I. Introduction
Visual inertial odometry (VIO) is the process of determining the location and orientation of an entity with the help of visual (camera) and inertial [inertial measurement unit (IMU)] sensors. A simultaneous localization and mapping (SLAM) framework is a system that has a global localization algorithm coupled with visual odometry [1]. Today, SLAM and VIO systems are being used in a wide variety of applications, including autonomous driving [2], [3], controlling and navigating aerial microautonomous vehicles and nanodrones [4], [5], [6], augmented reality, and enabling navigation on mobile devices [7]. In this article, it is assumed that the target entity only has a single RGB camera and a single IMU sensor.