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Hi, I'm Xingxin He (hex.16) , a robotics PhD student at HKUST and a former software engineer. I work on robot learning, control, and robotic systems that have to function in the real world.

This blog is where I write technical notes, working lessons, and field observations from building with robots, software, and geometry. If you are looking for

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68 notes
2026 · 10 Master DROID Action Spaces to Use Pre-Trained Policies
2026 · 08 Derive the Exponential Map for Rotation via Simple Physics
2026 · 07 A Visual Guide to Real-Time Action Chunking in Robotics
2026 · 07 A Cheat Sheet for Robotic Gripper State and Action Spaces
2026 · 07 Action Chunking in VLA: A Cheat Sheet for H and K Horizons
2026 · 07 Dataset Normalization Statistics in OpenPI and LeRobot
2026 · 06 How to Compute a Value Function? Policy Evaluation
2026 · 06 Value Function: From Gridworld to Bellman Equation
2026 · 05 A Visual Guide to Hand-Eye Camera Calibration in Robotics
2026 · 04 Unpacking "Unfolding Robotics": The Reading Notes
2026 · 04 Deriving Euler-Lagrange Equation of a Simple Double Pendulum
2026 · 03 The "It Just Works" Hardware and OS Stack for Franka Robot
2026 · 03 How to Enable Zero-Gravity Teleoperating a Franka Robot?
2026 · 03 Understanding PD Controllers in Robotics and Robot Learning
2026 · 03 Multi-Machine ROS2 for Robot Learning: A Guide to RMW
2026 · 03 How to Install ROS2 Without Docker or sudo apt in 2026?
2026 · 02 How to Derive the Policy Gradient with Monte Carlo Sampling?
2026 · 02 Understanding Action Chunking with Flow Matching
2026 · 02 A Beginner's Guide to Flow Matching
2026 · 02 How to Set Up Autograding in GitHub Classroom? (with Canvas)
2026 · 02 Why Naive Behavioral Cloning Doesn't Work?
2026 · 02 Why the Gymnasium API Looks the Way It Does?
2026 · 01 Understanding Franka Robot Control Parameters
2025 · 12 How to Train and Use a Neural Network? The TL;DR
2025 · 12 What is Ball Query and Multi-Scale Grouping?
2025 · 12 What is Farthest Point Sampling (FPS)?
2025 · 12 uv sync Different CUDA PyTorch and Torch-Dependent Libraries
2025 · 12 I Had His Number, But I Missed the Meeting
2025 · 10 How to Version Large Git Datasets with DVC and R2?
2025 · 10 A Guide to VS Code, MQTT, and SSH on HPC Clusters
2025 · 09 How to create Python binding for C++ libfranka via nanobind?
2025 · 09 The layer, image, and container in Docker
2025 · 07 What is a package.json?
2025 · 05 How to store JSON to an ENV variable?
2025 · 05 Diagram Mutating Data in Next.js
2025 · 05 Diagram Search and Pagination in Next.js
2025 · 04 Do I interpret Mediocristan and Extremistan correctly?
2025 · 04 How to make better decision?
2025 · 02 Who is Theodorus Ibn Warqa?
2025 · 02 Why do we have to pay a price for the goods we consume?
2025 · 02 I was Kidnapped by Deprival-Super Reaction Tendency
2025 · 01 Building Antifragile System
2025 · 01 Boost Productivity Using PowerToys Day 5 - FancyZones
2025 · 01 Use WebP to Save 30% Disk Space of Your Obsidian Vault
2025 · 01 JavaScript's var, let, const Confuse C++ Developer
2025 · 01 The Triad of Systems: Input, Process, Output
2025 · 01 Unit Cube and Canonical Cube are Different
2025 · 01 Boost Productivity Using PowerToys Day 4 - Peek
2025 · 01 Boost Productivity Using PowerToys Day 3 - Registry Preview
2025 · 01 3 Lines of Code Convince You to Use RAII in C++
2025 · 01 What We Can Learn from von Neumann's Strength and Struggle?
2025 · 01 How to Derive the Perspective Matrix with 2 Observations?
2024 · 12 Boost Productivity Using PowerToys Day 2 - Screen Ruler
2024 · 12 Boost Productivity Using PowerToys Day 1 - Shortcut Guide
2024 · 12 How I Setup My Obsidian Publish?
2024 · 12 When You See 403, Immediately Think of These...
2024 · 12 ☕How I Decide How Much Coffee to Drink a Day?
2024 · 12 Play with Azure Synapse Analytics
2024 · 12 Use Limit Comparison Test or Direct Comparison Test?
2024 · 12 Exploring the LRU Algorithm: A Journey into Cache Management
2024 · 12 How to concatenate C++ std::bitset?
2024 · 11 The Pitfall of Using C++ std::min and std::min_element
2023 · 12 Understanding Arc Length Parameterization with 🦏&🦗
2023 · 12 2 Professors Suggest Me Learning by Doing
2023 · 11 My Friend Li Lei Decides to Learn Artificial Intelligence
2023 · 02 Will ChatGPT Express Itself with Emojis❓
2022 · 02 What is RhinoInside®? Explain via a Console Program
2020 · 12 Perspective Projection: My First Lesson to Computer Graphics