Robotics Stack Exchange
Robotics Stack Exchange

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.

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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How do SLAM algorithms handle a changing environment?

I'm doing some groundwork for a project, and I have a question about the current state of SLAM techniques. When a SLAM-equipped device detects an object, that object's position is stored. If you look at the point cloud the device is generating,…
anaximander
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How to determine quality of ICP matches?

In SLAM frontends which use the Iterative Closest Point (ICP) algorithm for identifying the association between two matching point clouds, how can you determine if the algorithm is stuck in a local minimum and returns a wrong result? The problem is…
Jakob
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What is the difference between SAM and SLAM?

What is the difference between Smoothing and Mapping (SAM) and Simultaneous Localization and Mapping (SLAM)? These general approaches seem closely related. Can someone describe the differences?
Stefan
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Least squares map joining

There is a lot of background here, scroll to the bottom for the question I am trying out the map joining algorithm described in How Far is SLAM From a Linear Least Squares Problem; specifically, formula (36). The code I have written seems to always…
munk
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Who coined (or popularized) the term "SLAM"?

According to Wikipedia's article on SLAM, the original idea came from Randal Smith and Peter Cheeseman (On the Estimation and Representation of Spatial Uncertainty [PDF]) in 1986, and was refined by Hugh F. Durrant-Whyte and J.J. Leonard…
Ian
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Graph optimization with G2O

I'm trying to do graph optimization with G2O, mainly in order to perform loop closure. However finding minimal working examples online is an issue (I've found this project, as well as this one. The second one though has the form of a library, so one…
dim_tz
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GraphSLAM: why are constraints imposed twice in the information matrix?

I was watching Sebastian Thrun's video course on AI for robotics (freely available on udacity.com). In his final chapter on GraphSLAM, he illustrates how to setup the system of equations for the mean path locations $x_i$ and landmark locations…
Paul
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Scan Matching finds right rotation but false translation

I'm currently developing a SLAM software on a robot, and I tried the Scan Matching algorithm to solve the odometry problem. I read this article : Metric-Based Iterative Closest Point Scan Matching for Sensor Displacement Estimation I found it really…
PinkPR
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In the SLAM for dummies what is z-h in updating X?

In SLAM for Dummies there is on page 40 this formula: $X = X+K(z-h)$ What is $z-h$ in updating $X$?
user18147
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In the SLAM for Dummies, why are there extra variables in the Jacobian Matricies?

I am reading SLAM for Dummies, which you can find on Google, or at this link: SLAM for Dummies - A Tutorial Approach to Simultaneous Localization and Mapping. They do some differentiation of matrices on page 33 and I am getting different answers for…
half-potato
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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 implement FastSlam 2.0. Which I understand uses particle…
raaj
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Assumptions about the nature of landmarks in SLAM algorithms

I'm trying to understand the role of landmarks in SLAM algorithms. I've glanced over a few books concerning landmark based SLAM algorithms and I've come up with a rudimentary understanding which I believe is flawed. How I think SLAM works: As I…
Paul
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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 $$e_{ij}(x_i, x_j) = z_{ij} - \hat{z}_{ij}(xi, xj)$$ here $z_{ij}$ is the mean of virtual measurement and…
vyi
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Robot moving on a flat floor - 2D or 3D SLAM?

What is the best way to model the SLAM problem (offline) for a wheeled robot moving on a flat floor in 3D space (the pose has only 3 degrees of freedom)? In terms of sensor data, we have the wheel odometry and 3D measurements of landmarks (coming…
means-to-meaning
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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?
Nicolas Schejtman
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