Turning mode and whole region-coverage path planning and optimization of agricultural small UAV

Objective  The development trend of agricultural small UAV (ASUAV) is having a capability with autonomous flight, working route planning and optimization, precise control and variable operation. This study provides the optimized selection of flight heading, take-off and landing location, turning mode and flight point coordinate solution for ASUAV before autonomous flight operation under the condition of whole-area coverage.

Method  Turning mode strategy of ASUAV was studied based on autonomous flight at constant speed under constraint of the minimum turning radius. The path planning method under arbitrary convex polygons was analyzed and designed. An integerized route planning scheme was proposed based on the slight change of working width. Path planning and optimal selection under the condition of whole region-coverage were achieved in the structured farmland area.

Result  The whole-area coverage path planning method based on the optimal turning mode of ASUAV was applicable to the farmland with arbitrary convex polygon structure. GUI program could optimize flight route with the highest efficiency while calculating flight point coordinates of ground boundary. An irregular convex hexagonal field with an area of about 2.7 hm² was randomly planned in the field. The simulation results showed that when ASUAV was flying parallel to the longest side of the field, the invalid distance was the shortest with about 540 m, and the efficiency was the highest which was close to 90%.

Conclusion  The optimized turning mode, take-off and landing location, flight heading and route inflection point coordinates can realize the full area coverage. This result can provide a reference for ASUAV autonomous flight operation.