Removing scale biases and ambiguity from 6DoF monocular SLAM using inertial

This paper identifies various scale factor biases commonly introduced into monocular SLAM implementations as a result of the true scale factor of the map not being observable. A way to make the scale factor observable and remove any scale biases via the use of an inertial measurement unit (IMU) is presented and implemented. Results show that with an IMU the true scale of the map becomes observable over time and the use of a square root information filter allows the effect of initial scale biases to be removed completely from the solution resulting in an unbiased solution no matter what the initial scale assumptions are.