Research On Hardware-In-Loop Test For TCU Of Electronic-Mechanical Continuously Variable Transmission

In response to the call of the national energy saving,all the major car companies focus on the improvement and development of vehicle power transmission system and its control system.At present,the continuously variable transmission(CVT)is widely used in various vehicle types due to its driving smooth,high efficiency,energy-saving and other advantages,but most traditional continuously variable transmissions use pumps,valves,hydraulic torque converter and other hydraulic systems with the result that its fuel-saving efficiency is not very good.The electronic-mechanical continuously variable transmission(EMCVT)which is simple in structure and uses metal belt band to transmit power adopts gears,motors,springs and other low-cost,low-power,high-reliability mechanical components instead of pumps,valves and other hydraulic components to reach a more ideal fuel consumption.TCU,the electronic control system of EMCVT which is the key to make transmission and engine run suitedly is of great significance for improving the work efficiency of the engine and transmission as well as the car's driving comfort and fuel economy.Traditional bench test methods can not meet the needs of the rapid development of modern controllers,and hardware-in-loop simulation test technology which greatly shortens the development cycle of controller has become an important link in the development of modern controllers.In this thesis,built the TCU hardware-in-loop test system based on LABCAR simulation platform and made TCU basic functional test and validation.On the basis of an understanding of the principles,key technologies and research status in hardware-in-loop simulation testing technology,according to TCU functional test requirements,its working environment and the characteristics of the input and output signals,functional requirements and mission requirements of the designed HIL test system are confirmed.With the analysis of structural characteristics and functional properties of various HIL test systems,a plan of TCU HIL test system design based on LABCAR platform is proposed.At the same time,hardware boards are selected according to the type and characteristics of TCU input and output signals.Modular modeling method is used to build a real-time simulation model.Firstly,elaborate the composition of LABCAR GEVM model,then divide the entire car system into different modules and study their modeling.After being familiar with thecomposition and working principle of each sub-module,its function is achieved with C code based on Matlab/Simulink modeling environment and embedded in the program environment in the form of S-function.According to the characteristics of the sensors and actuators in actual EMCVT,establish signal interface model of sensors,actuators and the controller in LABCAR-OPERATOR and Simulink.Finally,use TCU HIL test system which is built based on LABCAR platform to make open-loop tests and closed-loop tests.The results showed that TCU hardware circuits are functioning properly and the speed control strategy can achieve effective control of EMCVT speed ratio.