As quality has improved and service intervals have become more extended, drivers are making fewer and fewer routine checks. As well as increasing fuel consumption and tyre wear, low pressure in tyres can result in failure - sometimes with appalling results. At present the EU is not proposing legislation but it is monitoring developments. If Brussels can get the wording right, the impact on safety would be enormous. The latest ruling of the US National Highway Traffic Safety Association requires all light vehicles from September 2007 to have a tyre pressure monitoring system (TPMS) that can detect when any of the tyres are 25 per cent or more below the recommended pressure, or a minimum specified activation pressure. Costs per vehicle are estimated to be US Dollar 48.44 to 69.89. A number of systems are available already but suppliers are not waiting for EU legislation before developing improved technologies. Schrader Electronics, Beru, SiemensVDO, Continental and EnTire are just some of those with systems that exceed the performance criteria of the Transportation Recall Enhancement, Accountability and Documentation (TREAD) act. TPMS are divided into two main groups: indirect and direct. Indirect systems cannot measure pressure explicitly but use information from ABS wheel speed sensors to determine if a tyre is under-inflated: in this condition the wheel rotates at a greater speed. These systems have two major drawbacks. They cannot detect if all four tyres have been inflated to an incorrect pressure, and some dynamic conditions such as tyre slip on low friction surfaces or off-highway driving can distort readings and give false alarms. Direct monitoring requires a transducer in each wheel capable of measuring temperature and pressure. Most take a lithium battery and are housed in a module that screws on the back of the tyre valve. The firm's next generation will use the strength of the radio frequency signal from each sensor to determine positions - the distance from each sensor to the central receiver is different. Schrader uses wireless auto location on its snap-in valve sensors. The battery remains the weak link. Nominal life is often given as 10 years but service life is hard to predict. EnTire, a joint-venture berween TRW and Michelin, says its sensor design makes removal of the battery as easy as possible. SiemensVDO does not consider the batteries in the wheel-unit to be a recycling problem. Beru is developing an integrated sensor that does not require a battery for the wheel electronics, which it says is a future. Michelin, working with Honeywell, is in the same area wirh its 'eTire II' system, which uses an 11g batteryless sensor patch bonded to the tyrewall. For commercial vehicle use, these can be interrogated by hand-held or drive-by readers to extract pressure and temperature data, streamlining the fleet management process. The drive-by system automatically formats and prints a report on tyre status. On an 18-wheeler the benefits are obvious. All the present TPMS suppliers see potential in the future for TPMS data to be linked to electronic slip control (ESC) systems to enhance vehicle safety. As ESC is mandatory in the US, it seems a logical development.


    Access

    Access via TIB

    Check availability in my library

    Order at Subito €


    Export, share and cite



    Title :

    Inflationary targets


    Additional title:

    Reifendruckkontrolle als Ziel


    Contributors:

    Published in:

    Automotive Engineer ; Jan ; 34-35


    Publication date :

    2007


    Size :

    2 Seiten, 4 Bilder



    Type of media :

    Article (Journal)


    Type of material :

    Print


    Language :

    English




    Fiscal Revenue and Inflationary Finance

    Choudhry, Nurun N. | TIBKAT | 1990

    Free access

    Comparison between different inflationary models in Bianchi IX spacetime

    Moneer, Eman M. / Alanazi, Meznah M. / Steklain, Andre Fabiano et al. | Elsevier | 2023


    Moving targets

    Online Contents | 1999


    Aerial Targets

    Online Contents | 1998