Design And Implementation Of A Data Acquisition System Based On OMAP-L138

Doppler log is used to measure the velocity of ships relative to the earth and water, and accumulate the voyage, widely applied in the field of autonomous navigation. As phased-array doppler log has several advantages, such as small size of array and no need of compensation for sound velocity, it has become the mainstream research direction currently.In the paper, according to the requirement of recording beam signals in four directions of phased-array doppler log which is applied in an autonomous underwater vehicle (AUV), a set of data acquisition system is designed, with the content of system project design, hardware circuit design and software programming. In the system, the OMAP-L138 processor is applied as the master control chip. On the basis of the demands of system functions and performance indicators, the peripheral circuit is developed, which contains four analog-digital converters used for completing the data synchronous acquisition in four directions, an MSP430 single chip processor and a real time clock used for power and time management, a SATA hard disk with large capacity used for the storage of the data obtained and the relevant time information, to realize the real-time acquisition and automatic storage of data under unattended conditions, providing support for testing the facticity, effectivity and instantaneity of field data.Under laboratory conditions, the functions of the system are verified, and the system performance is tested from multiple aspects. The results show that the data acquisition system designed in the paper implements the functional requirements, meets the desired indicators,works steadily and reliably and reaches the intended effects.Finally, the following improvement direction is put forward, providing reference for the further research of the data acquisition system based on phased-array doppler log.