Study On The Ignition Test System For Automobile Based On CAN-bus

With the development of auto industry, the excellent, intelligent and cheap system is urgently needed. The ignition system is a key part of automobile engine, its quality, performance and dependability have influenced automobile vehicle conditions, power, capability of emission directly. Therefore, how to measure the ignition systematic performance becomes the key question of engine measurements and diagnoses technology. After analyzing the domestic and international ignition parameter measurement method and current research situation, deep research for the theory and method of ignition parameter measurement has been done and a distributed automobile ignition parameter measurement system based on controller LAN (CAN) has been put forward.The whole frame of test system has been put forward and topological structure of the data interchange network has been confirmed after analyzing the operation principle of ignition and characteristic of parameter. Design of data interchange network based on CAN bus has been introduced. CAN bus is one of the field buses which are used most extensive in the world.The design plans of brushless motor controller node, temperature control node, distributor measurement node, ignition parameter measurement node have been confirmed. High speed A/D converter and first-in first-out memory FIFO have been adopted to realize effectively that the high-speed datum about ignition current and voltage are gathered. The speed cooperation between high-speed datum gathering module and low-speed control circuit has been solved through careful sequence analysis. Ignition signal analysis has been realized and ignition dwell angel and distant angles have been calculated in the distributor test node. Ignition system temperature has been monitored accurately in the temperature control node. Accuracy controls to brushless motor and ignition simulation in different rotational speed have been realized, and systematic flexibility and openness have been improved in the brushless motor node. Electromagnetic compatibility has been fully considered in this text, and effective anti-interference measure to strong electromagnetic interference in the ignition system has been taken, which guarantee that the measuring system can work normally.Whole software frames of test system and nodal driver, and each nodal driver procedure have been confirmed. CAN application layer protocol has been designed, which makes up the deficiency of CAN V2.0, and realizes more perfect functions on the foundation of the physics layer and data chain layer.Experimental results about relevant module have been provided in the text, and signal wave form has been drawn according to the high speed sampling datum of ignition signal.The experimental results have proved that good performance and higher intelligent degree are involved in the test system, which can reach modernized automobile ignition test request, and have the advantages such as high dependability, perfect stability, low price and wide application prospects.