2012 Annual Report
1a.Objectives (from AD-416):
The overall objective is to develop high throughput (~75 samples/s), economically feasible sorting devices for specialty crop product streams. The means for detection will include sensors and/or imaging coupled with algorithm development that differentiates good product from defective, contaminated, or otherwise undesirable product. Sorting devices based on these techniques may be high-speed and non-destructive for mass inspection or as an aid in the sampling and grading process. Specific objectives over the period covered by this project plan are: Detect insect damage in almonds; Detect fungal infestation in walnuts; Detect Olive fly infestation in olives and; Sort shells and kernels in the pistachio nut process stream.
1b.Approach (from AD-416):
1)Appropriate methodologies will be developed to create samples of the product defect to be identified in sufficient quantity for sorter and algorithm development..
2)Using primarily x-ray and color camera imaging technology features will be identified that distinguish undesirable product from good product..
3) Automatic algorithms will be developed to extract the identified features from images in real-time..
4)Material handling systems will be developed to allow construction of prototype sorting devices based on 1 through 3 above..
5)Prototype testing will be conducted to demonstrate the feasibility of implementing the technology in processing plant environments.
Over the past year, automatic detection algorithms have been developed for each of the four project objectives as described in the project plan. Status of each objective is as follows:
1. Almonds: Application of automatic algorithms so far suffers from high false positive rates. Work is ongoing.
2. Walnuts: Detection rates from x-ray images are disappointing. NIR is being investigated as a contingency.
3. Olives: Initial results show high accuracy in detecting insect damage in x-ray images, except in the earliest stages of development.
4. Pistachio nuts: Very high accuracy has been achieved. An initial single channel prototype sorting device has been built. A more sophisticated four channel version is under construction.
X-ray sterilization of insects for use in Sterile Insect Technique (SIT). While being an effective and ecologically benign method for insect control, SIT is hindered by the inherent difficulties in obtaining access to radioisotopes for insect sterilization. The x-ray irradiation unit built by ARS researchers in Albany, California, under an agreement with the Animal and Plant Health Inspection Service (APHIS) (see 5325-44000-010-01R, 2011 annual report) has been demonstrated to be effective for sterilizing Navel orangeworm (NOW) adult males. Dose rates of 70 Gy/min have been achieved. While the throughput is not high enough for the unit to be a practical means for use in an eradication program, the relatively low cost makes it very practical as a means for conducting SIT research at the laboratory level without the need for radioisotopes.
Haff, R.P., Saranwong, S., Kawano, S. 2012. Methods for correcting morphological-based deficiencies in hyperspectral images of round objects. Journal of Near Infrared Spectroscopy. 19:431-441.
Haff, R.P., Slaughter, D.C., Jackson, E.S. 2011. X-ray based stem detection in an automated tomato weeding system. Applied Engineering in Agriculture. 27(5):803-810.
Haff, R.P., Young, R. 2012. Modernization of the DFA Moisture Meter. Applied Engineering in Agriculture. 28(2):221-223.