Contents
What is IMU Fusion?
Three-dimensional inertial measurement units (IMU) provide a device’s specific force and angular rate using a combination of accelerometers and gyroscopes. IMUs often incorporate additional sensors like magnetometers to provide even more functionality.
What can an IMU do?
An Inertial Measurement Unit (IMU) is a device that can measure and report specific gravity and angular rate of an object to which it is attached. An IMU typically consists of: Gyroscopes: providing a measure angular rate. Accelerometers: providing a measure specific force/acceleration.
How does the IMU and GPs work together?
To simulate this configuration, the IMU (accelerometer, gyroscope, and magnetometer) are sampled at 160 Hz, and the GPS is sampled at 1 Hz. Only one out of every 160 samples of the magnetometer is given to the fusion algorithm, so in a real system the magnetometer could be sampled at a much lower rate.
How is the fusion filter used in GPS?
Create the filter to fuse IMU + GPS measurements. The fusion filter uses an extended Kalman filter to track orientation (as a quaternion), velocity, position, sensor biases, and the geomagnetic vector. This insfilterMARG has a few methods to process sensor data, including predict, fusemag and fusegps.
How is an IMU used in a UAV?
Typically, a UAV uses an integrated MARG sensor (Magnetic, Angular Rate, Gravity) for pose estimation. To model a MARG sensor, define an IMU sensor model containing an accelerometer, gyroscope, and magnetometer. In a real-world application the three sensors could come from a single integrated circuit or separate ones.
What does the insfiltermarg measurement noise mean?
The insfilterMARG measurement noises describe how much noise is corrupting the sensor reading. These values are based on the imuSensor and gpsSensor parameters. The process noises describe how well the filter equations describe the state evolution.