Research On Indirect Tire Pressure Monitoring System

With the development of economy, the car has entered thousands of households, has become the main means of transport. At the same time, the performance of the automotive active safety has been more and more users and developers attention. Tire as one of the three big hidden trouble for the auto safety, has been, all countries for a flat tire has also developed a corresponding laws, regulations and mandatory standard practice for installation of TPMS, which also contributed to the research and development in the field. Therefore, the research direction is advanced and certain economy. This article is based on the research of hardware project of Jilin University and enterprises, it also proves the feasibility of the direction. The TPMS system is the main vehicle safety tire pressure monitoring system, can take the initiative to predict vehicle tire pressure. So far, tire pressure monitoring method can be divided into indirect and direct two. Considering the actual development of economy, accuracy and effectiveness factors, conducts the research based on the frequency method of indirect TPMS is a series of key technologies: Tire torsional vibration modal analysis, the real car include the wheel speed signal processing, sensor error estimation and correction of, classic spectral estimation method, combined with parameter estimation of modern spectrum estimation research. Mainly divided into the following points:(1) In this paper, from the perspective of tire vibration mode, combined with the state space characteristic equation, the distribution of the characteristic roots in the s domain is used to analyze the influence of each factor on the system characteristics. The equation between resonant frequency and model parameters is established.(2) The principle of the error of the sensor is analyzed, and the influence of the process error on the signal is studied. By using the constraint condition of error and the relationship between the sampling angle and the differential equation of the signal, the Kalman filter algorithm is used to estimate the value of the angle error.(3) The paper analyses the wheel speed signal under different tire pressure. The resonance frequency is solved from two angles of power spectrum and parameter identification, and the result is in accordance with the resonance frequency of the mode. It shows that the method is feasible.(4) Make the tire test bench. Considering the vertical load and tire pressure, the speed of the three effects on the resonant frequency. The result is consistent with the theory analysis.Combined with experiment and theory analysis, carried out a detailed study of TPMS algorithm, to automotive safety system of indirect TPMS module development to provide certain reference, in the summary of the work and also puts forward some issues, and the future need to perfect place.