Research On Indirect Tire Pressure Monitoring Algorithm Based On Tire Rolling Radius And Frequency Domain Features

Today,cars have been integrated into people’s daily lives and have become an indispensable means of transportation.As the only component in contact between vehicle and road,the performance of tire determins the performance of vehicle.When tire under inflation,it will increase the resistance of vehicle,increase fuel consumption,and even cause a puncture.And that will be a great threat to Personal safety.Therefore,real-time monitoring of the tire pressure state and warning the driver when the tire pressure state is abnormal are of great significance to improving driving safety and driving economy.Tire pressure monitoring system(TPMS)is born to solve the above problems.It monitors the pressure state of each wheel in real-time while the vehicle is driving.When a wheel is under pressure,the system sends out an alarm signal to correct the problem before the failure occurs.The driver makes necessary reminders to ensure driving safety.China officially released the national standard for passenger car TPMS in 2017,which stipulates the test standards for both direct and indirect methods.This paper comprehensively considers economy,accuracy and installation difficulty,and conducts research on indirect tire pressure monitoring algorithm based on tire rolling radius and frequency domain features.This paper proposes an indirect tire pressure monitoring algorithm based on tire rolling radius and frequency domain features.For convenience,the following two methods are represented by the radius method and the frequency domain method in turn.The algorithm mainly includes the following points:(1)First,acquistion wheel speed and related vehicle state data.Then,combine the theory of wheel speed sensor to analyze the reason for the error of the wheel speed signal.At the same time,for the signal processing process of the frequency domain method and the radius method,two extraction methods are set up respectively.(2)The gear ring error parameters are identified by the recursive least square method,the gear ring error matching strategy is designed,the gear ring error is corrected,and the signal is reconstructed into a time uniform signal.For the difference in frequency domain,the corresponding signal components are extracted by designing filters.(3)First of all,from the spectrum estimation method,the analysis and elimination of the influence of the engine torsional vibration,the spectrum signal extraction and the extraction method of the resonance frequency,a detailed analysis of the frequency domain method tire pressure estimation algorithm is made,and the frequency domain method tire pressure estimation is determined the algorithm flow.Then,the radius method tire pressure estimation algorithm is analyzed in detail from the radius iteration method and the radius statistics method,and the radius method tire pressure estimation algorithm fusion method based on the radius iteration method and the radius statistics method is determined.(4)With frequency domain method underpressure confidence and radius method underpressure confidence as input,the fuzzy rule of counter adjustment step is established,and the recognition strategy is designed to realize tire pressure state recognition.Finally,an indirect tire pressure monitoring algorithm fusion algorithm prototype based on fuzzy rules is built on the MATLAB/Simulink platform.The algorithm was calibrated under normal wheel pressure and different underpressure conditions,and the algorithm was calibrated under normal wheel pressure and underpressure conditions.The offline simulation of real vehicle data is carried out,and the analysis shows that the designed fusion algorithm is accurate and effective.