NI CaseStudy Cs 14451
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Transcript of NI CaseStudy Cs 14451
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8/14/2019 NI CaseStudy Cs 14451
1/31/3 www.ni.c
High-Speed Seed Counting With LabVIEW and NI Vision
Author(s):
Michael D. Coleman, PhD - Coleman Technologies, Inc.
Introduction
The production and preparation of seeds for shipment to retailers and end users involves numerous steps where the seeds must be counted. Traditionally, this process uses photo
diode-based counters that are relatively slow and not easy to adapt to a variety of seed shapes and sizes.
An international horticultural company contacted Coleman Technologies (CTI), a Certified , to provide multiple high-throughput, high-accuracyNational Instruments Alliance Partner
seed counting systems. The company selected CTI for two primary reasons: the relatively low cost and unique design of our proposed system and our extensive experience indelivering machine vision applications.
The system requirements included counting accuracy greater than 99 percent, inspection of a variety of seed shapes with dimensions ranging from 0.5 to 20 mm, and seed counting
throughputs of up to 1,000 seeds/s.
National Instruments Tools Speed Up Vision Application Development
Our system utilizes a Gigabit Ethernet Basler Runner rul2048-19gm 2,000 pixel line-scan camera with an F mount 75 mm lens to image silhouettes of seeds passing through the drop
region in front of a pair of high-intensity backlights. A 45-degree angle mirror splits the field of view so that the charge-coupled device (CCD) can simultaneously view the drop region
from two angles 90 degrees apart (see Figure 1). The line scan CCD effectively images a horizontal plane in the drop zone.
Figure 1. Seed Counter Schematic
The ability to view the drop zone from two orthogonal directions significantly enhances the ability of the systems software to distinguish seeds whose silhouettes overlap in just one
view. The utilization of a single camera and mirror, as opposed to two separate cameras, significantly reduces system size and cost, in addition to greatly simplifying alignment and
timing of the two orthogonal camera views.
LabVIEW, NI Vision Development Module, and Vision Acquisition Software
NI measurement, automation, and vision acquisition software make it easy to configure and acquire images from a Gigabit Ethernet camera with . In this application, eachLabVIEW
half of the cameras field of view acquires images like that shown in Figure 2, which shows round seeds approximately 3 mm in diameter. The line scan camera acquires lines at 19
kHz, the maximum rate of the camera. The resolution of the system in the horizontal direction is 0.125 mm/pixel, which is sufficient to view the smallest seeds. Note that the apparent
size in the vertical direction is dependent on the velocity of the seeds. The optimum velocity for our system is 2 to 5 m/sec; the system is able to accurately count seeds at speeds
outside this range at reduced seed throughputs (< 1,000 seeds/sec).
"We created our seed counter system with LabVIEW and the NI Vision
Development Module, which make it simple to perform image analysis
on the data and display results to the user."- Michael D. Coleman, PhD, Coleman Technologies, Inc.
The Challenge:
Developing a system capable of accurately counting seeds at rates up to 1,000 seeds/s for a variety of seed shapes and sizes (0.5
to 20.0 mm).
The Solution:
Using NI Vision Acquisition Software to acquire high-speed, line-scan camera images of seeds falling through a drop zone and
combining a 45-degree angle mirror with analysis software to quickly and inexpensively produce a seed counter system.
Figure 1. Seed Counter Schematic
http://www.colemantech.com/http://www.ni.com/alliance/http://www.ni.com/labview/http://www.colemantech.com/http://www.colemantech.com/http://www.ni.com/labview/http://www.ni.com/alliance/http://www.colemantech.com/ -
8/14/2019 NI CaseStudy Cs 14451
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Figure 2. View of Falling Seeds
LabVIEW and NI Vision Ensure Quick Development
We created our seed counter system with LabVIEW and the . This add-on to LabVIEW makes it simple to perform image analysis on the data andNI Vision Development Module
display results to the user. Figure 3 shows the main application window, which helps the user set a target seed count. Once the count is reached, an on-screen indicator turns green
and a digital output line on an NI DAQ device is toggled.USB-6008
We developed a custom algorithm to associate seeds found in each view with seeds in the other view to avoid double counting seeds and to handle cases where seed silhouettes
overlap in one or both views. The software also has filters to avoid counting debris mixed with the seeds.
The application includes displays of the images taken from each view angle along with a plot of the position in the drop zone of each seed, as shown in Figure 3. Additional system
features include:
Alignment and diagnostic tools
Background correction
Configurable filtering parameters
Count logging to text files
Figure 3. Main Window of the Seed Counter
The production department and R&D currently use three seed counter systems. Our systems high throughput and flexibility to different seed shapes and sizes removes a major
bottleneck associated with previous seed counting methods. This application can easily be adapted to count a variety of other opaque objects, such as small food or manufactured
parts, at high throughput rates.
Author Information:
Michael D. Coleman, PhD
Coleman Technologies, Inc.
5131 West Chester Pike
Newton Square, PA 19073
United States
http://www.ni.com/labview/vision/http://sine.ni.com/nips/cds/view/p/lang/en/nid/201986http://www.colemantech.com/http://www.colemantech.com/http://sine.ni.com/nips/cds/view/p/lang/en/nid/201986http://www.ni.com/labview/vision/ -
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