【正文】 very high, and all the factors that may cause puncture less than when the primary cause of tire pressure. This is not sensational, even if you do not choose models with a tire pressure monitoring, but also increase the importance of vehicle tires, and vehicles to avoid serious injury. When the tire pressure is too high, it will reduce the tire contact area with the ground, at which point the tire pressure relative increase tire grip will be affected. In addition, when the vehicle through Goukan or bumps, the tires do not have enough space for absorption of vibration, in addition to affecting the stability and driving fort, it will also result in intensified the impact of the suspension system, which will bring hazards. Meanwhile, a puncture at high temperatures will be a corresponding increase in the hidden danger. Direct tire pressure monitoring device is installed in each tire by the pressure sensor in the direct measurement of tire pressure, use of wireless transmitter within the tire pressure information sent from the receiver module to the central system, then the tire pressure data display. When the tire pressure is too low, or leaking, the system will alarm automatically. Indirect tire pressure monitoring works: When a tire air pressure decreases, the vehicle weight would make the rounds of the rolling radius will bee smaller, resulting in faster speed than the other wheels. By paring the difference in speed between the tire in order to achieve the purpose of monitoring tire pressure. Indirect tire alarm system is actually calculating the tire rolling radius to rely on air pressure monitoring. Tire pressure monitoring devices have both advantages and disadvantages. Direct tire pressure monitoring devices can provide more advanced features, at any time within the actual determination of instantaneous per tire pressure, it is easy to identify the problem tire. Relatively low cost of indirect systems have been equipped with 4wheel ABS (each wheel equipped with a wheel speed sensor) the car just the software upgrade. However, the indirect tire pressure monitoring device with high accuracy without direct system, it does not identify the problem tires, and the system calibration is extremely plex, in some cases, the system will not work, for example, 2 of the same axle are low tire pressure time. In Europe and North America, through appropriate laws and regulations to improve safety awareness of people (such as: the European Commission will force the car to install tire pressure monitoring system). Tire pressure monitor manufacturers are mainly represented by the British SCHRADER, in tire pressure monitoring has mastered the core of the world39。s most highend technology, tire pressure monitoring products have been occupied by . and European markets original equipment vehicle tire pressure monitoring system TPMS75% above market share. (WheelSpeed Based TPMS, referred to WSB), this system is the system through the vehicle ABS wheel speed sensors to pare the difference in speed between the tire in order to achieve the purpose of monitoring tire pressure. ABS wheel speed sensors to determine by whether the locking wheel to decide whether to activate the ABS system. When the tire pressure decreases, the weight of the vehicle will bee smaller diameter tires, which can lead to changes in speed, this change can be used to trigger the alarm system to warn the driver (PressureSensor Based TPMS, referred to as PSB), which kinds of systems are installed in each tire by the pressure sensor in the direct measurement of tire pressure, use of wireless transmitter within the tire pressure information sent from the receiver module to the central system, then the tire pressure data to display. When the tire pressure is too low, or leaking, the system will alarm automatically. Both systems have advantages and disadvantages. Direct system can provide more advanced features, at any time within the actual determination of instantaneous per tire pressure, it is easy to identify the problem tire. Relatively low cost of indirect systems have been equipped with 4wheel ABS (each wheel equipped with a wheel speed sensor) the car just the software upgrade. However, the indirect system is no direct system with high accuracy, it does not identify the problem tires, and the system calibration is extremely plex, in some cases, the system will not work, for example, 2 of the same axle tire pressure is low. Hybrid TPMS: it bines the advantages of the two systems, it is the tire diagonal to each other within the two direct sensors and equipment, and equipped with a four indirect system. Compared with all use the direct system, this hybrid system can reduce costs and overe more than an indirect system can not detect low tire pressure simultaneously shortings. However, it still does not like the direct system to provide all four tires as the actual pressure within the realtime data. Tire pressure monitoring system is now still there are many areas for improvement need to be perfected. For indirect systems, coaxial or more than 2 tires gas shortage situation can not be displayed。 speed of 100 km / h above the monitoring of failure. For the direct system, wireless signal transmission in the stability and reliability, sensor life, the accuracy of alarm (with or without false positives, false positives) and the pressure sensor needs to be improved and so are the. Currently installed tire pressure monitoring system, Audi, BMW, Mercedes, Ferrari, Porsche and Volkswagen car parts can be said that TPMS is still a relatively highend products, from the universal popularity and there is a long distance. According to statistics, in 2004, the United States, 35% of registered new cars are equipped with TPMS, is expected to reach 60% in 2005. High priority vehicle safety in the future, sooner or later tire pressure monitoring system will be standard on all cars, like