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
2 answers
65 views

timeout error while saving map

Hi, Environment: ROS2 Foxy / ubuntu I am trying to save a map, but I receive a timeout error, I tried using SLAM and then cartographer but i always got the error. I tried also to increase the param ...
user avatar
1 vote
0 answers
161 views

Cheap global shutter cameras with external synchronization

Please recommend cameras for multi-camera setup satisfying the following conditions: Relatively cheap (up to 100$ per camera). Global shutter. No filters on lenses or pixels. Resolution of 1 MP or ...
user3234005's user avatar
0 votes
1 answer
2k views

Calculate transform from different poses

My robot is at a starting pose $s_0 = (x_0, y_0, \theta_0)$ and, while moving, I receive a sequence of motion measurements $[\mu_1, \mu_2, \: ... \: \mu_n]$, where $\mu_i = (\Delta x_i, \Delta y_i, \...
Federico Taschin's user avatar
0 votes
1 answer
3 views

Error while running rtabmap for the real robot!

Hi, I connected to the real vehicle and launched rtabamp, but it shows the following error: ...
user avatar
1 vote
1 answer
340 views

Scale factor of Monocular SLAM (Simultaneous Localization and Mapping )

I am using ORB-SLAM3 with a monocular camera on a drone for Augmented Reality application. I need to know the absolute scale of the map formed by the SLAM. I cannot use a stereo or RBG-D setup. Tthe ...
Manoj Sharma's user avatar
0 votes
1 answer
171 views

Relative scale problem

I am doing Monocular Visual Odometry, and I have problem with relative scale. Most of the time its value is between 0.8-1.1, but sometimes it goes crazy and it has value 3,4 and once it had value 25. ...
Cluv's user avatar
  • 1
0 votes
1 answer
6 views

rtabmap icp_odometry.cpp:453::callbackCloud() fatal error

Hello everyone, I get a strange error that I did not get before, I formated my laptop and rebuilt rtabmap and now I get this error while i play the same bagfile with the same parameters. [FATAL] (2021-...
user avatar
0 votes
1 answer
7 views

How do i solve this"... .so: undefined reference to '..."

Hi, I have gone through the internet for hours for similar cases to mine but I've tried all solutions and hasn't got my code working. I'm using a library called "vdo_slam" which has been ...
user avatar
0 votes
0 answers
196 views

Pose-Graph Optimization in MATLAB does not give expected results

I am trying to optimize a pose graph I created in MATLAB using either the optimizePoses(viewSet)-function on the imageViewSet that I have or the ...
DocRobson's user avatar
1 vote
1 answer
2k views

Frozen map + 'Message filter dropping' - Issues with mapping and navigation in ROS2 Foxy

sorry for the long post, just want to make sure i include all the details. I am working on learning ROS2 by building a robot which maps and navigates my apartment. I'm using the RPLidar A1 sensor ...
Jacob Waller's user avatar
4 votes
2 answers
1k views

What's the difference between factor graph optimization and bundle adjustment?

I see that in SLAM literature, factor graph optimization is frequently used. While in Structure from Motion (SfM) literature , they usually use bundle adjustment. What's the difference between the two ...
zhouch's user avatar
  • 41
2 votes
1 answer
208 views

How to detect loop closures in 2D laser SLAM?

I am trying to build an occupancy grid map using odometry and 2D lidar data through graph optimization. I am not aware of any reliable loop closing methods using only the 2D laser scans. I have been ...
anonymous's user avatar
  • 121
1 vote
1 answer
443 views

Use 2 Cameras as 1 Stereo Camera

I have one Picamera and one normal USB Webcam and would like to use them together as one stereo camera. Is this even possible as the 2 cameras aren't exactly the same? I would like to use them in ROS ...
DragonflyRobotics's user avatar
1 vote
1 answer
72 views

Drone lost traj recovery

So I am using slam algorithm to localize the drone which is gps denied . The input to the slam algo is imu data and a video . Now after the first run of the slam algorithm it creates the trajectory ...
Karan Katiyar's user avatar
2 votes
1 answer
518 views

How to calculate the ground truth of your own simple dataset for testing your SLAM Algorithm?

I have tested my SLAM algorithm on EuRoC, TUM and KITTI Datasets. But I would like to test on my own custom dataset. Moreover, I already rectify how to make my own dataset in TUM dataset format, but I ...
Qamar Ul Islam's user avatar
0 votes
1 answer
15 views

Problems with my robot and rtabmap

Hello everyone, after a month of trying to solve some issues , I haven`t got any lucky. That is why I am turning to this forum to see if someone can help me with it . Here is my problem in context: I ...
user avatar
1 vote
1 answer
332 views

No difference between UKF and EKF for SLAM

I built EKF and UKF SLAM algorithms. The problem is that I expected to see a difference because of the more precise approximation of the system in the UKF. Here's a screenshot from the estimated path ...
muller135's user avatar
0 votes
1 answer
3 views

RTABMAP estimate normals with external odometry

Is it possible to use external odometry to estimate normals with RTABMAP? Will the normals then be estimated based on the odom when the points where captured? I know icp_odometry have some parameters ...
user avatar
0 votes
1 answer
17 views

/rtabmap/cloud_map is only a 2D map

Hi! I ran the following demo for rtab-map ROS without changing anything: ...
user avatar
0 votes
1 answer
28 views

Realsense D435i distortion

Hi ! I'm an Embedded Systems student and I need your help :) ! First my distribution is Melodic and I'm on Jetson Xavier NX (Ubuntu 18.04 LTS). I use an Intel Realsense D435i to make 3D SLAM in RTAB-...
user avatar
0 votes
1 answer
2 views

Publish RTABMAP cloud_map as ordered point cloud

I am using a D435 and T256 to record 3d data with realsense_ros. D435 data is published as a ordered point cloud. Environment point cloud is assembled with RTABMAP and published as cloud_map. Is it ...
user avatar
1 vote
2 answers
56 views

Doubt regarding a slam parameter in research paper

I was reading about the SLAM problem in a research paper, Multi-robot Simultaneous Localization and Mapping using Particle Filters by Andrew Howard. What does '$m$' mean here? The SLAM problem for a ...
skpro19's user avatar
  • 314
1 vote
0 answers
56 views

SLAM - Angle calculation failure ?-EKF

i am currently building up a EKF SLAM. I dont know where my mistake is but i think it has something to do with the angle my robot is driving towards but im not completly sure. First i thought it could ...
muller135's user avatar
0 votes
0 answers
79 views

EKF Update Step measurement data doesnt fit state vector

I have an EKF SLAM Algorithm which tries to estimate the robots position (X,Y,Theta) + the X,Y coordinates of several landmarks. Like in the posted algorithm i have a range/bearing sensor. I ...
muller135's user avatar
0 votes
1 answer
11 views

catkin_make error while building hector_slam

hi, i was working on mavros in jetson nano(melodic, aarch64) i have cloned this to my catkin_ws: ...
user avatar
3 votes
1 answer
474 views

What is the difference between a Bayes Net and a Factor Graph

I am just getting started on understanding Factor Graphs, by going through the excellent guide Factor Graph For Robot Perception by Dallaert and Kaess While I am familiar with the SLAM problem, and ...
OlorinIstari's user avatar
2 votes
1 answer
323 views

What is the Point of Monocular SLAM

I am not a V-SLAM expert yet, but as far as I understand with monocular V-SLAM there is a scale ambiguity introduced by the fact that a camera essentially is an azimuth sensor that maps the 3D world ...
JJB_UT's user avatar
  • 120
0 votes
1 answer
565 views

Is Lidar SLAM with only lidar sensor and no loop closure detection just a odometry?

I'm a newbee to SLAM. I have a question that in Lidar SLAM(including 2D lidar and 3D lidar), if I only use a single lidar without any other sensors like IMU and no loop closure in the mapping process, ...
Gemini's user avatar
  • 1
0 votes
2 answers
83 views

Sparcification of SLAM with SEIF (Sparse Extended Information Filter)

I am studying SLAM (Simultaneous Localization and Mapping) with textbook "probabilistic robotics". I cannot understand well about Sparsification step, so I found original paper for that; ...
buzz's user avatar
  • 11
0 votes
1 answer
35 views

updating the map partially in a dynamic environment

Hello, I have generated map.pgm with gmapping using teleoperation and RPLidar, and I am ...
user avatar
0 votes
1 answer
2 views

what difference does it make in NavStack(move_base) with frame_id as map vs odom

We set global_frame for different nodes of the NavStack. Below are the ones I am eager to know about and how they affect the system. Costmap params: ...
user avatar
0 votes
1 answer
40 views

Compute how well a laser scan matches or overlaps with its environment given a map of the environment and location of the robot is known

If I knew the exact location of my robot and have an accurate map (for eg. an occupancy grid map) of the environment beforehand, how can I compute a measure of how well the laser scan data agree with ...
rob_newbie's user avatar
1 vote
1 answer
155 views

EKF SLAM Prediction Step

My question relates to the prediction step in EKF SLAM when we get measurements. This is a question I've encountered while implementing EKF SLAM in ROS. At the beginning of the SLAM loop, we predict ...
Pedro's user avatar
  • 111
0 votes
1 answer
8 views

RTABMAP 2D Occupancy Grid showing color

I am driving on a grey track with a green grass surrounding. I have a kinect plugin which I modified to reflect Intel d435 parameters. How can I have the 2D Occupancy Grid reflect the change in the ...
user avatar
0 votes
1 answer
5 views

Getting error after calling a service in eloquent

Hi! I`m trying to use a Rtabmap service, which is defined as follows: #request bool global bool optimized bool graph_only --- #response Then, I call: ...
user avatar
2 votes
1 answer
59 views

How can we calculate likelihood of sensor values wrt to actual real world?

I am trying to understand Bayes Filter. In its update step we have P(z_t|x_t) as observation model. Slide 37: Bullet 5 of this lecture states "Likelihood of ...
Tahir Mahmood's user avatar
0 votes
1 answer
74 views

amcl and odom error while rotating

hi, i am running hector slam using ydlidar and realsense t265 for odom. the position updates properly on the map when the bot is in linear motion but when the bot rotates, the entire map fluctuates ...
user avatar
0 votes
1 answer
2 views

how are you suppose to use the param tag

im using rtabmap and i think im using the params wrong. where do i need to place them do they need to go inside the node tag like: ...
user avatar
1 vote
1 answer
560 views

Hector_navigaton on ROS Melodic error

I'm a newbie on robotics, and currently, I'm working on a project to make an autonomous robot that can mapping the surrounding environment and decide the shortest route towards the goal while avoiding ...
Chris Putra's user avatar
0 votes
1 answer
14 views

Anyway to use the map data from this website for SLAM?

http://data.selfracingcars.com/ I was using RTABMAP before since I wanted to be able to differentiate between the green patch of grass and the actual track (which Lidar wouldn't be able to do as it ...
user avatar
0 votes
4 answers
28 views

is theconstructsim real or a scam

hi all. i have been learning ros for a while now online, and i was looking for a nice good and comprehensive course. i am sorry if this question is not appropriate but has anyone heard about ...
user avatar
3 votes
1 answer
627 views

What's the correct approach to merging of localization and odometry data?

We've got a mobile platform with a source of odometry and an IMU, which are merged in an EKF filter (robot_localization node), producing continuous odom->base_link transform. The robot is also ...
mayor_Burns's user avatar
0 votes
1 answer
198 views

How to use SLAM generated map to navigate my robot to the destination?

I am trying to understand various SLAM algorithms. In my case, I need my robot to start from point A and reach point B with maximum accuracy as well as precision for all the cases. Note that, as the ...
Pe Dro's user avatar
  • 133
0 votes
1 answer
24 views

RTAB-Map: Merge local grid maps of multi-session mapping

We have a large facility I want to map in stages. I've already created a decent map of a large portion of the facility but need to add additional rooms/corridors. I am able to continue mapping by ...
Christian Fritz's user avatar
1 vote
2 answers
1k views

Do IMU have value in SLAM?

IMU are often used in theoretical models involving SLAM. I'm a bit confused on their practical value since error accumulation is so bad that after a couple seconds you need to completely ignore it. ...
FourierFlux's user avatar
0 votes
1 answer
41 views

Rtab-map : unexpected occupancy grid map

Hi, I just started using Rtabmap and I'm having an unexpected 2D occupancy grid map. First, here are the parameters I'm setting in the launch file: ...
user avatar
1 vote
1 answer
115 views

Which scan matching algorithm can be used to extract the moving objects (in 2D lidar scanner)?

There are different types of scan matching algorithms to match consecutive 2D lidar scans, see https://youtu.be/nvFcN2-NqRc?t=421 (ICP, correlative matching, RANSAC). Most of the algorithms return the ...
ywiyogo's user avatar
  • 141
2 votes
1 answer
96 views

What is the state-of-the-art approach to detect moving objects from mobile robot with 2D Lidar only?

Having a setup of a mobile robot with a 360° 2D lidar (1 plane). What is the current easiest approach to detect moving object with a high reliability from a moving robot? To make it simple, we ...
ywiyogo's user avatar
  • 141
1 vote
1 answer
307 views

How do robots move parallel to a wall/line?

I have been studying robotics by myself, lately. I noticed that there are various mapping, localization methods (popularly under SLAM), but are there concepts relating to the robot moving in a ...
Pe Dro's user avatar
  • 133
0 votes
1 answer
44 views

rtabmap: Did not receive data since 5 seconds ! (but it should be receiving !)

Hello, I'm using ros-noetic-desktop-full/focal,now 1.5.0-1focal.20200826.205403 amd64 [installed] on Ubuntu 20 rtabmap says it's not receiving data but the topics ...
user avatar

1
3 4
5
6 7
32