Title Page
Contents
ABSTRACT 8
Ⅰ. Introduction 9
1.1. Strawberry Harvesting and Sorting Technology 9
1.2. Strawberry automatic measurement using LiDAR sensor 13
Ⅱ. Related Work 16
2.1. Automatic Strawberry Size Measurement and Weight Estimation 16
2.2. Deep Learning-Based Keypoint Estimation Model 20
2.3. LiDAR Application 21
Ⅲ. Proposed Method 22
3.1. HRNet-Based Sizing Point Detector 25
3.2. Physical Distance Calculation 27
3.3. Weight Estimation 29
Ⅳ. Numerical Experiments 30
4.1. Dataset 30
4.2. Experiment Results 34
Ⅴ. Discussion 46
Ⅵ. Conclusion 54
References 60
Appendices 67
[Appendix 1] Full data (300 samples) for strawberry size and weight prediction. 67
[Appendix 2] Prediction of strawberry size for M-sized strawberries. 72
[Appendix 3] Prediction of strawberry size for L-sized strawberries. 73
[Appendix 4] Prediction of strawberry size for XL-sized strawberries. 74
Abstract (in Korean) 75
〈Table 1〉 Size Measurement Techniques and Methods in Fruits: A Comparative Analysis of Research Cases in Apples, Strawberries. 15
〈Table 2〉 Dataset of white background experiment 33
〈Table 3〉 Presents the results of the size estimation experiment. 37
〈Table 4〉 Comparison table with previous strawberry sizing methods. 50
〈Figure 1〉 Establishment of an optimal object reading system for strawberry harvest 12
〈Figure 2〉 Illustrates the three-step process for strawberry size and weight prediction 24
〈Figure 3〉 The individual strawberry sizes and weights are manually measured using different methods. 32
〈Figure 4〉 Scatter plot of strawberry actual size and predicted size 39
〈Figure 4-1〉 A graph of the difference between the actual size and the estimated size of M-size strawberries 40
〈Figure 4-2〉 A graph of the difference between the actual size and the estimated size of L-size strawberries 41
〈Figure 4-3〉 A graph of the difference between the actual size and the estimated size of Extra L-size strawberries 42
〈Figure 4-4〉 Relative errors in weight by strawberry size (M, L, XL). 43
〈Figure 4-5〉 Relative error distribution plot for the width, height, and weight of individual strawberries 44
〈Figure 5〉 Some examples of size measurement results. 45
〈Figure 6〉 Example of strawberries with inaccurate keypoint detection. 51
〈Figure 7〉 The two samples with the largest errors in weight estimation. 52
〈Figure 8〉 Some examples of unusually size, shape strawberries size measurement results. 53
〈Figure 9〉 Illustrates the bulk harvesting and wholesale selling processes of various fruits. 58
〈Figure 10〉 Illustrates the current and future research directions spanning three stages. 59