Ohio University Mechanical Engineering Conceptual Design Report GREENHOUSE CROP COVERING SYSTEM. Green Edge Engineering Solutions: OU G.E.E.

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1 Ohio University Mechanical Engineering Conceptual Design Report GREENHOUSE CROP COVERING SSTEM Green Edge Engineering Solutions: OU G.E.E.S Eric Alexander Stephen Bartone David Berndt Derek Bissett Benjamin Bruno Benjamin Palko Date: 11/21/2011 Abstract This report will discuss the problem identification and conceptual design creation of an improved greenhouse crop protection system for Green Edge Gardens. A problem statement was created using expert knowledge from various farming industry perspectives. Benchmarking showed that there are patents on similar covering systems but nonrelated to greenhouse farming. Concept evaluation and development are in progress with analysis of feasibility and effectiveness.

2 1.0 Concept Generation 1.1 Problem Statement for Concept Generation Throughout the cold weather growing season, our customer at Green Edge Gardens must cover their crops at night in all eight of their standard 96 X 30 greenhouses. They must then be uncovered in the morning to receive sunlight. The process takes several man-hours to complete and Kip would like a more efficient way to cover/uncover the crops to reduce the total amount of man-hours associated with them. The goal of the project is to implement a simple, effective, and affordable system that could be readily and easily adaptable for other local greenhouse farmers that wish to grow year round. For reference, our teams Revised Needs Statement reads as follows: To design and implement a user friendly plant protection system for use in unheated greenhouses in Southeastern Ohio that is operable by one employee and which maintains solar irradiance in the daytime, allows moisture and air flow suitable for crop health, costs less than $500, requires less than one minute per operation (cover or uncover), is easy to maintain, and has a minimum three year lifetime. Our most heavily used resource for information that led to problem identification was the partial owner of GRG, Kip Rondy. His expertise helped us get a sense of the day-to-day duties and issues that are encountered in the winter growing season. We were also able to question one of Kips employees, Dan. Dan is Kips main greenhouse caretaker and spends a lot of time inside the greenhouses. Dan was able to share with us some of the difficulties of moving around the greenhouses and how accessibility to the crops is an important factor in the covering design. Additional expert advice came from Horticultural & Crop Scientist, Dr. Matt Kleinhenz, and from fourseason organic greenhouse farmer Eliot Coleman. A telephone interview with Dr. Kleinhenz informed us of details regarding specifically to plant health. This was extremely useful because it taught us what kind of living conditions we need to produce and maintain underneath the cover so the plants can thrive. Literature from Eliot Coleman was used to view the entire system and idea of winter harvesting from a broader point of view. We learned about cold weather harvesting techniques and climate differences from region to region on a national scale. Our methods of problem identification have been derived mostly from asking experts in the field. The several experts we have consulted with are each enlisted in different sub-sectors of the farming/growing industry. From the Horticulturalist telling us what the plants need to GRG s on-site harvester telling us what will make his or her job easier; This new information from the experts was used to find an allencompassing solution that satisfies from all angles of critique. 1.2 Patent Search The main aspect of the project that was searched was current patents on retractable covers and covers that were used to cover plants. The first one that was found was patent number 2,898,607. It is a retractable pool cover that uses a motorized reel and mounted tracks along the side to guide the cover as it is deployed and retracted. Another similar retractable cover is patent number 4,459,711. It is a pool cover

3 that utilizes a pulley system. If we decide to use a roll there is a possibility that the ideas from this patent could be changed or improved to help in our design. The next one that was found was US 2005/ A1 which is an individual row cover to protect plants from frost. It utilizes a hoop system and is designed for small gardens. The next patents that were found were patent number 894,341 and 932,971. They are both methods for covering vegetables if there is too much heat or if there is going to be a frost. They are both patented by the same individual and the designs are nearly identical. They both utilize a box method using wooden slats to adjust the amount of light allowed by the plants. They both also have a roll attached to then with burlap to protect the plants. The next patent that was examined was 5,070,641. It is a cloth that has an adhesive the can be applied to the ground to give protection to plants. The final patent that we examined was patent number 7,637,053. It is a protective tarp that protects citrus trees during periods of cold weather. It uses a rolled tarp that is deployed by two people over a frame above the trees and is secured by draw strings. It uses a blower system to make sure there is always heat on the trees. 1.3 Concept Generation With our revised needs statement determined, our members began independent brainstorming of design concepts. The structured portion of our iterative concept generation process began with a brainstorming session. New information was gathered when some applicable literature from an Eliot Coleman was dissected and a phone conference with Dr. Matt Kleinhenz brought further enlightenment. These new findings were applied in a group sketch brainstorming session in which each of our members devised at least one design concept. These design concepts were analyzed in a Concept Scoring Matrix to determine the most promising features of each design. The individual design components of each design were considered independently in this evaluation to determine the most desirable concept features. The features deemed most applicable entered a feature integration process to develop a cohesive design concept. Meanwhile, design concepts were presented to our customer, Kip Rondy of Green Edge Gardens, to gain understanding of the customer s perception of each design. Also during this time, the specific needs of the employees of the customer were documented to provide further insight into the convenience of the proposed designs. The feedback from the customer was utilized in the feature integration process to ensure the design satisfied the needs of the customer and that no particulars were overlooked. 2.0 Concept Screening and Evaluation 2.1 Concept Screening The team narrowed down the field of all initial design concepts to about ten concepts. This was done by eliminating obviously overcomplicated ideas, dangerous ideas or ideas that did not match well with the customer needs statement. The remaining concepts fell into two main categories; either systems that utilized a cover that is rolled up onto a spool for storage as seen in Figure 1 or systems that bunch the cover up for storage similar to a shower curtain as seen in Figure 2.

that could be evaluated and compared individually.

4 Figure 1. Cover rolled into a spool. Figure 2. Cover bunched. From these two main concept categories the team broke each of the concepts into smaller subsystems that could be evaluated and compared individually. The subsystems for each of the designs were rated based upon pros versus cons using a 1 to 10 scale with ten being the best score. The simplified concept scoring matrix can be seen below.

5 Table 1: Concept Scoring Matrix Concept Cover Storage Driving Mechanism Deployment Method Housing 1 Derek 2 Derek 3 Ben B 4 Ben B 5 Ben P 6 Ben P 7 Eric 8 Eric 9 Dave Stephen (Each member reviewed the subsystems/components of each design and rated it based upon our customer needs. The scores were then averaged to obtain a final rating.) Each subsystem was given a rating based upon simplicity, ease of use and adhering to customer needs. After scoring we felt that some part of each concept could be integrated to form one final conceptual design. However, before narrowing our options further we decided that all available options seemed strong candidates for selection so we contacted Kip Rondy at Green Edge Gardens to see if he believed that one of the two main concept categories could provide him with a better solution to his problem. If so, then we would be able to concentrate our efforts moving forward upon improving design concepts from that particular category. From our discussion with Mr. Rondy we found that he thought both concepts would be feasible and each would have unique advantages. He liked the compactness of a rolled system, yet he also thought a bunched system would perform better under freezing temperatures. He also seemed to like the adaptability and adjustability of the bunched system. In light of this information, we decided that it would

6 be best to reconvene and try utilizing the advantages of both systems so that we could create a final conceptual design that would provide the best overall solution for our customer. 2.2 Data and Calculations for Feasibility and Effectiveness Analysis The integration of the best qualities from each design proposed in table 1, Concept Scoring Matrix, is being analyzed with respect to feasibility and effectiveness in order to improve our concept screening process. Prior to the rating of any designs, feasibility and effectiveness were defined based on the scope of our concepts. Feasibility was defined as having the ability meet the design requirements, considering time, cost, ease of use, and ease of maintenance. Effectiveness was defined as a system that allows for protection from the winter elements while maintaining plant survival. To further research the feasibility of the desired specifications from our customer, we were able to use the information given to us from our phone conversation with Dr. Matt Kleinhenz. Specifically, he was able to give us important information with regards to covering the crops inside the greenhouse during the winter months. According to his research, he told our team that keeping the cover completely off of the plants will provide the best growing conditions for them. This is something that Kip is not doing, at least completely, with his current system. This is an aspect that we would like to incorporate into our final design. The feasibility of doing this was confirmed by Dr. Kleinhenz, again through his research. He said that freezer burn is more likely to occur if the cover is touching the crops. He also showed us pictures of a farm in Michigan that is currently keeping their cover completely off of their crops and having very successful harvests. This concept was also confirmed by Elliot Coleman, for he too suggested that we make sure we keep the cover completely off of the plants if at all possible. He, again, is an organic farmer in Maine who is currently growing crops year round with great success. Where his farm is located, he has to keep his covers on throughout all of the winter months. He has had time to experiment and has documented his findings on different covers and covering methods. He too found that keeping the cover off of the crops is better than allowing it to touch. Our top priority is to meet the design requirements that Kip is looking for. Cost is the next thing that is in our thoughts, but it is not something that we are greatly concerned with as of now. A big expense that Kip is paying for, outside of the $ budget, is the cover itself. The rest comes out of the budget he provided and any additional money that we will be receiving from the University. This section will need to be revisited as time goes on and a final conceptual design has been chosen. An in depth cost analysis will then be conducted as well as structure strength calculations as needed. Additional calculations and evaluations will also be made as needed. 2.3 Concept Development, Scoring and Selection The goal of our team was to implement the best subsystem(s) from each design to develop the best possible solution. After numerous consultations with Dr. Kleinhenz and reiterating literature from Mr. Coleman, one design constraints became apparent: the covering system needs to be elevated off of the

7 plants. As discussed above there are two storage subsystems; bunching the cover or having the cover on a spool, both will be able to maintain this needed elevation off the plants but their storage becomes a concern. In the coming winter months testing on each storage method will be performed and hopefully will answer question about the durability of the row cover when fully saturated and frozen in the cold weather. Once this concern is met the selection of the subsystem will follow. The cover still has three proposed driving mechanisms: human pulled cover on guide wires (table 1 concepts 1, 4, 7, and 9), pulley system (table 1 concept 10), and a crank system (table 1 concepts 2 and 3). The scoring from table 1 favored the driving mechanism of the human pulled cover on guide wires and the pulley system. The driving mechanism using human pulled cover on guide wires or wire was favored because of the ease of use and also that the designed system could be operated from either side of the greenhouse reducing the limitations of the system. The driving mechanism using the pulley system was favored for the minimal wear placed on the cover and the covering speed could be drastically reduced. The continuous refinement of the ideas discussed is ongoing, and a collaboration of the best is being established.

8 OHIOU ME SrD Decision Checklist For Significant Decisions Checklist Item N Notes for this Decision: The issue requiring a decision has been stated clearly and is understood by all members of the team. All issues are brought forth a team meetings to be discussed fully The deadline for making the decision is set, based on its priority and relation to the overall project schedule. The decision maker(s) who has final authority for making the decision has been identified by team consensus. The impact of the decision on the overall project has been determined, and the appropriate time and resources for making the decision have been scheduled. The reversibility of the decision has been assessed, and if the decision is reversible the latest reversal date and process for reviewing the decision prior to that date have been scheduled. The impact of the decision on safety (including any aspect from manufacturing through customer use) has been assessed and safety critical items have completed or been scheduled for a Design for Safety review prior to decision approval. The data or information required to make a good decision has been identified, gathered and reviewed, and all other people or things that could influence the decision have been consulted. The process for making the decision has been identified by team consensus and appropriate tools and documentation have been used. Diversity of team member perspectives and cognitive styles was used to ensure that multiple alternatives and adverse consequences (risks and implications) were considered (as applicable), and sufficient intellectual debate / conflict occurred concerning the leading options. The final decision does not appear to be merely the least common denominator of the options. The cognitive biases that impact decisions were discussed and addressed, including confirmation bias and the tendency to accept opinions as facts. We rate the item's priority as a team then use our action items list to post a deadline for the item No one person has the final say, if possible we come to a team consensus by fully discussing all options The long term impact of decisions is always at the forefront of our decisionmaking process Remaining flexible in this aspect can help in the design process by allowing rapid redesign/adaptability of our design Safety first, all ideas are first viewed from a safety standpoint All meetings begin with information gathering reports so that informed decisions can be made A continuous work in progress; we have made an effort to follow the meeting structure set up by the team. Which allows for information sessions, discussion, debate and finally consensus As a team we try to support all ideas with fact and make it a habit to question other's ideas

9 The need for external review and approval of the decision has been determined, and that external review has been completed or scheduled within the overall project schedule. The results of the decision have been reviewed by the team, and lessons learned from that review (what actually happened as a result of the decision versus what they expected to happen) are used to build team skills for decision making. Some decisions were sent to Mr. Rondy or Dr. Kremer for their opinion other were sent out for our Mentor to review Bad decisions provide the team with learning experiences and success provides us with a platform to work from

10 OHIOU ME SrD Conceptual Design Checklist Checklist Item The Conceptual Design decisions have been reduced to the appropriate scope for the most effective decision process. N Notes for this Decision: Although still dealing with multiple designs we have managed to cut down the field of initial concepts and have a reasonably sized scope we are now working with All applicable items in the SrD Decision Checklist have been followed for the significant CD-related decisions. Used as a model for decision making All relevant questions about assumptions, feasibility, risks or other aspects of the conceptual design alternatives have been addressed. We have consulted with multiple experts and have stayed in contact with our partner Mr. Rondy to address these issues All alternative solutions that have been used in other industries or fields that merit comparative evaluation in the concept selection process have been included. Patent research has been executed and evaluated, and any unique and potentially valuable technology in the design concepts has been considered for invention disclosure and patent application. The maintenance and repairability of the final concepts was included in the system-level conceptual design and the selection of the final concept. We have found that the pool covering industry is one of the only industries that deals with similar issues as our own Several patents from various types of industries were researched including crop covering and pool covering systems We are making design decisions keeping in mind the major customer need of user friendliness Decision matrices or similar tools are used as appropriate to organize and communicate the basis of key decisions, and the ratings used in the decision matrices are supported in the text of the report. The decision differentiators are highlighted and discussed in the CD report, and are consistent with the weighted customer requirements. N A Concept Scoring Matrix was implemented in the iterative process of whittling down initial concepts The Conceptual Design Report includes a convincing case that the selected concept is worthy of support for prototype development. N We have not chosen a specific design yet, however we have narrowed our option down to two main ideas.

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