Design and realization of digital compass with magnetometers

To solve the high cost of design and the high failure rate of common digital compass used triaxial magnetic sensor, this paper designed a digital compass which is composed of two-axis magnetic intensity sensor and two-axis accelerated sensor. It uses the direction cosine transformation matrix between the geographic coordinate system and the carrier coordinates of the Earthpsilas magnetic field and gravitational field to compute the absolute heading angle. The specific system architecture and the detailed mathematical model were also proposed in this paper. Aiming at the measurement errors caused by the fixed disturbance magnetic field in the environment, the digital signal filtering and zero drift compensation methods were adopted to improve the measurement accuracy. Using Honeywell magnetometer sensor HMC1052 and ADXL202 accelerometer sensor of AD Company as the key elements, the device has the advantage of low cost, strong anti-interference and high sensitivity, and so is suitable for the embedded application.