Key technology of data acquisition for tri-unit rotating inertial navigation system

Compared with the classical strap-down inertial navigation system(SINS) and the rotating inertial navigation system in being, tri-unit rotating strap-down inertial navigation system has many advantages. Nevertheless, it brings some new problems to data acquisition. As data quantity is large, to ensure all of the data sampled coming from the same time, the impact of time asynchronization both between inertial sensors and between inertial sensors and gratings is analyzed in detail. Then several solution are taken, such as synchronous pulse, data latch and angles average. In order to decrease motor rotating impact on temperature acquisition, the causes are described concretely and digital transmission is taken. Moreover, a new communication between digital temperature sensor DS18B20 and DSP is designed in hardware. The result shows the data acquisition instrument comforts anticipative requirements such as time synchronization and resistant to electro magnetic interference(EMI). So it lays down the foundation for the realization of high-precision, low-cost inertial navigation system.