Field Exercise 12 - Unmanned Aerial System Flights

INTRODUCTION

          For field exercise twelve our geospatial field methods class observed two Unmanned Aerial System (UAS) Flights. Both flights were done at the UW-Eau Claire Priory because there was a wide grassy expanse next to the parking lot that contained enough open space for both take off and landing. Both Unmanned Aerial vehicles (UAVs)(the iris and matrix) were multi-rotor UAVs so they didn't need a lot of room for take off and landing anyways. Below in figure one is an image showing the launch area for the UASs.

Figure 1: shows an image of part the UW-Eau Claire Priory property. The area surrounded by the red box was the grassy expanse south of the parking lot that the class used for the two UAS flights.

          It is important to remember that a UAS is composed of at least three different pieces of equipment. The first piece of equipment is the UAV or flight platform itself. The UAV is almost always rigged with different measuring tools, camcorders, and cameras so that imagery or climate data can be processed. The second piece of equipment is the transmitter. The transmitter contains the controls for the UAV and always has the final say in what the UAV does. This means that it can override autopilot in case of an emergency. The third piece of equipment is the base station and it contains the brains for the whole operation. All data acquired by the UAV is sent to the base station where it can be processed. The base station also relays the mission plan to the UAV. In our classes case we also had a tablet which acted as sort of a second base station.

METHODS

Mission Programming

 

          In field exercise four I discussed the versatility and applications of the different UAV types. This information can be viewed here. Because different UAV types have different applications the missions that they complete are going to be very singular to each flight scenario. This means that a different mission has to be programmed before each flight. This is not a problem because there is cheap easy to use software (mission planner or droid planner) out there that allows programmers to lay out a flight plan in a manner of minutes. I personally tested some flight planning software and it was as easy to use as Microsoft paint. I simply created way points where I wanted them by tapping on the screen and the UAV would fly to those points. Since the UAVs were multi-rotor UAVs I could also have them stall for a set amount of time. The image in figure two below shows the mission planner interface.

Figure 2: shows the mission planner interface. The touch screen of the tablet allows the programmer to draw out their desired mission with their fingers.

There were many other features I could've explored with the mission planning software but didn't have the time for. The software can be downloaded onto a phone or tablet with no license and it's free. Once a mission has been created for the UAV to fly It just has to be uploaded onto the platform through the base station pictured in figure three below.

Figure 3: shows the base station computer. The base station is the brains of the UAS and relays information to and from the flight platform.

Pre Flight

          Before the UASs could be launched a lot of pre flight and safety procedures had to be observed. The UAVs we were flying were not incredibly dangerous although their rotors probably could have taken a finger off, but they are expensive so great care was taken to ensure that they would take off, fly the mission, and land safely. The first thing taken into consideration was the weather. Wind speed, wind direction, and the probability of precipitation were three major weather factors that were taken into account. I f the wind had been too strong or it had started raining the flights would've been a no go. Rain was threatening but no actual precipitation had fallen, and the wind bordered on too strong to fly. The next thing checked was the UAV itself: props secure, cracks/chips, battery secure, antenna secure, sensor connected? Everything was a go so we powered up and performed another checklist: connected to satellites, connected to base station, batteries over 95 percent, transmitter on, batteries charged on transmitter, mission created, sensors on? The UAS was now ready to launch so we performed the take off sequence: throttle down, platform on, spectators clear, kill switch off, clear for launch, take off. Take off was performed manually by the course instructor and then switched over to autopilot so that the UAS could fly the mission that was programmed into it. It should be noted that during the "batteries charged on transmitter" phase, the batteries began smoking and had to be replaced with new ones. Images of the two UAVs in pre flight mode is provided in figures four and five below.


Figure 4: shows Iris UAV in pre flight mode

Figure 5: shows the Matrix UAV in pre flight mode

UAS Flights

          The first flight done with the Iris multi-rotor UAV went the whole length of the mission which looked like a Greek key design. The mission was really just created so that the class could see the UAVs in action. Even though the UAVs fly their missions on autopilot that doesn't mean that the pilots have nothing to do. It is important that there is a pilot manning the base station to give constant updates to the pilot on the transmitter controls what the status is of the flight. Updates on how many satellites are in contact with the UAS and the accuracy of the flight path are important. The second flight ended abruptly because of too much wind. The pilot manning the bay station informed the transmitter pilot that the UAV was trying to correct it's position on the flight path, but the UAV couldn't handle the wind gusts so it began to wobble dangerously. The transmitter pilot then flipped the HOME switch on the transmitter controls to bring the UAV straight back to the launch site. Figure six below shows the Matrix heading back to the launch site after it lost it's battle with the wind.

Figure 6: shows the end of the second flight performed by the multi-rotor Matrix flight platform

DISCUSSION/CONCLUSION

          Although I did not personally fly either of the UAVs observing the mission planning, pre flight, and launching proceedings was a good experience. It's not until you go through a process with someone who has done it a hundred times before that you learn all of the ins and outs of that process. Watching our course instructor harp on the importance of the pre flight and launch checklist really got it through to the whole class that these things are important to the success of the UAS mission. UAVs cost upwards of five hundred dollars and just one slip up can cost a flyer their UAV which is why it is so important to be completely prepared before launching.