A Structured Light System for Relative Navigation Applications

Technical details associated with a relative navigation system that uses the images formed by structured light beacons placed at known locations on the target vehicle platform are presented. Automated means of generating illumination signatures for the beacons are discussed along with the digital logic associated with camera synchronization and beacon identification processes. Relative pose estimation formulations are presented and it is shown that, by using the image formation model, the translation vector can be expressed in terms of the elements of the orientation matrix relating the frames affixed to the target and the camera. By utilizing the Cayley transform, the relative pose estimation problem is shown to reduce to a set of quadratic equations that are amenable to efficient numerical solution and reasonable uncertainty quantification. An engineering breadboard prototype sensor is developed to demonstrate the workings of the structured light sensor. The performance of the sensor and the relative pose estimation algorithm implementation is benchmarked by comparing the experimental results against standard methods that use well-calibrated targets for pose estimation.