In this video, we see a little toy vehicle with two wheels that is unstable by itself. However, when an attached gyroscope is running (a rotating mass) it stabilizes itself.
When the mass starts to rotate and accelerates, at some point, see here, the vehicle suddenly starts to lift itself from lying on the table to an upright position. I am wondering, where does the torque/force came from to lift the vehicle?
See my 2012 answer for an explanation of gyroscopic precession, and the forces involved.
This exposition of the physics of gyroscopic precession is not in terms of the angular momentum vector. Instead this exposition capitalizes on symmetry; a wheel is very symmetric.
Specific to the device demonstrated in that video:
The suspension of the gyro wheel of that device is such that an actuator is set up to change the orientation of the gyro wheel with respect to the device.
The camera angle of the video is unfortunate: the actuator is to a large extend obscured. Whoever made that video did a poor job; the crucial bit is obscured.
The actuation movement can be seen at 1:30 into the video. You see the actuator changing the angle of the gyro wheel with respect to the device as a whole.
