Research On The System Of Self-balanced Vehicles Based On Pressure Sensors For Steering

Since the idea of service robots was put forward,many scholars and industrial personnel have devoted themselves to the research.As an important branch of the research field of the service robots,the design and research of the self-balanced vehicle has always been a hot topic.In addition,the self-balanced vehicle has the characteristics of the simple structure,compact size,light weight and suitable for shuttle in the complex environment with the simple operation and a strong interest,so it is widely favored by the people.Firstly,this paper introduces the development history,mathematical model and operation principle of the two-wheeled self-balanced vehicle and the multi-parameter system model of two-wheeled self-balanced vehicle is established.The dynamic model of the self-balanced vehicle is established by Lagrange method.Considering the relationship between generalized force and system kinetic energy,the mathematical model of the system is greatly simplified,and the nonlinear multi-parameter combination system of two-wheeled self-balanced vehicle could be better represented.The dynamic model of two-wheeled self-balanced vehicle is simulated on the MATLAB/Simulink platform.The simulation results show that the mathematical model established by Lagrange method could effectively characterize the actual running state of the selfbalanced vehicle.Secondly,the control methods and structures of balanced vehicle were studied and summarized.It is noticed that the traditional self-balanced vehicle is controlled by steering handle or steering rod.Although the flexible steering could be achieved,its mechanical structure is more complex,and the weight and volume of the vehicle body are increased.Therefore,this paper puts forward the idea of realizing steering function based on pressure sensor.The pressure difference value of left and right pedals is obtained by using the sensor,and a certain duty ratio is calculated after normalization.The duty ratio of maintaining balance and realizing steering are added to get the final control duty ratio,and the speed of brushless DC motor is adjusted to realize differential steering.Thirdly,the system of self-balanced vehicle is assumed to run in discrete straight line at any time.On this basis,an equivalent linear operation model is proposed.The balanced control strategy,speed control strategy,current control strategy and steering control strategy are analyzed,and a three-loop PID controller is established.At the same time,in order to make the controller better adapt to different application scenarios,this paper presents a multi-level parameter design method to improve the robustness of the system.Finally,on the basis of theoretical analysis and simulation verification,a prototype of two-wheeled self-balanced vehicle system is built.Experiments are carried out on the balance state,the accuracy of body inclination output,and indoor and outdoor operation effects.The experimental results show that the control system of two-wheeled selfbalanced vehicle based on differential pressure steering not only has flexible and stable steering,but also has strong robustness and complete function.