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Questions tagged [slam]

This tag is for code related to SLAM (Simultaneous Localization and Mapping (SLAM) which is the computational problem, often related to robotics and/or drones, of constructing or updating a map of an unknown environment while simultaneously keeping track of an agent's location within it.

The following definition from Wikipedia:

In robotic mapping, simultaneous localization and mapping (SLAM) is the computational problem of constructing or updating a map of an unknown environment while simultaneously keeping track of an agent's location within it. While this initially appears to be a chicken-and-egg problem there are several algorithms known for solving it, at least approximately, in tractable time for certain environments. Popular approximate solution methods include the particle filter and extended Kalman filter.

SLAM on Wikipedia

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How to check whether Essential Matrix is correct or not without decomposing it?

On a very high level, my pose estimation pipeline looks somewhat like this: Find features in image_1 and image_2 (let's say cv::ORB) Match the features (let's say using the BruteForce-Hamming descriptor matcher) Calculate Essential Matrix (using…
Milan
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OpenCV: What does it mean when the number of inliers returned by recoverPose() function is 0?

I've been working on a pose estimation project and one of the steps is finding the pose using the recoverPose function of OpenCV. int cv::recoverPose(InputArray E, InputArray points1, InputArray …
Milan
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Google Cartographer: Internal coordinate systems

I am studying Google Cartographer SLAM. Working with submaps in the library API (which is not at all documented) I discovered the following entities representing coordinates: Trajectory (list of sensor poses with connected submaps) Global pose…
Andrei Vukolov
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Why is gimbal lock of euler angle a problem in non-linear optimization(SLAM, Simultaneously Localization And Mapping)

I understand how the gimbal lock happens when using euler angle. However, I don't know why the gimbal lock is a problem in the SLAM(maybe in non-linear optimization). In the process of non-linear optimization, it seems that a problem occurs when…
defacto
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Creating augmented reality using Python, OpenCV and SLAM

I was wondering if I could build an augmented reality system in Python using OpenCV and SLAM. If so, do you have any tutorials or documentation that you could recommend? I've been scratching my head for awhile now trying to find resources to start…
Shooky
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Why is my ORB SLAM 2 launch file crashing?

I am using ROS Melodic on Ubuntu 18.04. I was trying to implement orb slam 2 on a usb camera using this tutorial:https://medium.com/@mhamdaan/implementing-orb-slam-on-ubuntu-18-04-ros-melodic-606e668deffa I followed all the steps mentioned, but when…
Nidhi
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How to implement a loop closure algorithm for ARFoundation

I build an app which is used for meassuring outside environments on a larger scale (image the size of a regular personal driveway) using AR. In order to increase the reliability of the system I want to implement a loop closing algorithm that allows…
Drohnendon
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What's consistency mapping in SLAM?

I always see "consistent mapping" or "map consistency" in SLAM papers and articles, but I have no idea about what consistent map is. I have found enter link description here, but it did not solve my problem. Furthermore, what is local consistentcy…
Fred Yu
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gtsam - bearing only slam landmark initialization

I am using gtsam in a bearing only approach to slam for college. My question is regarding the initializaton of the landmarks. My teacher said there was something called 'smart factors' that I could use instead of normal factors for the landmarks,…
dig301
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Eigen matrix product doesn't work correctly in ORB-SLAM3 in release mode on windows

The whole picture of the problem is as below: I cloned the ORB-SLAM3 from https://github.com/rexdsp/ORB_SLAM3_Windows. It can be built and works well. Then I tried to evaluate its accuracy with EuRoC MH_01_easy, but found it was at least 10 times…
yazou
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What's the difference between factor graph optimization and bundle adjustment?

I see that in SLAM literatures, factor graph optimization is frequently used. While in Structure from Motion literatures, usually they use bundle adjustment. What's the difference between the two methods ? Furthermore, can we implement one method…
zhouch
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How to obtain the derivative of Rodrigues vector and perform update in nonlinear least square?

I am now interested in the bundle adjustment in SLAM, where the Rodrigues vectors $R$ of dimension 3 are used as part of variables. Assume, without loss of generality, we use Gauss-Newton method to solve it, then in each step we need to solve the…
Adrian
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ROS ORB-Slam2 Map Point Vector is Empty

I am trying to get mapping to work with ROS. I have a Raspberry Pi 3B+ with a Picamera v2 running ROS Noetic. It is running cv_camera_node to broadcast the camera images. I also have an Ubuntu 20.04.1 running ROS Noetic along with ORB-SLAM2. I was…
DragonflyRobotics
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Find relative scale in monocular Visual Odometry without PnP

I am implementing a standard VO algorithm, with a few changes, i.e. extract features, match the feature points, find the essential matrix and decompose to get the pose. After initialization however, instead of using 3D-2D motion estimation (PNP) for…
OlorinIstari
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Frames are not seen in BGR scale (OpenCV)

I'm trying to write the code for SLAM using OpenCV from scratch. While I'm trying to show detected features from each frame in colored-circular mark, I've got a problem showing this in color. Summary For goodFeaturesToTrack function,…
Henry KIM
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