Interface & modes

The algorithms for sensor fusion are TDK-InvenSense IP and runs in encrypted form on the DMP or as a binary on the host. Sensor fusion outputs quaternions, which is a 3D representation of the movement of an object in space. As long as the application is using quaternions, there is no need for the system developer to get burdened with the details of sensor fusion implementation

Software Downloads | InvenSense Developers (tdk.com)

Euler angles are a representation of an angular frame, as are quaternions and rotation matrices.

Euler angles are a set of three angles, corresponding to pitch, roll, and yaw. Euler angles may be constructed according to many conventions. The axes of and ordering of ordering of pitch, roll, and yaw vary by convention. 

Euler angles are not commutative. For any Euler angles A, B, a rotation A followed by B is not 

(B + A) is necessarily equal a rotation B followed by A (B + A). Because of this algebraic property, Euler angles are often not very useful for signal processing applications.

Euler angles suffer from a pair of singularity points at which only two of the three angles are significant. The derivative of the Euler angles is discontinuous at this point. This condition is often called gimbal lock.

Embedded MPL is the same as Embedded MotionApps Platform. It is the software solution for MotionProcessing from InvenSense, that is used with its production proven hardware such as IMU-3000, and MPU-6050, and MPU-9150. The intended applications for Embedded MotionApps Platform are microcontroller based, and expected to run in very small memory and processing footprints.

To create and use a mapping gyro bias to temperature, using the ML_BIAS_FROM_NO_MOTION tracker to discover gyro bias and the IMU/MPU’s built in temperature sensor to determine temperature. The mapping of gyro bias to temperature will stay constant [1] throughout the lifetime of the part, so a bias, once learned, can be used to calibrate the gyro at any time it is at that temperature. When ML_LEARN_BIAS_FROM_TEMPERATURE is active, the Embedded

MotionApps Platform will store bias and temperature information discovered from ML_BIAS_NO_MOTION calibration events. When ML_BIAS_FROM_TEMPERATURE is active, stored bias and temperature information is used to update the gyro bias as temperature changes.

[1] The mapping of gyro bias to temperature is affected by mechanical stress on the sensor package. This includes stress due to soldering, tension or compression of the printed circuit board. More information is available in the IMU/MPU product specification.

Mount the sensor on a stable, vibration-free surface using the orientation recommended in the datasheet. Improper mounting may affect accuracy.