A study of efficient sensor I/O interface and signal acquisition techniques for electrical control units.

Abstract: Agricultural vehicles use electronic control units (ECUs) as control system. HistoricallyECUs have only been equipped with a minimum of features. With therecent progress in electronics, which have made components faster, smaller andcheaper, the trend is now to integrate more advanced functionality into the ECUs. Agricultural vehicles are present all over the world and they have to operateunder a wide variety of conditions. This put high requirements on the system andit is critical that a modern ECU can detect and locate errors. For an ECU to beable to operate on a world-wide market it is required to be flexible, expandableand robust. In addition to these requirements it is also wanted that an ECU havea long lifespan and a low cost. In this thesis different problems that modern ECUs have to face are investigated.Suggestions of how to solve these problems are also presented. Thereare two focuses in the thesis, 1) how ECUs can acquire information from its inputs/outputs; and 2) the requirements of the ECU hardware. This thesis does not aim to deliver a fully specified system description butrather to provide an overview of how an ECU can be designed and which problemsthat it has to face. A selection of areas of ECU design which are investigated in this thesis are,1) typical inputs/outputs; 2) analog-to-digital converters and their application; 3)how multiplexers can be used; 4) requirements of general purpose inputs/outputs(GPIO); 5) monitoring of a controller area network (CAN); 6) power-supply requirementand monitoring; 7) monitoring of the vehicle’s battery; 8) memory; 9)requirement of the microcontroller (MCU);Agricultural vehicles use electronic control units (ECUs) as control system. HistoricallyECUs have only been equipped with a minimum of features. With therecent progress in electronics, which have made components faster, smaller andcheaper, the trend is now to integrate more advanced functionality into the ECUs.Agricultural vehicles are present all over the world and they have to operateunder a wide variety of conditions. This put high requirements on the system andit is critical that a modern ECU can detect and locate errors. For an ECU to beable to operate on a world-wide market it is required to be flexible, expandableand robust. In addition to these requirements it is also wanted that an ECU havea long lifespan and a low cost.In this thesis different problems that modern ECUs have to face are investigated.Suggestions of how to solve these problems are also presented. Thereare two focuses in the thesis, 1) how ECUs can acquire information from its inputs/outputs; and 2) the requirements of the ECU hardware.This thesis does not aim to deliver a fully specified system description butrather to provide an overview of how an ECU can be designed and which problemsthat it has to face.A selection of areas of ECU design which are investigated in this thesis are,1) typical inputs/outputs; 2) analog-to-digital converters and their application; 3)how multiplexers can be used; 4) requirements of general purpose inputs/outputs(GPIO); 5) monitoring of a controller area network (CAN); 6) power-supply requirementand monitoring; 7) monitoring of the vehicle’s battery; 8) memory; 9)requirement of the microcontroller (MCU);