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This paper proposes a smart main relay assembly or power relay assembly for xEV battery system. The role of main relay assembly is to connect and disconnect main high voltage battery and loads including the inverter. Current main relay is usually a special electro-mechanical relay which has a gas chamber to suppress electrical sparks between relay contacts for switching high current safely. The gas-chambered electro-mechanical relay is relatively too heavy and bulky to decrease design flexibility and may worsen fuel economy. The proposed smart main relay assembly uses IGBT (insulated gate bipolar transistor) for transient states to switches on or off, and uses relays for steady states to connect or disconnect current. As no spark induces to relay contacts directly with the proposed method, conventional electro-mechanical relays without gas-chambers can be used. Therefore the mass and volume can be reduced to increase gas mileage and also reduce the material cost.

In-Vehicle Network (IVN) protocol such as CAN, MOST, Flexray and etc. have been extensively applied in automotive communication systems. Analyzer development for network diagnoses purpose correspondingly becomes an emerging industry in automotive field. To reduce the increasing software development costs for protocol of various types, reusable analyzer software architecture and standardized system composition mechanism are needed. In this paper, we propose reusable analyzer software architecture, a system integrating mechanism and a component replacing policy. We built the reusable architecture by extracting similarities of different analyzer development. In system integrating phase, components are abstracted so that they can be located, compared and selected by system integrators. And component replacing policy is used to reuse the software for new analyzer development.

This paper presents a conditional misfire monitoring method to reduce the computing burden of the motoring. In this conditional monitoring method, the ECU performs misfire detection only when there is high probability of misfire events. The condition for performing the misfire detection is determined by the pre-index which is defined as the deviation of the segment durations of the crankshaft in this paper. The quantity of the code of calculating the pre-index is 7 times less than that of a conventional monitoring method so that the computing burden can be reduced with the conditional monitoring method. The experimental results shown that the pre-index and the conditional monitoring method are valid.