Citation
Ruixin, Zhao
(2024)
Object detection of autonomous vehicle in complex traffic scenarios based on improved YOLOv8s.
Doctoral thesis, Universiti Putra Malaysia.
Abstract
With the rapid development of autonomous driving technology, road object detection
has become a critical research field, as it is regarded as an essential component of the
perception systems in autonomous driving. As deep learning based methods continue
to improve in generalization capability and accuracy, they are gradually replacing
traditional algorithms and have become the mainstream approach for object detection.
However, the traffic scenario object detection algorithms proposed in the literature
typically focus on a single field and still struggle to balance detection accuracy and
real-time performance, thus limiting their practical applicability. Moreover, many
methods fail to adapt to the diverse and complex conditions in real-world traffic,
including occlusions, and the presence of small objects (in images, where object sizes
are smaller than 32×32 pixels), all of which can significantly reduce detection
accuracy. To address these problems, this study proposes two improved algorithms
based on You Only Look Once version 8 small (YOLOv8s), namely Transformer
Attention Mechanism-YOLOv8s (TAM-YOLOv8s), which significantly improves the detection of occluded objects, and Z-YOLOv8s, which significantly improves the
detection of both small and occluded objects. Specifically, TAM-YOLOv8s introduces
the Revisiting Perspective Vision Transformer with Cross-stage Partial Bottleneck and
Two Convolutions (RepViTC2f) module into the backbone to strengthen global
modeling capabilities, and integrates a Large Selective Kernel Network (LSKNet) in
the detection head. Experimental results on the Berkeley Deep Drive 100K
(BDD100K) dataset demonstrate that TAM-YOLOv8s achieves a mean Average
Precision (mAP@0.5) of 70.7%, which is 2.8% higher than the original YOLOv8s,
while maintaining a detection speed of 89.24 Frames Per Second (FPS). It also
achieves consistent improvements on Karlsruhe Institute of Technology and Toyota
Technological Institute (KITTI) (92.7%) and Malaysia-Universiti Putra Malaysia
(Malaysia-UPM) (77.7%). Building on TAM-YOLOv8s, Z-YOLOv8s further
incorporates a Space-to-Depth Convolution (SPD-Conv) module into the backbone
and replaces the original Spatial Pyramid Pooling Fast (SPPF) module with Softpool-
SPPF, thereby more effectively capturing the features of small objects in complex
backgrounds. Consequently, Z-YOLOv8s achieves an mAP@0.5 of 75.2% on
BDD100K (an improvement of 7.3% over YOLOv8s) at a detection speed of 78.41
FPS, and outperforms YOLOv8s by 3.8% and 4.8% on the KITTI and Malaysia-UPM
datasets, respectively. Overall, TAM-YOLOv8s effectively addresses occlusion issues
in complex traffic scenarios, while Z-YOLOv8s performs well in detecting small and
occluded objects, achieving a balance between detection accuracy and processing
speed. These findings underscore the significant potential of the proposed algorithms
for applications in intelligent transportation systems and autonomous driving.
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Additional Metadata
| Item Type: |
Thesis
(Doctoral)
|
| Subject: |
Self-driving cars |
| Subject: |
Machine translating |
| Subject: |
Deep learning (Machine learning) |
| Call Number: |
FK 2024 83 |
| Chairman Supervisor: |
Associate Professor Tang Sai Hong |
| Divisions: |
Faculty of Engineering |
| Keywords: |
Road environmental; Object detection; YOLOv8; Deep learning; Autonomous vehicle. |
| Sustainable Development Goals (SDGs): |
SDG 9: Industry, Innovation and Infrastructure, SDG 11: Sustainable Cities and Communities, SDG 12: Responsible Consumption and Production |
| Depositing User: |
MS. HADIZAH NORDIN
|
| Date Deposited: |
08 Jul 2026 03:41 |
| Last Modified: |
08 Jul 2026 03:41 |
| URI: |
http://psasir.upm.edu.my/id/eprint/126942 |
| Statistic Details: |
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