Research On Key Technology Of Two-wheel Selfbalancing Robot With Adjustable Center Of Gravity

The two-wheeled self-balancing robot has a small footprint and flexible movement.It can not only be used in real life as a manned vehicle,but also can be used as a mobile robot platform to become a delivery robot,adventure robot,etc.by carrying different functional modules.It has a huge scientific,technological development prospect and economic development space.However,the existing two-wheeled self-balancing robot lacks adaptability in non-structural environments due to control methods,structural design,and dynamic characteristics.It is unable to continuously cross high obstacles to a small wheel radius and has poor ladder climbing stability.Aiming at this problem,this paper proposes a self-balancing robot with adjustable centroid,two-wheeled deformable ladder climbing,and its overall structure,center on gravity adjustment device,deformable wheel deformation scheme,control method designs and other key issues are studied.The specific research content is as follows:(1)The design of the whole machine plan of the self-balancing robot with adjustable center of gravity,two-wheeled deformable ladder climbing.The ladder climbing scheme for the self-balancing robot is determined and the mechanical structure of the robot is introduced in detail.The relationship between the variables during the obstacle crossing process of the circular wheel is deduced,and a wheel-leg deformable wheel is proposed.Use the steering gear to drive the deformation based on the principle of crank slider and groove cam,which can adapt to different environments.According to the results of limited component analysis,the structure optimization and improvement on the pivotal parts of the deformation wheel is Improved.Analyzing the stable position of the self-balancing robot over obstacles,centroid adjustment device adopts a gear-spur rack drive to adjust the location of the center of the body autonomously.(2)A dynamic model of a two-wheel self-balancing robot with adjustable centroid is built.The Lagrangian modeling method is used to establish a single-period dynamic model of the two-wheel self-balancing robot with adjustable center of gravity of the ladder climbing process.After simplification,the system state equation is obtained,which provides a basis of subsequent controller designed.The stability of the robot is analyzed,and the steady-state motion law of the robot is gained.From the perspective of torque,the feasibility of controlling the speed of the robot by adjusting the displacement of the slider by the center of gravity is analyzed when the inclination of the fuselage is small.(3)ADAMS dynamics simulation was conducted.The out joint simulation is achieved by SOLIDWORKS,MATLAB and ADAMS software.A control method is designed to divide the robot control into a balance ring and a speed ring.The balance ring is based on a sliding mode control method to ensure the balance of the robot,and the speed loop is based on the ladder trajectory cycle to control the movement away the robot through the slide block forward and backward translation.After the simulation,the simulation animation and post-processing curve are obtained,and the simulation curve is analyzed to optimize the parameters of the control system,which provides data onto the subsequent physical modol.(4)Building a scaled down physical prototype of experimental verification.Including balance anti-jamming experiment,level walking experiment,steering control experiment,grass and lower obstacle crossing experiment and stairs climbing experiment.By analyzing the data onto the center of gravity adjustment slider displacement,robot traveled speed and robot running displacement error during driving,the feasibility of the center of gravity adjustment device to control the robot travel speed is verified,and the robot is stable and continuous in a variety of environments.It is proved that the design of a two-wheeled self-balancing robot can not only be used in environments such as flat ground,grassland,slopes,etc.,but also can continuously cross obstacles in a staircase obstacle environment,which is scientific and reasonable.