Matrix Alterations Test

On June 14th, 2016 we finally caught a brief window of good weather to take the Matrix out and see if our alterations cured any of the issues we previously had.

Mike Bomber was the pilot in command (PIC) and I was the pilot at the controls (PAC) and Dr. Joesph Hupy was the spotter.

Mike flew the platform manually for a while test the loiter function as we were able to identify issues while in loiter previously.  We did not see any of the previous issues during this test. We decided to create a small mission in Mission Planner to fully test platform.  We ran the mission 4 times while we adjusted a few settings improving the flight characteristic. No issues were encountered during any of these flights.

I examined the same Vibration and Max Consistency XYZ reports in Mission Planner to compare with previous good flights. The reports are not as good as previous flights but they are certainly better then the flights where the issues occurred.

(Fig. 1) Vibration report from flight after alterations were made to the Matrix platform.

(Fig. 2) Max Consistency XYZ report from the flight after alterations were made to the Matrix platform.

Additional research and flights will be conducted to continue to improve the functionality and reliability of the Matrix platform.

UAS Platform Alterations

In late May we were flying the Litchfield mine site and the Matrix platform was not following the flight plan as precisely as desired. We speculated it was being affected by electromagnetic interference (EMI) but were uncertain so we grounded the platform until we could identify the problem.

I worked with Mike Bomber who is the current UAS technician to try and locate the issue with the platform. I downloaded the Flash Logfiles from the Pixhawk to examine the various reports created. The most noticeable variation between a good flight and the flight which had issues was the amount of vibration (Fig 1 & 2).

(Fig. 1) A good flight vibration readout from Mission Planner Flash Log files.

(Fig 2) The vibration readout from the flight when incurred issues. You can see a drastic increase in vibration near the end of the flight plus error logs were recorded which sent the platform into a fail safe mode.

Secondly we analyzed the Max Consistency XYZ which displays the raw magnetic field values for x, y, and z axis. The information contained here relates to the GPS location. The graph shows there was no consistency at all during the trouble flight (Fig. 3)

(Fig. 3) Max consistency XYZ from the trouble flight. You can see issues throughout the majority of the flight.

Due to the recent issues with the Matrix and information from the flight logs we decided to move a few items on the Matrix frame to reduce vibration and eliminate possible interference between electrical components. Additionally we changed the GPS to a newer model which utilizes various satellites for better location accuracy. 

We moved the the Pixhawk from the middle of the frame to the top utilizing the mount and bubble top from the Hexacopter. The plate was mounted on rubber dampeners to help reduce the vibration to the Pixhawk. 

Additionally, we installed the new GPS with a copper grounding plate mount. We had installed the same model GPS on a different platform and we achieved connection with 20 satellites.

(Fig. 4) Matrix platform with changes made based on the information from the Mission Planner Flash Log files.

  We hope to be able to perform a few test flights in the upcoming weeks.