink and Adams,the robot is moved on a 15° ramp and a 20° staircase with the designed foot trajectory and the control method base on virtual model controls is improved,the data shows that the quadruped robot could move smoothly and maintain a certain accuracy of the direction.