đ About Me
I am currently pursuing a Ph.D. at the College of Information Science and Electronic Engineering at Zhejiang University under the supervision of Prof. Shen Hui-liang. Prior to this, I received postgraduate exemption and my Bachelorâs degree from the same college.
My research interests include 3D Object Detection, 4D Radar Perception, Multi-modal Fusion, and 3D Reasoning. Recent research focuses on integrating LLMs with 4D imaging radar and vision fusion in an end-to-end architecture.
đ„ News
- Currently exploring the potential of large vision-language models in 3D spatial reasoning.
- Currently investigating the use of generative models in occupancy prediction for autonomous driving.
- Currently implementing knowledge distillation to enhance the performance of 4D millimeter-wave radar.
đ Educations
- 2023.09 - present, Ph.D. candidate in the College of Information Science and Electronic Engineering, Zhejiang University, Hangzhou.
- 2019.09 - 2023.06, B.E. in the College of Information Science and Electronic Engineering, Zhejiang University, Hangzhou.
đ» Projects
- 2025.08 - present, ChinaEye Valley Co-operative Project on maternal and infant health risk assessment.
- 2025.12 - present, Collaboration with VIVO on 4D dynamic scene reconstruction under sparse-view, combining generative models.
- 2024.01 - 2026.06, National Key R&D Program of China, 4D radar object detection and tracking in autonomous driving.
- 2022.06 - 2023.12, Collaboration with Apple on image denoising based on transfer learning and generative models.
- 2021.06 - 2022.06, Student Research Project SRTP on face video heart rate signal measurement via rPPG.
đ Publications
âRaGS: Unleashing 3D Gaussian Splatting from 4D Radar and Monocular Cues for 3D Object Detectionâ, IEEE/CVF Conference on Computer Vision & Pattern Recognition (CVPR), 2026. [Paper] 
Xiaokai Bai, Chenxu Zhou, Lianqing Zheng, Si-Yuan Cao, Jianan Liu, Xiaohan Zhang, Zhengzhuang Zhang, Hui-Liang Shen.
âBoosting Instance Awareness via Cross-View Correlation with 4D Radar and Camera for 3D Object Detectionâ, IEEE Transactions on Multimedia (TMM), 2026. [Paper] 
Xiaokai Bai, Lianqing Zheng, Si-Yuan Cao, Xiaohan Zhang, Zhe Wu, Beinan Yu, Fang Wang, Jie Bai, and Hui-Liang Shen.
âSGDet3D: Semantics and Geometry Fusion for 3D Object Detection Using 4D Radar and Cameraâ, IEEE Robotics and Automation Letters (RAL), vol. 10, no. 1, pp. 828-835, 2025. [Paper] 
Xiaokai Bai, Zhu Yu, Lianqing Zheng, Xiaohan Zhang, Zili Zhou, Xue Zhang, Fang Wang, Jie Bai, and Hui-Liang Shen.
âLGDD: Local-Global Synergistic Dual-Branch 3D Object Detection Using 4D Radarâ, IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS), 2025. [Paper] 
Xiaokai Bai, Qin Yang, Zili Zhou, Fuyi Zhang, Zhe Wu, Si-Yuan Cao, Lianqing Zheng, Beinan Yu, Fang Wang, Jie Bai, and Hui-Liang Shen.
âSD4R: Sparse-to-Dense Learning for 3D Object Detection with 4D Radarâ, IEEE Intelligent Transportation Systems Conference (ITSC), 2025. [Paper] 
Xiaokai Bai, Jiahao Cheng, Songkai Wang, Yixuan Luo, Lianqing Zheng, Xiaohan Zhang, Si-Yuan Cao, and Hui-Liang Shen.
âOmniHD-Scenes: A Next-Generation Multimodal Dataset for Autonomous Drivingâ, IEEE Transactions on Pattern Analysis and Machine Intelligence (TPAMI). [Paper] [Project] 
Lianqing Zheng, Long Yang, Qunshu Lin, Wenjin Ai, Minghao Liu, Shouyi Lu, Jianan Liu, Hongze Ren, Jingyue Mo, Xiaokai Bai, Jie Bai, Zhixiong Ma, and Xichan Zhu.
âDoracamom: Joint 3D Detection and Occupancy Prediction with Multi-view 4D Radars and Cameras for Omnidirectional Perceptionâ, IEEE Transactions on Circuits and Systems for Video Technology (TCSVT). [Paper] 
Lianqing Zheng, Jianan Liu, Runwei Guan, Long Yang, Shouyi Lu, Yuanzhe Li, Xiaokai Bai, Jie Bai, Zhixiong Ma, Hui-Liang Shen, and Xichan Zhu.
âBeyond Registration: Self-Supervised Unknown Border Completionâ, Chinese Conference on Pattern Recognition and Computer Vision (PRCV), 2025. [Paper]
Xiaokai Bai, Jun Ma, Leyuan Yu, Runmin Zhang, Hui-Liang Shen, Beinan Yu, and Si-Yuan Cao.
âBoosting Conditional Diffusion Models Using Intermediate Segmentation Map for Infrared Small Target Detectionâ, Chinese Conference on Pattern Recognition and Computer Vision (PRCV), 2025. [Paper]
Xiaokai Bai, Wenkai Zhao, Xiaohan Zhang, Yicheng Tong, Si-Yuan Cao, and Hui-Liang Shen.
âStructure-Aware Radar-Camera Depth Estimationâ, IEEE International Conference on Robotics and Automation (ICRA), 2025. [Paper] 
Fuyi Zhang, Zhu Yu, Chunhao Li, Runmin Zhang, Xiaokai Bai, Zili Zhou, Si-Yuan Cao, Fang Wang, and Hui-Liang Shen.
âS-BEVLoc: BEV-based Self-supervised Framework for Large-scale LiDAR Global Localizationâ, IEEE Robotics and Automation Letters (RAL), 2025. [Paper]
Chenghao Zhang, Lun Luo, Si-Yuan Cao, Xiaokai Bai, Zhu Yu, Yisen Wang, Beinan Yu, and Hui-Liang Shen.
âRethinking Early-Fusion Strategies for Improved Multispectral Object Detectionâ, IEEE Transactions on Intelligent Vehicles (TIV), 2024. [Paper] 
Xue Zhang, Si-Yuan Cao, Fang Wang, Runmin Zhang, Zhe Wu, Xiaohan Zhang, Xiaokai Bai, and Hui-Liang Shen.
đ Honors and Awards
- 2024-2025, Five-Good Graduate Student (top 1%)
- 2024-2025, Outstanding Graduate Student Cadre (top 5%)
- 2023-2024, Excellent Postgraduate student of Zhejiang University (top 5%)
- 2022-2023, Outstanding Graduate of Zhejiang Province (top 1%)
- 2022-2023, Postgraduate exemption based on being in the top 5%
- 2021-2023, Zhejiang University Student Research Training Program (SRTP), Outstanding
- 2021-2022, Zhejiang University Student Entrepreneurship Competition, Second Prize
- 2021-2022, Silver Award in the Zhejiang Internet+ Innovation and Entrepreneurship Competition
- 2021-2022, Zhejiang Provincial Government Scholarship (top 2%, ïż„6,000)
- 2021-2022, Honorable Mention in the Mathematical Contest in Modeling (MCM)
- 2021-2022, Zhejiang University Excellent Student (top 3%)
- 2020-2021, Zhejiang University First-Class Academic Scholarship (top 3%, ïż„6,000)
- 2020-2021, Zhejiang University Outstanding Senior Student
- 2019-2020, Zhejiang University First-Class Academic Scholarship (top 3%, ïż„6,000)
- 2019-2020, Zhejiang University Excellent League Cadre
â Services
- Reviewer of IEEE/CVF Conference on Computer Vision and Pattern Recognition (CVPR)
- Reviewer of ACM International Conference on Multimedia (ACMMM)
- Reviewer of Association for the Advancement of Artificial Intelligence (AAAI)
- Reviewer of Pattern Recognition (PR)
- Reviewer of IEEE Transactions on Geoscience and Remote Sensing (TGRS)
- Reviewer of IEEE Transactions on Circuits and Systems for Video Technology (TCSVT)
- Reviewer of IEEE Robotics and Automation Letters (RAL)
- Reviewer of IEEE International Conference on Robotics & Automation (ICRA)
- Reviewer of IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS)
- Reviewer of IEEE Intelligent Transportation Systems Conference (ITSC)