Portable orientation estimation device based on accelerometers, magnetometers and gyroscope sensors for sensor network

In this paper, we developed a portable orientation estimating device equipped with the Bluetooth network module. Accelerometers and magnetometers are used to measure absolute orientation against the Earth. Gyroscope sensors are used to measure the local angular velocity. By integrating the measured absolute orientation with the local angular velocity using an unscented Kalman filter (UKF), the stability and robustness of estimating absolute orientation are improved over either sensor alone. Since this device has the Bluetooth module, we can easily construct sensor networks.