Questions tagged [localization]
Localization is the problem of estimating a robot's pose relative to a map of its environment.
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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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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 ...
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1answer
21 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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36 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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1answer
14 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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29 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 ...
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15 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;
...
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1answer
25 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 ...
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54 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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48 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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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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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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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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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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1answer
25 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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1answer
43 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 ...
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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 ...
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1answer
47 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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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 ...
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1answer
41 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 ...
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1answer
42 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, ...
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1answer
73 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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30 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 ...
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1answer
53 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. ...
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54 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 ...
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1answer
48 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 ...
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30 views
Angular movement of a controlled arm relative to an object via Two IMUs
I've been tasked to use two YEI 3-space sensors (IMUs) to detect the azimuth and elevation (altitude in the image below) angle of a moving arm with respect to a fixed object, with a sensor on the end ...
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34 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 ...
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1answer
35 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 ...
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1answer
32 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 ...
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2answers
57 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 $(x', y', \theta')$ ...
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1answer
35 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 ...
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31 views
Robot Localization - Motion and Sense Probability
I'm currently taking Udacity's AI for robotics course and came across a question that stumped me. The problem plays on localization probability given uncertainty in our measurement updates.
The first ...
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18 views
Bundle Adjustment for Monocular SLAM
I am confused with how monocular BA works in visual-based SLAM. Is there any tutorials I can do in openCV to provide me some visualization aid?
Thank You.
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1answer
74 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 ...
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1answer
47 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 ...
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2answers
68 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 ...
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1answer
67 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....
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3answers
153 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 ...
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1answer
47 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 ...
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35 views
Determining Orientation of a Robot Relative to a Line on Table
I am currently busy with a robot that needs to obtain it's orientation relative to a line seen by a camera. At the moment, I am using Hough lines to obtain a gradient for the line, but the gradient ...
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23 views
Hint regarding Localization & Map Scaling
I just started with mobile robotics. I'm trying to do a collaborative system between a mobile robot and a ceiling camera (Raspberry). They should do all tasks as a "team". Means Calibration, ...
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1answer
34 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?
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1answer
105 views
How many landmark measurements to localize a planar robot?
How many landmark measurements are required to localize a robot (i.e. find its x,y position and orientation) moving in a 2D world using 1. only range measurements 2. range plus bearing measurements?
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1answer
93 views
Where to include velocity in a Kalman filter
I am trying to understand some of the basics of the Kalman filter. The problem I am working on is quite complex, but I have spent some time trying to simplify the problem with an example.
So, let's ...
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3answers
76 views
Is SLAM done only first time in a given environment
I am training Turtlebot 2 to move around the office. I come from robotics hardware background but relatively new to computer vision and robotic mapping.
Here are my two fundamental questions related ...
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2answers
75 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 ...
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1answer
56 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 ...
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1answer
58 views
Robot localization in a known map without knowing its initial position in that map
Firstly I would like to say that I'm no expert in Bayesian Filters such as Kalman Filter and Particle Filter, but I've used the EKF before in a robot that has both wheel encoders and an IMU to ...
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3answers
81 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 ...
