Based on virtual instrument technology, the automobile dynamic performance measurement system is set up to improve the current testing methods whose results are not humanization. The system which is developed with LabVIEW and consists of lap-top, sensor, sample-and-hold accessory and data acquisition card, can valuate the automobile dynamic performance, including the display of velocity, acceleration, distance. The feasibility and practicability was proved by experiments and error analysis on

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... is system. The results show that the system has a stable and repeatable performance, can reflect the test data exactly. part of the text. Punctuation appears after the equation but before the equation number. The use of Microsoft Equation is allowed. Scope Because of the automobile development is much faster, also the structure and the driving condition are more and more complex, almost manufacturers are eager to update the dynamic property during the designing and producing. Controlling the automobile property by measuring and result analysis, we can improve the practicability and economic benefits. But the traditional measuring equipment can only have the defined functions and the user can't change anything before equipment delivery. Traditional measuring equipment isn't enough on expansion capability and openness, and some other disadvantages such as the big volume, expensive cost and so on. So we need an effective and suitable solution to promote testing efficiency and reduce the cost, which could be fit the testing requirement on speed, accuracy, data analysis and practicability. So combine with the software and hardware made by NI company, we can create a system for testing the automobile dynamic property. This kind of testing system is portability and analyzability. With LabVIEW platform, the system is good at fields for data collection of virtual instrument, data testing and analysis, displaying the result. And also we can get the real-time speed, acceleration and the maximum speed directly during testing process. Theoretical foundations for creating test system Automobile dynamic property includes 3 elements: the maximum speed Vmax, acceleration time t and grade ability imax. And the relating dynamic testing also contains 3 sections: the highest speed test, acceleration test and minimum stabilized speed test. The composition of testing system Automobile dynamic property testing is basing on the collecting, handling and analyzing the speed signals from the sensor by virtual instrument. Use the software to reach the collection, displaying and analyzing functions. This kind of system has 2 parts software and hardware. The composition of system hardware The hardware contain OES-Ⅱnon-contact speed sensor, DAQcard-AI-16E-4(NI-6041E), SC-2040 data keeping card, DIY voltage converter and lap-top. The composition of system software The software is the core part of the testing system. The target of the program is that we can collect signals from speed sensor, analyze and display instantaneous speed of automobile, distance, maximum acceleration. The program of automobile dynamic performance measurement system is based on the LabVIEW virtual instrument (VI).