| As a kind of basic measuring instrument, data acquisition system plays a very important role in many fields. For example, in radar systems, geological exploration,medical equipment, aerospace, we usually need to measure and analyse a large number of various high frequency and real-time signals. In these applications, the acquisition systems are required to be able to measure and display the waveform and related parameters. At the same time, the acquisition systems should store the data. And when we measure a signal, some related signals should also be measured synchronously. The accuracy and the number of channels and synchronization performance of the data acquisition system are very important. so it is very necessary to study on the multi-channel synchronization, high precision and anti-jamming data acquisition system.In this thesis, I study on multi-channel synchronization data acquisition system based on USB interface, which has 32 channels, 50MSPS maximum sampling rate,16bits resolution, and the synchronization is less than 1 sampling point. The main research contents include the following parts:(1) Methods to improve the synchronization performance between different channels of multi-channel and high-speed acquisition system, analyzes the main factors which influence the performance of synchronization, and puts forward the corresponding solutions according to these factors, the requirements of the inter channel synchronization performance is less than 1 sampling points.(2) Complete the hardware design of 32 channels data acquisition module. the module structure is analyzed, and the design of the analog channel, data acquisition module, control module, digital storage module, data transmission module is discussed.This paper discusses from the aspects of device selection and circuit design. At last,complete the implementation of all the modules.(3) study on the factors that affect the precision of the acquisition system. And put forward some methods related to reduce the noise and crosstalk to improve precision of the system.In this thesis, the multi-channel high-precision acquisition module is designed to realize the 32 channels,50MSPS high speed and high precision data acquisition, the synchronization between the channels is lower than 20ns, which can meet the needs of most applications. |
