3.1 System Requirements Analysis

3.1.1 System Functional Design Requirements

This hardware processing platform has three main types of tasks: First, data acquisition, including collecting output signals from inertial measurement units (IMUs) and receiving external system correction information, such as GPS data; Second, data processing and computation, including error compensation for inertial measurement units, initial alignment, navigation parameter solution, and online correction filtering; Third, navigation data output, including navigation parameter output and information exchange with the master control device.

The specific functions to be implemented by this hardware circuit system include:

(1) High-precision analog-to-digital conversion for three-channel accelerometer analog signals;

(2) Timed acquisition of digital signals from three-channel gyroscopes;

(3) Timed acquisition of one-channel GPS signal and its one-pulse-per-second (1PPS) time base signal;

(4) Timed acquisition of one-channel barometer digital signal;

(5) Timed acquisition of two-channel odometer pulse signals;

(6) Timed acquisition of digital signals from 5 temperature sensors;

(7) Perform navigation solution processing on the acquired signals and package various data, then output them via one CAN interface, one RS232 interface, and one RS422 interface, respectively.

**3.1.2 System Performance Design Requirements