Questions tagged [localization]
Localization is the problem of estimating a robot's pose relative to a map of its environment.
235
questions
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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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0answers
25 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
43 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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47 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
24 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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29 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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24 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
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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
18 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
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2answers
52 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
31 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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23 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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15 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
57 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
37 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
59 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
56 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
103 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
30 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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0answers
32 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 ...
1
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0answers
22 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
31 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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loop closing in grid based fastslam 2.0
I understand how grid based fastslam 2.0 works
I just would like to know how to implement a loop closure functionality in a grid-based fastslam 2.0?
Since at each state we only consider the last state ...
1
vote
1answer
92 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?
2
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1answer
51 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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24 views
Ceiling Camera & robot - SLAM still neded?
I've got a question regarding the topic of SLAM. My composition consists of a mobile robot and a top down looking 2D camera with wide-angle lens. It is comparable to a survaillance camera mounted on ...
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3answers
70 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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1answer
65 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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0answers
31 views
MAV drifting away from its takeoff position
I am working on MAV control in GPS denied environment using px4flow and Lidar sensor.While in simulation and during experiments on real vehicle, MAV doesnt stay at its position and drifts in random ...
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1answer
45 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 ...
0
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1answer
46 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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0answers
22 views
Robot localization including the orientation of the boundary
Consider a SLAM system for a mobile robot that is able not only to predict the position wrt the map boundary but also to measure the orientation of the boundary once it is reached. If the measured ...
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Integrating Arduino Cloud Platform into ROS
I have an existing ROS framework used for an autonomous driving vehicle. I am working on tests to understand how localization is affected by light. My existing hardware does not have a lux measurement ...
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21 views
What is the difference between SLAM and cooperative localization?
I need to ask this simple question for my own understanding. I am new to the field and want to differentiate between the two.
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2answers
64 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 ...
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1answer
115 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. ...
2
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2answers
49 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/...
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1answer
52 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 ...
3
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1answer
45 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 ...
2
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2answers
23 views
How to calculate the mean of an unsymmetric distribution (Particle Filter)
I'm attempting to implement a variant of Monte Carlo localization in a 2D space with obstacles. While the object is moving around the obstacles the particles flow around the obstacle like in images ...
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Differences between strapdown inertial navigation and motion models
In a state estimation scheme with a simple IMU/GNSS setup using EKF, I have always thought the prediction step would be done using a motion model and all sensor measurements would be incorporated via ...
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1answer
45 views
Can drone fly in predefined fixed trajectory without GPS
Is it possible to make a drone to fly in fixed altitude and move in fixed trajectory without GPS. (Drone has to move in fixed path which is already defined).
I am saying without GPS because drone has ...
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0answers
39 views
How do I set the weights of an Unscented Kalman Filter?
In most of the papers I have read, calculation of weights is done by the following formula:
Where L is the dimensionality of my state and lambda is calculated by:
And the usual values for alpha, ...
2
votes
2answers
77 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 ...
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0answers
48 views
Sensorfusion of odometry, accelerometer and gyroscope using Indirect Kalman Filter
I'm trying to implement an indirect Kalman for pose estimation of a wheeled robot.
I found two papers that describe this approach.
CMU. Journal (2006) Vol. 5(1)
IFAC Conference on Embedded Systems
...
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0answers
25 views
Max angle of beam against surface (ultrasonic sensor)
I am trying to localize a robot within a rectangular room (182cm x 243cm) with completely black walls (so IR sensors and LIDAR are out of the question). I am trying to figure out if I can position ...
3
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1answer
119 views
Likelihood Field Matching
I have LIDAR data of an environment in my hand and I want to apply likelihood field matching to this data. I found a source. But I don't understand what the variables of the algorithm mean and how it ...
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1answer
84 views
Fusing absolute robot localization from markers
I have a system which is composed of a rig of 8 cameras which are used for detecting markers in the environment and which outputs 8 estimates of the absolute robot's position and orientation.
Now, I ...
3
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2answers
70 views
bluetooth that could track mobile phone location
newbie here.
after my research, i couldnt find anything that could found what i wanted to search for my project(following robot for indoor location).
without gps, bluetooth only, could i get the exact ...
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0answers
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Problem with UKF weights when calculating predicted state
I'm having troubles implementing a UKF during the calculation of $\overline{\mu_t}$, specifically in this step:
$$\overline{\mu_t} = \sum_{i=0}^{2n}w_m^{[i]}\chi_t^{*[i]}$$
My problem I'm facing is ...
