Modeling And Experiment Of Anti-Pinch System Of Power Window Based On Current Ripple

Driven by the rapid development of modern power electronics technology,the automotive industry is transitioning from purely mechanized products to intelligent products,and car windows are typical of them.However,in recent years,there have been many accidents in which electric windows of automobiles have killed passengers,so the anti-trapping algorithm of electric windows has also become one of the hotspots of intelligent research in automobiles today.Although the complexity and functionality of domestic automotive electronic products are constantly being improved and strengthened,there is still a large gap between the reliability of automotive electronic products and foreign electronic products of the same type,which restricts the rapid development of China’s electronic products to a certain extent.In this context,this paper studies the anti-trapping system of power windows,especially in terms of anti-trapping strategies and algorithms.In this thesis,an electric window anti-pinch algorithm based on the current ripple extreme value detection method is designed by comparing the mainstream anti-pinch algorithms at home and abroad.This algorithm judges the magnitude of the window force through the period of the motor current and the motor current ripple;The lift position of the window glass is recorded by the number of motor current ripples.In order to verify the feasibility and stability of the anti-pinch control algorithm,the entire electric window anti-pinch control model is build in this thesis through the Matlab/Simulink software platform.The model includes three modules:motor module,window controller module and ripple calculation module.The parameters of the motor module in the model are combined with the technical parameters of the actual motor.The window controller module built on the Simulink/Stateflow platform realizes the function of controlling the motor module to perform corresponding actions according to the input anti-trapping criterion value.For this window control module,a fault tolerance mechanism is set up for the problem that the current ripple caused by the sudden resistance of the window cannot be stabilized quickly,which improves the stability of the window control system.The ripple calculation module built on the Simulink platform realizes the functions of converting the square wave of the ripple,counting the current ripple of the motor and calculating the period.Because the actual current ripple has high frequency interference,the wavelet transform method is used to reduce the noise of the simulated current ripple signal containing the interference glitch in this thesis.Simulation verification shows that the current ripple processed by the wavelet transform has a great degree improvement of recognition in the motor control module,and thus improve the accuracy of ripple count and cycle calculation.After the theoretical analysis and software simulation in the previous article,the hardware is designed on this basis in the thesis,using the STM32F103VET6 single-chip microcomputer as the control core,and designs the current ripple extraction circuit,voltage bias circuit and motor control circuit,combined with the actual operation of the window.The parameters are used to calculate the current ripple period threshold,count threshold and current amplitude threshold and add the wavelet transform noise reduction algorithm to the system.Finally,experiments have verified that the window anti-pinch system designed in this paper has anti-pinch function.Based on the system structure and control principle,an anti-pinch control strategy based on the current ripple extreme value detection method is designed in this thesis.From simulation and experiment,the anti-pinch control algorithm is verified to have good stability and reliability.The design and research of anti-pinch control system have certain theoretical significance and practical value.