Research And Realization Of Strapdown Attitude Reference System Based On Embedding System

As an Inertial Navigation System, Strapdown Attitude Reference System is fixed on the carrier. It realized a built-in inertial navigation system platform within the computer .By acquiring the gyro and accelerometer signals, the computer complete real-time calculation of the attitude matrix, then extracted roll angle and pitch angle from the matrix vector. Attitude Reference System now is widely used in antenna stability, geographic exploration, tanks, ships, oil drilling platforms, sea surface tracking, and robot control. At present, domestic and foreign products is still lack of reliability, stability, real-time ability while prices are very expensive. In recent years, Digit Signal Processors (DSP) , with characteristics of high precision, real-time , low power consumption, particularly suite for digital signal processing, have been widely used in embedded systems. This project studied and developed a Strapdown Attitude Reference System based on TI's DSP chip, also completed the system architecture design and implementation.The whole system is composed of three parts: an IMU (Inertial Measurement Unit), an analog-digital conversion with signal interface unit based on MCU, and a data-processing module based on DSP. The IMU, which consists of three orthogonal FOG (Fiber Optic Gyro) and three orthogonal accelerometers, detects the angular velocity and acceleration of gravity in X-axis, Y-axis and Z-axis.The MCU realize A/D system conversion, then the DSP complete Attitude calculation. To improve the accuracy, the system has used an Adaptive Extended Kalman Filter for accelerometer and gyro signal denoising. This paper has introduced the principle of Attitude Reference System and related algorithm. It also provides a detailed description of hardware and software design, and a simulation of the Adaptive Extended Kalman Filter by Matlab.