Research On Hardware-in-the-loop Test System Of Power Shift Transmission Electronic Control Unit

The power shift transmission electronic control unit is responsible for receiving the operation command of the tractor driver and controlling the transmission to achieve smooth gear shifting.The electronic control unit needs to perform a large number of tests before entering the market to meet the reliability requirements.The hardware-in-the-loop test performs closed-loop testing on the controller by simulating the real vehicle,which can greatly shorten the controller development time and improve the eontroller quality.This thesis takes the hardware-in-the-loop test system for the power shift transmission electronic control unit as the research object.Based on the NI hardware and software platform,PXI fault injection board and AMESim software,the hardware-in-the-loop test system for the power shift transmission electronic control unit is developed.This thesis first analyzes the overall requirements of the hardware-in-the-loop test system of the electronic control unit,and determines the overall scheme of building the hardware-in-the-loop test system of the electronic control unit based on the PXI system.Use VeriStand as the main control software and program development software for the hardware-in-the-loop test system.The hardware-in-the-loop CAN communication database and the underlying software of the electronic control unit diagnostic instrument were developed by using VeriStand,which realized the communication between the hardware-in-the-loop test system and the electronic control unit and the reading of the diagnostic trouble code of the electronic control unit.Using VeriStand,the hardware-in-the-loop simulation driving,fault injection and electronic control unit diagnostic interface software were developed to achieve better human-computer interaction.The simulation software of position sensor and temperature sensor is developed by VeriStand.The model of speed sensor is established in AMESim.The speed signal conditioning circuit and temperature signal conditioning circuit are designed.The sensor signals required by the electronic control unit are generated by software,model,board and signal conditioning circuit.The solenoid valve coil current collecting circuit is designed to realize the power level hardware-in-the-loop test.The test cases were designed by using the methods of classification,methods of boundary analysis and methods of calculating mistakes.The automated test script software was written by VeriStand,and the test cases were automatically executed.The engine,proportional solenoid valve,wet multi-plate clutch,power shift transmission transmission system,gear pump,pressure regulator and tractor vehicle dynanics model were established by AMESim.The model was optimized by linear analysis and genetic algorithm.The comparison simulation and test results showed the model achieves a balance between simulation accuracy and calculation step size.In this thesis,the calibration software is used to calibrate the hardware-in-the-loop test system.The results show that the signal meets the electronic control unit requirements,and the electronic control unit diagnostic instrument can successfully read the diagnostic trouble code.The hardware-in-the-loop test system was used to test the startj shift and fault diagnosis fimctions of the electronic control unit.The results show that the hardware-in-the-loop test system works normally,the electronic control unit shift and fault diagnosis functions are good,and the hardware-in-the-loop test can save electronic control unit test time and reduce test cost.