What is VIO?

VIO typically refers to Visual-Inertial Odometry. It is a technique used in robotics and computer vision to estimate the pose (position and orientation) of a device (e.g., a robot, a drone, or a handheld device) by fusing data from a camera (visual) and an inertial measurement unit (IMU). The camera provides visual information about the environment, while the IMU provides information about the device's acceleration and angular velocity. By combining these two sources of information, VIO systems can estimate the device's trajectory and build a map of the environment simultaneously. It's commonly used for navigation, localization, and mapping in scenarios where GPS is unreliable or unavailable, such as indoors or in dense urban environments.