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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.

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provide world map for ekf global localization problem

I am trying to implement the ekf_localization algorithm in page 217 (Table 7.3) of the probabilistic robotics book by Thrun. From my previous post, I understand that I need to extract observed ...
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41 views

EKF localization data association

I am working with ROS indigo and clearpath huskyA200 and wanted to implement the EKF localization with unknown correspondences with my own hokuyo lidar data for a school project. Giving the algorithm ...
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Relation between GraphSLAM and Iterative closest Point algorithm

I have lots of doubts about GraphSLAM, The GraphSLAM Algorithm with Applications to Large-Scale Mapping of Urban Structures. When I practically implement it I get matrix singularity error. I taken ...
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44 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-...
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30 views

GraphSLAM equation doubt

I have question about GraphSLAM implementation. To find out the path and map using GraphSLAM we rely on this equation: $$\mu=\Omega^{-1}\xi$$ where $\Omega$ is our information matrix which ...
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24 views

Graph Slam Landmark remove and then again add it

I try to implement Graph Slam in real dataset. My data set have some data that describe that the Robot observe same landmark over and over with a large amount of time difference. Prof. Sebastian ...
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2answers
26 views

How to detect loop in robot movement observing odometer data

I have some odometer data. This data are based upon robot movement. I can transfer those raw data to a motion equation from where I get x,y,and theta co-ordinate of a Robot. If I plot those x,y ...
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47 views

Multiple View Triangulation method used by COLMAP

I'm looking at how COLMAP does multi-view triangulation. I can't work out what this function is doing. I can't find any formulas which look similar. The input "proj_matricies" come from pose data, the ...
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25 views

EKF localization with known correspondences to understand SLAM

I am working with ROS indigo and clearpath huskyA200. I want to implement the EKF localization with known correspondences to understand SLAM better and I’ve been reading probabilistic robotics book by ...
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28 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 ...
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1answer
22 views

Why does the low variance resampling algorithm for particle filters work?

I am studying and coding particle filters and I am using the Low variance sampling algorithm suggested in the Probabilistic Robotics book. I understand the procedure for the algorithm. A random number ...
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23 views

How to generate Particle in Particle Filter

I try to implement FastSlam 1.0. To implement this I need to create particles. Now my confusion is that How to create Particles?I have some odometry and Measurement data. Using those data values how ...
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21 views

Graph slam augmentation of Identity Matrix

I am trying to implement GraphSlam. I go through this paper http://robots.stanford.edu/papers/thrun.graphslam.pdf. I have some doubt about the algorithm. I attached a picture with this question My ...
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47 views

Matrix is singular error in GraphSLAM

I have gone through The GraphSLAM Algorithm with Applications to Large-Scale Mapping of Urban Structures. I implemented the code for GraphSLAM. The fundamental formula of GraphSLAM is $$\mu = \Omega^...
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8 views

Transforming incremental pose from camera frame to wheeled robot base frame

I compute odometry using the stereo camera by minimizing reprojection error. I compute the incremental pose change between frames from time t-1 and t. The odometry is referenced to the left camera ...
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16 views

How to calculate the uncertainty of structures in Bundle Adjustment?

The following is a standard Bundle Adjustment formulation. \begin{equation} \textbf{e}{_{ij}}=\textbf{z}_{ij}-\pi(^{C_i} \textbf{T}_{w} {^w\textbf{p}_j}) \end{equation} $$ \textbf{f}(\textbf{x})=\...
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33 views

Actual dimension of Omega in Graph Slam

I have a doubt about GraphSlam Algorithm introduce in this paper. I add a picture to express my doubts (from page 411, 9th in paper): As per my knowledge $\Omega$ is the information matrix. So in ...
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1answer
41 views

GraphSLAM data accumulation problem

I try to implement GraphSLAM from this tutorial, The GraphSLAM Algorithm with Applications to Large-Scale Mapping of Urban Structures. I have some doubt while studying this paper. I hope people who ...
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38 views

GraphSlam Matrix Subtraction doubt

I am trying to implement GraphSlam from this paper. I have some doubt regarding the algorithm described in this paper at table2: Algorithm GraphSLAM_linearize. I have a doubt in line 7. As per my ...
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38 views

GraphSlam doubt about variable elimination technique

I am trying to implement Graph Slam. For tutorial purpose I read the paper "The GraphSlam Algorithm with Application to Large-Scale Mapping of Urban Structures" by Sebastian Thrun. At the beginning of ...
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71 views

How to update a new pose in iterative pose optimization problem?

There are multiple ways to update new pose in iterative pose optimization problem. The easiest one we often find in papers in robotics is as SO3 + translation Update on right \begin{equation} \...
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28 views

ROS: joint_state_publisher dies when used in remote launch file

I've been trying to run robot_state_publisher and joint_state_publisher on a remote TX1 running Ubuntu 16.04 and ROS Kinetic. When running the node from a local launch file (manually ssh into the ...
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Any reference for “3D feature matching + ICP”?

One of the simple tricks in getting high performance for a global 3D point cloud registration is combining "3D feature matching + ICP". For example FPFH matching + RANSAC for initial pose estimation ...
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How can I get the distance from a robot to a beacon?

I'm planning to create a Raspberry Pi robot to map a room. I intend to use a particle filtering algorithm as one of the central points of the project, that will allow me to work out my position ...
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63 views

Confusion of EKF equations

I read Probabilistic Robotics by Sebastian THRUN (online version). I also read http://ais.informatik.uni-freiburg.de/teaching/ws12/mapping/pdf/slam04-ekf-slam.pdf Question1 : What will be the ...
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Map merging of mobile Robots

I have Five Robots data.Which I used to generate maps. More preciesly Robot 1 generate Map1. Robot 2 generate Map 2, Robot 3 generate Map3, Robot4 generate Map 4 , Robot 5 geberate Map 5. Now these ...
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EKF based Slam implementation with landmark identification in Global frame

I am working on mobile Robotics. I want to implement Slam. I have a very specific question about EKF Slam. To implement Slam I read the book "Probabilistic Robotics". I read its online version. There ...
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33 views

What features are tracked during SLAM?

How does the SLAM algorithm decide which features to track in the data incoming from various sources like LIDAR and depth camera?
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12 views

Sigma calculation for EKF based Slam

I am working on EKF based slam. I go through Probabilistic Robotics. I attachd a picture here. I have doubt about how to calculate Sigma. I am happy if someone share their views about Sigma. How to ...
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24 views

EKF Slam landmark estimation doubt

I am novice in Slam. I want to implement EKF based slam. For that I consider the book PROBABILISTIC ROBOTICS by Sebastian THRUN. ...
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2answers
55 views

Why use GraphSLAM?

I am doing some project on Slam. I have a data set of a moving Robot which can give me the value of forward velocity(m/s) and angular velocity(rad/s) and time(s). Now if this data are provided I can ...
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32 views

How does marginalization of variables effect least squares SLAM energy function?

Consider a simple example of Bundle Adjustment where I have robot and landmark poses $x = \left[ x_p \text{ } x_m\right]^T$ and measurements given by $z$, such that a simple factor graph can be ...
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18 views

remote 3d slam with limited sensing and bandwidth

I'm trying to implement a 3d visualization for a remotely operated robot, which will be equipped with either stereo grayscale cameras or one grayscale camera and a line striping system that can ...
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OpenEKFMonoSLAM

I'm trying to make OpenEKFMonoSLAM work with different datasets. As far as I can see, it is failing with images bigger than 240x320 in ransac.m Here's a screenshot of the error. Does anybody came ...
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111 views

Which is a good and cheap 3D LIDAR or other options?

Our team is planning to go for European Rover Challenge (ERC) 2018 for which we are designing an Autonomous rover. In order to implement SLAM, we need a way of mapping (with a range of atleast 2-4 ...
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35 views

Does marginalization increase the number of edges in Graph SLAM?

I thought marginalization does not change the number of the edges but this material (page 11) describes that as a result of marginalization we will have more edges in graph. Why does it increase the ...
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34 views

Sonar Slam with 5/8 Ultrasonic Sensors

I am trying to build an autonomous driving car which uses mostly onboard ultrasonic sensors for localization. I use the SRF05 sensors which have a beam width of 55°. 3 are looking forward, 2 sideways ...
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Graph Slam Path and Map

Any one have any idea about Graph Slam. To implement graph slam you have to write down a equation mu=(inverse)omega*Xi; The result is the path and map. Now which one is path? Is mu represent the Path?
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What are the video recording tools for SLAM?

Recent demonstration videos of SLAM papers show pretty nice camera motion while mapping. eg ElasticFusion I was wondering if there is an open source tool for that. It seems like ElasticFusion in the ...
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How to penalize blurred images in Bundle Adjustment?

We know that when rotational and linear velocity of the camera is high it is highly likely to get blurred images. The blurred image affects the quality of the accuracy in the feature tracking problem. ...
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2answers
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Why do we need a marginalization in Bundle Adjustment?

A common practice in Bundle Adjustment is to reduce the state dimension by marginalizing structure or pose states to improve the optimization speed. In case 3d points(structure) $\textbf{p}_i$ are ...
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2answers
78 views

Scale estimation in datasets for monocular odometry

Suppose I've developed a monocular SLAM or odometry algorithm. Then I want to test it on some dataset, for example KITTI, TUM etc. How should I deal with the absolute scale in this way? Thanks.
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Separated unscaled translation vector and scale for the ground truth poses of Kitti Odometry datasets

Kitti dataset provides Ground Truth Poses for its odometry datasets.However, can I acquire the unscaled-translation vector of the translation for which I can compute the scale myself? I want to ...
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4answers
362 views

3D mapping using only a 2D Lidar

How can I map a 3D environment using only a 2D lidar? The lidar would be hand held and it would have 6 DoF. So if I move it in arbitrary motion in all 6DoF, I expect my algorithm to generate a 3D map ...
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21 views

Updating the covariance matrix with limited amount of corrections

I am doing small experiment with mobile robot wall following and EKF SLAM with only one short range laser. The robot starts to predict its position directly when its founds the first landmark and its ...
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1answer
85 views

Camera ego-motion estimation via dense optical flow

Help me please resolve some questions in the article 1) "A Robust Method for Computing Vehicle Ego-motion", Gideon P. Stein et al. According to this paper we can find three components of motion (...
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74 views

What is appearance-based SLAM?

To my understanding appearance-based SLAM uses only information coming from sensors for mapping and localization. It completely discards control information from actuators. I'm I correct?
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129 views

Kangaroo x2 and Sabertooth 2x32?

I have successfully used sabertooth 2x32 vai USB cable . The code is listed below ,sabertooth dip switch configuration is (On off on on on on 1-6). USB cable connected directly (No ttl cable or ...
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72 views

Methods for odometry/IMU/Gyro free lidar pointcloud registration for pose estimation

I am currently trying to register a pointcloud in time to find my change in position and heading at each timestep (High speed application). So this is essentially an implementation of SLAM. I am ...
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3answers
83 views

loop closure detection in visual SLAM

A robotic system is moving a getting its current location using visual odometry (incremental estimation of rotation and translation). To correct its localization, a loop closure technique may be added....