Research of Tire Pressure Monitoring System

Abstract

Nowadays, the car has become an important means of transportation, the safety of the car has been paid more and more attention by people. The abnormal running will lead to flat tire, TPMS system for the timely monitoring of tire pressure, application of different types of TPMS system are different from each other. Based on the sensor types, monitoring methods and monitoring principle of TPMS system for the classification and different mathematical models are given for different TPMS systems. A more comprehensive definition of the structure of all types of TPMS, which will facilitate analysis and design of TPMS. 1.Introduction Since the industrial age, the automobile has gradually become an important means of transportation. How to ensure traffic safety has been the focus of people's attention. After a lot of research and data accumulation, it summed up traffic safety have great relevance with the working conditions of tires. Therefore, the research on the tire pressure monitoring has become the focus of attention. ] 3 [ Statistical data show that the accidents caused by tire puncture accounted for about 30% to 40% of highway accidents. Meanwhile, under pressure is also a significant risk of traffic accidents. Pressure is a important factor that leads to the change of tire performance, high pressure will decrease the elasticity of tire, reduce the contact area with the ground, and reduce the coefficient of friction. Eventually, high pressure will lead to the vehicle to skid, not smooth, bumps, flat tire, etc; but when the tire pressure is too low, not only will increase the driving resistance and fuel consumption, but also enable the tire a sharp rise in temperature, causing a flat tire. Obviously, to maintain proper tire pressure can not be ignored. ] 1 [ Now TPMS (Tire Pressure Monitoring System) on the market is mainly divided into two types, the indirect TPMS (WSB TPMS) and the direct TPMS (PSB TPMS). ] 4 [ 2.Indirect TPMS Indirect TPMS is using the ABS wheel speed sensor or other non-pressure sensor signal, calculating indirect tire pressure by the tire mechanics model and algorithm, or using the pressure differences between the tires to monitor tire pressure, there are three common monitoring method. 2.1 Frequency Analysis Method This type monitor tire pressure by monitoring the vibration frequency related to tire pressure. The rubber tire will produce a similar vibration like the spring when automobile is running, and there exit a linear relationship between the elasticity coefficient and the tire pressure. Therefore, processing the signal generated by the ABS wheel speed sensor with VSC, the torsional vibration frequency of the tire can be obtained, then the elasticity coefficient of the tire can be obtained, and then the tire pressure can be calculated. Relation to k m f π 2 = , the control flow chart is as follows: 2nd Workshop on Advanced Research and Technology in Industry Applications (WARTIA 2016) © 2016. The authors Published by Atlantis Press 746 Figure 1: Vibration analysis TPMS working principle diagram 2.2 Speed Analysis Method The tire radius is compared with the nonlinear change of the static wheel speed, and the difference is zero when the tire radius is close to the optimum value. The principle is: when the tire pressure drops, rolling radius of the tire will decrease, resulting in high speed than the other tires. By comparing the rotational speed of the tire between the tire pressure monitor to achieve the purpose. Generally used for static nonlinear methods, such as: