A Path Planning Method of Alleviating Spraying Deviation for Agricultural Rotorcraft

In recent years, although rotary-wing rotorcrafts have developed rapidly in low-altitude and low-volume spraying of plant protection, the spraying drift is still a pressing concern. Since the spraying liquid is atomized under the action of the nozzle, and the particle size of the droplets is relatively small, which is easily get drifted along with the natural wind, leading to great risk of off-target deposit. In order to solve the above problems, this paper proposes a path planning method that adjusts and sets waypoints online. Using the natural wind speed from the anemorumbometer and motion state of the rotorcraft from the navigation module, the spraying deviation is estimated to provide waypoint adjustment for the rotorcraft. However, it may not agree with the limit of the motors. Therefore, a path planning optimization model is constructed to minimize the spraying deviation of the droplets under the condition of satisfying the maneuvering constraints of the rotorcraft. The experimental results verify the effectiveness of the method.