Design Of Synchronous Data Acquisition System On Noise Signal Location

Noise positioning is of great significance in large mechanical processing and fault diagnosis, it can be realized by method of TDOA or CBF. TDOA algorithm has simple principle and high computation speed, but lack of positioning accuracy. CBF algorithm based on microphone array has high accuracy, but it is complex and has low resolution. Multi-channel synchronous data acquisition system is needed.A32-channel synchronous data acquisition system was designed in this paper based on embedded microprocessor (S3C6410) and four AD7606according to the requirement of noise positioning. Microprocessor is used for noise signal acquisition, reading, transmission and display. Bulk storage of noise data is realized by USB flash disk. LCD touch screen is used to display collected data and noise waveforms. The system has16bits sampling accuracy,50kSPS sampling rate and less than3%error rate, meets the requirements of noise signal acquisition.Firstly, control system and data acquisition system were designed with ARM11(S3C6410) as the main chip. A/D power module, A/D driver module, data storage module and communication module were included in data acquisition system.The PCB of data acquisition system was designed at last.Secondly, a memory-mapped driver design method is used to achieve synchronization control of S3C6410on four AD7606under embedded environment, according to the hardware designed and noise acquisition requirement in this paper. This method is used to directly store collected data in user space and avoid data loss. AD7606triming analysis, memory mapping principle and mapping menthod are mainly included in the whole system. The process of driver design in this paper was introduced in details from kernel space to user space. The performance of system was tested through a number of grouping experiments.Finally, control system and data analysis system were designed to accomplish noise data acquistion and display based on development environment of Qt and VC++. Error analysis on acquisition signal and standard signal is to verify the accuary of system.