Chapter 34

Precision Viticulture

Unmanned Aerial Vehicles

Unmanned aerial vehicles (UAVs), commonly known as drones, are among the most successful technologies in precision viticulture and smart farming. The use of UAVs to monitor vineyards offers excellent possibilities for acquiring field data in a simple, fast, and cost-effective manner compared to other methods. With UAVs, the actual flight process is relatively straightforward. UAVs are controlled using software on a ground control device (typically a tablet, laptop, or smartphone); the operator outlines the area to be surveyed in a Google map-type view. The software programs the flight, overlaying lines on the map to show the drone’s flight path. The information is uploaded to the drone over a wireless link. Takeoff, flight, and landing are completely autonomous (manual override allows the operator to avoid unexpected objects in the flight path, such as a manned plane).

Advantages and Disadvantages

There are three main advantages in using unmanned aerial systems (UAS) for vineyards. The first advantage is cost. Collecting images and data is less costly using a UAS than using a satellite or manned airplane. The second advantage is timeliness. UAS have the ability to fly and capture images on short notice or during small windows of opportunity. This is particularly important for applications in growing grapes, in which timeliness in collecting images is often critical. The third advantage is the ability to collect high-resolution aerial images by flying at a lower altitude below the cloud level, which results in much more precise data and images. For some diseases, it is necessary to see an individual leaf on a grapevine. For example, diseases such as grapevine leafroll have no treatment options, so infected grapevines need to be removed before other plants are affected.

Despite the potential advantages of UAVs in viticulture, several challenges must be addressed before these machines can be effectively used for disease and pest scouting. The first challenge is the lack of suitable, lightweight, and cost-effective sensors. The standard multi-band cameras that are commercially available have limitations, either in optical or spectral resolution.

UAV Platforms

UAV or drone-based platforms are a technology that can be used to obtain quantitative plant information for tens or even hundreds of lines in a crop field using noninvasive imaging techniques and protocols. Fully integrated remote sensing platforms consist of unmanned aircraft equipped with multiple sensors, utilizing communication and global navigation satellite system (GNSS) tools to acquire crop canopy images from the field. UAV classifications are globally based on their wing design, which impacts their autonomy, size, and weight.

Fixed-Wing UAVs

Fixed-wing drones are designed in a manner similar to more traditional types of aircraft, which resemble airplanes (Figure 34.9). They are composed of a central body with two wings and a single propeller. Once in the air, the two wings generate lift that compensates for its weight—allowing the aircraft to remain in flight. Fixed-wing UAVs can be launched by manually throwing them into the wind or by accelerating down a runway into the wind.

Multi-Rotor UAVs

Multi-rotor UAVs, also known as drones, are aircraft that utilize multiple, fixed-pitch propellers for lift and propulsion, enabling vertical take-off and landing, stable hovering, and precise maneuverability in any direction (Figure 34.10). Common configurations include quadcopters (four rotors), hexacopters (six rotors), and octocopters (eight rotors), with each rotor’s speed adjusted by the flight controller to control the drone’s movement, stability, and position.

Vertical Take-Off and Landing UAVs

Vertical takeoff and landing (VTOL) drones, commonly known as hybrids,  are becoming more common because autopilot, gyroscope, and accelerometer technology can be integrated into the UAV to facilitate remote piloting of these complex systems (Figure 34.11). VTOLs combine many of the best attributes of fixed-wing and multi-rotor drones. VTOLs have the capability to take off, hover, and land vertically without the need for a conventional runway. VTOL aircraft combine the advantages of fixed-wing airplanes (speed, range, efficiency) with the vertical lift and landing capabilities of helicopters. This makes them highly versatile for various applications, especially in environments where traditional runways are unavailable or impractical.

Federal Aviation Administration’s Regulations for Drones

Commercial drones weighing more than 0.55 pounds must be registered with the Federal Aviation Administration (FAA). The registration number provided by the FAA must be displayed on the drone. The registration process for a drone weighing between 0.55 and 55 pounds is relatively easy and can be completed online. Registration of drones weighing more than 55 pounds requires validation by a notary that the purchaser of the drone is the same person registering the aircraft.

Drone Swarms

Introducing UAVs into traditional agriculture has significantly reduced working hours and labor requirements while improving the efficiency of agricultural operations. However, since UAVs rely on limited battery power, employing a multi-UAV system (i.e., drone swarms) is more efficient than using a single UAV. For instance, using a single UAV for spraying or monitoring extensive vineyards is time-consuming and energy-intensive. In contrast, a multi-UAV system allows for simultaneous cooperative work, where individual UAVs perform specific tasks on assigned farmland areas, thereby expediting the completion of agricultural tasks on extensive vineyards.

Applications of UAVs in Precision Viticulture

Unmanned aerial vehicles (UAVs) are increasingly used in remote sensing applications for precision viticulture. Equipped with sensors of different types, UAVs can be utilized to identify which zones of the crops require different management, such as specific inputs. This enables farmers to respond promptly to any detected problem. UAVs can be utilized in a multitude of other applications in precision viticulture, including health monitoring and disease detection, growth monitoring and yield estimation, weed management and detection, among others.

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