دانلود رایگان ترجمه مقاله بهینه سازی پوشش هوایی در مدیریت کشاورزی دقیق (نشریه الزویر 2013)

بهینه سازی پوشش هوایی در مدیریت کشاورزی دقیق: رویکرد الهام گرفته از هارمونی موسیقی

Aerial coverage optimization in precision agriculture management: A musical harmony inspired approach

Abstract

The coverage path planning (CPP) problem belongs to a sub-field of motion planning where the goal is to compute a complete coverage trajectory from initial to final position, within the robot workspace subjected to a set of restrictions. This problem has a complexity NP-complete, and has no general solution. Moreover, there are very few studies addressing this problem applied to aerial vehicles. Previous studies point out that the variable of interest to be optimized is the number of turns. Thus, by minimizing the number of turns, it can be ensured that the mission time is likewise minimized. In this paper, an approach to optimize this cost variable is proposed. This approach uses a quite novel algorithm called Harmony Search (HS). HS is a meta-heuristic algorithm based on jazz musician’s improvisation through a pleasant harmony. Finally, the results achieved with this technique are compared with the results obtained with the previous approach found in the literature.

1 Introduction

Coverage path planning problem is the computation of a path that passes through all the required points in the workspace from a starting point to a final point. This problem has been mostly addressed to Unmanned Ground Vehicles (UGVs) applied in cleaning, farming, de-mining, etc. The

problem of covering a determinate area with an Unmanned Aerial Vehicles (UAVs) is directly related to the aforementioned problem. However, the aerial coverage path planning (CPP) problem is subjected to harder restrictions. Typically, UAV’s have limited working cycles compared with ground robots (i.e. the mission time has to be carefully optimized). Furthermore, they are not able to take off or land in random places (initial and final positions are usually pre-defined).

Depending on the application, the problem restrictions can slightly change. Herein, the problem of covering a wide area with an irregular shape is considered for mosaicking purpose. Mosaicking is the technique of mapping an overall area by stitching a set of geo-referenced images acquired. In order to achieve this objective with an UAV, the workspace is sampled by using a regular grid (kind of Sukarev grid), where each cell corresponds to an image sample. Then, a complete coverage trajectory must be generated ensuring that no points are revisited, taking into account pre-defined take off and landing positions, a required minimum number of turns. In this way, the coverage time is minimized.

The study case presented is based on a vineyard parcel (see Fig. 1), since irregular shape fields are more challenging for addressing the related problem. Mosaicking procedures can be applied in vineyards parcels for weeding, frost monitoring, fruit maturity, as well as for measuring other biophysical parameters of interest.

The organization of the paper is as follows: After this brief introduction, Section 2 reviews some related works. Section 3 introduces the HS algorithm and shows how the CPP problem is addressed by employing this optimization technique. Section 4 presents the results obtained and makes a comparison with other techniques. Finally, Section 5 provides the concluding remarks of this work.