Abstract: Methods, systems, and apparatus for performing bundling adjustment using epipolar constraints. A method includes receiving image data from a headset for a particular pose. The image data includes a first image from a first camera of the headset and a second image from a second camera of the headset. The method includes identifying at least one key point in a three-dimensional model of an environment at least partly represented in the first image and the second image and performing bundle adjustment. Bundle adjustment is performed by jointly optimizing a reprojection error for the at least one key point and an epipolar error for the at least one key point. Results of the bundle adjustment are used to perform at least one of (i) updating the three-dimensional model, (ii) determining a position of the headset at the particular pose, or (iii) determining extrinsic parameters of the first camera and second camera.

Abstract: Techniques for addressing deformations in a virtual or augmented headset described. In some implementations, cameras in a headset can obtain image data at different times as the headset moves through a series of poses of the headset. One or more miscalibration conditions for the headset that have occurred as the headset moved through the series of poses can be detected. The series of poses can be divided into groups of poses based on the one or more miscalibration conditions, and bundle adjustment for the groups of poses can be performed using a separate set of camera calibration data. The bundle adjustment for the poses in each group is performed using a same set of calibration data for the group. The camera calibration data for each group is estimated jointly with bundle adjustment estimation for the poses in the group.

Abstract: Methods, systems, and apparatus, including computer programs encoded on computer storage media, for calibrating an augmented reality device using camera and inertial measurement unit data. In some implementations, a bundle adjustment process jointly optimizes or estimates states of the augmented reality device. The process can use, as input, visual and inertial measurements as well as factory-calibrated sensor extrinsic parameters. The process performs bundle adjustment and uses non-linear optimization of estimated states constrained by the measurements and the factory calibrated extrinsic parameters. The process can jointly optimize inertial constraints, IMU calibration, and camera calibrations. Output of the process can include most likely estimated states, such as data for a 3D map of an environment, a trajectory of the device, and/or updated extrinsic parameters of the visual and inertial sensors (e.g., cameras and IMUs).