# Questions tagged [localization]

Localization is the problem of estimating a robot's pose relative to a map of its environment.

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### Robot-to-robot relative position over time?

I have 3 robots and I know the starts and end coordinate of each of them. For example for Robot 1 I have Xr1, Yr1 and Xr2,Yr2 coordinates pair , same for Robot2 and 3. I have lateral cameras so can ...
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### Can we use neural networks to solve the problem of SLAM? and how?

As a neural network can estimate almost any arbitrary function, I was wondering if we can use it to replace traditional SLAM algorithm. If that is possible, please explain how exactly you think it can ...
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### robot_localization not fusing imu data

According to the documentation in : http://docs.ros.org/en/noetic/api/robot_localization/html/state_estimation_nodes.html I was able to transform the imu data header fram from "imu_link" ...
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### Difference between odometry and localization wrt determining robot's pose?

AFAIK, localization is used to determine a robot's pose from a given a map and sensor data. I know of statistical localization approaches which use particle filters to determine a robot's location ...
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### Include information on the environment in map-aware particle filter

I have a robot equipped with some sensors for estimating the movement in a 2D environment (IMU, odometer). The robot is free to move within an area delimited by some walls. The map of the environment (...
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1 vote
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### How to get from lidar coordinates to gps coordinates

I build a map from lidar slam lego-loam, which is a lidar odometer, and then I want to use this map by gps localization. I know the map will have errors in some ...
• 111
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### I'm trying to understand an equation from a motor simulation $\dot w_i (u_ i ​ ,w_i,l _i ​ , \dot l _ i ​ )$

I have a simulated motor and I'm not understanding the math to control it. This is the equation for the force of the motor, also called an 'actuator'. $\dot w_i (u_ i ​ ,w_i,l _i ​ , \dot l _ i ​ )$ w ...
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### Why does the complexity of the particle filter scales exponentially with the number of dimentions?

In the AI for Robotics course from Udacity, Sebastian Thrun mentions that "the complexity of the particle filter grows exponentially with the number of dimensions". Why is this the case? We ...
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### Fusing uncontineuous global pose data

I am fusing the map pose data which is calculated from the fiducial_slam node. Here the topic being fused with ekf_node is /fiducial_pose (geometry_msgs/PoseWithCovarianceStamped). The problem i'm ...
1 vote
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### robot_localization EKF node does not publish on /odometry/filtered (ROS2 Foxy)

I am using ROS2 Foxy and Gazebo 11 in Ubuntu 20.04. I have a URDF description of a mobile robot that uses 4 wheels for mecanum drive. Using the robot_localization package, I am creating an EKF node ...
1 vote
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### Is VIO a good solution for autonomous drone navigation at higher altiutues (200+ms)?

When it comes in indoor scenarios, VIOs may provide good performance, but when it comes to outdoor environments and high altitudes without proper GPS coverage/stability, are current VIOs capable of ...
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### World and Map Frame for a real robot

I am trying to develop a robot for mapping purposes. Currently, I have a Velodyne VLP16 lidar and an IMU. I am having a bit of a confusion in stating the transforms of the system. For the lidar and ...
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### how can i drive the linear state space model of this ackerman steering model

i have an ackerman steering model like so : ...
1 vote
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### Is there a device for detecting what room you are in of a building?

I have found some inspiration for creating an smartphone application. But one of the main segments of the app requires it to know where the smartphone is located. It doesn't have to be that precies. ...
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### Using Google Cartographer library standalone

I am working on a project that requires the analysis of the results of different SLAM libraries with respect their accuracy on building a map. Right now, I am more interested in the development with ...
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### GPS+IMU sensor fusion not based on Kalman Filters

Do you know any papers on or implementations of GPS + IMU sensor fusion for localization that are not based on an EKF (Extended Kalman Filter) or UKF (Unscented Kalman Filter)? I'm asking is because ...
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### What is a general definition for pseudo-measurement (e.g., zero-velocity update as often used in robotics)?

I understand what a pseudo-measurement, but I am curious if there is a formal definition of the pseudo-measurement. A pseudo-measurement is sort of a constraint on the states of a system, which can be ...
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1 vote
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### How to calculate extrinsic calibration of a non-overlapping multicamera rig?

thanks for taking the time to check my question. Firstly, let me describe the current configuration, I am using 4 cameras that produce non-overlapping images and the goal is to calculate their ...
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### Covariance of Gaussian after sequence of homogeneous transformations

Assume we have a robot that moves and observes landmarks on his path. The path is composed of $k$ poses $s_1 \: ... s_k$ where $s_i = [x,\ y,\ \theta]$. From the sensors, we read the motion ...
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### Localization of a mobile robot with odometry using quadrature encoders . Is it feasible?

My goal is to localize a mobile differential drive platform using just quadrature encoders using dead reckoning. The robot will operate indoors and is to execute goal to goal trips through hallways ...
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### How to extract robots coordinates using ICP algo

I would like to know How to extract robots localization from the icp or ndt algo, currently I'm using scan registration for this reason
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### How to perform map matching algo using lidar scan s

I have run a code to extract features from lidar scans like poles and facades, and I created the reference map just concatenating results from each scan (i.e local map) now my question is; How can I ...
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1 vote
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### Self localization for 3 wheeled omnidirectional robot

I am trying to self localize a 3 wheeled omni directional robots using just motor encoders I followed the odometry method mentioned in equations 5,8,9 of https://bibliotecadigital.ipb.pt/bitstream/...
1 vote
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### 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 ...
1 vote
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### Localization and Mapping in a Small Crop Field

I have a small crop field inside my house and I want to create a map of it. The goal is to create a map so that I can monitor the growth of the plants and do some post processing to analyze the ...
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### multirobot_map_merge package not working properly

I am trying to map a Gazebo environment using 2 husky bots using the multirobot_map_merge package. However, the merged map being produced is wrong and the robots are not being localized correctly ...
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1 vote
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### 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 ...
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### How to handle curved paths in maze

-I have an RPi on Ubuntu with ROS (Kinetic). The task is to solve a maze. I have implemented a left-hand algorithm to navigate through the maze. -The robot is equipped with 3 ultrasonic HC-SR04 ...
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### 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 ...
1 vote
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### Extract laser scan from a map and known location

If we have the map of an environment (an occupancy grid for instance) and precisely know the pose of the robot within it. How can one reconstruct what the laser scan should look like at a given ...
1 vote
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### Fusing cross-correlated measurements for mobile robot's localization using unscented kalman filter (ukf)

I'm currently working on a mobile robot's indoor localization. On the perception side, I can only rely on a 2D lidar and wheel odometry. I have used these sources as input of different localization's ...
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### 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; ...
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### 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 ...
311 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 ...
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### 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 ...
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1 vote
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### Getting the new heading after a Transformation

Lets say I have 2d poses as such (angles in degrees): world_to_robot = {0, 4, 45} robot_to_object = {4, -4, -45} From a graph it would be easy to see that: world_to_object = {4, 8, theta}, what goes ...
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### Self localization inside machine of interest

I have a type of flight sensor interfaced with Arduino Uno via I2C. The sensor is VL53L0X i am getting the 1D measurement value of distance in mm which i can monitor using serial monitor in Arduino ...
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### Likelihood field sensor model (Probabilistic Robotics, Thrun et al., p.169-174)

I am currently working on the "likelihood field" sensor model (aka "endpoint model") by Thrun et al. (book: Probabilistic Robotics, Thrun et al., p.169-174) In this context I have ...
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### 2D point cloud registration success probability

I am trying to implement localisation by storing images from a camera and their accompanying point clouds from a 2D lidar during mapping. During localisation I then use image matching to suggest the ...
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### LiDAR Feature Extraction

I'd like to extract "features" of an environment scanned with a 2D LiDAR. I tried to create a temporary occupancy map to extract "corners" with the Harris Corner Detector. However ...
1 vote
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### How does a Tesla or any self-driving car self-drive to a remote place and align itself to an object?

I am trying to understand the technology/procedure related to one of the trivial functions of a modern self-driving cars. Let us consider the example of Tesla's Model S (or any). The car is parked at ...
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### Calculate the Vehicle corner points given localization

I am trying to calculate the corner points of the vehicle given the details below: Localization data from rear axle of the vehicle Length and Width of the vehicle Heading of the vehicle ENU Could ...
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### What is the difference between Markov localization and hidden Markov localization?

I just started studying localization for robotics. I started with Markov localization. There was a cool lecture on Udacity. I also came across another localization called hidden Markov localization, ...
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### Estimate noise covariance matrix of measurements using a ros-bag

I am facing the following issue, and some hint or orientation would be great. I am working on a project in which I was given a ROS bag, and I have to implement a localization node using SLAM. To do so,...
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### How does loop closure backpropagate the robots states into prior times?

I have read some about loop closure and I am somewhat confused. Suppose we implement something like EKF slam using LIDAR and suppose loop closure is aided by computer vision based features so that if ...
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### Bearing landmark localization

I am trying to initialize the position of a set of landmarks using only bearing observations. Each robot pose, described by position (x,y) and orientation (theta), observes a small set of landmarks. ...
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### Kalman Filter for 2d pose

I'm really sorry if this is a dumb question, but I don't have a clue on how to do this. I'm trying to write a kalman filter with a State vector of : {x, y, ẋ, ẏ, ẍ, ÿ } To estimate the 2 dimensional ...
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### Applying Rotation & Translation Matrix Obtained from Iterative Closest Point

Suppose I have M lidar contour points from t = k and N lidar contour points from t = k+1. (Some of you might question why I have differing number of contour points, and the reason is that these lidar ...