
Liu Xu刘旭
My research and engineering work includes SLAM localization integration, 3DGS-based scene reconstruction and object search, WAM-based mobile manipulation, and UAV hardware integration and flight testing.我的研究与工程工作涵盖 SLAM 定位联调、基于 3DGS 的场景重建与物体搜索、基于 WAM 的移动操作,以及无人机硬件集成与实飞验证。
These projects examine how scene understanding becomes physical execution: relating a past photograph to the current 3D map, choosing a base pose for precise manipulation, and integrating localization, planning and sensor mounting for indoor flight. Ablations, real-robot restoration and swarm acceptance tests provide evidence for these design choices.这些项目关注场景理解与真实执行之间的连接:旧照片如何对应到当前三维地图,停靠位姿如何影响精细操作,以及定位、规划与传感器安装如何共同影响室内飞行。通过消融实验、实机复原与集群验收,检验这些设计选择。
Spot the Difference
Online 3DGS for object and contextual-anchor search在线 3DGS 中的物体与上下文锚点搜索
Liu Xu · First author · Manuscript under review刘旭 · 第一作者 · 稿件审稿中
Drag right to reveal the real robot向右拖动,查看实机
Simulation demonstrates sequential search for the object and its original location; real-robot trials show grasping and return.仿真展示物体与原始位置的顺序搜索;实机展示抓取与返回过程。
View simulation separately单独观看仿真View real robot separately单独观看实机
From a photograph to the current 3D scene从目标照片到当前三维空间
A past photograph records an object and its relationship to the surrounding scene. Once the object moves, restoration requires finding both the displaced object and its now-empty original location. Object appearance helps with the first search; recognizing the second also requires the surrounding context.旧照片记录了物体及其与周围环境的关系。物体被挪走后,复原需要同时找到被移动的物体和已经空置的原位置。物体外观有助于搜索前者,识别后者还需要利用周围环境的上下文。
Online 3DGS integrates camera observations as the robot explores. The current map and goal photograph condition a flow-matching model that produces an eight-channel Restoration Field for object, anchor and exploration readout. Persistent readout in observed regions connects spatial predictions to Nav2 navigation and Contact-GraspNet grasp proposals, linking reconstruction, search and physical execution.机器人探索时,在线 3DGS 持续整合相机观测。当前地图与目标照片共同驱动条件流匹配模型,生成八通道恢复场,提供物体、原始锚点和探索区域的空间信息。通过已观测区域中的持续读出,再接入 Nav2 导航与 Contact-GraspNet 抓取候选,将重建、搜索与实机执行连接起来。
Input roles and the empty-anchor bottleneck输入分工与空置锚点搜索
The map supplies observed geometry, while the photograph supplies appearance and context across time. In the same held-out evaluation, shuffling goal photographs, zeroing the online triplane input and removing anchor affinity reduce ordered localization from 34.8% to 1.8%, 0.8% and 8.4%, respectively. These controls show dependence on both the evolving spatial representation and the remembered scene context in this evaluation.地图提供已观测的空间结构,照片提供跨时间的外观与上下文。在同一组未见场景评测中,打乱目标照片、将在线三平面输入置零、移除锚点关联后,顺序定位成功率由 34.8% 分别降至 1.8%、0.8% 和 8.4%。这些对照说明,持续更新的空间表示与目标场景中的上下文都参与了定位。
Across ten real trials, eight reach object localization and five reach anchor localization; those five complete restoration. The largest stage loss is therefore finding the original location. This directs improvement toward contextual matching of the empty support region.十次实机实验中,八次成功定位物体,五次成功定位锚点,并完成复原。阶段间最大的损失发生在原位置搜索。进一步改进的重点因而指向空置支撑区域的上下文匹配。
Simulation: 34.8% ordered localization across 15 held-out HM3D scenes. Real restoration: 5/10, with stable placement on the correct support and horizontal error <0.25 m. Simulation evaluates localization; real trials additionally evaluate grasping and placement.仿真:15 个未见 HM3D 场景中的顺序定位成功率为 34.8%。实机:5/10 完成复原,要求在正确支撑面上稳定放置、水平误差 <0.25 m。仿真评估定位,实机进一步验证抓取与放置。
Copy-Paste
Iterative World Action Model for precise scene restoration用于精细场景恢复的迭代世界动作模型
Liu Xu · First author · Manuscript under review刘旭 · 第一作者 · 稿件审稿中
Drag right to reveal the real robot向右拖动,查看实机
Simulation demonstrates object restoration across multiple scenes; the real robot grasps, transfers and places a bottle.仿真展示多场景物体复原任务;实机展示瓶子的抓取、搬运与放置。
View simulation separately单独观看仿真View real robot separately单独观看实机View experimental recording查看实验记录
Docking for the manipulation that follows面向后续操作的停靠选择
Copy-Paste studies precise restoration to a visual reference with a mobile manipulator. Base placement changes the camera view and the arm’s starting state; errors during grasping, transfer and release can propagate to the final object position. A reachable base pose must therefore be judged by the restoration it enables.Copy-Paste 研究移动操作机器人如何依据视觉参考完成精确复原。底盘停靠位置会改变相机视点和机械臂起始状态,抓取、搬运与释放中的误差也可能传递到终态。因此,停靠位置的选择需要考虑它能否支持后续复原,而不只判断机械臂是否可达。
Current point clouds produce docking candidates. A utility predictor trained on complete restoration outcomes of a frozen WAM helps rank feasible poses together with prior scores. Removing utility scoring while retaining the same twelve candidates reduces mean simulation success across three training seeds, each evaluated on the same 150 cases, from 71.1% to 47.3%. This makes manipulation outcomes the supervision for choosing where the robot should begin.方法根据当前点云生成停靠候选,效用预测器以冻结 WAM 的完整恢复结果训练,并与候选先验分数共同排序。在保留相同十二个候选、每个训练种子评估相同 150 个案例的条件下,移除效用评分使三个种子的仿真平均成功率由 71.1% 降至 47.3%。这一设计把后续操作结果作为停靠选择的依据。
Prediction refinement and physical feedback预测修正与真实执行反馈
Before action generation, two recursive rounds refine the predicted future. The robot then executes the first 24 actions, observes again and replans. Prediction refinement addresses the model’s proposed future; new observations address what actually happened during execution. In the simulation inference study, a third round adds little success while increasing planning latency, making the amount of refinement a practical system trade-off.动作生成前,模型进行两轮递归未来预测细化;随后执行前 24 步动作,重新观测并规划。预测细化修正模型预想的未来,新观测则反映真实执行后的状态,两者在不同阶段发挥作用。在仿真推理对照中,第三轮细化的成功率增益已经很小,而规划时延上升,细化深度因而需要与执行系统的响应时间共同考虑。
Training uses 1,769 simulation trajectories and 600 real demonstrations. Real evaluation covers three object types, two tables and five trials per pair: 19/30 successful restorations at ≤30 mm. Final position error is 30.7 ± 12.7 mm, mean ± sample SD over all 30 trials. Success also requires safe release and the object resting on the task surface without gripper support; orientation is not evaluated.训练使用 1,769 条仿真轨迹和 600 条真实示范。实机测试覆盖三类物体、两张桌面、每组五次,共 30 次;19 次满足复原成功条件(位置误差 ≤30 mm)。全部 30 次的终态位置误差为 30.7 ± 12.7 mm(均值 ± 样本标准差)。成功还要求安全释放、物体无需夹爪支撑,评价关注位置。
AeroMaze UAV Swarm
Autonomous exploration and traversal in unknown indoor environments未知室内环境中的集群自主探索与穿屋
2025.07 — 2026.05
Drag right to reveal the real robot向右拖动,查看实机
Ten-UAV indoor exploration in simulation and three-UAV traversal in real flight.十机室内自主探索仿真与三机实飞穿屋测试。
View simulation separately单独观看仿真View real robot separately单独观看实机
Multi-UAV planning and mission interfaces多机规划与任务接口
Ten-UAV indoor traversal couples local collision avoidance with the gaps between vehicles. I led EGO-Planner adaptation for planning, avoidance and replanning, adjusting safety margins, velocity constraints and takeoff order for narrow openings, corners and intersecting paths. ROS2 topics and services connect mission initialization, odometry, cameras, trajectories and completion results.十机穿屋需要同时处理局部避障与队伍间隔。我负责 EGO-Planner 的规划、避障与重规划适配,针对窄门、转角和多机路径冲突调整安全距离、速度约束与起飞顺序;通过 ROS2 Topic/Service 接通任务初始化、里程计、相机、轨迹和完成结果。
For three real UAVs, I contributed to FAST-LIO scan-to-map matching, initial alignment and odometry fault investigation, including contributions to increasing LIO updates from 10 Hz to 100 Hz. Hardware integration covered part of the selection, mounting, power wiring, interface configuration and troubleshooting for Livox Mid-360, cameras, Jetson Orin NX, flight controllers and airframes.三机实飞阶段,我参与 FAST-LIO 的 scan-to-map 匹配、初始对齐与里程计异常排查,以及将 LIO 更新频率由 10 Hz 提升至 100 Hz 的联调。硬件工作涉及 Livox Mid-360、相机、Jetson Orin NX、飞控与机架的部分选型、安装固定、供电接线、接口配置和故障排查。
Sensor mounting constrains the planner传感器安装与规划约束
LiDAR mounting changes both localization features and what the planner can observe. The VR1 development material records that forward tilt captures more ground features but introduces a blind zone; matching the real-platform tilt requires planner retuning. Mounting geometry and avoidance parameters therefore need to be considered together.雷达安装方式会同时改变定位可用的特征和规划可见的障碍物。VR1 开发材料记录了前倾雷达带来的地面特征收益与观测盲区,以及保持实机倾角后重新调整规划参数的需求。这使硬件安装几何与避障参数成为需要共同考虑的设计因素。
In VR1, simulated localization noise does not reproduce accumulated drift, and simulated LiDAR does not observe moving drones. Real deployment therefore calls for separate checks of coordinate alignment, drift and returns from other vehicles. These differences explain why completing a simulated route alone is insufficient preparation for reliable indoor flight.VR1 仿真中的随机定位噪声不会复现累积漂移,仿真雷达也不观测移动无人机。迁移到实机时,需要另外检查坐标对齐、漂移及其他无人机的点云回波。这些差异说明,仿真路线验证之外,定位与真实传感器观测仍需要针对性联调。
Team acceptance: 10/10 UAVs finish simulation in 166 s, first of eight teams by completion speed. Basic Sequence, Alternate Sequence and Demo Day real-flight tests take 50 / 60 / 72 s; each reports 100% success (3/3), with the team second of eight by completion speed.团队验收:仿真十机全部完成,用时 166 s,八支队伍中完成速度第 1。实机 Basic Sequence、Alternate Sequence 和 Demo Day 用时分别为 50/60/72 s,各项成功率均为 100%(3/3),完成速度第 2。
Background教育与经历
Education教育背景
Nanyang Technological University南洋理工大学
2025.08 — Present至今M.Sc. in Smart Manufacturing · Singapore智能制造 · 硕士研究生 · 新加坡
CGPA 4.56 / 5.0
Taiyuan University of Technology太原理工大学
2021.09 — 2025.06B.Eng. in Vehicle Engineering车辆工程 · 本科
GPA 3.47 / 5.0 · Top 30%年级前 30%
Technical toolkit技术工具
- Code & systems编程与系统
- C++11/14 · Python · Linux Shell · Git · CMake · Docker
- Robotics & simulation机器人与仿真
- ROS1/2 · MuJoCo · Habitat · LIBERO · Unity HiFi · EGO-Planner · Nav2 · URDF · RViz2
- Perception & learning感知与学习
- FAST-LIO · YOLO · PyTorch · OpenCV · LiDAR–IMU localization & sensor fusion激光雷达–惯性定位与多传感器融合
- Engineering & platforms工程与平台
- SolidWorks · Catia · ANSYS · AutoCAD · Jetson Orin NX · LiDAR · RGB/depth cameras · flight controllers · UWBRGB/深度相机 · 飞控 · UWB
Honors & qualifications荣誉与资格
- Academic Excellence Scholarships校级学业优秀奖学金 2023.06 · 2024.06 · 2025.03
- Bronze Award · Chuangyi Cup Student Innovation & Entrepreneurship Competition“创祎杯”大学生创新创业大赛铜奖 2023.08
- First Prize · Knowledge Quiz Group, 2nd University Student AI Technology Competition第二届大学生 AI 科技竞赛知识竞答组一等奖 2023.09
- 3D Mechanical Design Application Engineer Certificate (3Dv4)3D 机械设计应用工程师证书(3Dv4) 2024.09
- TOEFL 95 · GRE 319
Internship experience实习经历
Internship experience实习经历
Tianjin Luxin Machinery天津鲁信机械有限公司
Mechanical Equipment Engineer · Maintenance Department机械设备工程师 · 维护部
Contributed to troubleshooting and replacing production-equipment sensors, encoders, limit switches and actuators.参与生产设备传感器、编码器、限位开关与执行机构的故障排查和更换。
SF Airlines顺丰航空有限公司
Aircraft Maintenance Engineering Trainee · Excellent Engineer Program机务工程储备实习生 · 卓越工程师计划
Supported line maintenance and fault analysis; used Python and Excel to structure, classify and analyze maintenance records.参与航线维修及故障排查,使用 Python 与 Excel 结构化维修记录,分析异常类别和重复性故障。
Bofeike (Tianjin) Technology博菲克(天津)科技有限公司
Mechanical Engineer · R&D Department机械工程师 · 研发部
Worked on automotive fluid-pipeline component design, UGNX modeling and assembly checks, and ANSYS structural analysis.参与汽车流体管道部件设计,使用 UGNX 建模与装配检查,并基于 ANSYS 开展结构分析。
OTHER MANUSCRIPT / THIRD AUTHOR其他研究稿件 / 第三作者
Uncertainty-Aware Dynamics Learning via Offline Generative Prior Extraction and Online Bayesian Posterior Refinement
IEEE Transactions on Industrial Informatics · Regular Paper · Under review · April 2026Regular Paper · 审稿中 · 2026 年 4 月