Rico贾若童的博客

Robotics - [3D SLAM - 6] KISS ICP Review

KISS-ICP: Simple Odometry, Done Carefully The paper’s core claim is simple: you do not need a complicated frontend, feature extraction, normals, surfels, IMU fusion, or learned components to get s...

Posted by Rico's Nerd Cluster on March 17, 2025

Robotics - [3D SLAM - 4] GICP

Generalized ICP, BFGS Optimization

1. Intuition In GICP (Segal et al, 2009), each matched pair is not just two points $p_s$ and $p_t$. Each point also carries a local covariance estimated from its neighbors (for example, 20 nearest...

Posted by Rico's Nerd Cluster on March 7, 2025

Robotics - [3D SLAM - 3] Lidar Odometry

Direct Lidar Odometry, NDT, Incremental NDT, Indirect Lidar Odometry, LOAM

Direct Lidar Odometry When given two scans, a direct NDT method means no features are extracted. The two scans would directly go through NDT for finding their relative poses. The workflow is as fo...

Posted by Rico's Nerd Cluster on March 4, 2025

Robotics - [3D SLAM - 2] Scan Matching Hands-On Notes

Preact-Mojave, Lidar-Only Front-End

Preact-Mojave Build & Workflow The ROS2 driver for Preact-Mojave can be found here. When testing it, I ran into below questions: Why make provision & make ros2? make provisi...

Posted by Rico's Nerd Cluster on March 3, 2025

Robotics - [3D SLAM - 1] Scan Matching

3D Point-Point ICP, 3D Point-Plane ICP, NDT

The Scan Matching Problem When we run scan matching, we usually have two point clouds: a source scan $S_1 = {\mathbf{p}_1, \ldots, \mathbf{p}_n}$ (the new measurement), and a target scan $S_...

Posted by Rico's Nerd Cluster on March 1, 2025

Robotics - [Bugs - 2] SLAM Related Small Bugs

Passing Ptr By Value

⚠️ Beware of Passing Smart Pointers by Value Passing a smart pointer (e.g. std::shared_ptr or boost::shared_ptr) by value is fine when you’re only modifying the object it points to. But if you int...

Posted by Rico's Nerd Cluster on February 1, 2025

Robotics - [Bugs - 1] SLAM Related "Epic Bugs"

G2O Optimization Vertex Updates, Compiler-Specific Bugs, Yaml-cpp

Below is a list of bugs that took me multiple hours, if not days, to troubleshoot and analyze. These are the “epic bugs” that are worth remembering for my career. Epic Bug 1: G2O Optimization Didn...

Posted by Rico's Nerd Cluster on February 1, 2025

ROS2 - Time Synchronizer

ApproximateTimeSynchronizer The ApproximateTimeSynchronizer is useful when multiple ROS topics need to be processed together, but their timestamps do not match exactly. In this example, color imag...

Posted by Rico's Nerd Cluster on January 16, 2025

ROS2 - QoS

Reliability Reliability controls what happens while publisher and subscriber are already matched and communicating. Reliability Meaning Behavior Typical use ...

Posted by Rico's Nerd Cluster on January 13, 2025

ROS2 - Packages

Pure Python Packages

ROSPy for a pure ROS 2 Python package, you usually do not need a CMakeLists.txt. There are two valid ROS 2 Python package styles: ament_python style, No CMakeLists.txt. 1 2 3 4 5 package.xm...

Posted by Rico's Nerd Cluster on January 11, 2025

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