Autonomous docking of spacecraft using the Cognachrome Vision System

The University of Maryland Space Systems Laboratory and the KISS Institute for Practical Robotics (with cooperation from Newton Research Labs) have simulated autonomous spacecraft docking in a neutral buoyancy tank for inclusion on the UMD’s Ranger space vehicle. Using a composite target of three brightly-colored objects designed by David P. Miller, the spacecraft knows its distance and orientation, and can servo to arbitrary positions around the target.

The primary sources of information for this project are:

Determining your position from a composite target

The following is adapted from:

David P. Miller and Anne Wright. Autonomous Spacecraft Docking Using Multi-Color Targets. In Proceedings of the 6th Topical Meeting on Robotics, Monterey, CA, February 1995.


The target is composed of three parts: "L", "C", and "R" (left, center, and right). "X" is the position of the camera. Note that q is measured in the plane of LRX, not LRC.


Relationships yielding the 3-dimensional position of the robot relative to the target, given the 2-dimensional positions (in camera space) of the three target elements as viewed from the robot. xl, yl, xc, yc, xr, yr are the positions, in camera space, of the left, center, and right targets, respectively, as viewed from the robot.

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