The Resarch Of ECU Simulation System Used For Vehicle Fault Diagnostic Scanner Development

With the rapid development of electronic technology, today’s cars are equippedwith hundreds of electronic components, thousands of wires controls the coordinationof the various parts of the car. The cars have become from a simple mechanicalproducts to the advanced mechatronic product, a so-called "E-car". Automotiveelectronics is becoming more and more popular. Automotive ECU (electronic controlunit) is increasing rapidly, the failure of any component in the system are likely to leadto the failure of the entire system. Because of the complex of the system, vehiclemaintenance becomes very difficult. For these failures, artificial diagnosis has becomepowerless, in order to speed up the repair process, so we need a special automotivefault diagnostic scanner which can detect the faults automatically. During thedevelopment process of the common diagnostic scanner, we are facing the highdevelopment costs and test difficulty issues.In this thesis, in order to solve the problems encountered in the developmentprocess of common diagnostic scanner, I did some research on the commonly useddiagnostic protocols such as K line protocol and CAN protocol. Developed the ECUsimulator that can be used both for K-line and CAN line ECUs, which greatly reducesdevelopment and testing process of the common automobile failure diagnostic R&Dcosts, improved the R&D efficiency. Firstly, reviewed the development status ofvehicle diagnostic techniques and then described the problems encountered in thedevelopment process of the common diagnostic scanner. Then described the ISO9141communications protocol and ISO11898communication protocol, and analyzed thecomposition and characteristics of the CAN bus.Based on communication protocols, ECU simulators can be divided into K-linesimulator and CAN line simulator. This paper gives the design model of the ECUsimulator, which is composed by software and hardware systems. K-line ECUsimulator software system is based on μC/OS-Ⅱ operating system, hardware systemuses the MAX232chip as the core of a signal converter. The CAN line ECU simulatorsoftware system is a run on PC application software, hardware system use the Infineon C161PI microprocessor as the core of a signal converter. This paper describes theideas of simulator software design and software user interface and operating method.Also did the analysis of the ECU internal encryption algorithm.Finally, through the test of real ECUs, proved the effectiveness of both K-line andCAN line ECU simulators.