Source: WASHINGTON STATE UNIVERSITY submitted to
SHAKE AND CATCH HARVESTING FOR FRESH MARKET APPLES
Sponsoring Institution
National Institute of Food and Agriculture
Project Status
EXTENDED
Funding Source
AFRI COMPETITIVE GRANT
Reporting Frequency
Annual
Accession No.
1005200
Grant No.
2015-67021-22841
Project No.
WNP03728
Proposal No.
2014-03813
Multistate No.
(N/A)
Program Code
A1521
Project Start Date
Dec 15, 2014
Project End Date
Dec 14, 2018
Grant Year
2015
Project Director
Karkee, M.
Recipient Organization
WASHINGTON STATE UNIVERSITY
240 FRENCH ADMINISTRATION BLDG
PULLMAN,WA 99164-0001
Performing Department
Agricultural Research Center
Non Technical Summary
Traditional apple harvesting requires a large, semi-skilled workforce for a short time. Shake-and-catch technology has been successful in harvesting fruit for the processing market, but no commercial success has been achieved in harvesting fresh market apples because of fruit damage. Lack of such technology is a crucial problem for the industry because the cost of manual labor is increasing and labor availability is increasingly uncertain.Our overall objective is to develop a fresh-market apple harvesting technology to reduce dependence on seasonal labor. Our hypothesis is that new, narrower apple canopies provide opportunities for localized shaking and catching with minimal fruit damage. Research methods include identification of mechanisms for localized shaking and catching, and their integration and evaluation in commercial orchards. First, we will study the effects of different combinations of shaking pattern, amplitude and frequency in fruit removal efficiency. Second, various fruit catching, deceleration and singulation mechanisms will be evaluated to maximize fruit collection and minimize damage. In addition, strategies for tree training, pruning and thinning will be studied to improve the ease of catching surface insertion into tree canopies. Overall, our system will minimize the impact force between fruit and catching surface and lessen fruit-to-fruit contact, the two primary causes of fruit damage.The success of our system will reduce labor demand as well as injuries associated with ladder use and repetitive motion, leading to a significant positive impact on the long-term economic and social sustainability of the U.S. apple industry.
Animal Health Component
0%
Research Effort Categories
Basic
40%
Applied
40%
Developmental
20%
Classification

Knowledge Area (KA)Subject of Investigation (SOI)Field of Science (FOS)Percent
4021110202070%
2051110106030%
Knowledge Area
205 - Plant Management Systems; 402 - Engineering Systems and Equipment;

Subject Of Investigation
1110 - Apple;

Field Of Science
2020 - Engineering; 1060 - Biology (whole systems);
Goals / Objectives
Our major long-term goal is to reduce the dependency on a large number of seasonal semi-skilled workers through automation and mechanization in the production of high quality apple for the fresh market. The overall objective of this project is to develop a mechanical harvesting solution for fresh market apple. This objective is based on the hypothesis that simple, narrow, accessible and productive (SNAP) tree canopies in modern orchards will provide an opportunity for localized shaking and precise catching in harvesting fruit in mass with minimal damage.Specifically, in this project we propose the following four research objectives:Study mechanisms for targeted shaking of tree branches for localized removal of appleInvestigate mechanisms for catching harvested apple with minimal damageStudy horticultural strategies for improved shake-and-catch harvestingEvaluate integrated shake-and-catch system in production orchard environments
Project Methods
Obj #1: Study of Mechanisms for Targeted ShakingMethods: Two different shaking mechanisms will be fabricated and tested. The first mechanism will apply linear vibration (shaking energy) to the targeted branches on a tree. The second shaking mechanism to be studied is based on our innovative new design of a dual-motor actuator. This new mechanism allows us to generate and apply various shaking patterns for more effective and controllable removal of apples in the targeted zones. Some example shaking patterns are a circular shaking and an 8-shaped shaking. A shaking hook will be attached to the developed shaking mechanisms for securely engaging the target branch.Field experiments will be carried out to study the effects of different combinations of shaking amplitude, frequency, and pattern type on energy distribution to different zones in a tree and on the fruit removal efficiency. First, a factorial design of 3 levels of each variable will be used. Several targeted tree branches will be used to evaluate the shaking performance under all tested combinations of these parameters. Trees will be shaken at three to four branch locations until all apples in the target zone are detached (or until we reach 3 s shaking duration, a time determined based on preliminary tests). Data will be analyzed statistically to identify the optimal combination of frequency, amplitude, and pattern in achieving a high removal rate in the targeted zone with a minimal removal elsewhere.A high speed video will be used to capture fruit motions for estimating the removal rates over time. From these tests, an optimal window of shaking frequency, amplitude, pattern type and duration will be identified. This information will be used to develop a shaking actuator that can deliver an optimal shaking energy to the apple tree/branch for efficient removal of apples from a targeted zone. The shaking actuator will be integrated with the catching frame for systematic evaluation of the harvesting system.Performance of targeted shaking mechanism will be evaluated by two different measures: fruit removal rate (% removal) within and outside the targeted zones and potential for fruit damage. Fruit Removal Rate within and outside the targeted zones is defined as the ratio of the number of fruit removed from the corresponding zones to the total number of the fruit in these zones.We will use a 'potential for fruit damage' concept as the second parameter to evaluate the performance of shaking mechanisms. First, an experiment will be designed to confine fruit within 5~10 cm using a soft catching surface near the fruit. The effect of shaking frequency, amplitude, and pattern type on the potential of fruit damage will be estimated based on the number of fruit-to-fruit and fruit-to-limb contacts as well as by the actual damages. A second measure for the potential for fruit damage is acceleration at the time of fruit separation.Obj #2: Study Different Mechanisms for Fruit CatchingMethods We have conceptualized an innovative catching that will have multiple layers where each layer will be inserted about halfway into the canopy between trellis wires so that fruit can be captured just underneath the branches trained to trellis wires. This design will have a set of flappers made of flexible materials for fruit deceleration and two roller-based fruit singulating devices. These two devices collectively will capture, decelerate, singlulate and convey harvested fruit away from the harvesting zone. There will be two sets of decelerating and singulating devices in each layer to capture fruit from two sides of the canopy. The length of the catching surface can be adjusted based on interplant spacing. Each layer of catching surface can be controlled individually to place them such that fruit collection can be maximized while minimizing fruit travel distance.Some fruit may be detached during insertion of catching surfaces into the canopy. Lower catching surface will be inserted first so that detached fruit can be captured by the surface immediately below the one being inserted. In addition, the lowest catching surface will be designed to have better enclosure around tree trunks, which will help capture those fruit not captured by higher level catching surfaces.Performance of catching mechanisms will be evaluated based on fruit collection rate and potential for fruit damage. Fruit collection rate is defined by the ratio of the number of collected fruit and number of removed fruit. The potential for fruit damage will be estimated using the number of fruit-to-fruit contacts during fruit collection and the average travel distance for fruit to the catching surface. High speed camera will be used to record the images of fruit movement during falling and within the catching mechanism. Then, an image processing technique will be used to estimate fruit-to-fruit contact and travel distance.Obj# 3: Horticultural strategies to improve shake-and-catch systemMethodsWe will study the influence of branch location, branch size and branch angle on harvest efficiency and fruit quality. These tree factors will be evaluated in an observational manner that will lead to development of practical strategies to improve removal efficiency and minimize fruit damage through appropriate training and pruning. Individual fruit will be labeled prior to shake-and-catch testing and their position will be recorded so that fruit position can be related to quality and damage assessment after harvest. These horticultural studies will investigate the potential for canopy modification through training, summer pruning and fall pruning methods to create a layered canopy structure with 'windows' for insertion of catching surfaces into the canopy while minimizing fruit-to-fruit contact during removal and catching. In several commercial orchards, growers have developed architectures that exhibit several formal layered fruiting zones. This study will learn from these existing training and pruning strategies and will focus on further improving them.We will also study fruit spacing in existing orchards and the effect of fruit spacing on fruit removal efficiency and fruit quality. If necessary, appropriate thinning guidelines will be developed that reduce number of fruit clusters and fruit density to minimize fruit-to-fruit contact during removal and catching. Pruning guidelines will also focus on maximizing optimum branch position and size so that localized fruit removal will be effective while minimizing detachment from non-target zones.Obj #4: Evaluate Targeted Shake-and-Catch System Methods An integrated shake-and-catch apple harvesting system research prototype will be built and mounted on an orchard tractor. Apples caught by the catching surface will be quickly removed from the area through signulating rollers with minimal fruit-to-fruit and fruit-to-machine impact. Samples will be collected randomly from the harvested fruit to be sent to our fruit quality lab for quality analysis. In addition, control samples will be collected from manually harvested apples in the same orchard-plot at the same time targeted shake-and-catch harvesting is performed.The experimental plan includes a randomized block design with two shaking frequencies and two shaking amplitudes for the system-level evaluation. Shaking duration will be kept constant. Each combination of factorial treatment levels will have five replicates. The experimental unit for each replicate will include five trees randomly selected from a given row of the orchard. Data will be collected at the individual tree level before combining it for five trees within each experimental unit so that tree level variability can also be studied. The experiments will be repeated for linear and pattern shaking.The performance of shake-and-catch system will be evaluated using three different measures; fruit removal rate, fruit collection rate, and fruit damage rate.

Progress 12/15/16 to 12/14/17

Outputs
Target Audience:The outcomes of this project were used to communicate with researchers, growers, manufacturing industry, and other stakeholders from around the world through publication and presentation in local, national and international meetings and conferences. Project outcomes were also demonstrated and discussed with local news outlets, which disseminated the information to growers, researchers and general public in the Pacific Northwest region. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?One PhD student and two visiting scholars were actively involved in this project. Two post-doctoral researchers also helped planning and implementing experiments. PIs, Post-docs, students and scholars interacted frequently to discuss the progresses, address challenges and plan future tasks and activities. Post-docs, students, and scholars carried out most of the day-to-day research activities including data collection and analysis. Post-docs, students and scholars were also supervised for research paper writing, presentation and publications. How have the results been disseminated to communities of interest?The prototype of shake-and-catch platform was demonstrated and tested in several commercial orchards in Washington State. Apple growers have shown huge interest and have provided various types of support including access to their orchards for experiments. We presented various aspects of the developed shake-and-catch harvesting platform and field evaluation results in various national and international conferences such as '2017 ASABE International Annual Meeting held in Spokane, WA (July, 16-19, 2017)'. These presentations initiated dissemination of findings to various stakeholders and initiated a lot of discussion in the scientific community for future research and development. What do you plan to do during the next reporting period to accomplish the goals? Modification of catching surface to improve the engagement with tree canopy (avoiding the obstacles of fruit branches, offshoots, etc.) to reduce fruit dropping through the the gaps between catching frames used from two sides of the tree rows; Repeat pruning trials and study the relationship between fruit bearing shoot and fruit removal efficiency with various apple varieties. Improve the robustness and maneuverability of the multi-layer shake-and-catch platform, and demonstrate to the growers and public.

Impacts
What was accomplished under these goals? Summary of Impacts In this study, we have focused on improving the quality of harvested fruits by optimizing the design of shake and catch platform and its operation, identifying and minimizing bruising sources during harvesting, and improving the crop architecture. These innovations are expected to help make the mechanized harvesting technology commercially adoptable. When commercially adopted, the developed mechanical shake and catch harvesting system can significantly improve the harvesting efficiency of fresh market apples and potentially reduce labor use to less than 20% of current use. Obj.# 1: Study of Mechanisms for Targeted Shaking Major activities completed / experiments conducted; Fruit response test was conducted under varying shaking frequencies; Fruit motion and detachment study was conducted under continuously changing frequencies from low to high; A hydraulically-driven (MGG20016-BA1B3, Parker Hannifin Corp., Mayfield Heights, OH) vibratory shaker, which was modified from a commercial handheld reciprocating saw (SP200, STIHL Inc., Virginia Beach, VA), was used for the shaking experiments; Data collected; Fruit acceleration was recorded for the fruits at different location of branches, and under different shaking frequencies. High speed videos of fruit detachment process were recorded under continuous changing frequencies over 5 s; The developed shaker was used for the system evaluation with 20 Hz, and also the shaking duration of 2 and 5 s was applied. The number of detached fruit and overall fruit at each section were recorded. Summary statistics and discussion of results; For 'Envy', an acceleration of ~ 5 g (g= 9.8 m·s2) was enough to detach fruit. The fruit location index of >0.06 was essential for efficient fruit removal. High shaking frequency (e.g. 20 Hz) removed majority of the fruit in a short shaking duration but some of the fruit may get excessive energy, while low shaking frequency (e.g. 10 Hz) was not sufficient for fruit removal. 4) Key outcomes or other accomplishments realized. Tree branch diameter and length played a critical role in fruit removal efficiency. Appropriate tree pruning is essential to achieve high level of fruit removal efficiency. It might be beneficial to gradually increase shaking frequency from low to high to remove majority of the fruit while keeping damage percentage a low level. Obj.# 2: Investigate mechanisms for catching harvested apple with minimal damage 1) Major activities completed / experiments conducted; Two three-layer catching frames were developed; six pieces of cushioning surfaces (density of 44.9 kg m-3 and firmness of 4.8 kPa) were used for the catching frames. Each catching surface was 2.5 × 1.2 m with an adjustable elevation angle (α = 15°) to enlarge the fruit coverage area and minimize the possibility of fruit impact bruising. 2) Data collected; Overall fruit collection efficiency was calculated using the number of successfully collected fruit over the total harvested fruit. 3) Summary statistics and discussion of results; Fruit collection efficiency ranged from 95% to 99% in all tests. Some fruit were dropping from the gaps between two sides of catching system; a few bounced out after heating the cushioning surface. 4) Key outcomes or other accomplishments realized. Results will be useful in developing next generation prototype; one improvement will be to minimize the gap-between the catchers from two sides. Obj.# 3: Study tree training, pruning and thinning strategies to improve shaking efficiency, catching efficiency and fruit damage rate Major activities completed / experiments conducted; Harvesting test was conducted in the trees with two different pruning treatments: 6" and 9" pruning. A shoot index (ratio of diameter/length) was introduced to the trellis trained branches to evaluate the fruit removal efficiency and harvested fruit quality with respect to the biophysical attributes of fruit bearing branches. 2) Data collected; Total number of fruit in a set of randomly selected braches, and number of harvested fruit from those branches; Fruit removal condition and fruit location in a branch; Biophysical attribute of branches before and after harvesting activity; Fruit quality analysis based on USDA standards; 3) Summary statistics and discussion of results; Fruit removal efficiency in the trees with 6" pruning was significantly higher than that in the trees with 9" pruning (91% and 81%); Fruit with larger shoot index (i.e., fruit bearing offshoot with relatively thicker diameter, and shorter length) had higher likelihood to be removed from the branches; No significant difference was observed in the quality of harvested fruit between two types of pruning strategies. 4) Key outcomes or other accomplishments realized. Results from this objective will be useful for horticultural improvements that can be adopted for making tree canopies more suitable for mechanical harvesting. Obj. #4: Evaluate integrated shake-and-catch platform in orchard environments in terms of fruit removal and collection efficiencies, and fruit quality Major activities completed / experiments conducted; A multi-layer shake-and-catch harvesting system was developed using a four-wheel hydraulically-driven self-propelled orchard platform (OPS, Blueline, Moxee, WA); Trees were shaken at the middle of each branch (or P1), and close to the trunk (or P2); Two shaking durations were used; 2 s and 5 s. Harvesting test was conducted using the integrated shake-and-catch harvesting platform with five apple varieties trained at three different canopy architectures ('Jazz'- vertical fruiting wall, 'Gala' - V-trellis, 'Envy' - V-trellis, 'Fuji' - V-trellis, and 'Cosmic Crisp' - Bi-axis). 2) Data collected; Fruit removal efficiency, collection efficiency, coverage efficiency, damage percentage ('Extra Fancy', 'Fancy', & 'Downgrade' levels) were estimated; 3) Summary statistics and discussion of results The shaking duration of 2 s and 5 s had only slight difference in terms of fruit removal efficiency and fruit quality. Majority of fruits were detached within the first 2 s; Shaking at the location close to the tree trunk (P2) obtained higher fruit removal efficiency, especially when the trunk fruit were taken into consideration. Overall fruit removal efficiency was up to 78% for shaking at middle of each branch up to 90% for shaking at the location close to the tree trunk; Fruit quality decreased for P2 compared to that for P1. The percentage of marketable fruits ('Extra Fancy' & 'Fancy') was about 90% for 2 s shaking and shaking at P2. 4) Key outcomes or other accomplishments realized. This study revealed that 2 s shaking is sufficient to remove majority of the fruits, and the shaking close to trunk achieved higher overall fruit removal efficiency but slightly smaller percent of fruit were of fresh market quality.

Publications

  • Type: Journal Articles Status: Published Year Published: 2017 Citation: Fu, H., He, L., Ma, S., Karkee, M., Chen, D., Zhang, Q., & Wang, S. (2017). Jazz Apple Impact Bruise Responses to Different Cushioning Materials. Trans. ASABE, 60(2), 327336.
  • Type: Journal Articles Status: Published Year Published: 2017 Citation: He, L., Fu, H., Karkee, M., & Zhang, Q. (2017). Effect of fruit location on apple detachment with mechanical shaking. Biosyst. Eng., 157, 6371.
  • Type: Journal Articles Status: Published Year Published: 2017 Citation: He, L., Fu, H., Sun, D., Karkee, M., & Zhang, Q. (2017). Shake-and-Catch Harvesting for Fresh Market Apples in Trellis-Trained Trees. Trans. ASABE, 60(2), 353360.
  • Type: Journal Articles Status: Awaiting Publication Year Published: 2017 Citation: He L., Fu, H., Xia, H., Karkee, M., Zhang, Q., & M. Whiting. (2017) Evaluation of a localized shake-and-catch harvesting for fresh market apples. Agricultural Engineering International: CIGR Journal. (In press)
  • Type: Conference Papers and Presentations Status: Published Year Published: 2017 Citation: He, L., Zhang, X., Ye, Y., Karkee, M., & Zhang, Q. (2017). Shaking Location and Duration Effect on Mechanical Harvesting of Fresh Market Apples. ASABE Paper No. 1701056. ASABE, St. Joseph, Mich.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2017 Citation: Zhang, X., He, L., Majeed, Y., Karkee, M., Whiting, M. D., & Zhang, Q. (2017). A Study of the Influence of Pruning Strategy Effect on Vibrational Harvesting of Apples. ASABE Paper No. 1700812. ASABE, St. Joseph, Mich.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2017 Citation: Zhang, J., He, L., Karkee, M., Zhang, Q., Zhang, X., & Gao, Z. (2017). Branch Detection with Apple Trees Trained in Fruiting Wall Architecture using Stereo Vision and Regions-Convolutional Neural Network(R-CNN). ASABE Paper No. 1700427. ASABE, St. Joseph, Mich.


Progress 12/15/15 to 12/14/16

Outputs
Target Audience:The outcome of this project was communicated with researchers, growers, manufacturing industry and other stakeholders from around the world through publication and presentation in local, national and international meetings and conferences. Project outcomes were also demonstrated and discussed with local news outlets, which disseminated the information to growers, researchers and general public in the Pacific Northwest region. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?One PhD student and three visiting scholars were actively involved in this project. Two post-doctoral researchers also helped planning and implementing experiments. PIs, Post-docs, students and scholars interacted frequently to discuss progress, address challenges and plan future tasks and activities. Post-docs, students, and scholars carried out most of the day-to-day research activities including data collection and analysis. Post-docs, students and scholars were also supervised for research paper writing, presentation and publications. How have the results been disseminated to communities of interest?The prototype shake-and-catch system was demonstrated and tested in several commercial orchards in Washington State. Apple growers have shown huge interest and have provided various types of support including access to their orchards for experiments. We presented various aspects of the developed shake-and-catch harvesting system and field evaluation results in various national and international conferences including '2016 CIGR International Conference on Agricultural Engineering, held in Aarhus, Denmark (June, 26-29, 2016), 2016 ASABE International Annual Meeting held in Orlando, FL (July, 17-20, 2016), and AgriControl 2016, The 5th IFAC Conference on Sensing, Control and Automation in Agriculture, held in Seattle, WA (August 14-17, 2016). These presentations initiated dissemination of findings to various stakeholders and initiated a lot of discussion in the scientific community for future research and development. What do you plan to do during the next reporting period to accomplish the goals? Shake-and-catch system will be integrated to a self-propelled platform, and more field tests will be continued to evaluate the functionality and performance of the targeted shake-and-catch harvesting system; Multi-layer catching function will be added to the system to explore fruit dropping characteristics and fruit collection efficiency in wider canopy regions; Repeat pruning trials and study the relationship between fruit location and fruit detachment efficiency on various apple varieties

Impacts
What was accomplished under these goals? Summary of Impacts In this study, we have focused on improving the quality of harvested fruits by optimizing the design of shake and catch system and its operation, identifying and minimizing bruising sources during harvesting, and improving the crop architecture. These innovations are expected to help make the mechanized harvesting technology commercially adoptable. When commercially adopted, the developed mechanical shake and catch harvesting system can significantly improve the harvesting efficiency of fresh market apples and potentially reduce labor use to less than 20% of current use. Obj.# 1: Study of Mechanisms for Targeted Shaking The shaking mechanisms developed in last reporting period were used in experiments for this year Obj.# 2: Investigate mechanisms for catching harvested apple with minimal damage 1) Major activities completed / experiments conducted; A pendulum impact device was developed to test the impact strength between fruit and various catching materials in the laboratory environment; A fruit catching prototype was modified based on the finding with previous catching surface. New features added include a bounce buffer and a rolling buffer. Lab test was conducted to evaluate the effect of buffers and catching angles. An air pressured catching device was developed and tested in the field condition. The catching device was designed to incorporate the following two critical functionalities: (1) decelerate the fruit falling from branches; and (2) separate fruit before they land on the catching surface. 2) Data collected; Impact force exerted at different apple zones when dropped on different catching cushion materials from varying drop heights; Accelerations of a simulated apple (Impact Recording Device) when dropped from varying heights to different the catching device with or without buffers; Fruit quality data for the fruits collected using a air catching device with varying air flow pressure 3) Summary statistics and discussion of results The bruising-resistance of apples improved noticeably with the use of appropriate cushioning materials; Top zone of apple surface was found to be the most sensitive area for inducing bruising under mechanical impact; The catching device with two buffers (bouncing and rolling) provided the highest level of protection to the collected fruit; Catching surface elevation angle of 25° was relatively better than other two surface angles considering both fruit transfer velocity and fruit impact strength in the catching device; The fruit catching tests carried out in the field using an air catching device indicated that the percentage of damaged apples can be reduced by 36.9%. 4) Key outcomes or other accomplishments realized. Results from the evaluation of different types of catching mechanisms and varying catching surface angle will be useful for developing next generation of the prototype, which can potentially lead to commercialization of the shake and catch harvesting system Obj.# 3: Study tree training, pruning and thinning strategies to improve shaking efficiency, catching efficiency and fruit damage rate Major activities completed / experiments conducted; Harvesting test was conducted in the trees with two different pruning treatments (6" and 9" pruning); A fruit location index was introduced to the trellis trained branch/fruit section to evaluate the fruit removal efficiency with respect to the fruit location 2) Data collected; Total number of fruit in a set of randomly selected braches, and number of harvested fruit from those branches; Fruit detachment condition and the fruit location in a branch 3) Summary statistics and discussion of results Fruit removal efficiency in the trees with 6" pruning was noticeably higher than that in the trees with 9" pruning branches; Fruits with smaller fruit location index (i.e. fruit closer to the shaking point, in relatively thicker twig, and shorter twig length) had higher possibility to be detached from the branches 4) Key outcomes or other accomplishments realized. Information and results from this objective is useful for horticultural changes that can be adopted for making canopies friendlier for mechanical harvesting Obj. #4: Evaluate integrated shake-and-catch system in orchard environments in terms of fruit removal and collection efficiencies, and fruit quality (Karkee - Lead) Major activities completed / experiments conducted; Harvesting test was conducted using the integrated shake-and-catch harvesting system on eight varieties of apples with three different tree canopy architectures in Washington State. 2) Data collected; Number of fruit in targeted branches, number of harvested fruit from each branch, number of fruit collected from each branch, fruit quality assessment based on USDA standards 3) Summary statistics and discussion of results For the varieties and architectures tested, fruit removal efficiency varied from 66% to 95% under the shaking frequency of 20 Hz. For most of tested varieties, removal efficiency was 80% or higher within the targeted area. For example, removal efficiency of 86% and 88% were achieved for "Jazz" and "Pink Lady" varieties respectively. "Gala" and "Envy" varieties were the most difficult to detach from branches, which achieved only 68% and 66% of fruit removal efficiency. Developed catching device collected a large percentage of the harvested fruit from target region ranging from 91% to 100%; In these experiments, percentage of fruit with US Extra Fancy quality (bruise area diameter less than 12.7 mm) varied from 57% to 89%. Fresh market quality varied from 78% to 94%. With some varieties including "Jazz" and "Pink Lady", the harvesting system achieved both good fruit removal efficiency and good fruit quality. Both of these two varieties had 94% of fresh market quality fruit, with fruit removal efficiencies of 86% and 88% for "Jazz" and "Pink Lady" respectively. 4) Key outcomes or other accomplishments realized. Fruit removal efficiency and fruit quality were depended on the cultivars, some varieties such as Jazz, Fuji, and Pink Lady were found to be promising for mechanical harvesting in terms of both fruit removal efficiency and fruit quality.

Publications

  • Type: Journal Articles Status: Under Review Year Published: 2016 Citation: He, L., H. Fu, D. Sun, M. Karkee, and Q. Zhang. 2016. A shake and catch harvesting system for trellis trained apple trees. Transactions of the ASABE. (under review)
  • Type: Journal Articles Status: Under Review Year Published: 2016 Citation: Fu, H., L. He, S. Ma, M. Karkee, Q. Zhang, and S. Wang. 2016. A shake and catch harvesting system for trellis trained apple trees. Transactions of the ASABE. (under review)
  • Type: Conference Papers and Presentations Status: Published Year Published: 2016 Citation: Karkee, M., Q. Zhang, M. Whiting, L. He, H. Fu, and H. Xia. 2016. Localized shake-and-catch harvesting for fresh market apples. CIGR-AgEng Conference. June 26-29, Aarhus, Denmark.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2016 Citation: He, L., H. Fu, D. Sun, M. Karkee, and Q. Zhang. 2016. A shake and catch harvesting system forJazz apples trained in vertical fruiting wall architecture. ASABE Paper No. 162461420. ASABE, St. Joseph, Mich.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2016 Citation: Fu, H., L. He, S. Ma, M. Karkee, and Q. Zhang. 2016. Impact bruise responses for Jazz apple on different materials of catch surface. ASABE Paper No. 162461461. ASABE, St. Joseph, Mich.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2016 Citation: He, L., H. Fu, M. Karkee, and Q. Zhang. 2016. Effect of fruit location on apple detachment with mechanical shaking. IFAC AgriControl 2016, August 14-17, Seattle, USA.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2016 Citation: Fu H., L. He, M. Karkee, and Q. Zhang. 2016. Bruise responses of apple-to-apple impact. IFAC AgriControl 2016, August 14-17, Seattle, USA.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2016 Citation: Ma, S., M. Karkee, H. Fu, D. Sun, and Q. Zhang. Air Suspension-based Catching Mechanism for Mechanical Harvesting of Apples. In proc. of 5th IFAC Conference on Sensing, Control and Automation Technologies for Agriculture. August 14-17, 2016, Seattle, WA, USA.


Progress 12/15/14 to 12/14/15

Outputs
Target Audience:The outcome of this project was communicated with researchers, growers, manufacturing industry and other stakeholders from around the world through publication and presentation in local, national and international meetings and conferences. Project outcomes were also demonstrated and discussed with local news outlets, which disseminated the information to growers, researchers and general public in the Pacific Northwest region. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?One PhD student and three visiting scholars were actively involved in this project. Two post-doctoral researchers also helped planning and implementing experiments. PIs, Post-docs, students and scholars interacted frequently to discuss the progresses, address challenges and lay out future tasks and activities. Students and scholars carried out most of the day-to-day research activities including data collection and analysis. Students were also supervised for research paper writing, presentation and publications. How have the results been disseminated to communities of interest?The prototype of shake and catch system was demonstrated and tested in several commercial orchards in Washington State. Apple growers have shown huge interest and have provided various types of support including access to their orchards for experiments. What do you plan to do during the next reporting period to accomplish the goals? Field tests will be continued to validate function of the developed shake and catch prototypes. Shaking and catching mechanisms will be integrated into a system for system level evaluation New training and thinning strategies will be explored; pruning trials will be repeated.

Impacts
What was accomplished under these goals? Summary of Impacts This study puts a huge emphasize on improving the quality of harvested fruits by optimizing the design of shake and catch system, and investigating the bruising sources during harvesting, which is a major concern for the technology commercialization. When commercially adopted, the developed mechanical shake and catch harvesting system can significantly improve the harvesting efficiency of fresh market apples and potentially reduce labor use to less than 20% of current use. Obj.# 1: Develop of an effective shake and catch system for mechanical harvesting of fresh market apples 1) Major activities completed / experiments conducted; A shaking prototype with an ability to adjust frequency and amplitude was designed and fabricated. Laboratory and field tests were conducted to estimate optimal shaking frequency, shaking amplitude and shaking direction in terms of high fruit removal rate and good fruit quality 2) Data collected; Fruit removal rate, shaking duration, and fruit quality were recorded during the shake harvesting; tests were carried our with three different apple varieties and two different tree architectures 3) Summary statistics and discussion of results Preliminary results showed that the shaking frequency and amplitude have an influence on the fruit removal percentage and fruit quality Further experimental analysis of the prototype is ongoing 4) Key outcomes or other accomplishments realized. This task will lead to identification of optimum combination of frequency and amplitude of shaking for different apple varieties. Such information will be useful to design next generation prototypes and commercial machines for shake-and-catch apple harvesting. Obj.# 2: Investigate mechanisms for catching harvested apple with minimal damage 1) Major activities completed / experiments conducted; An fruit catching prototype was developed with fruits deceleration and separation mechanism; lab and field tests were conducted to study the effect of catching angle on fruit bruising 2) Data collected; Field data was collected with different catching mechanisms and varying catching angle; Dataset included measures such as collection percentage, and fruit quality for three different varieties and two different tree architectures 3) Summary statistics and discussion of results Preliminary results showed that the new catching prototype developed in this work performed better than a regular foam catching surface in terms of fruit quality; The results also showed that catching surface would minimize the fruit bruising percentage if the collection surface is at 25 degrees to the horizontal surface Further experimental analysis of the prototypes is ongoing 4) Key outcomes or other accomplishments realized. Knowledge on type of catching mechanism and optimal catching angle will be useful for developing next generation of the prototype and for commercialization of the shake and catch harvesting system Obj.# 3: Study tree training, pruning and thinning strategies to improve shaking efficiency, catching efficiency and fruit damage rate Major activities completed / experiments conducted; Apple tree architectures were investigated for designing effective shake and catch system Two different pruning strategies were applied to more than 50 trees of two different varieties of apples produced in a commercial orchard 2) Data collected; Harvesting efficiency data is currently being collected 3) Summary statistics and discussion of results Effect of two different pruning strategies will be studied during data analysis 4) Key outcomes or other accomplishments realized. Information and results from this objective is useful for horticultural changes that can be adopted for making canopies more friendly for mechanical harvesting. Obj. #4: Evaluate integrated shake-and-catch system in orchard environments in terms of fruit removal and collection efficiencies, and fruit quality (Karkee - Lead) N/A

Publications

  • Type: Journal Articles Status: Accepted Year Published: 2015 Citation: De Kleine, M. E., and M. Karkee. 2015. A Semi-automated harvesting prototype for shaking fruit tree limbs. The Transactions of ASABE. Accepted.