Questions tagged [localization]
Localization is the problem of estimating a robot's pose relative to a map of its environment.
260
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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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10 views
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 ...
1
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1answer
22 views
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 ...
3
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1answer
23 views
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 ...
0
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1answer
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 ...
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1answer
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
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13 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 ...
1
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1answer
24 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 ...
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0answers
18 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/...
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24 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 ...
1
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1answer
77 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 ...
1
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1answer
55 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 ...
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0answers
29 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 ...
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0answers
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 ...
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26 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 ...
0
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1answer
35 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 ...
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0answers
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 ...
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2answers
32 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 ...
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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 ...
0
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2answers
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;
...
0
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1answer
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 ...
2
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1answer
91 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 ...
0
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1answer
53 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 ...
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0answers
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 ...
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0answers
13 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 ...
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0answers
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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0answers
115 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 ...
0
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1answer
31 views
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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2answers
73 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 ...
0
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0answers
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 ...
1
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1answer
66 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 ...
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0answers
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 ...
0
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1answer
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 ...
0
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1answer
58 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, ...
0
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1answer
134 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,...
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0answers
34 views
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 ...
0
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1answer
78 views
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. ...
2
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0answers
56 views
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 ...
2
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1answer
72 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 ...
2
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0answers
41 views
How do you handle angle discontinuities in estimation problems?
When one is implementing a state estimator in a system that involves kinematics, will inevitably face the problem of angle discontinuities, i.e., the fact that the angles have to be wrapped between ...
0
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1answer
61 views
ICP(Iterative Closest Point) with Partially Overlapping Conditions & Changing Point Numbers
I am currently working on fixing vehicle odometry data using lidar contour points. Since I am receiving lidar data in the form of countour points, I thought I'd use ICP to correct the odometry error ...
0
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1answer
38 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 ...
2
votes
2answers
60 views
Compute path in absolute frame from sequence of measurements
I have a sequence of measurements $\{(x_i, y_i, \theta_i)\}_{i = 1 \:...\: N}$. Each of these represents the new pose of the robot seen from the previous pose, i.e. a measurement $(x', y', \theta')$ ...
0
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1answer
39 views
Motion model and homogeneous transformation issue on a drone
I am trying to develop a EKF-SLAM algorithm for a drone, and I want to estimate its position in the inertial/world reference frame. I have as control variables the linear and angular velocities in the ...
0
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1answer
87 views
EKF sensor fusion
What is the standard way to fuse multiple sensor measurements in an EKF framework?
Say you have Odometry, IMU and some form of Lidar which can produce landmarks.
EKF is normally presented as a ...
0
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1answer
61 views
EKF-SLAM what should the observation model be?
I am implementing an EKF algorithm for a drone localization, and while I was defining the observation model I got a bit confused.
This is my situation:
I have a drone which is able to give me the ...
0
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2answers
73 views
Which math books would help in learning SLAM systems? [closed]
Recently I started studying papers on SLAM systems by Durrant-Whyte for my research and I'm finding some difficulties in the math (matrices and probability) that is tackled in these papers.
Which ...
0
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1answer
82 views
Kalman filter with a known motion model
I have a robot whose pose $(x, y)$ is defined relative to the global frame. I have a sensor which estimates the robot's current pose in the global frame, and the sensor is known to have Gaussian error....
0
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3answers
233 views
Difference between SLAM and Localization
What are the differences between SLAM and Localization if you have a known map? How does the position probability update differ between the two?
In particular I'm curious on if localization is a ...
0
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1answer
84 views
How can i fusion gyroscope and accelerometer when accelerometer has only roll,pitch val?
I'm currently studying IMU Sensor with 6dof(gyro and accelerometer).
My goal is to get Orientation of robot, and i found out that only 6dof imu sensor wouldn't be
possible to get a correct Orientation ...
