Liebersbach, Robert | Engineering Papers

NASA NTRS2009

Converting CSV Files to RKSML Files

A computer program converts, into a format suitable for processing on Earth, files of downlinked telemetric data pertaining to the operation of the Instrument Deployment Device (IDD), which is a robot arm on either of the Mars Explorer Rovers (MERs). The raw downlinked data files are in comma-separated- value (CSV) format. The present program converts the files into Rover Kinematics State Markup Language (RKSML), which is an Extensible Markup Language (XML) format that facilitates representation of operations of the IDD and enables analysis of the operations by means of the Rover Sequencing Validation Program (RSVP), which is used to build sequences of commanded operations for the MERs. After conversion by means of the present program, the downlinked data can be processed by RSVP, enabling the MER downlink operations team to play back the actual IDD activity represented by the telemetric data against the planned IDD activity. Thus, the present program enhances the diagnosis of anomalies that manifest themselves as differences between actual and planned IDD activities.

Trebi-Ollennu, Ashitey↗

NASA NTRS2007

Fusing Image Data for Calculating Position of an Object

A computer program has been written for use in maintaining the calibration, with respect to the positions of imaged objects, of a stereoscopic pair of cameras on each of the Mars Explorer Rovers Spirit and Opportunity. The program identifies and locates a known object in the images. The object in question is part of a Moessbauer spectrometer located at the tip of a robot arm, the kinematics of which are known. In the program, the images are processed through a module that extracts edges, combines the edges into line segments, and then derives ellipse centroids from the line segments. The images are also processed by a feature-extraction algorithm that performs a wavelet analysis, then performs a pattern-recognition operation in the wavelet-coefficient space to determine matches to a texture feature measure derived from the horizontal, vertical, and diagonal coefficients. The centroids from the ellipse finder and the wavelet feature matcher are then fused to determine co-location. In the event that a match is found, the centroid (or centroids if multiple matches are present) is reported. If no match is found, the process reports the results of the analyses for further examination by human experts.

Huntsberger, Terrance↗