Research And Design Of Multi Channel Dynamic Signal Acquisition System

With the development of science and technology,dynamic testing technology combines electronic technology,sensor technology,digital processing technology,interface technology and other technologies,and is widely used in mechanical state fault detection,aerospace environment testing,national defense industrial equipment testing,automobile industry testing and other fields.Among them,dynamic signal acquisition is the foundation and key of dynamic test technology.First of all,This dissertation analyzes the development and demand of dynamic signal acquisition system in various fields,and expounds the development process and development trend of similar products at home and abroad.According to the design index,the overall design scheme of the system is put forward.Through reasonable circuit design and logic analysis,the whole system is built.The whole system mainly includes signal conditioning and acquisition module,data processing and transmission module and signal generation module.The signal conditioning and acquisition module includes four acquisition channels.Two low-frequency channels are used for external ICP / IEPE sensors,which can collect vibration signals in the range of 1Hz ? 10 k Hz.Two high-frequency channels are used for collecting other dynamic signals with the highest frequency of 204.8 k Hz.Select 24 bits ?-? The sampling rate is up to 1.25 MSa/ s,which realizes high precision and large dynamic range acquisition.In the data processing and transmission module,Ethernet interface is used to realize the data communication between the upper and lower computers.The signal source module can output single frequency signal,frequency shift keying(FSK)signal and slope frequency shift keying(sfsk)signal orthogonally,which is used to generate test signal for signal acquisition system test and calibration.Finally,the test system is built to complete the power supply,signal source,acquisition channel and Ethernet transmission.The test results show that all parts of the system can work normally and stably.The channel spurious free dynamic range(SFDR)is higher than 100 d B,the low frequency channel dynamic range(DR)is higher than 100 d B,and the high frequency channel dynamic range(DR)is higher than 90 d B.The test results achieve the expected targets,and verify the feasibility of the system scheme.