VIO = Visual inertial odometry = 視覺 + IMU

What's the VIO?

VIO = Visual inertial odometry = 視覺 + IMU

I hope I can have a small UAS as Auterion to fly in the place without GNSS.

In the following website (https://docs.px4.io/v1.12/en/computer_vision/visual_inertial_odometry.html), it said 

"Visual Inertial Odometry (VIO) is a computer vision technique used for estimating the 3D pose (local position and orientation) and velocity of a moving vehicle relative to a local starting position. It is commonly used to navigate a vehicle in situations where GPS is absent or unreliable (e.g. indoors, or when flying under a bridge).

VIO uses Visual Odometry (opens new window)to estimate vehicle pose from camera images, combined with inertial measurements from the vehicle IMU (to correct for errors associated with rapid vehicle movement resulting in poor image capture).

This topic shows how to set up PX4 and a companion computer to use the supported VIO setup."