Design Of Inertial Navigation System Attitude Information Correction

Attitude information is an important parameter in the navigation system and is the prerequisite for spacecraft and aircraft working. Attitude control failure means that the spacecraft malfunctions. Attitude control needs attitude measurement first, which is usually estimated by the gyroscope. But the high cost and large volume of traditional gyroscope limits its applications and the precision of MEMS gyroscopes is low. Gyroscopes drift will also cause large attitude error in short time. To solve the above problems, this paper presents solutions of calibrating the gyroscopes attitude information with magnetoresistive sensor and MEMS acceleration sensor and constructs attitude information correction hardware platform based on ARM7-core processor LPC2103. A series of designs and experiments were carried out in the paper.First, this paper described the development situation and theory of geomagnetic navigation, based on which a method of getting attitude information with magnetoresistive sensors and MEMS sensors was put forward: 3-axis accelerometer sensor gave accelerometer vector information, by which the pitch and rool angles were measured, and then with the help of the geomagnetic components given by magnetoresistive sensor, the pitch angle was measured. Software and hardware solutions of the sttitude correction system was proposed and realized. In the hardware design part, the characteristics of the sensor and the host processor were introduced ,the power module, signal processing module , set / reset module and LCD module, circuit design and PCB EMC design were designed ; In software design, sensors signal acquisition, anti-electromagnetic pulse interference filter , attitude information calculation were realized and attitude information was displayed on the LCD with graphics and text mode .In addition ,the mechanism of the system sensors error was discussed and the error compensation test was made.The experimental results showed that the attitude information system error was about 1°, which achieved the desired objectives basically.