| The tire pressure appearance directly influences safety, the fuel economy and tire life-span of vehicle. Too low tire pressure, Too high tire pressure, or quick air leakage of the tire, constitutes one important factor affecting not only the driveability but also the safety performance of motor vehicles, even directly cause accident. While a too low pressure would accelerate tire wear due to doubled (and redoubled) ground friction, besides the escalation of fuel consumption. Result in 414 people death in the tire trouble in American every year, 10275 people get hurt, 20% tire blow-out troubles are cause by the too low pressure, American annually pass to maintain suitable car tire pressure can reduce 10% gasoline dosage and save USD 2,000,000,000, if prolong tire average life 5%, produce 100,000,000 less to discard a tire annually. So keep the tire pressure to be placed in a normal value, not only be advantageous to vehicle safety, and can economize oil to consume, extension tire of service life.In specific consideration of such a demand, tire pressure monitoring system (TPMS) has been developed and designed; aimed at enhancing the automotive safety, such a new technology capitalizes on the automotive electronic, sensor and wireless communication techniques, so as to monitor, in a real-time manner, the pressure of all tires during the running of the wheels, and give an alarm in case of leak or low pressure or high pressure. But is not all TPMS products can attain thus of request.Currently domestic and international TPMS product from the top of the technique route is mainly divided into two greatest types, namely the indirect type of TPMS and the direct type of TPMS. The so-called indirect type isn't and directly measure tire pressure, measuring tire under-inflation indirectly by means of wheel speed sensor which makes use of ABS system. So-called direct type, be from spread a sensor to directly measure each tire pressure, through a wireless communication deliver a data information to receiver and CPU to carry on an operation, carry out the monitor to the vehicle tire pressure thus with giving alarm signal.Indirect type of TPMS because the oneself existent technique blemish is no longer an essential Technique route, after even if being an improvement of mix type of TPMS, It is no good in market yet. There has been more than 90% adopting direct type of TPMS in the global OEM market currently. The TPMS of direct type has some a technique crux to need to be solve with breakthrough currently and technical requirements and safety and credibility of foreign essential product also still need to be raise.Recent years, the domestic studies TPMS the development also becomes gradually hot, the many enterprise throws vision in succession toward that field, those enterprise, main concentration at direct type TPMS, through development for several years, some enterprises have already controlled know how and the product has already been placed in The world's leading. very few car installed TPMS in China, first of all this be an all new product, how evaluate with test the TPMS good and bad doesn't have too many experience, on the other hand that product didn't have the request of national standard and laws, and car manufacturer also know very few to abroad of laws and standard.By now, the United States has been the first and the only country that has developed and put into compulsory implementation of the TPMS regulation. National Highway Traffic Safety Administration (NTHTSA) drafted the regulation FMVSS138, in which it is required that, from September 2007, all the four-wheel passenger cars and commercial vehicles with the GVW not exceeding 4,536kg sold within the territory of the United States should be fitted with TPMS. Plus, International Organization for Standardization (ISO) released ISO 21750: 2006 relating to TPMS in 2006. Also, Society of Automotive Engineers (SAE) developed the TPMS related standard -- SAE J 2657 for light-duty vehicles in 2004. The EU is discussing establishment TPMS laws, but making progress very slow-moving. The aforesaid three standards put forward requirements for TPMS from different aspects, but these standards be have as follows of weakness: One is the technical requirements is more lower and have not to appear the safety that the product should have; Two is evaluate parameter not overall, only match these foreign laws and standard, its product uncertain safety, credibility and economy. Thus the standard of the low level can't do a good evaluation and test to the TPMS product (quality not divide), and cause the manufacturers lack the motive of development.In one word, regardless set out from function and product quality of evaluation TPMS, or consider from normalizing and guiding the healthy development of the TPMS industry, It is urgently need to draw up the TPMS of China standard, At the beginning, will analyze TPMS characteristic, make sure the technical requirements of evaluation, and to make sure a test method.This text passes an extensive investigation and collects a domestic and international TPMS product of function and technical requirements, analysis to adopt different technique route of difference and merit and shortcoming, combine foreign TPMS standard and laws in the meantime of research analysis, put forward the TPMS should have of the basic function requirements, signal receive dependable requirement, radio communication emission characteristic requirement, and parts electricity and environment adaptability etc. in many ways concrete parameter, carry on an overall evaluation to the TPMS product, and studied to make sure each test method, become a set of integrity of TPMS system evaluation requirement and test method, If the TPMS product match the those requirement and test, It is safety, credibility, good fuel economy. For example the creative put forward Requiring a much shorter time(6 s) to give the under-inflation alarm(foreign laws is 20 min);The creative puts forward Specifying the signal receiving performance and test methods in static state and dynamic state; The creative puts forward Specifying the radio communication emission characteristics of the system (request to lower transmitting power and cumulative transmitting time to avoid interference mutually) ;The creative puts forward indicating the current pressure value of each tire and shall have self inspection function when it is started and shall have quick air leakage alarm function, etc.This text passes to carry on a TPMS verification to experiment towards Various type vehicle such as the passenger car, heavy bus, heavy truck ,etc. It is make sure that the evaluation parameter and the test method is fit with different type vehicle, the TPMS isn't only be applicable to four-wheeler the passenger car, but also and equally applicable to heavy duty commercial vehicle, and this test is still a first time at that field. This text suggest with this research the evaluation parameter of and test method for the main technique contents draw up a Chinese TPMS nation standard which is leads at the international level, not only can normalizing and guiding the healthy development of the TPMS industry. But also display China in the technique field of the automotive electronics new development and new contribution. |
