Rico贾若童的博客

Robotics - [3D SLAM - 2] Lidar Odometry

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

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 - 1] Scan Matching

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

Point-Point ICP If we write out our state vector as [theta, translation], the pseudo code for point-point ICP is: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 pt_pt_icp(pose_estimate, source_scan, target_...

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

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

Robotics - A Survey On Oil Pipe Inspection Robotics (Revising)

Non-Destructive Testing Methods American Society for Testing and Materials (ASTM) and American Society of Mechanical Engineers (ASME) develops standards for pipe inspections Ultrasonic Testing...

Posted by Rico's Nerd Cluster on December 20, 2024

Robotics - [ROS2 Foundation] Ros2 Miscellaneous Thingies

Name Spacing

Namespacing If you have something like: 1 2 3 4 5 class FiveCardStudPlayer : public rclcpp::Node { public: FiveCardStudPlayer() : Node("five_card_stud_player"){ ... }} And you launc...

Posted by Rico's Nerd Cluster on November 30, 2024

Robotics - [ROS2 Foundation] Ros2 Bags

Introduction ros2 bag is a command line tool for recording data published on topics in your system. It accumulates the data passed on any number of topics and saves it in a database. You can then ...

Posted by Rico's Nerd Cluster on November 30, 2024

Robotics - [ROS2 Foundation] Ros2 Rclpy Executor Callback Model

Rclpy Executors, Rate Object

Rclpy MultiThreadedExecutor rclpy.executors.MultiThreadedExecutor is implemented entirely in Python, not as a direct wrapper around the C++ rclcpp::executors::MultiThreadedExecutor. Internally it ...

Posted by Rico's Nerd Cluster on November 27, 2024

Robotics - [ROS2 Foundation] Ros2 Composition Instead Of Nodelets

Components

Reference The basic idea of ROS2 composition is to have a unified API in place of ROS1 nodes and nodelets. Nodelets in ROS1 are compiled into shared libraries and can be loaded into one process du...

Posted by Rico's Nerd Cluster on November 26, 2024

Robotics - [ROS2 Foundation] Ros2 Rclcpp Executor Callback Model

Executor, Callbacks, Threading Model

C++ Executors In ROS2, we can have multiple logical nodes executing their callbacks of timer, subscription, etc. in executors. There are three types of executors: SingleThreadedExecutor, StaticSin...

Posted by Rico's Nerd Cluster on November 25, 2024

Rico's Nerd Cluster