1. On-the-go Caliper and
Counter Device for Shade and
Fruit Tree Nursery Inventory
Management
J.S. Owen Jr., W. Shi, S. Singh,
H.M. Stoven, K. Lewis

2. Seasonal Counts for Inventory
Images by Jim Robbins

3. Automation of Inventory
Processes for Nurseries
Dr. James Robbins – Extension Specialist
Image by Jim Robbins

4. Caliper as an Estimate of Grade
Tallymaster – 2003

6. On-the-Fly Tree Caliper
Measurement
2 Class 3 lasers, 60 Hertz camera

7. On-the-Fly Tree Caliper
Measurement
Capture multiple frames per tree at
varying angles

8. Caliper
 2 Class 3 lasers
 Caliper estimation at 60 times
per second (60 Hz)
 Filtered from light
 Algorithm incorporated to
process staked trees
 Caliper measured at:
 distance of 10 to 20” from tree
 6” (±2”) above the graft union or
soil travelling 3 mph

9. Field Caliper GUI
 User can specify if stakes are used and diameter of stake
 Reports optimum measuring distance range and maximum
allowed traveling speed to ensure adequate estimates per
tree (approx. 12)

10. Unstaked Tree Accuracy
+/- 2.5mm

11. Unstaked Tree Accuracy
200 Caliper Ests Manual Utool
180
160
Number of trees
140
120
100
80
60
40
20
0
4 5 6 7 More
Nursery tree grade

12. Staked Tree Accuracy

13. Staked Tree Accuracy

14. Staked Tree Accuracy
 Limitation for staked trees
 Need to know the caliper of the stake
 Caliper of stake and tree must be significantly different (ratio of
stake caliper to tree caliper)
 Left figure shows stakes deemed acceptable, right figure shows
stakes that are not viable.

17. Counter Software
 Graphic User Interface to include user
input, pausing and saving data

18. On-the-Fly Tree Counter
 J frank Schmidt, OR - 45 Sergeant crabapples travelling < 3 mph. Trees
were counted 5 times with an average accuracy of 97%
 Willow Drive Nursery, WA - 20 apple small caliper seedlings travelling
approx 2 mph. Trees were counted 10 times with an average accuracy of
95%.
 At Dave Wilson Nursery, CA - 50 cherries trees travelling approx 2.5 mph.
Each of the tree cultivars were counted 10 to 20 times with an average
accuracy of 97%
 At J frank Schmidt, OR - 45 Gymnocladus seedlings travelling approx 2.5
mph. Each of the tree cultivars were counted 4 times with an average
accuracy of 97%
 At J frank Schmidt, OR on 708 Staked 2 year old red pointe maple (½ - 1 ¼
caliper, 12 inch spacing) 91 to 90% accuracy. Low accuracy was result of
a dust film on lens.

19. Localization
 Post-processed
 Device: U-blox 6T
 Cost: $300 to $400
 Sub-meter accuracy
 Field tested
○ Spring (WA)
○ Fall (OR)

20. Localization
 Tractor track:
raw data in
red
 Processed
data in green.

21. Localization
 Tractor’s speed plot: during travel at
~3.0 mph

22. http://www.cascrop.com/