DYNAMICALLY-CONTROLLABLE NOZZLE FOR PRECISION AGRICULTURAL SPRAYING

• Sponsoring Institution: National Institute of Food and Agriculture
• Project Status: COMPLETE
• Funding Source: SMALL BUSINESS GRANT
• Reporting Frequency: Annual
• Accession No.: 1025951
• Grant No.: 2021-33530-34568
• Cumulative Award Amt.: $100,000.00
• Proposal No.: 2021-01011
• Project Start Date: Jul 1, 2021
• Project End Date: Sep 30, 2022
• Grant Year: 2021
• Program Code: [8.13]- Plant Production and Protection-Engineering

Recipient Organization
OGIVE TECHNOLOGY
43 PARKSIDE DR
DAVIS,CA 956161844

Performing Department
(N/A)

Non Technical Summary
Rapid advancement in pesticide application includes robotics, autonomous vehicles, and unmanned aircraft; yet, these systems still rely upon and are limited by existing, legacy spray nozzles.The goal of the project is a controllable nozzle, with deformations of the exit orifice providing control of the spray flow, pattern, droplet size and motion. The nozzle materials and properties will be designed to allow simple actuation by piezo-active elements, providing low-cost, low power consumption, rapid response, and low mass. Piezo-electric actuators for human interface haptics (e.g., mobile phone keyboard feedback) have high durability, long life and low cost. The performance goals of the nozzle system are a greatly expanded 3-D control space (flow rate, droplet size and spray pattern and velocity), a ten-fold reduction in actuator mass and power requirements and ten-fold increase in response time.The novel aspects are: a) A deformable nozzle shape, with heterogeneous material properties, allowing orifice shape deformations to alter spray formation; b) Low mass, low power piezoelectric actuators; c) Nozzle design to translate linear actuation to curvilinear alterations in the orifice shape; d) Actuators to allow spray aiming; and, e) Integration into industry standard pressure and PWM control systems to achieve defined spray characteristics such as flow rate, droplet size, spray velocity and spray pattern.The final system will address the unique needs of modern precision agriculture spray systems such as precision, target-sensing weed sprayers and unmanned aircraft; yet, it will also be compatible with and provide new capabilities for conventional ag sprayers.

Animal Health Component

45%

Research Effort Categories

Basic

15%

Applied

45%

Developmental

40%

Classification

Knowledge Area (KA)	Subject of Investigation (SOI)	Field of Science (FOS)	Percent
402	5310	2020	100%

Knowledge Area
402 - Engineering Systems and Equipment;

Subject Of Investigation
5310 - Machinery and equipment;

Field Of Science
2020 - Engineering;

Keywords

control

drift

droplet

efficacy

jet

nozzle

precision

spray

Goals / Objectives
A superior ag spray control system is needed in order to advance the full capabilities of precision agriculture. Current spray technology does not have the requisite spatial and temporal resolution.The goal of this project is the development of a novel spray nozzle and associated control system that will meet the quantitative performance criteria of: 1) operational flow control turn down ratios of minimum 3:1 and optimally 8:1; 2) individual nozzle control with minimum of ancillary systems (pneumatic, hydraulic, etc.); 3) minimal mass, as small as possible but definitely less than the 1 kg of current PWM systems; 4) small spatial footprint, optimally no larger than existing nozzles, i.e., less than 8 cm3, and 4)Minimal power consumption, i.e., less than 7 - 10 Watt/nozzle. Specifically, the goal is a small, low-mass, low-power, 3:1 to 8:1 flow control range, continuous-flow, rugged, low-cost spray controller.The eventual goal is a revolutionary nozzle - where not only flow rate but also the droplet size, spray pattern, angle and dynamics are controlled by a small, wireless, battery (or vibration energy harvesting system) powered actuator.

Project Methods
The approach isto produce 1-3 prototype/candidate designs that demonstrate feasibility of a controllable nozzle with a 5:1 flow turn down fan nozzle mimicking the range of a 11010 to a 11002 agricultural fan nozzle and continuously controllable with a digital signal. The designs will include the nozzle, the actuator component and the controlling circuitry. The objectives follow a logical design and development path of developing the deformable nozzle, concurrently selecting and integrating the appropriate piezo electric actuator, then testing the candidate assembly and finally, developing the necessary controlling electronics for the entire system.

Progress 07/01/21 to 09/30/22

Outputs
Target Audience:The target audience, at this point of the development effort, is focused on technical investors and decision makers in the precision agriculture sector.Specifically, the highest priority target audience are developers, integrators and providers of precision spray systems.Precision spray systems are defined as those that identify and target individual plants or portions of plants for delivery of biologically active materials such as nutrients, pesticides, growth regulators or pollination. An additional audience is the technical community, consisting of industrial and academic researchers and scientists in the spray application field. Changes/Problems:An anticipated, the goals of the project have proven ambitious, with the greatest challenge being the amount of force required to alter the geometry of the nozzle.The force levels with the current prototype exceed the desired range.Currently, the power requirement for the actuation are higher than desired.However, they are still far below the current and competing technologies.Work is currently addressing this problem and concurrently, a work-around is being investigated in which the nozzle would have a multi-stage actuation system, with the primary force applied by a conventional electric motor and the fine tuning of the nozzle adjust provided by the low power-piezo actuator. What opportunities for training and professional development has the project provided? Nothing Reported How have the results been disseminated to communities of interest?The goals, motivation, work and accomplishments of the project have been disseminatedthrough two primary means.In the technical arena, project work has been discussed with a number of potential customers, including ag robotics and remotely-piloted aircraft companies.Concurrently, the technical work has been reported at an international conference on International Advances in Pesticide Application in Germany in 2022 and subsequently published in the journal Aspects of Applied Biology.The project and goals have also been presented at two technology commercialization events.Ogive participated in the University of California Innovation Academy, developing and presenting a business and development plan.Further, Ogive was accepted into the 2021 cohort of the Clean Tech Open, an international program for development of companies and technologies with potential to provide environmental benefits. What do you plan to do during the next reporting period to accomplish the goals? Nothing Reported

Impacts
What was accomplished under these goals? A novel, dynamically-controllable nozzle was developed.The flow turn-down achieved was 5:1, which was within the target design range and exceeded the minimum of 3:1.The material used was a pliable, multi-component elastomer and the size (volume, mass) of the nozzle was identical to current existing spray nozzles.An actuation system for piezo-elements was developed and successfully integrated into a wireless, tablet-based interface.Power consumption for the controller was minimal, based on a small portable battery.The concept of a dynamic, pliable nozzle design was established.Further, the nozzle was surprisingly rugged and durable, exceeding expectations of the initial design.Computational fluid dynamics (CFD) tools were used to model flow and design the nozzle, in line with target design methods.?

Publications

• Type: Conference Papers and Presentations Status: Published Year Published: 2022 Citation: Giles, D.K. 2022. Dynamic flow control for agricultural chemical applications. International Advances in Pesticide Application. Munster, Germany. Association of Applied Biologists.
• Type: Journal Articles Status: Published Year Published: 2022 Citation: Giles, D.K. 2022. Dynamic flow control for agricultural chemical applications. Aspects of Applied Biology. 147: 229-234.

Progress 07/01/21 to 02/28/22

Outputs
Target Audience:The target audience is for this research and development effort is initiallythe potential customers for the resulting product Concurrently, the additional audience is the investment community, as the company is likely to require venture capital to move forward from R&D to product development. We have discussed our technooogy with conventional aerial spray researchers and also the CEO's/CTO's of remotely piloted aircraft manufacturers and operators. All are supportive of our project and are eager to cooperate. We have also met with a large international agrochemical comapny who is very eager to investigate our technology and potentially invest. We completed the CleanTech Open start-up accelerator program in which we conducted a business and sustainability review of the company plan and presented to investors. Changes/Problems:Objective 1 is underway; but, as we anticipated, is the most technically challenging, and not yet completed. With the dependence of Objective 2 on Objective 1, we have not addressed the experimental testing of the design. Addressing Objective 1, we have continued our analysis of existing spray nozzles and focused our work on developing the 11002 to 11010 range of operation. While we have focused on the use of 3-D printed elastomer materials, we have been delayed with vendor response times, to the point of great frustration. The 3-D printer materials that are readily available, while suitable for laboratory / prototype work have very short functional lives due to water and sunlight. This is a significant limitation for any product for the agricultural spraying market so we have chosen to not waste time or resources doing development work with materials that are known to be unacceptable for the final product. Therefore, we are pivoting to metallic and Teflon/Viton type materials. This has required us to revise our design approach. What opportunities for training and professional development has the project provided? Nothing Reported How have the results been disseminated to communities of interest?We reported our progress - along with our potential market and motivation - extensively durign the CleanTech Open accelerator program. While this was primarily business-based, we also provided some technical details to the investment community. What do you plan to do during the next reporting period to accomplish the goals?With the electronic aspects of the project complete; we will be addressing the mechanical design phases as follows: Feb - May 2022: Complete Technical Objective 1, with the mechanical design of robust test nozzles being the priority. CFD modeling is essentially complete, the task now is to locate and use vendors capable of delivering nozzle prototypes from during materials, most likely from molding and machining rather than 3-d printing. May - Aug 2022: Complete technical Objective 3, with the robust nozzle designs being integrated into the test fixtures and ready for experimental characterization. Sept 2022:Complete final technical report for Phase I.

Impacts
What was accomplished under these goals? Our original objectives can be summarized as in general approaches of: Objective 1: Design the deformable orifice / nozzle component: Objective 2: Analyze and select candidate actuators for the nozzle design: Objective 3: Experimentally evaluate the performance of the prototype with spray liquid; and Objective 4: Develop a prototype/demonstration control circuit for the nozzle assembly. We currently have accomplished Objectives 2 and 4. As to Objective 2, we have four candidate piezo actuators that are at the performance level we require. These leading candidate actuators were custom fabricated by Pi Electronics and provide a 2 mm displacement at the millisecond range we require (Figure 1). The typical travel distance is a 1 mm and the size is 36 x 6.15 x 0.67 mm, easily compact enough for our single nozzle operation. While these actuators are currently well above the OEM cost that we foresee for a viable product (~ $175 in quantity one), the economies of scale are quite significant in the electronics industry for these components and scaled custom fabrication can reduce these costs by orders of magnitude. Objective 4 was recently completed. This circuit design was conducted in collaboration with Dr. Daniel Jenkins under a sub-contract. This was just completed as of December 2021 due to unavailability of the Texas Instruments DRV 2700RGPT High Voltage Driver Chip. This chip is core to the current design of the driver circuit and there are not obvious "work arounds". Currently, we have two functioning prototype circuit boards (Figure 2), fabricated using salvaged driver chips. We are being extremely cautious with these boards as the availability of replacement parts is currently uncertain, with all vendors showing no stock on hand. Despite the challenges of component selection and availability, the circuit is working and is wirelessly integrated into a tablet application (Google / Android) and with operational issues. ?

Publications