Research On Adaptive Changing Sampling Rate And Resolution Data Acquisition System

Data acquisition technology plays an important role in information acquisition and processing, therefore, it's essential to develop a common data acquisition system so that the repetitive development of hardware can be avoided, the cost of research and development lowered and the product designing efficiency improved. In view of the current data collection system is not universal in application, the design of the sampling rate and resolution of adaptive signal changes according to the data acquisition system. Real-time anglicizing and processing on signal, adjusting system parameters, making data acquisition system in the best condition. On the premise of the sampling rate, DSP processing can reduce the volume of data and improve dynamic range and efficiency of the system. To sum it up, the main aspects of this paper as follows:First, a solution of the self-adaptive variable sampling rate and resolution data acquisition system is presented, introducing the hardware design and the software of the solution respectively. System principle, whole system frame diagram and chip selection are also introduced.Second, the designing of the hardware is determined. PGA202/203, MAX274 and the analog-digital conversion chip AD7864 which are used in the front-end signal conditioning circuit are introduced in detail, in addition, the application of CPLD (Complex Programmable Logic Device) and DSP (Digital Signal Process) are also introduced. Then the hardware schematic diagram and PCB (Printed Circuit Board) are pictured and the debugging work is completed, meanwhile problems emerging in the PCB designing process of the high-speed digital circuits are analyzed.Third, the self-adaptive variable data acquisition system sampling rate and resolution algorithm is studied, and the algorithm is experimented on TMS320VC33. The system firstly analyzes the amplitude and spectrum of the acquired signal at real time to judge whether the system is at its best state. If the sampling rate and resolution don't meet the signal requirements, the system is adjusted to the optimal signal acquisition state of the corresponding signal. Then the data acquisition work is continued to complete the sampling rate and resolution process of the self-adaptive system.The solution is complete, effective and meets design requirements. It has provided beneficial enlightenment for us on further research and design of a higher performance variable sampling rate and resolution data acquisition system...