International Journal of Hybrid Information Technology Vol.7, No.3 (2014), pp.39-48 http://dx.doi.org/10.14257/ijhit.2014.7.3.06 ISSN: 1738-9968 IJHIT Copyright ⓒ 2014 SERSC Error and Noise Analysis in an IMU using Kalman Filter S.A.Quadri and Othman Sidek Collaborative Microelectronic Design Excellence Centre (CEDEC) Universiti Sains Malaysia, Engineering Campus, Nibong Tebal reachquadri@yahoo.com Abstract Kalman filtering is a well-established methodology used in various multi-sensor data fusion applications. In our experiment, we first obtain measurements from the accelerometer and gyroscope and fuse them using Kalman filter in an inertial measurement unit (IMU). We estimate Kalman filter output and estimation error. The affect of process noise and measurement noise on estimation error is tested. It is explored that the measurement noise has significant role to increase estimation error in the data fusion process. Keywords: Kalman filter, Data fusion, Accelerometer, Gyroscope, Process noise, Inertial measurement unit, Measurement noise 1. Introduction In recent years, with the development of sensor technology and processing algorithms, multi-sensor data fusion has received significant attention in many engineering applications. Data fusion plays a critical and fundamental role in achieving accuracy and precision. For many applications, accuracy and precision are key performance metrics. One of the main concerns in any fusion technique is the risk of producing a fused system result that is actually performing worse than the best individual tool. Poor estimation could be responsible for poor performance of data fusion system. The paper presents fusion of two estimates from gyroscope and accelerometer in an IMU employing Kalman filter, which is well-known optimal estimator. The noise and other inaccuracies contribute to estimation error in fusion process. This brief paper presents the effect of measurement noise and process noise on the estimation error. 2. Inertial Measurement Unit An inertial measurement unit (IMU) is an electronic device that measures and reports on a craft's velocity, orientation, and gravitational forces, using a combination of accelerometers and gyroscopes. IMUs are typically used to maneuver aircraft, including unmanned aerial vehicles (UAV), spacecraft, including shuttles and satellites. An IMU works by detecting the current rate of acceleration using one or more accelerometers, and detects changes in rotational attributes like pitch, roll and yaw using one or more gyroscopes. A basic unit with assembly of components is shown in Figure 1. A detail description of principle, working and application of IMU could be found in [1-3].