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Den här rapporten beskriver ett examensarbete i elektroteknik på Kungliga tekniska högskolan. Syftet var att skapa en unik systemlösning där ett CAN-adapterkort (Controller Area Network) skulle integreras med ett system för övervakning av däcktryck i tunga fordon. Målet var att presentera mätvärden från ventilsensorer på en persondator. Systemet för övervakning av lufttryck heter J1939 – TPMS och är en färdig produkt. J1939 – TPMS skickar CAN-ramar på en CAN-buss i J1939-format. Dessa ramar ska läsas in av adapterkortet och presenteras på ett terminalprogram på en persondator. Arbetet har bestått av att utreda hur systemet J1939 – TPMS fungerar i detalj. Rollen för protokollet J1939 och dess förhållande till CAN har förklarats. Hur J1939-ramar tolkas och hur mätdata rörande TPMS avkodas har beskrivits i detalj. Principer för hur en CAN-nod fungerar har klargjorts. Baserat på detta har ett CAN-adapterkort konstruerats. Konstruktionen har inneburit komponentval, design av elektronikschema, design av mönsterkort och utveckling av inbyggd programvara. Resultatet blev ett färdigt och fungerande CAN-adapterkort som har testats med J1939 – TPMS. Kraven för projektet uppfylldes. Dock så kommer mer arbete med kortet och systemet behövas för att det ska bli en färdig produkt. Arbetet genomfördes hos Motion Control i Västerås AB i samarbete med Transeco Däckservice. / This report describes a degree project at the Royal Institute of Technology. The purpose was to create a unique system solution in which a CAN adapter card (Controller Area Network) was to be integrated with an air pressure monitoring system for heavy duty vehicles. The goal was to present measurement values ​​from valve sensors on a personal computer. The air pressure monitoring system is called J1939 - TPMS and is a finished product. J1939 - TPMS sends CAN-frames to a CAN-bus in J1939 format. These frames are to be read by the adapter card and presented on a terminal program on a personal computer. The job has been to investigate how the J1939 - TPMS system works in detail. The role of the J1939 protocol and its relationship with CAN has been clarified. Also, a detailed description of how J1939 frames are interpreted and how the measuring data TPMS is decoded is done. Principles for how a CAN node works has been clarified. Based on this, a CAN adapter card has been designed. The design has included component selection, design of electronics schema, design of computer cards and development of embedded software. The result was a ready-to-use CAN adapter card tested with J1939-TPMS. Requirements for the project were met. However, more work with the card will be needed to make it a finished product. The work was carried out at Motion Control in Västerås AB in cooperation with Transeco Däckservice (Transeco Tire Service).

As the introduction of semiconductor¡Bcomputer¡Bnetwork communcation¡Bmulti-media technology¡K¡Ketc. and the development and application of relevant automotive electronics, the car has becoming a high technological product instead of a traditional and machnical conveyance. Based on IC Insights, over 40% of vehicles will be equipped with automotive electronics and the automotive electronics market will reach the scale of US$192 billion in 2010. The scale of market is expected to reach the record of US$400 billion that represented over 50% of vehicles will be equiped with automotive electronics in 2015. The automotive electronics was divided to six functional field including ¡§Powertrain¡¨¡B¡¨Body¡¨¡B¡¨Chassis¡BSecurity¡¨¡B¡¨Safety¡¨ and ¡§Driver information¡¨. According to the research of IEK, ¡§Tire Pressure Monitoring System¡¨ is the most potential product in ¡§Safety¡¨ field for Taiwan manufacturers of IT industry to invest their resource. Based on Strategy Analytics, the global market of Tire Pressure Monitoring System reaches the scale of US$200 million in 2004 and the growth is expected to reach the record of US$1,279 million in 2008 and 63.6% annual compound growth. Quality Function Deployment (QFD) is a systematical tool with customer orientated concept. Adopting QFD method to product design efficiently is able to shorten development time¡Breduce cost and improve quality to satisfy customer¡¦s needs in his or her mind. This research is completed by case study of Tire Pressure Monitoring System (TPMS) which is developed by certain Taiwan company with potentials that is chosen by specialists. In this research we try to collect related information about certain company and explore customer¡¦s real-life needs by conducting questionnaire surveys. Kano¡¦s two-dimensional quality model is applied to identify customer¡¦s critical quality requirements. Quality factor¡Bsub-system/component and process are deployed by the matrix method of QFD to recognize key items for improving product design.

Tire pressure monitoring systems (TPMSs) predict over- and underinflated tires, and warn the driver in critical situations. Today, battery powered TPMSs suffer from limited energy. New sensor features such as friction determination or aquaplaning detection require even more energy and would significantly decrease the TPMS lifetime. Harvesting electrical energy inside the tire of a vehicle has been considered as a promising alternative to overcome the limited lifetime of a battery. However, it is a real challenge to design a system, that generates electrical energy at low velocities while being robust at 200 km/h where radial accelerations up to 20000 m/s2 occur. This work focusses on developing different electromechanical energy transducers that meet the high requirements of the automotive sector. Different approaches are addressed on how the change of acceleration and strain within the tire can be used to provide mechanical energy to the energy harvester. The energy harvester converts the mechanical energy into electrical energy. In this thesis, piezoelectric and electromagnetic transducers are discussed in depth, modelled as electromechanical networks. Since the transducers provide energy in the form of an AC voltage, but sensors require a DC voltage, various common interface circuits are compared, using LTspice and applying method of the stochastic signal analysis. Furthermore, a buck-boost converter concept for the electromagnetic energy harvester is optimized and improved. Experiments on a tire test rig validate the theoretically determined output and confirm that well designed energy harvesters in the tire can generate much more energy than required by an TPMS not only at high velocities but also at velocities as low as 20 km/h.