For our second field activity, we learned how to use and develop surveying missions to be programmed to a multi-rotor using mission planning software, as well as running through the preparation for a multi-rotor flight. Mission planning and preflight checks can make or break a survey and therefore proficiency and thoroughness in both of these aspects is integral in collecting useful data and preventing the destruction of expensive equipment. This activity was carried out in a computer lab in Phillips Hall and the preflight check was done between Phillips Hall and Davies Center.
Mission Planning Software Methods
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| Figure 1: Mission Planner logo |
The first step in flying a programmed mission is using the necessary software to design and plan said mission. This can be done with a program suitably called Mission Planner. When you enter Mission Planner, you are prompted with a world map. From here you can zoom in on the location in which you want to conduct your mission and begin planning it. Before planning a mission it is important that your mission area will not interfere with any no fly zones or other hazards like hospital helicopter routes. Airport no fly zone radiuses are depicted as purple circles on Mission Planner and have to be avoided. Once you find your area to conduct a mission, begin planning using the tools they provide. A simple point to point mission can be created by clicking on the map and selecting waypoints. Each waypoint can be customized to a certain altitude, speed in which it is reached, whether or not it is a take off or landing point and more. All this information from the actual mission will be stored in the telemetry log which will show what the UAS did in reality. waypoints can also be automatic using the drop box and creating various shapes like circles or boxes.
If you are using mission planning for surveying you can click <Auto WP to survey> and when you create a box on the map, an automatic zigzag pattern will appear. There are a variety of options to alter this pattern which will appear on the right side of the program. You have the ability to select your aircraft and camera, adjust speed, altitude and these adjustments will display on the mission. The program takes into account field of view and therefore if you do a mission at a high altitude, you will perform less zigzags and the mission will go faster. The opposite is true for a low altitude mission. The lower the altitude, the smaller the field of view and in order to get proper overlap for surveying, more zigzags must be made, lengthening the mission. It is important to find a happy medium between these too so that your mission does not exceed the time your battery will last. Mission length is calculated at the bottom of the screen automatically making it easy to determine which way you need to adjust your flight parameters. Once you have a mission that you want to fly, you can save it to be later uploaded to a UAS.
Flight Preparation Methods
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| Figure 2: Mission Planner interface using a waypoint circle. Notice on the bottom left the ability to edit each waypoint |
If you are using mission planning for surveying you can click <Auto WP to survey> and when you create a box on the map, an automatic zigzag pattern will appear. There are a variety of options to alter this pattern which will appear on the right side of the program. You have the ability to select your aircraft and camera, adjust speed, altitude and these adjustments will display on the mission. The program takes into account field of view and therefore if you do a mission at a high altitude, you will perform less zigzags and the mission will go faster. The opposite is true for a low altitude mission. The lower the altitude, the smaller the field of view and in order to get proper overlap for surveying, more zigzags must be made, lengthening the mission. It is important to find a happy medium between these too so that your mission does not exceed the time your battery will last. Mission length is calculated at the bottom of the screen automatically making it easy to determine which way you need to adjust your flight parameters. Once you have a mission that you want to fly, you can save it to be later uploaded to a UAS.
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| Figure 3: Waypoint Box Survey interface. Notice the right hand side displays aircraft selection, speed, altitude and preferred flight time. Also notice camera selection ability and mission area editing. Below you can see estimated flight specs such as total distance, distance between lines, flight time, area covered, and photo interval suggestion. To the left notice enlarged stats |
After planning a mission, you and your team have to travel to your study area with your UAS of choice and prepare to fly. It is very important that every measure is taken to ensure a successful and safe flight and his can be accomplished by following a preflight check such as the one below.
Before the preflight check, it is important to assign roles to each team member to ensure all facets of the flight are accounted for and monitored. There three positions that need to be filled. The first is the individual who focuses on the computer known as the pilot in command (PIC). The PIC's job is to fill out the preflight check by communicating with the pilot at the controls and set up the modem so the computer can communicate with UAS. The modem is attached to the computer via a USB connection and then is attached to the top of a "Wonder Pole" which telescopes upwards to establish a stronger connection to the UAS when it is in flight in an attempt to avoid communication issues caused by extraneous signal noise nearby. The PIC will also upload the mission plan to the UAS and ensure each step is accounted for as to not send the UAS on back to its last mission. During a mission, the PIC will be focused solely on the computer ensuring proper signal strength and satellites are obtained
The second position is the pilot at the controls (PAC). This individual is in charge of physically checking to make sure all of the components the PIC is listing off in relation to the UAS and transmitter in the preflight check are in good operating condition and turned on. During a mission, the PAC is always at the ready with the transmitter to assume control of the UAS in instance where a mission becomes too dangerous (eg. oblivious citizens or other manned aerial vehicles present) or satellite signals are lost causing the UAS to lose GPS capabilities. This is why it is important that the PIC and PAC have good communication and remain focused even when a program is controlling the UAS.
Finally, a third position is the spotter. The spotter is in charge of assisting the PAC when needed with the preflight check. They can help with any last minute repairs or wherever they are needed. During a mission the spotter assists in keeping a visual on the UAS as you can never have too many people keeping an eye on the mission and making sure everything is running smoothly.
As you can see on the preflight check mentioned above, there are a lot of things to check and that is good. The more you take the time to check, the less likely you are to have a failed mission. I wont describe all of the checks since some are self explanatory, but there are some that have more too them that are good to know in order to have a successful mission. The first thing the PIC fills out is the Multicopter Log which asks for date, time, individuals acting as PIC, PAC and spotter, battery voltage and percent (both before and after), flite time, battery name, and the weather. It is important when filling out the battery information that you use voltage and not percent. While the may actually be half charged, once you plug it in it will display 100% since the computer considers that to be full charge. If you fly according to percent battery and the voltage is low, there is a good chance your UAS will lose charge and crash. It is also a good idea to check your computer battery to ensure that it will be functional throughout the whole operation.
Upon completing the multicopter log, the PIC then can begin the preflight check. This process involves the PIC yelling out the checklist to the PAC and the PAC responds with "good" or "okay" once the item in question is functional. The first few checklist items are to ensure that multirotor is structurally sound and connected. This means checking to see that the legs, frame, wires, battery and propellers are free of cracks, loose screws, dirt, worn down areas and anything else that might threaten the stability of the craft. It is important the check to make sure the battery is not only secure, but also in balance with the rest of the multirotor. An unbalanced battery can cause rotors to work too hard to level out the craft draining the battery quicker or cause it to not function properly all together. The next part of the check ensures that the wireless communications are functioning and connected. This includes making sure Antennae are secure and out of the path of the propellers, connecting the sensor, turning the transmitter (TX) on and powering up the UAS. Once this is done the PIC makes sure the modem is connected, and that the base station is connected to the UAS. This is the computer in conjunction with the modem and wonder pole. Next the mission planning software is accessed and is connected to the UAS via a detected number (eg. 50600). A loading bar will appear and afterwards the platform will show up on a map via GPS. At this point you can look at the number of satellites currently connected to the UAS and make sure that this number never falls below 6. The more satellites connected, the better the UAS can position itself in three dimensional space. Lose that capability and your mission could fail. Another helpful number displayed on the mission software is the h drop. This number displays the horizontal differential position a number you want to be low.
Continuing on with the preflight checklist, the battery voltage and percent need to be documented again, and once the mission is uploaded, all the waypoints are written and the sensors are on and ready the UAS is ready to enter the takeoff sequence.
Before taking off it is important to clear the area of all spectators. THIS IS VERY IMPORTANT. Though UASs are cool, they can be dangerous if handled incorrectly or if others are acting carelessly around them. To prevent unneeded injuries it is important to make sure the area around the UAS is cleared. Before activating the UAS it is important that the TX throttle is down so that when it is connected with the UAS, it doesn't cause it to throttle up unexpectedly. The kill switch on the TX is then deactivated and the TX is armed. The multirotor is then sent up into a loitering mode and satellite connectivity is checked again making sure that number does not fall below 6. The mission is then free to begin. Upon completion of the mission, the UAS will return and the base station, battery and TX can be disconnected. The sensor should be checked again too.
Discussion
There hasn't been any data collected from this activity yet, but it was interesting to have a hands on approach to creating a UAS mission and preparing and arming a UAS for flight. Learning about the necessary steps and precautions needed to be taken before operating a UAS was a surprisingly long, thorough and much more necessary process than I thought it would be before coming into this weeks class. All UAS operators of all backgrounds should follow a similar process in preflight checks to ensure the safety of themselves and those around them. If accidents occur because of careless flying of UAS it could be detrimental to the viability of this technology for use in the public domain.
Conclusion
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| Figure 4: Preflight Checklist |
Before the preflight check, it is important to assign roles to each team member to ensure all facets of the flight are accounted for and monitored. There three positions that need to be filled. The first is the individual who focuses on the computer known as the pilot in command (PIC). The PIC's job is to fill out the preflight check by communicating with the pilot at the controls and set up the modem so the computer can communicate with UAS. The modem is attached to the computer via a USB connection and then is attached to the top of a "Wonder Pole" which telescopes upwards to establish a stronger connection to the UAS when it is in flight in an attempt to avoid communication issues caused by extraneous signal noise nearby. The PIC will also upload the mission plan to the UAS and ensure each step is accounted for as to not send the UAS on back to its last mission. During a mission, the PIC will be focused solely on the computer ensuring proper signal strength and satellites are obtained
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| Figure 5: Base station set up with wonder pole. |
The second position is the pilot at the controls (PAC). This individual is in charge of physically checking to make sure all of the components the PIC is listing off in relation to the UAS and transmitter in the preflight check are in good operating condition and turned on. During a mission, the PAC is always at the ready with the transmitter to assume control of the UAS in instance where a mission becomes too dangerous (eg. oblivious citizens or other manned aerial vehicles present) or satellite signals are lost causing the UAS to lose GPS capabilities. This is why it is important that the PIC and PAC have good communication and remain focused even when a program is controlling the UAS.
Finally, a third position is the spotter. The spotter is in charge of assisting the PAC when needed with the preflight check. They can help with any last minute repairs or wherever they are needed. During a mission the spotter assists in keeping a visual on the UAS as you can never have too many people keeping an eye on the mission and making sure everything is running smoothly.
As you can see on the preflight check mentioned above, there are a lot of things to check and that is good. The more you take the time to check, the less likely you are to have a failed mission. I wont describe all of the checks since some are self explanatory, but there are some that have more too them that are good to know in order to have a successful mission. The first thing the PIC fills out is the Multicopter Log which asks for date, time, individuals acting as PIC, PAC and spotter, battery voltage and percent (both before and after), flite time, battery name, and the weather. It is important when filling out the battery information that you use voltage and not percent. While the may actually be half charged, once you plug it in it will display 100% since the computer considers that to be full charge. If you fly according to percent battery and the voltage is low, there is a good chance your UAS will lose charge and crash. It is also a good idea to check your computer battery to ensure that it will be functional throughout the whole operation.
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| Figure 6: Multirotor (Matrix) used in preflight check |
Upon completing the multicopter log, the PIC then can begin the preflight check. This process involves the PIC yelling out the checklist to the PAC and the PAC responds with "good" or "okay" once the item in question is functional. The first few checklist items are to ensure that multirotor is structurally sound and connected. This means checking to see that the legs, frame, wires, battery and propellers are free of cracks, loose screws, dirt, worn down areas and anything else that might threaten the stability of the craft. It is important the check to make sure the battery is not only secure, but also in balance with the rest of the multirotor. An unbalanced battery can cause rotors to work too hard to level out the craft draining the battery quicker or cause it to not function properly all together. The next part of the check ensures that the wireless communications are functioning and connected. This includes making sure Antennae are secure and out of the path of the propellers, connecting the sensor, turning the transmitter (TX) on and powering up the UAS. Once this is done the PIC makes sure the modem is connected, and that the base station is connected to the UAS. This is the computer in conjunction with the modem and wonder pole. Next the mission planning software is accessed and is connected to the UAS via a detected number (eg. 50600). A loading bar will appear and afterwards the platform will show up on a map via GPS. At this point you can look at the number of satellites currently connected to the UAS and make sure that this number never falls below 6. The more satellites connected, the better the UAS can position itself in three dimensional space. Lose that capability and your mission could fail. Another helpful number displayed on the mission software is the h drop. This number displays the horizontal differential position a number you want to be low.
Continuing on with the preflight checklist, the battery voltage and percent need to be documented again, and once the mission is uploaded, all the waypoints are written and the sensors are on and ready the UAS is ready to enter the takeoff sequence.
Before taking off it is important to clear the area of all spectators. THIS IS VERY IMPORTANT. Though UASs are cool, they can be dangerous if handled incorrectly or if others are acting carelessly around them. To prevent unneeded injuries it is important to make sure the area around the UAS is cleared. Before activating the UAS it is important that the TX throttle is down so that when it is connected with the UAS, it doesn't cause it to throttle up unexpectedly. The kill switch on the TX is then deactivated and the TX is armed. The multirotor is then sent up into a loitering mode and satellite connectivity is checked again making sure that number does not fall below 6. The mission is then free to begin. Upon completion of the mission, the UAS will return and the base station, battery and TX can be disconnected. The sensor should be checked again too.
Discussion
There hasn't been any data collected from this activity yet, but it was interesting to have a hands on approach to creating a UAS mission and preparing and arming a UAS for flight. Learning about the necessary steps and precautions needed to be taken before operating a UAS was a surprisingly long, thorough and much more necessary process than I thought it would be before coming into this weeks class. All UAS operators of all backgrounds should follow a similar process in preflight checks to ensure the safety of themselves and those around them. If accidents occur because of careless flying of UAS it could be detrimental to the viability of this technology for use in the public domain.
Conclusion
Mission planning and having a thorough preflight check are important components in any successful surveying mission. Any deficiencies in either can lead to failed missions or even worse, destroyed equipment or physical injuries. Anyone who wants to conduct UAS missions must be strict with following safety guidelines and have a good handle on the functionality of their UAS for their safety and for those around them.
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