Path Planning for Multiple Land Surveying UAVs
Dr. Kelly Cohen
Dr. Manish Kumar
The unmanned aerial vehicle (UAV) is a versatile platform that is breaking out as a disruptive technology. One of the many civilian applications for UAVs is to automate land monitoring and surveying. Land surveying is typically performed by teams of two to four surveyors, and current surveying techniques leave room for improvement. Using a swarm of 5 collaborating UAV’s to automate the land surveying process will save surveyors’ time and money, as well as reducing potential risks to equipment and personnel. Optimizing the flight path for a UAV to survey an area of land can be done using a variety of methods. This paper investigates using genetic algorithm based three-dimensional path planning of a surveying UAV, given topographical elevation data, a prescribed area of operations as well as additional constraints such as no fly zones and other air traffic/FAA restrictions. A genetic algorithm traveling salesman solver is used to calculate the constrained time-optimal path to survey designated area of interest for two cases, one UAV and up to 5 UAVs. Figures of merit and the cost function that drive the optimal path-planning problem are explored. Route planning methodology is developed and simulation results are presented.
This work shows the feasbility of using genetic optimization for UAV flight planning, with K-Means clustering to distribute paths based on a UAV endurance estimate. This methodology may be improved by incorporating UAV flight dynamics into the cost function, moving to an energy based cost function and improving the cluster estimation method to go beyond distance. The path planning algorithm should also take into account the effects of ground concavity on the result of the photogrammetric post processing quality. To bring the AirTheo product to reality. A UAV flight controller will need to be developed which takes the GPS coordinate paths from the ground station and fly its path. Other control point estimation methods will need to be considered for land survey areas that aren't rectangular. The path planning computer and UAV flight computer will also need to be programmed to maintain line-of-sight with the calibration module for improved accuracy.