Design Of Test System For Vehicle Air Conditioner Usage And Load Characteristic Modeling

The development of driving cycles of vehicle performance detection depends on the operating characteristics of the vehicle in the actual road driving,which are affected by the factors such as climate,traffic,vehicle states and driving habits,and so on.Based on the requirements of China Automotive Technology & Research Center to develop the Chinese driving cycles of vehicle performance detection,this paper constructs the test system to test the vehicle air conditioner usage and load characteristic,and to study its influence on the vehicle fuel consumption.The main works are as follows:(1)The test system functional requirements and architecture were confirmed,then the hardwares,such as the data acquisition unit and sensors were selected.(2)A virtual test system was built based on NI sb RIO 9636 board.Data collector software and the host computer software were compiled based on the Lab VIEW development environment.The data collector software is run on the data acquisition device,with the sampling frequency of 10 Hz to achieve multi-channels signal acquisition and upload them to the portable computer.The host computer software is run on the portable computer,which aims to achieve the function of data receiving,data displaying,data recording and so on.The whole system realizes the real-time and synchronous acquisition of the intake air quality of the engine,the vehicle speed and its track,the ambient temperature,and so on.(3)The basic functional tests and the special vehicle tests were carried out.The basic functional tests proves that the test system accomplished reliably the data acquisition function in real-time.We choose the passenger vehicle to carry out the special vehicle tests.With different air conditioner gears and loads have been selected,and the vehicle traveled along the test route,and the test system recorded test data simultaneously.(4)The collected data were processed,and the results showed that the overall vehicle driving speed was in the range of 5～70 km/h,the vehicle air conditioner usage and load would increase vehicle fuel consumption.The vehicle fuel consumption increased by17.86% when air conditioner was in the high-gear;the vehicle fuel consumption increased by 7.62% when the vehicle was in full load;the vehicle fuel consumption increased by7.59% when air conditioner was in the low-gear;and the vehicle fuel consumption increased by 26.48% when air conditioner was in the high-gear and the vehicle was in full load.