Design And Research Of On-Board Data Acquisition System For ITS Based On Virtual Instrument Technology

Real - time traffic information Acquisition is the key to urban intelligentized transportation, and has wide applications in transportation planning and transportation manage control utilities., Based on Virtual Instrument technology, This paper is aimed at design of on-board data acquisition system which can acquire position ,velocity, acceleration and pose angle for ITS. Many aspects are concerned in Vehicle Information Acquisition System. This paper only studies positioning, data collection of Vehicle Information acquisition system.This paper describes the structures and functions of the vehicle device component and discusses the realization of concrete hardware and software in detail. In data acquisition aspect, the data of GPS are inputted computer by RS232 serial interface, the acquisition data of inertial measure unit are inputted computer by (SCXI) Signal Conditioning extensions for Instruments, these data are processed by computer then positioning information, velocity, acceleration and pose angle state detection are acquired. In positioning aspect, the embedded vehicle positioning system is designed by combination GPS receiver/inertial measure unit for improving precision of position. Inertial measure unit (IMU) are one of the most widely can provide continuous position, velocity and also orientation estimates which are accurate for a short term, but are subject to drift due to sensor drifts. The result of GPS and IMU which are integrated by Kalman filter can limit shortcomings of the individual systems namely, the typically low rate of GPS measurements as well as the long term drift characteristics of IMU. Integration can also combine the advantages of the two systems based on, such as, the uniform high accuracy trajectory information of GPS and the short term stability of IMU.At last this paper processes the experiment results and gives the conclusion and prospects.