Questions tagged [slam]

SLAM (Simultaneous Localization And Mapping) refers to a robot building a map of its environment through it's sensor data (mapping) and keeping track of its own position in that map (localization) at the same time.

Filter by
Sorted by
Tagged with
0
votes
1answer
91 views

ICP(Iterative Closest Point) with Partially Overlapping Conditions & Changing Point Numbers

I am currently working on fixing vehicle odometry data using lidar contour points. Since I am receiving lidar data in the form of countour points, I thought I'd use ICP to correct the odometry error ...
2
votes
2answers
60 views

Compute path in absolute frame from sequence of measurements

I have a sequence of measurements $\{(x_i, y_i, \theta_i)\}_{i = 1 \:...\: N}$. Each of these represents the new pose of the robot seen from the previous pose, i.e. a measurement $(x', y', \theta')$ ...
2
votes
2answers
153 views

How to handle landmarks in Bundle Adjustment?

At the moment I try to understand Bundle Adjustment on a level to be able to implement it on my own. The major point I'm still confused at is the management of the landmarks. So, let's think of a few ...
0
votes
1answer
150 views

Technologies needed for indoor and outdoor navigating robot

Before I begin, I should add that I am a complete beginner in robotics and hope that I can figure out where I should start by asking this question. I am trying to make a robot that is able to ...
0
votes
1answer
69 views

EKF-SLAM what should the observation model be?

I am implementing an EKF algorithm for a drone localization, and while I was defining the observation model I got a bit confused. This is my situation: I have a drone which is able to give me the ...
1
vote
1answer
93 views

What is the concepts of submaps in LIDAR based graph slam algorithms?

I have been reading some slam papers recently and many of the papers mention building and performing scan matching on submaps instead of individual poses. Does it mean that a submap is just a single ...
0
votes
2answers
82 views

Which math books would help in learning SLAM systems? [closed]

Recently I started studying papers on SLAM systems by Durrant-Whyte for my research and I'm finding some difficulties in the math (matrices and probability) that is tackled in these papers. Which ...
0
votes
3answers
275 views

Difference between SLAM and Localization

What are the differences between SLAM and Localization if you have a known map? How does the position probability update differ between the two? In particular I'm curious on if localization is a ...
0
votes
2answers
125 views

Guidance on SBC for Visual-Based SLAM [closed]

Intro: I am a student that just started a project regarding prototyping a mobile robot that involve Indoor SLAM implementation. I am very new to the field of computer vision, SLAM and SBC (single ...
2
votes
0answers
105 views

Applying initial guessing to LiDAR point cloud for ICP processing in Graph SLAM

I am currently in the process of implementing Graph SLAM using ICP and g2o in python 2.7 The data I have are pose data (4 x 4 transformation matrix) and lidar data ( in the format of [x y z 1] with ...
0
votes
1answer
92 views

On the covariance matrix of the EKF SLAM

In the covariance matrix of the EKF SLAM, there are components that specifies the correlation between landmarks. Are those values important? Because while we bulding map of landmarks, we only draw the ...
2
votes
6answers
9k views

What does Simultaneous Localization And Mapping (SLAM) software do?

I took a course to have a better understanding of drones and their design. At the end of the course there was a test question that I got wrong and I would like to understand why. I was supposed to ...
1
vote
1answer
44 views

Dual constraint non-linear optimization for SLAM

I am trying to achieve a nonlinear optimization for SLAM on a function that contains two different constraints, like this : $$ T_{opt} = \underset{T}{\arg\min} \sum_i(\left\lVert T.X_i - x_i \right\...
0
votes
1answer
40 views

Good Software Projects for Aspiring Engineers [closed]

With the pandemic going on, our school has decided to officially shutdown all sponsored club meetings. Now that we are all digital, our robotics club was looking for projects that students can do at ...
17
votes
4answers
10k views

What is inverse depth (in odometry) and why would I use it?

Reading some papers about visual odometry, many use inverse depth. Is it only the mathematical inverse of the depth (meaning 1/d) or does it represent something else. And what are the advantages of ...
1
vote
0answers
42 views

Intel Realsense Cameras for Object Avoidance and SLAM to go to destination

My goal is to make a UAV which can search an area while avoiding obstacles. I figured I would navigate using the SLAM and Intel Realsense D435i (a stereoscopic camera with an IMU built in), but all of ...
3
votes
3answers
101 views

Is SLAM done only first time in a given environment

I am training Turtlebot 2 to move around the office. I come from robotics hardware background but relatively new to computer vision and robotic mapping. Here are my two fundamental questions related ...
1
vote
3answers
310 views

Grid based SLAM using BeagleBone Green Wireless and RPLIDAR

I've written a grid based DFS algorithm with a PID-based steering system to maneuver a 30cm2 square-grid maze all in Python. The robot is a 4 wheel drive with an approximate size of 20 cm. The ...
3
votes
2answers
2k views

FastSlam 2.0 Implementation?

I have studied Claus Brenner's lectures on how to implement the FastSLAM 1.0 algorithm, where each particle maintains the robot pose, and maintains EKF's of the landmarks. However, I'd like to ...
2
votes
2answers
153 views

Is pose estimation using images necessary in visual-inertial SLAM

In visual SLAM, pose estimation is performed between two adjacent frames or keyframes using feature detection and pose estitmation from corresponding features. However in visual-inertial SLAM, pose ...
3
votes
2answers
104 views

What Software Is Used For Autonomy Software Simulation?

I don't have a physical robot but I would like to test the performance of my C++ code for odometry, SLAM, and path planning. Are there any good simulation software where I can test my algorithm ...
1
vote
1answer
39 views

How to derive the camera trajectory from ICP

This may be a very simple question so please bear with me... Suppose I have a stationary object and point clouds, $n$ $(x,y,z)$ points, of that object taken by a moving camera at time steps $t_i$, $...
1
vote
2answers
38 views

Can standard SLAM techniques be used in maritime environments, where waves and currents move the vessel even with no control input

I am trying to implement a functioning SLAM system for an autonomous surface vessel (ASV). I don't have any direct experience with SLAM, and I am therefore researching the topic before I try to ...
1
vote
1answer
56 views

How does scan matching find overlapping regions in two scans?

I have been reading about scan matching and so far I have gathered that scan matching tries to find the transformation (rotation and translation) which leads to the best match between overlapping ...
4
votes
1answer
188 views

How to avoid matrix singularity in GraphSLAM

I am trying to implement GraphSLAM from Sebastian Thrun's paper, The GraphSLAM Algorithm with Applications to Large-Scale Mapping of Urban Structures. When I compute the inverse of my information ...
2
votes
2answers
81 views

What's the difference between Pose Measurement and Position Measurement?

I have read a robotic related paper called Estimating SE(3) elements using a dual quaternion based linear Kalman filter, and the author proposed that the equation of position measurement is denoted as:...
0
votes
0answers
25 views

How to obtain live vertical height values using LIDAR

I plan to control the flying height of my drone using a LIDAR (in real-time). Therefore, I would be attaching the LIDAR to my UAV, pointing vertically downwards. However, after looking at some of the ...
0
votes
1answer
37 views

Feasibility of SLAM with heterogeneous sensors

Why are there so few published implementations of SLAM with support for heterogeneous sensors? Heterogeneous sensors include LIDAR, monocular cameras, stereo cameras, thermal sensors from more than ...
0
votes
0answers
39 views

Are there any Algorithms/Papers about 3D Mapping the Interior of Buildings using Computer Vision and IMU Data?

I was wondering if it would be possible to do something like this: Vision-based Autonomous Navigation and Mapping with a Small Quadrotor without using lidar/lasers. I have tried ORB-SLAM, but the ...
0
votes
2answers
73 views

Variables that Improve SLAM

I have a general question regarding SLAM as I am not an expert on the topic. What are the variables that can improve map generation? The ones I can think of are: A higher resolution camera ...
0
votes
1answer
58 views

Teaching AMCL and SLAM

In trying to explain these important concepts and algorithms it would be super useful to have a video or animation that illustrates through simulation the underlying math. All the videos and articles ...
0
votes
2answers
75 views

SLAM and navigation

I have a question about SLAM. Is it common for SLAM to be used for mere map generation? For instance, have a map generated using ORB-SLAM and then freeze the map for future path planning where future ...
0
votes
1answer
53 views

Odometry heading and laser scan heading not point to same direction

please help, after so much research still cant find a single solution from google. some say offset, but there is no offset in the configuration. problem: odom direction and laser scan heading didnt ...
1
vote
1answer
136 views

How to plot the 3D camera trajectory from a VSLAM output

I am totally new to VSLAM algorithms and would want to plot the path followed by the moving camera. I am using the open source implementation of ORB_SLAM2 for a rgb-d camera on benchmark dataset. The ...
1
vote
1answer
64 views

Is it to possible to measure a room exact with rplidar?

I want to measure a room using rp3+, rplidar, ROS and SLAM. It should be easy possible to create mapping of the room. But how exact it would be? Is it possible to get less than 1 cm precision over ...
2
votes
1answer
23 views

Depth images with undetectable outlines

I'm trying to capture depth images with a RGBD camera, but all of the images have undetectable outlines around objects: Is this expected from RGBD cameras or is mine a dud? It's an Astra Pro.
0
votes
0answers
60 views

TUM RGBD SLAM dataset file format inconsistency?

I'm looking at the TUM dataset and wonder why the depth images and the file formats appear to be inconsistent. According to the file formats: The depth images are scaled by a factor of 5000, i.e.,...
4
votes
6answers
6k views

What's the difference between the term "pose estimation" and "visual odometry"?

I'm reading a paper: Choi C, Trevor A J B, Christensen H I. RGB-D edge detection and edge-based registration[C]//Intelligent Robots and Systems (IROS), 2013 IEEE/RSJ International Conference on....
5
votes
1answer
151 views

How to derive the Time-Update equation of SLAM

I was going through the tutorial on SLAM by Hugh Durrant-Whyte and Tim Bailey† and found this Time-Update equation (equation 4 in the paper): $ P\left(\mathrm{x}_{k},\mathrm{m} | \mathrm{Z}_{0:...
0
votes
1answer
171 views

Data structure to store a robot map

I'm studying robotics at the university and I have to implement on my own SLAM algorithm. To do it I will use ROS, Gazebo and C++. I have a doubt about what data structure I have to use to store the ...
1
vote
1answer
463 views

How to implement RANSAC and kalman filter or particle filter algorithms with ROS packages?

I'd like to implement those algorithms by using ROS packages to solve one way the SLAM problem. I know that gmapping, Rviz, slam_gmapping and robot_pose_ekf (for extended kalman filter) could be ...
2
votes
1answer
171 views

ORB-SLAM pose estimation

I've been reading about ORB-SLAM and ORB-SLAM2, but I can't quite figure out how pose estimation is done. I see that it uses a bag-of-word method for loop detection, but how are current features ...
0
votes
2answers
49 views

Relative quaternion to global with uncertainty

in this perfect tutorial i found how i can compose two poses with uncertainty and how i can transform one representation to another with uncertainty http://ingmec.ual.es/~jlblanco/papers/...
2
votes
1answer
161 views

Camera pose to world coordinate transformation

I have managed to receive camera_pose for ORB-SLAM by following their code. If I run $ echo /world /camera_pose I receive something like this: ...
3
votes
1answer
119 views

Error term formulation in Graph SLAM (conceptual doubt)

I am reading A Tutorial on Graph-Based SLAM.Grisetti, Kummerle, Stachniss & Burgard On page 5, the error function is introduced as follows $$e_{ij}(x_i, x_j) = z_{ij} - \hat{z}_{ij}(xi, xj)$$ ...
-1
votes
2answers
272 views

I have to implement my own SLAM algorithm [closed]

I'm studying robotics and one practice that I have to do is to implement my own SLAM system on ROS. I need some advice about where to start. Where do I start?
4
votes
3answers
3k views

A sensor that can see glass/transparent objects and surfaces

I am currently thinking about making a robot that will autonomously drive around the place. The place I want this robot to drive in however contains quite a few glass walls. When mapping the area I ...
9
votes
1answer
275 views

In practical terms, how close is the accuracy of camera-based visual odometry/SLAM methods to lidar-based methods for autonomous car navigation?

Benedict Evans, a general partner at Andreessen Horowitz, claims that “almost all autonomy” projects are using lidar for SLAM, and that not all of them use HD maps. An MIT group is testing self-...
6
votes
2answers
95 views

How does a self-driving car locate itself when the environment changes?

There's something I don't quite understand about SLAM. When a self-driving car wants to locate itself using a prior map, how does it do that when the environment keeps changing, e.g., new cars parked ...
2
votes
1answer
65 views

Lost on Graph slam's loop cloursure

What is the definition of loop closure in Graph Slam? Ref: Graph Slam The theory of Graph Slam define here but I think there is no hints about loop closure. I give this reference for review ...

1 2
3
4 5
7