Design,Analysis And Experiment Of A Six Wheel-legged Robot

With the increasing development of information technology and AI(artificial intelligence)technology,unmanned and informationized have gradually become the trend of future warfare.The development of UGCV(Unmanned Ground Combat Vehicle),which is one of the sea,land and air trinity,has also received more and more attention.The complex and changeable environment of the battlefield puts forward higher requirements for the maneuverability and terrain adaptability of UGCV.Wheel-legged robots have both the high terrain adaptability of the legged structure and the high mobility of the wheeled structure,which has become a direction for UGCV.In this thesis,aiming at the battlefield environment,based on the wheel-leg tandem structure,a mobile robot with the wheel as the main and the leg as the supplement was designed.And the wheel-leg kinematics and compound obstacle crossing were analyzed.Finally,the motion performance of the robot was tested through a series of experiments.The main work of this thesis is as follows:Firstly,the overall design scheme of the wheel-legged robot was determined according to the functional requirements,and detailed structural of the mechanical part of the overall scheme was designed.According to the lizard bone structure and the size ratio relationship,the robot leg motion form,leg layout and the size ratio relationship of every part were determined.Then aiming at the robot chassis system in the scheme,the selection principle of standard parts were analyzed from the wheel structure,guiding system structure,braking system structure,leg structure.In addition,the detailed structure model is shown.Secondly,the wheeled kinematics and the kinematics of the single-leg structure were discussed.In the wheeled kinematics,the forward and inverse analytical relationship between the overall speed of the robot movement and the orientation change and the speed and deflection angle of each wheel was analyzed.Aiming at the characteristics of the hub motor selected that it can be measured but cannot be accurately controlled,the trajectory influenced by unmatched wheel speed was analyzed,which provides a theoretical basis for the control of the robot when the navigation signal is lost.In the aspect of leg,the D-H link method was used to analyze the forward and inverse kinematics of a single leg.The relationship between the rotation angle of joint and the position of the various parts of the leg was established.Furthermore,the gait planning and obstacle crossing performance under compound motion were analyzed.Aiming at the characteristics of the robot leg with only two degrees of freedom,the foot trajectory of the non-slip two-state gait was developed.Then,the influence of the foot-end wheel motion on the height and width of the robot obstacle crossing was analyzed,and the functional relationship between the wheel drive torque and the height,width of the obstacle crossing was given.Further,a detailed scheme of the robot to cross high obstacles under the combined action of wheels and legs was designed.Finally,a physical prototype of wheel-legged robot was built,and a series of typical motions were experimented with the software and hardware control system of the robot.Through turning in situ experiment,arbitrary radius steering experiment and translation experiment,the performance of the robot in wheeled motion was verified.The two-state gait experiment verifies the movement performance of the robot leg.Through the compound span height experiment and the composite barrier width experiment,the obstacle crossing performance of the robot under composite motion was verified.