Calibration against orientation drifts in a real-time Embedded inertial Measurement Unit

This paper presents the development and implementation of an Inertial Measurement Unit (IMU) where Micro-Electro-Mechanical System (MEMS) sensors are used to measure angular velocity and acceleration, a magnetic sensor (magnetometer) is used to calibrate against orientation drifts, a Global Positioning System (GPS) signal receiver is integrated and an extended Kalman filter algorithm is applied for real time signal processing to estimate the attitude of an object in space. The MATLAB/Simulink Embedded tool and C30/MPLAB Compiler are used to design, compile, and download directly into the target. An update rate of 100Hz with real time floating point processing can be achieved for the extended Kalman algorithm using a Microchip 16 bit dsPIC33f256 microcontroller.