10-DoF MEMS IMU features algorithm to deliver precise orientation sensing

June 26, 2012 // By Paul Buckley
Analog Devices, Inc. has introduced a 10-degree-of-freedom (DoF) MEMS inertial measurement unit (IMU) with an embedded sensor fusion algorithm that delivers accurate orientation sensing in platform stabilisation, navigation and instrumentation applications.

The ADIS16480 10-DoF MEMS IMU is the latest addition to ADI's iSensor MEMS IMU portfolio and integrates a tri-axis gyroscope, tri-axis accelerometer, tri-axis magnetometer, a pressure sensor and Analog Devices' ADSP-BF512 Blackfin processor in a single package.

The ADIS16480 incorporates an extended Kalman filter (EKF) that fuses the sensor inputs over time to render exceptionally precise positioning while reducing design time and cost compared to other MEMS IMUs. This is particularly useful in systems that require real-time positioning yet where movement is constant, complex and dynamic, such as military and commercial aircraft navigation, unmanned vehicles, movable platform positioning, and industrial robotics.     

Kalman filtering is a mathematical algorithm that estimates the given state of a noisy, variable process by taking multiple measurements over time, and merging these with a predictive state estimator. When embedded in the ADIS16480, the Kalman filter intelligently combines the MEMS IMU's motion sensor inputs to deliver exceptionally precise positioning data, even under complex operating conditions characterised by constant, unpredictable movement. By embedding the filter in the Blackfin processor's core, ADI also saves designers the time and cost associated with the intensive code development, testing and external processing required by other MEMS IMUs.      

With a 330-MHz bandwidth that is 6x wider than competing sensors, the ADIS16480 iSensor 10-DoF MEMS IMU combines ADI's high-performance iMEMS technology and precision sensor-signal processing to support closely aligned (0.05 degree) and phase-matched axes, and industry leading non-linearity of 0.01%. Every MEMS IMU is uniquely factory calibrated, which significantly reduces the time and risk associated with development and integration, as well as providing extremely low sensitivity to thermal drift.       

ADI has also further extended its iSensor MEMS IMU portfolio by introducing the ADIS16448 10-DoF and ADIS16485 6-DoF MEMS sensors. The ADIS16448 is designed for platform stabilisation, navigation and instrumentation applications and delivers the industry's best combination of price, performance and package density (24-mm x 38-mm x 11-mm). The ADIS16485 MEMS IMU