Research Of DAQ System For Vehicle Roadway Test Based On Wheel Force Measurement

The DAQ(Data Acquisition) system for automobile roadway test based on wheel force measurement, is a kind of important equipment for vehicle test. The movement of vehicle is a result of force effect made by the ground and the wheels, so it is of great significance to measure the wheel force in multi- direction for researching and estimating the dynamic performance of the vehicle, such as braking, accelerating, suspension, tire abrasion and road profile collecting.Aiming at developing a kind of general DAQ system for automobile roadway test, the principle and precept of wheel force measurement is researched in this paper. as well as the design of wheel force measuring instrument, the DAQ machine and the handheld device. The system is constructed and applied in roadway test to validate the preciseness and reliability of the system. The discussion covers:1. Using spoke sensor as the wheel force sensor, an embedded circuit is designed to sample the wheel force signal. And the wheel force instrument is constructed using non-contact signal transmission, which could achieve direct measurement of wheel force in six (or three) directions.2. A DAQ machine is designed in modulized structure, composed of a main module card and several functional module cards. After signal in different channels is sampled by the functional module card, the main module card collect all the data and store them in the FLASH memory, and data files could be output to the PC. The system could be expanded for different objects or channels by adding functional cards.3. The software in PC is designed in graphic interface to achieve data analysis and could provide results and parameters of the test automatically.4. Finally the system is applied in roadway test. All the data meets the requirement and the result shows that the design is reasonable and convenient for use.This paper provides a general precept for the development of DAQ system for automobile roadway test. The design method of this system is of great significance for designing similar systems. The DAQ system has been made into product, providing foundations for system upgrading and further design.