Vertical-Gyro / Attitude and Heading Reference System Application

The Vertical-Gyro (VG) / Attitude and Heading Reference System (AHRS) application enables the OpenIMU hardware to fuse inertial-sensor information (accelerometers, rate-sensors, and — for the AHRS — magnetometers) to generate an attitude solution. The solution makes use of the high data-rate (DR) rate-sensor output to propagate the attitude forward in time while using the accelerometers and magnetometers as references to correct for estimated rate-bias errors and attitude-errors at a lower DR.

The mathematics behind the algorithm are quite a bit more complicated than the math associated with the Static-Leveler application. The full description is not discussed here, as . However, the complete formulation is provided in the “Ready-to-use Applications” section.

The VG/AHRS example application performs the following functions:

• Sets the default OpenIMU configuration
• Acquires sensor data - acceleration, angular-rate, local magnetic-field, and sensor temperature data
• Executes the VG/AHRS algorithm
• Populates the output data structure
• Generates and sends the following output message to the UART - the output message description is To Be Provided