Research On Hardware-in-the-loop Test Of Commercial Vehicle ATM Shift Control

The automatic manual transmission is referred to as AMT transmission,which is based on the manual transmission by adding an optional shifting mechanism and a clutch operating mechanism,and is controlled by a controller to complete the automatic shifting.AMT transmission maintains the basic structure of the original manual transmission,and has the advantages of high transmission efficiency,compact structure,low cost,easy manufacture,and can greatly reduce the labor intensity of commercial vehicle drivers.At present,AMT transmission has a good development prospect in the commercial vehicle market.In the development process of AMT transmission,the development and testing of transmission controller is particularly important.The traditional test usually adopts bench test and real vehicle test,which is not only time-consuming and labor-intensive but also costly.The system has been researched accordingly.The main research work of this paper is as follows:1)According to the analysis of the functional requirements of the AMT transmission controller,the overall design scheme of the hardware in the loop test system of the AMT transmission controller is proposed.The requirements and objectives of the test system are analyzed.The system is divided into the upper computer and the lower computer architecture.The upper computer communicates with the lower computer real-time emulator through the network cable.2)The commonly used shift laws of AMT transmissions are studied,and the optimal dynamic shift curve for this project model is formulated using the acceleration method.The shift process control logic for each gear shift is formulated.According to the shift law curve and the shift process control logic,a virtual controller model is built using Simulink and Stateflow.The engine model is built using the look-up table method,and the dynamic response characteristics of the engine are simulated using the transfer function.Build clutch model,transmission model,vehicle dynamics model,driver model.3)Build the hardware platform and software platform of the hardware-in-the-loop test system.The main tasks include the selection of the chassis,the selection of hardware boards,the transformation and connection of the controller wiring harness,the modification of the model interface in the software part,the compilation of the model,and the host computer.Veri Stand project configuration and test system integration debugging,etc.4)By studying the commonly used software testing methods,an appropriate test case design method is selected,and the corresponding test items are formulated according to the functional requirements of the controller.The test case writing software is used to write the corresponding test cases for testing,and the results are analyzed to verify the results.The shift function of the tested controller found the existing problems,which provided help for the subsequent program optimization and subsequent bench experiments and real vehicle experiments.