Week 8: Martell mission, M600 down for maintenance

Field Report

Week 8: 10/12/20-10/18/20

Group 2: Jesse Giampaolo, Nick Dayton, Cole Bramel

Context 

AT 40900 is the first part of the Unmanned Aerial Systems Capstone for seniors enrolled in the UAS program at Purdue University. As a class, we are currently tracking the foliage as it changes color and eventually drops at Martell Forest from the end of September through late October or early November. This data will hopefully help Aish (Forestry PhD student) and Dr. Hupy (AT 409 professor) achieve species and genotype level identification of the trees at Martell. Zach and Will (UAS grad students) are also helping with this project to show that such identification can be accomplished with UAS collected data. 

To achieve the data collection this semester, the At 409 class has been broken down into groups consisting of three students each and as a class are collaborating to collect data from a minimum of three missions per week. For this research, the more missions the better the data set will be (ideally). A mission consists of two successful flights over the two different plots of interest (NW & NE) at Martell using a DJI Matrice 600 equipped with a Zenmuse XT2 and a Sony α6000 (Figure 8.1). The North-West plot consists of naturally occurring oak and other trees. The North-East plot consists of 10-12 year old precision planted red oak trees which have been professionally maintained.

Figure 8.1: DJI Matrice 600 equipped w/ Zenmuse XT2 & Sony Alpha 6000

Week 8 Overview

This week was expected to be a typical data collection week. As a class we planned four missions in the event that one was cancelled due to weather. As the week progressed, however, high winds and light rain prevented multiple outings to be postponed or cancelled. There were only two successful flights conducted over week 8: one on Tuesday () by crew 3 and the other on Friday (10/16) by crew 1. We had planned to fly Thursday (10/15) morning from 0930-1200. This was postponed and eventually rescheduled to Sunday (10/18) due to high winds. The rescheduled flight on Sunday had to be cancelled altogether due to projected high winds for the duration of the day. In the meantime, Jesse was able to gain access to the department’s truck for future missions.

 Week 8 Planned Flight: 10/15/2020

Last week we, crew 2, established that we will be regularly flying on Thursdays from 0930-1200 (weather permitting) for the remainder of the data collection period for this study. The scheduled flights have been on the outlook calendar since then. Jesse posted a reminder via MS Teams on Wednesday night of this week before we attempted to fly on Thursday morning. This post also asked for clarification on issues encountered during the Tuesday morning flight conducted by crew 3.

Crew 3 reported via MS Teams on Tuesday after their flight that they had encountered some issues with the M600. The SD card for the Sony Alpha 6000 was missing. This was later found in the case. It had just fallen below some lens wipes. They also reported that the batteries in the M600 reached low enough voltages during flight that it engaged in the return to home sequence. This disrupted their flight and prematurely ended the mission over the NE plot of Martell. The data they collected ended up being okay due to the amount of overlap with the NW plot flight. The more concerning issue reported was a loose propeller. This was found to be a common issue among M600s when the prop bolts are over-torqued. The screws can strip and even fall out during flight (Figure 8.2). New bolts were ordered and according to Kaleb, the M600 was repaired and test flown sometime before Wednesday evening. 

Figure 8.2: Damage resulting from an over-torqued prop bolt on an M600
Source: https://forum.dji.com/forum.php?mod=viewthread&tid=139731 

On Thursday morning at approximately 0845, Kaleb informed us that the M600 was ready to fly, but we would need Dr. Hupy’s approval that it was ready to return to service. We agreed to stand by until 1015 at which we would postpone the flight to 1600 later that day if we had not gotten the okay to fly the M600. At 0938, Dr. Hupy gave us the go-ahead, but there were on and off showers in the area and they were not predicted to leave until after 1200. See Figure 3 for the satellite radar at the time. We included this solely for illustration purposes. We consulted the METAR and TAF first as these are the approved sources for aviation weather. We decided to postpone our flight until 1600 later that day.