Parameter Identification And Hierarchical Sliding Mode Control Of Inverted Pendulum Based On Semi-physical Simulation Platform

With the increasing development of system simulation and control chip performance,pure mathematical simulation is not enough for the current control requirements.The semi-physical simulation technology from this has gradually gained popularity.Because it combines the advantages of pure mathematical simulation and physical experiment,it has been widely used in the industry.This paper analyzes and researches the semi-physical simulation technology,combines the actual situation in the school,and controls the design cost under the premise of ensuring performance,and builds a semi-physical simulation platform based on STM32 to meet the needs of teaching and scientific research.In order to verify the reliability of the semi-physical simulation platform,a series of experiments were carried out with the inverted pendulum as the controlled object.As a naturally unstable nonlinear system,the inverted pendulum has the characteristics of multivariable and strong coupling.Its structure is not complicated,and the control effect is displayed intuitively.It is an ideal controlled object for checking the correctness of the control algorithm and the performance of the controller.This paper organically combines theoretical analysis and physical objects,uses a built-in semi-physical simulation platform to collect the input and output data of the system,preprocess the data,use the processed data for dynamic parameter identification,and design a hierarchical sliding mode controller.The host computer monitors the system status in real time and feeds back the performance of the controller in time to realize the first-order linear inverted pendulum balance control with better robustness.First,the Lagrangian equation is used to mathematically model the first-order linear inverted pendulum system,and the friction force is taken into account to establish a nonlinear model of the inverted pendulum.In view of the fact that the parameters of the controlled object are unknown or changed in the actual project,this article uses the least square method to identify the parameters of the inverted pendulum trolley mass,the mass of the pendulum and the length of the pendulum,and the coefficient of friction,and achieves a good identification.The effect is to construct a hierarchical sliding mode controller based on the identified parameters.Secondly,the hierarchical sliding mode control algorithm is used to realize the balance control of the inverted pendulum.In order to improve the dynamic performance and robustness of the system,this paper designs a new type of self-adaptive based on the power reaching law and the variable speed reaching law.The approaching law can not only enhance the dynamic characteristics of the system,but also adjust the approaching speed adaptively according to the state,so as to achieve the purpose of suppressing system chattering.The reaching law can reach the sliding mode surface within a finite time.When a bounded external disturbance occurs in the system,the system state and its derivative can quickly converge to the neighborhood near the equilibrium point.Through Matlab/Simulink simulation,it can be seen that the hierarchical sliding mode controller with adaptive approach rate has strong robustness.Finally,the Embedded Coder in Simulink is used to automatically generate C code,after debugging in Keil5,it is burned into the main control unit through the USB serial port,and the control of the inverted pendulum is realized.