Progress 09/01/17 to 04/30/18
Outputs
Target Audience:The technology developed by this project will create a novel, fast, and effective strategy for the deployment of semiochemical-based pest control strategies, heretofore thought to be a high-maintenance and cumbersome strategy due to the reliance of many semiochemical products on manual applications. SPLAT-UAV technology will enable mating disruption products to be applied over larger crop areas in less time, while still maintaining the same degree of efficacy and longevity as manual application processes. In the long term, our customers for SPLAT-UAV application systems will be U.S. growers seeking to reduce their reliance on chemical pesticides, such those who are facing difficulties with regulation or resistance; those for whom chemical options for control are unavailable or are not delivering adequate crop protection; and organic growers. Application of pheromone-based SPLAT formulations using UAVs will either require far less chemical pesticide to be applied than a standard insecticide cover spray (i.e., in the case of an attract-and-kill formulation) or will control pest populations without the use of any pesticide at all, as in mating disruption. Today's semiochemical control products, while undoubtedly safer and more sustainable that traditional pest control tactics, are hampered by the need for manual attachment throughout the crop, leading to high monetary and time costs required to complete larger applications. Reliable, automated, and rapid UAV application of SPLAT technologies will retain the advantages of semiochemical-based pest control (environmental safety, low risk of resistance, etc.) without the practical limitations of manually applied products. Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?
Nothing Reported
How have the results been disseminated to communities of interest?A major component of ISCA's Phase I and Phase II projects for the USDA SBIR program consists of establishing and maintaining informative and productive relationships with the various stakeholder groups affected by a particular insect management problem or opportunity, from agricultural producers and their customers, manufactures and distributors, to government officials and pest control advisors. ISCA continues to work with grower communities to achieve an ideal balance of product efficacy and application efficiency. The reduction in UAV costs and the introduction of a variety of drones and quadcopters to the commercial and recreational markets has greatly increased interest in and feasibility of their use for agricultural applications. What do you plan to do during the next reporting period to accomplish the goals?
Nothing Reported
Impacts
What was accomplished under these goals?
Task 1: Carry out mechanical and electrical design of a UAV applicator capable of carrying 10 lb of SPLAT product and applying with 4 ft. accuracy. Over the course of Phase I, ISCA developed three prototype applicators to enable UAVs of varying sizes and designs to apply SPLAT formulations. The first prototype, designed as a proof-of-concept model, consisted of a rack-and-pinion mechanism, operated by microcontrollers, that changed the rotational movement of a DC motor to a linear movement, in which the rack (a linear gear) pushed a plunger inside a 250-g cartridge, extruding the SPLAT formulation from the cartridge. This applicator was designed to fit on a relatively small drone frame (max. 1-kg payload). The second and third prototypes were designed to be adapted for larger drone models with heavier payloads, to enable larger scale SPLAT applications. Prototype 2 was specifically created to be assembled on a frame produced by the engineering company ISCA originally intended collaborating with on this project. This applicator was capable of carrying four 750-gram cartridges of SPLAT, constructed of Aluminum-6061 and PLA (3D printing material). However, due to time and practicality constraints, this design was abandoned before flight testing. Prototype 3 was the result of extensive testing on a variety of different UAV frames and control systems, to identify the most efficient combination of these technologies for application of SPLAT formulations. After careful consideration of payload capacity, flight time, flight stability and user-friendliness, the engineering team elected a DJI MG-1S frame, equipped with an A3 flight controller. This drone model has a tank that can carry up to 10 kg of pesticide, and is equipped with efficient pumps and nozzles that we determined were capable of applying ISCA's flowable SPLAT formulation. To render the application of heavier, more viscous SPLAT formulations more reliable and effective, we also designed a detachable applicator to handle these thicker products. The Prototype 3 drone is capable of carrying up to four large tubes of product (3 kg of SPLAT material); SPLAT is ejected from these tubes by the action of linear actuators (up to 250 N of force/actuator), which move back and forth in the linear movement required to extrude the product. ISCA engineers also evaluated different guidance systems to ensure precise and accurate SPLAT applications by our prototype UAV applicators in the field. For Prototype 1, a sonar system was used to detect the individual trees to which the product was meant to be applied. However, these sonar sensors had a limited detection range¾ if the drone flew more than 4 m above the canopy, sensors were no longer able to recognize the tree¾and were vulnerable to detection errors, namely, mistaking a branch for a new tree and as a result, applying more product than the user desires. For this reason, the sonar sensor-based guidance system was abandoned in favor of a global positioning system (GPS) to apply the product based on the spacing between trees in the field, for Prototypes 2 & 3. The GPS module allows the applicator to adjust itself based on the drone speed during the mission. The user provides the distance between the trees, the number of dollops to be applied per tree, and the dollop size. After providing these inputs, the drone applies the product automatically during flight. Task 2: Implement guidance software and combine with the drone applicator developed in Task 1 to carry out semi-field tests, to assess its capacity to apply the SPLAT product accurately over a predetermined field setup. Following the design and lab testing of the UAV SPLAT applicators, semi-field tests were carried out to assess their performance in an outdoor, less controlled environment, using a variety of flight controllers. The trials included takeoff, mission planning, and safe and automated landing with and without maximum payloads. The first drone tested, a Tarot model, had difficulties in take-off and mission planning tests, during which unpredictably altitude changes occurred and one propeller became detached, causing the drone to crash. The MG-1S drone performed much better during flight tests, demonstrating safe take-off and landing (with and without payload), carrying out successful application of both liquid (water) and SPLAT, and maintaining its programmed height above crop trees with a high degree of accuracy and precision. This drone model also performed well when the thick-SPLAT applicator was attached, both with product loaded (8.2 kg payload) and unloaded (3.5 kg payload). In both cases, the UAV sustained its ability to safely take off, fly and land, and also utilized the thick-SPLAT applicator to extrude and drop dollops of the formulation of a programmed size while in flight. Task 3: Conduct field trials in California almond fields, comparing drone-applied SPLAT and manually applied SPLAT on the following parameters: ability to suppress pest population, reduction of crop damage, and time and cost required to carry out the application. ISCA's first field trial of the UAV SPLAT applicator was performed on a 2-acre plot in commercial almond fields in Bakersfield, CA. The Prototype 3 SPLAT-UAV system was used to apply ISCA's mating disruption formulation for navel orangeworm, SPLAT NOW, to the almond trees. The second field trial was conducted in almond fields in Chowchilla, CA, on a 12-acre plot, with the same SPLAT-UAV system. For both trials, this drone-based application method was compared to manual application of SPLAT NOW, on the basis of time required to complete the application as well as the efficacy of pest control achieved. The Prototype 3 drone system flew in the range of 1.5-3 m above the almond crop, and the SPLAT NOW dollops reliably landed on the leaves of the trees below. The drone proved capable of applying the MD product over up to 6 acres per flight (10 min). This represented a significant time reduction compared to manual application of SPLAT NOW. Data is still being collected on pest infestation and damage in almond fields treated for MD by the UAV-SPLAT system; these results are expected to be completed by mid-November 2018, and will be submitted in an addendum to the Phase I final report.
Publications
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