AT209 First weeks

This semester I was assigned to teach AT209 Civilian Unmanned Systems. I was assigned this fairly late in the summer, one week before classes started, and was very fortunate to have the assistance of Dr. Hupy and Zach Miller for course planning. AT209 is the third course in the UAS major and the first course in the UAS minor. The objectives for this course are as follows:
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     This course is about utilizing Unmanned Aerial Systems (UAS) as an applied tool in civilian market-based applications. Although piloting, mission planning, and crew resource management fundamentals will be integrated into the curriculum, the key focus will be on proper data collection, processing, and analysis. Safety and ‘drone ethics’ will also be stressed throughout the course. The course is not designed to make you an expert in UAS, but for you to have a strong foundation upon which to pursue UAS applications in the workplace, or further graduate research.  

      The course will be taught with a mix of labs and lecture, with hands-on learning applied as much as possible. Students should expect to become familiarized with basic concepts that relate to becoming an FAA Part 107 commercial pilot. Students will also learn core fundamentals of using UAS for applied Geospatial Data applications.  

  

Students should expect to complete a robust series of readings and online tutorials outside of class sessions. These materials will be fundamental for understanding what the weekly material covers. The student should expect to complete pre-class quizzes on these materials, thus ensuring that all students are aware of what will be covered in the weekly class period. Overall, the objective of this course is to instill the following skills:  

• The ability to think of UAS data collection in a geospatial manner  
• The ability to critically think of what type of platform is best suited for the given task/goal, and how best to collect that data with the proper sensor.  
• The fundamental difference between Radio Control aerial platforms, and those that allow the use of autopilot/ground station technology.   
• How to survey Ground Control Points (GCP) using current GPS technology, as well understanding the limits of GCP points   
• Construction of technical style reports in a web or blog based format.  Construction of instructional materials, in both written and video format 

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In order to teach these objectives we decided to base the lectures and labs around an in depth exploration of sensors and FAA part 107 preparation. Sensors were chosen as the focus of this class to ensure that the students have a comprehensive undersanding of sensor operation either early in the major or immediately in the minor.

The first weeks of the course are an investigation of digital photography. We decided to begin with digital photography because of the pervasive nature of digital cameras on UAS platforms. The lectures for this section focus on manual settings for digital cameras. While most digital cameras have good automatic settings, it is important for the students to understand how to manually correct for bad images in data collection. We designed a lab excersize intended to provide students an opportunity to investigate the effects of these settings using a DJI Mavic 2 Pro and DJI Mavic Airs. Using iPads provided by Purdue the students took a picture at each aperture, ISO, and shutter speed available on the vehicles.The students saved these images to their own student folders, and will be using those photos in labs focusing on image processing.

Troubleshooting new equipment

Recently our lab received a Zenmuse XT2 and a PPK unit for one of our M600 Hexacopters. We quickly equipped the M600 with the PPK unit, and an undergraduate flight team began using the vehicle.

Figure 1: M600 with PPK attached

Figure 2: PPK unit

Figure 3: Sony Alpha a6000 camera tied to PPK unit

 We quickly discovered that while the PPK system was logging position data, the attached Sony Alpha a6000 was not capturing images.

After a brief discussion with the flight crew they informed me that while they had correctly hooked up the PPK system and powered it on they had not pressed any of the buttons. We decided that the system was might not have known when the mission was supposed to begin, because it didn't interface with the flight planning software that they were using.

On the next flight the flight crew pressed the control button before arming the vehicle and beginning the flight. They pressed the control button again once the vehicle had landed, but did not hear a shutter noise from the camera. When they returned to the lab to look at the data we found that, once again, the position log existed but the only image found was taken before the vehicle began it's mission. This began an in depth investigation into the problem by myself, the flight crew, and Dr. Hupy. We focused our investigation on the camera, since the PPK system was creating the position log. We began by going through as many settings as we could to better understand the camera. During this process I discovered that the camera has a sleep setting that is set to one minute by default. Since the vehicle usually takes over one minute to get to it's target area it made sense that the camera would go to sleep before the vehicle reached the target area. I set the camera to 30 minutes, and we got the vehicle ready for another flight the following day.

The next day I accompanied the flight crew as a way to get out of the lab for a bit. The flight crew pressed the capture button at the beginning of the flight, and at the end of the flight hearing the shutter sound each time. After returning to the lab we discovered that the only pictures that existed were the ones taken at the beginning and end of the flight.

This was incredibly frustrating and led to another day of troubleshooting. The first thing we did was ensure that the camera settings were how we had previously set them. We discovered that whenever the vehicle is powered off the sleep setting is reset to one minute. After resetting the camera to the settings we wanted the vehicle was taken outside and walked around. The vehicle was supposed to be set to capture an image every so many meters, but while we walked the vehicle around we did not hear shutter sounds unless we pressed the control button. We then reset the camera sleep settings to one minute, and walked the vehicle around pressing the control button ever 45 seconds. We discovered that the camera would not go to sleep if the PPK system was giving it triggers. After these tests we learned that the sleep setting was not the problem, but the problem was more likely to be a problem with the PPK communicating with the camera.

We returned to the lab to investigate the PPK once again. All of us were searching through different sections of the manual. I had taken the PPK file details section, and in this section contained the details of .txt files associated with the equipment. I found the section shown in figure 4, and it looked like a promising find.

Figure 4: Configuration file

As it turned out the default setting for the PPK system is for the system to only trigger when the control button is pressed. This was modified to 2D distance and the vehicle was walked around again. This time the shutter sound could be heard at regular intervals, and was confirmed to work. I look forward to using this system in the future as PPK is a powerful data collection tool.