Research On Massive Data Acquisition System

Magnetic Flux Leakage (MFL) inspection is the main method of on-line inspecting long distance oil-gas transportation pipeline. Pipeline MFL inspection device is applied to detect defects of pipeline in time in order to prevent pipeline leakage accident. As MFL inspection device works inside the pipeline using many sensors for real-time data acquisition, it should have the function of acquisition and store in the system. In this paper, a massive data acquisition system based on FPGA (Field Programmable Gate Array) is designed to acquire and store pipeline MFL inspection data in real-time.First, because of channel-number difference ,the structure differences between traditional multi-channel acquisition system and massive data acquisition system are analyzed aiming at a design with multi-channel high-speed AD as the kernel part. The massive data acquisition system which is designed in this paper can acquire 400 channels with the rate of 1KHz per channel. The caches in the system ensure the real-time and continued acquisition, storing the data into hard disk. The reading and writing hard disk in the way of PIO form is designed to saving the data in the caches to the hard disk directly, in the aim of getting rid of the limitation of traditional PC. The hard disk with large capability can keep a long-time run.Aiming at each functional module designed in the system, testing methods and corresponding results are presented respectively in the paper. Experiments indicate that each functional module can run stably with good performance, and they can be used in the pipeline MFL inspection device with no problems.The system has some features as follows: Utilizing the parallel-structure advantage of Verilog HDL in working-speed, realize the synchronization in both high-speed acquisition and high-speed storing. The device modules can be increased or decreased according to the system requirements, which settle the foundation for the application of the system. In the same time, reliability of the system and capability for multi-channel acquisition is improved greatly via applying FPGA. Simplify the mass wire and ensure the communication between FPGA and other equipment by SPI bus, which enhance the feasibility of the system.