Research On Hardware-in-Loop Testing System For Automotive Powertrain ECU

Automotive electronic control technology based on ECU has greatly improved dynamic, fuel economy, and reduced exhaust gas emission of automobile. Nowadays, ECU's structure and control technology becomes more and more complex, but the development cycle becomes more and more short. To solve the contradiction between complex requirements and rapid development, the development of ECU often adopts V-model. In the V-model development lifecycle, hardware-in-the-loop (HIL) testing plays an important part, which can shorten development cycle, improve reliability and quality of ECU. In this paper, to solve the difficulty of ECU testing, and for the HIL testing of automotive powertrain ECU, a testing tool is introduced, which is called hardware-in-the-loop testing System. It applies to HIL testing of different kinds of automotive powertrain ECU in laboratory environment.HIL testing System is a testing and debugging tool for the development of ECU, which provides a virtual automobile environment in laboratory, generates all kinds of sensor signals of automobile, and provides various simulated actuators for ECU. Furthermore the testing system also can test whether the driving signals of ECU are normal and whether the software control strategy is correct. For this purpose, this paper presents a thorough research on the HIL testing for automotive powertrain ECU. The main contents are as follows:1) Analyzes in detail the current situation of HIL testing at home and abroad. By analyzing input and output signals of many kinds of automotive powertrain ECUs, an overall project design is put forward.2) In this paper, a circuit model is set up for ignition coil. ECU drives only primary winding of ignition coil, for which reason and considering the testing requirement of ECU, the simplified circuit model is set up. The simplified circuit model keeps primary winding only, and adds bleeder circuit which ensures the current curve of circuit model is in accordance with real ignition coil. Through the simulation analysis, proves the simplified circuit model can simulate the primary winding current of ignition coil exactly. The model has the characteristic of simple structure, so it fits to the development of simulated actuator.3) Describes the model creation method of automobile sensor output signal, introduces emphatically the model creation method of camshaft position sensor, crankshaft position sensor and knock sensor output signals. Base on the model, two-channel direct digital synthesizer (DDS) method is put forward. By using this method, camshaft position sensor, crankshaft position sensor and knock sensor simulated signals can be generated. By using high-end MCU and two-channel DDS, realizes the generation of three complex signals at the same time and without aggravating the hardware cost.4) Designs and develops HIL testing system for automotive powertrain ECU, which has independent intellectual property. Through verification testing, proves the validity of the system. This system realizes the in-line testing without test bench in laboratory environment, and solves the problems of difficulty and high cost of in-line testing.5) Based on the structure of HIL testing system, A ECU reliability testing system is set up, which can realize the unmanned operation, multiply samples reliability testing of ECU. This system can test fourteen samples at the same time, and realize automation completely in testing, test data recording and test error recording.