NASA’s Langley Research Center has developed a novel method to calculate the relative position and orientation between two rigid objects using a simplified photogrammetric technique. The system quantitatively captures the relative orientation of objects in six degrees of freedom (6-DOF), using one or more cameras with non-overlapping fields of view (FOV) that record strategically placed photogrammetric targets.
This high-speed camera system provides an algorithmic foundation for various photogrammetry applications where detecting relative positioning is important. Originally developed to evaluate the separation stage of NASA’s Max Launch Abort System (MLAS) spacecraft crew module, this technology has also been used to evaluate the effect of water impact on the MLAS crew module and for trajectory analysis of military aircraft.
The NASA technology uses a photogrammetry algorithm to calculate the relative orientation between two rigid bodies. The software, written in LabVIEW and MATLAB, quantitatively analyzes the photogrammetric data collected from the camera system to determine the 6-DOF position and rotation of the observed object.
The system comprises an arrangement of arbitrarily placed cameras rigidly fixed on one body, and a collection of photogrammetric targets rigidly fixed on the second body. The cameras can be either placed on rigidly fixed objects surrounding the second body (facing inwards), or can be placed on an object directed towards the surrounding environment (facing outwards). At any given point in time, the cameras must capture at least five non-collinear targets. The 6-DOF accuracy increases as additional cameras and targets are used. The equipment requirements include a set of heterogeneous cameras, a collection of photogrammetric targets, a data storage device, and a processing PC. Camera calibration and initial target measurements are required prior to image capture.
A nonprovisional patent application on this technology has been filed. This technology has potential applications in satellite- based star tracking, car crash dynamics, vehicle separation tests, computer-assisted surgery, ballistics testing, terrestrial surveying, and wind tunnel testing.