Rico贾若童的博客

Robotics - [2D SLAM 1] Introduction and Scan Matching

Point-Point ICP, Point-Line ICP

Introduction The assumption of a robot moving on a 2D plane is a strong one. However, many indoor robots do have support an assumption. Maps in this case can simply be interpreted as an image. Low...

Posted by Rico's Nerd Cluster on April 10, 2024

C++ - Move Semantics, Perfect Fowarding

Universal Reference, `std::move` with Emplace

Universal Reference And Perfect Forwarding Perfect forwarding in C++ preserves both the type and the value category of an input argument. Refresher - Value categories: lvalue rvalue ...

Posted by Rico's Nerd Cluster on April 10, 2024

Robotics - Point Cloud Processing and KNN Problem

Bruteforce KNN Search, KD Tree, OctoTree

Overview Here is a post about the LiDAR Working Principle and different types of LiDARs. One lidar model is the Range-Azimuth-Elevation model (RAE) Its ...

Posted by Rico's Nerd Cluster on April 7, 2024

C++ - Datastructures

Priority Queue

std::priority_queue (Priority Queue, or Max-Heap) 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 #include <iostream> #include <...

Posted by Rico's Nerd Cluster on April 4, 2024

Point Cloud Library

Point Infrastructure Point Cloud Members PointCloud Type includes points: point vector PointTypes PointType include: pcl::PointXYZ pcl::PointXYZI pcl::PointXYZRGB pcl::PointXYZRGB...

Posted by Rico's Nerd Cluster on April 4, 2024

Robotics - IMU Hands-On

IMU tools Velocity drift observed. Here, I’m proposing a two-phase static test to confirm true sensor drift: Initialization—standstill for N seconds to estimate biases. Static logging—remain...

Posted by Rico's Nerd Cluster on April 2, 2024

Robotics - IMU Pre-integration Optimization Implementation

IMU Pre-Integration, GNSS, UTM

G2O Recap - What’s An Edge A single edge is a “difference” between two conceptual entities. The entities are conceptual because they don’t need to map exactly to your implementation. For example, ...

Posted by Rico's Nerd Cluster on April 1, 2024

ROS Infrastructure Notes

A Running List of ROS Infrastructure I found Useful

ROS Actions The ROS Action really is a mechanism that keeps track of the exeuction state of a task. ROS Actions are built on top of ROS topics. Lifetime of ROS Actions Pending : The goal...

Posted by Rico's Nerd Cluster on April 1, 2024

Robotics - IMU Pre-integration Model

Pre-Integration Model

Motivation In previous posts, we have seen the ESKF framework, where IMU data is fused with observations (GNSS, encoders) following this incremenetal order: 1 ESKF Prediction with IMU | ESKF Pred...

Posted by Rico's Nerd Cluster on March 24, 2024

Robotics - [ESKF Series 5] Why Using Error-State Kalman Filter (ESKF) For IMU

ESKF, GINS

ESKF Handles Rotations on SO(3) Better Key issue: Rotations lie on the special orthogonal group SO(3), which is a nonlinear manifold (not a simple vector space like position). A standard EKF typic...