The Piccolo Command Center (PCC) software allows an operator to plan and execute flights using the Piccolo autopilot.  However, it can be difficult to analyze post-flight telemetry.  Additionally, access to the PCC software is limited.

To address this problem I created a matlab function “log2kml.m” to convert Piccolo log files into KML files readable by Google Earth (GE).  This function reads the space delimited log file into Matlab.  It then filters out bad GPS points.  Finally it steps through the data to create a KML polyline.  The line is segmented based on the flight mode to clarify what the autopilot was doing.  The function uses the KML toolbox created by Rafael Fernandes de Oliveira.  It can be found at http://www.mathworks.com/matlabcentral/fileexchange/34694.  This toolbox is put together well and was easy to use.

The results shown below make the high performance of the autopilot clear.  Since the points are 3D there is some distortion of the actual ground path.

AUVSI 2011 NCSU Competition Run

This visualization  allows us to analyze certain maneuvers much more easily.  A point of concern on autonomous take-offs has been a “dip” that occurs as the aircraft switches from prioritizing altitude to prioritizing airspeed.  Using the “Elevation Profile” tool in GE alongside the flight path allows for a clear observation of the performance.

Autonomous Take-off Performance

It can now clearly be seen that the aircraft does level out, but does not lose altitude.  We can also determine that it levels off at an altitude of 21 meters or 68 feet above ground level.  This new knowledge can now be applied to improving future performance, or at least avoiding flying in to trees at the end of the runway.

For comparison a screenshot from the PCC is shown below.  Since the blue line representing the flight path is so course, the fine motion of the aircraft is only apparent when animated.  The profile view only shows the current position of the aircraft.  Finally, the 3D view isn’t apart of the base software package resulting in the “License Required” text being splashed across the screen.

PCC View