The Design Of Dynamic Parameters Acquisition System For Rocket Engine

The modern dynamic parameters testing technique is playing more and more important role in development of rocket engine. According to the requirement of the rocket engine dynamic parameters testing system, a 2-channel acquisition system based on PCI bus was designed, with a max sample frequency of 10Msps, an accuracy of 12-bit and a max capability of 32M for each channel.The system consists of two sub-modules, the DAQ card and the software platform. The DAQ card is in charge of data acquisition, storage and transmission according to instructions sent by software, while the software platform is responsible for module driver, proceeding control and data processing.The AD9238 is used to realize the A/D conversion and the data are stored in the DDR SDRAM. The DAQ module is controlled by FPGA and the interface of DDR is realized based on FPGA. Using DDR as memory device has developed the storage speed and Capacity. The interface chip uses the PCI9030.The control programme describes the circuit behavior in VHDL by employing the modularized design method and uses state machines to synchronize the control signals. Using TimeQuest Timing Analyzer Eliminated the violative timing paths, improved the Stability and Reliability of the system.The software platform is developed under the LabWindows/CVI. The testing system developed was of friendly communicating interface, less time-consuming and well functional expansibility. Consist of data acquisition, wave display, data processing and wave storage modules. Using DLL Technique call the Drive Program, realized the control of acquisition processes, including module search, parameter settings and data transmission. The programme for data processing accomplishes time domain and frequency domain analysis and can transform the data document to text documents, convenience for storage and print. The tested results indicated that the system has met the design requirement.