The Embedded Data Acquisition And Processing For The Combined Screens

The crowding level of the Vertical Target is a essential measurement parameter in the Exterior Ballistic Experiment of the weapon system. The Six-light-screen Array Measuring System, the Dual-CCD Intersection Measuring System and the Four Combination Screen Testing System had been sprung up around the testing of this parameter in recent years. Among them, the Four Combination Screen Testing System has a simple principle and lower costs, which has a good application prospect. This paper is aimed at the design of the Four Combined Screens Array Testing System, it had researched the total scheme of embedded data acquisition and processing.First, it had researched and analyzed the composition and operational principle of the Four Combined Screens Array Testing System, compared and analyzed the measurement error of the Four Combined Screens Array Testing System and the Six Light Screens Sky Screen Vertical Target on the platform of Matlab. The results show that not only the Four Combined Screens Array Testing System has fewer test screen surface than the Six Light Screens Sky Screen Vertical Target, but also has higher measurement accuracy.Second, it had designed the hardware circuit based on the task which have to be completed of the data acquisition system. The design principle of the hardware circuit is enough to use. The hardware circuit mainly includes:Delay Trigger Circuit and the Embedded Data Acquisition Module and the Image Acquisition Module which is based on the PC 104 Plus Bus. It has designed the delay trigger circuit which can limit the pulse width of the input signal in a certain range in order to prevent the false triggering of the acquisition card, which is used to complete the anti-interference logic processing and delaying to the output signal from the sky screen target. The delay trigger circuit consist of the SCM control circuit and the FPGA logic circuit. The platform of the embedded data acquisition system consist of the PC104 host PM-PV-D4251/N4551/D525 and the data acquisition card PCH8502. From the point of view that a comprehensive consideration of the data bandwidth, interface and which is convenient to the system construction, we choose the spyder 3 series High Speed Linear CCD cameras from the Dalsa company.Third, it had designed the corresponding utility software for the hardware which is used. The utility software is using VB6.0 development. The software design adopts modularization design, which consists of data acquisition software and image acquisition software. The data acquisition software is used to accomplish the control of the data acquisition card and the acquisition, processing and display of the signal of projectile shape, which gains the time when the projectile is passing by the target accurately to the processing of the collected signal of projectile shape by using the related algorithm. The image acquisition software is used to accomplish the control of High Speed Line Array CCD of the Gigabit Ethernet port, which is to be realized the acquisition and processing of the image of a projectile when it is passing by the target.Last, it had done a laboratory validation of the performance and working situation to the designed embedded data acquisition system. It had tested and verified the sampling frequency that use the standard sine wave signal; it had tested and verified the Frequency-response Characteristic by the Single sine wave. It had done the live ammunition shoot experiment to the data acquisition system, which use the air gun bullet, the results show that the designed embedded data acquisition system can correctly accomplish the collecting task of analog signal and image information, which is stable and reliable and can be successfully used to the Four Light Combined Screens Array Testing System.