Abstract-This paper proposes a hierarchal approach to solving a spraying mission assignment and path planning problem by using multi-quadcopters in an upland area. A mathematical model of the mission assignment and path-planning problem has been established. An inner-and-outer loop structure is employed in the hierarchal approach, in which the inner loop utilizes a genetic algorithm-based Travelling Salesman Problem (TSP) method while the outer loop uses a nonlinear programming method based on the optimal results given by the inner loop. In the end, simulation comparisons to a multi-TSP-based conventional approach have been carried out to illustrate the performance of the proposed approach.

This paper proposes a fixed-time differentiator running in parallel with a feedback linearization-based controller, which allows quadrotors to track a given trajectory. The fixed-time differentiator estimates outputs' derivatives in a predefined convergence time, largely compensating for initial condition problems and solving the delay problem. Combined with a state reconstruction step, a whole observer-estimatorcontroller scheme for trajectory tracking problem of quadrotors can be constructed. Also, an LMI optimization-based algorithm to tune parameters of the differentiator is also developed here. The high performance of the proposed model is illustrated by simulation results.