# Questions tagged [localization]

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

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156 views

### SEIF ,online version of Graph slam create doubt in Motion Update state

I have a thesis work about Graph Slam The GraphSLAM Algorithm with Applications to Large-Scale Mapping of Urban Structures I try to implement it with the help of this paper but during the ...
223 views

### How to synchronise data for fusion in Kalman from multiple sensors with different timestamp information?

I'm using Kalman filter to track the position of a vehicle and receive position data from 2 sensors: A GPS sensor and an Ultrasonic sensor for which I want to implement sensor fusion into the Kalman. ...
65 views

### 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 ...
22 views

### 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 ...
56 views

### 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, ...
96 views

### Basic question about Markov Localization, probability and belief distribution shift

I am starting in robotics, and reading about Markov Localization, I have one doubt, probably very stupid, but, well, I want to solve it. Let's take the CMU Website example: https://www.cs.cmu.edu/afs/...
113 views

### 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,...
32 views

### 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
92 views

### Localize a Mobile Robot on a Mirror

I am currently busy with a project which requires me to construct a robot capable of cleaning a heliostat (movable mirror used to redirect sunlight). Heliostats are basically large flat mirrors that ...
12 views

### convert to a reference frame for lidar scan in kitti data

my question is how to convert from lidar scans frame to the reference frame, I'm working with Kitti data set which contain the oxts data (transformation from word frame to imu) and another file like ...
23 views

### 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 ...
66 views

### Localisation of Robot in a Rectangle

I am wondering how to go about localising a robot in a rectangle drawn on a smooth surface. Basically, there is a tape that lines the shape of the rectangle, and the color of this tape is unique in ...
70 views

### Effect of platform speed (how fast it is moving) on the quality of SLAM

I want to know how big of on an impact does the speed of the platform on which your sensors are mounted have on the quality of the outcome of a SLAM solution. Are there are any methods that are better ...
80 views

### Collaboration of mobile robot and survaillance camera - classic localization (still) needed?

Just started with the topic of mobile robotics.. so I'm still into concept making and little programming, but have not setup everything or tested at all. I got a (differential) mobile robot (lego ...
71 views

### 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 ...
17 views

### 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/...
128 views

### EKF SLAM : Missing older landmarks in new observation

I am a beginner to SLAM and robotics in general and I have been trying to implement SLAM on my GoPiGo3 robot car kit using primarily Chapter 10 from Probabilistic Robotics by Sebastian Thrun as ...
66 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 ...
70 views

### 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 ...
80 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 ...
23 views

### Cartographer: What determines how many nodes are added to a trajectory?

I'm testing cartographer using the Deutsches Museum public bag. I'm trying different Lua settings and checking how it affects the mapping process, etc. What I notice is that, no matter what ...
44 views

### Uncertainty in grid based fastslam

Given I am building a grid map, and poses are represented using particles, how can I calculate the uncertainty of a pose In a grid based fastslam 2.0?
45 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; ...
35 views

### Vehicle Odometry Correction Using Lidar Contour Points (Localization)

I am currently working on a project where... Vehicle travels from point A to B GPS trajectory is used as a reference Vehicle odometry (bicycle model without slip angle beta) was used to estimate a ...
30 views

### 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 ...
3k views

### Kalman filter GPS + IMU fusion get accurate velocity with low cost sensors

I'm new to all this robotics stuff. Especially to Kalman filter. My initial goal is to have velocity as accurate as possible Here is my case: I have a phone which is mounted, for example in the ...
53 views

### 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 ...
21 views

### 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 ...
26 views

### 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 ...
60 views

### building a grid map from gps trajectory poses

I am trying to create a feature grid map with Images from camera mounted to the top of the car. Novatel ProPak RTK gps poses Beforehand, I've checked to ensure that the standard deviations of the ...
33 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 ...
25 views

### SLAM Initialize new landmark - specifically the covariance

Im trying to bring an EKF - SLAM to life but it keeps on failing. Specifially, I think, my mistake lies in the initialization of the new cone <-> covariance. I multiply the Jacobian (derived ...
52 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 ...
27 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 ...
3k views

### Which is a good and cheap 3D LIDAR or other options? [closed]

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 ...
34 views

### 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 ...
7k views

### How to make an “invisible line following robot”?

I would like to build a robot which follows a virtual path (Not a visible path like a 'black line on a white surface', etc). I'm just enthusiastic by seeing some sci-fi videos which show robots carry ...
50 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 ...
7k views

### Hector SLAM, Matching algorithm

I'm trying to understand the scan-matching part of Hector SLAM (PPT summary). It seems a little difficult to understand, in some cases, how is it possible to actually perform the alignment of the ...
12 views

### 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 ...
11k views

### Accelerometer, gyro, and magnetometer sensor fusion in 2d

I have not yet built this so this is basically a theoretical question. I am still wrestling with some C code to manage i2c ...
12 views

### What are the state-of-the-art variants of the basic ICP algorithm for point cloud registration?

The questions is quite straightforward. For the past few days I've been looking into point cloud registration. It looks like it all started with the basic ICP algorithm as described in P. J. Besl and ...
32 views

### 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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### 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 ...
42 views

### 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 ...
110 views

### 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 ...
13 views

### Improvements over FastSLAM2.0

Are there some papers and/or works that describe improvements for the FastSLAM2.0 algorithm? I'm particularly interested in the following areas: The map is completely unknown at the beginning of the ...
8 views

### ECEF postion vs. LAT/LON/Height position with odometry

So I do have a wheeled robot and I want to fuse position data with odometry data. Someone suggested using the position encoded in ECEF rather than using the LAT/LON/Height information I get from the ...