Questions tagged [lidar]
Lidar (also written LIDAR, LiDAR or LADAR) is a surveying technology that measures distance by illuminating a target with a laser light. Lidar exists as an acronym of Light Detection And Ranging.
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Multisession odometry
I have two bag files with significant overlap and multiple loop closure opportunities. However, these bag files were recorded at different times. I want to use these bag files to reconstruct a scene ...
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Follow wall and avoid obstacles using lidar
I want to follow a wall and avoid any obstacles on the way.
My robot has a 360 degree sensor (lidar). I want to calculate a line (vector) to follow.
I tried a lot of different solutions but I didn't ...
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How does BA work for 3d lidar? Particularly VLP16/VLP32 aren't dense enough
How do you run bundle adjustment on a sequence of 3d lidar recordings if the scan is relatively sparse? I read something about attempting to match up planes/edges but there wasn't much detail given. I ...
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Error RVIZ extrapolation into the future on the same machine
I get the following error when trying to view my RPLidar A2 scan in rviz2. It’s on a differential drive robot controlled using Odrive and ros2 control using Articulated Robotics. I am running ...
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How does NDT work with global bundle adjustment?
I was reading about pointcloud matching and SLAM.
NDT is one approach to scan matching, what I am confused on is how you do global bundle adjustment using NDT occupancy grid.
https://www.researchgate....
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How do I integrate webots sensor plugins into a ros2 URDF/Xacro file?
I am trying to set up a Lidar, IMU, and depth camera in Webots on a ROS 2 robot in its xacro file (starting with just the Lidar).
I currently have the following:
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Webots: Spawn multiple nodes and disable collision between them, but not the environment
In Webots, I am spawning 10 vehicle nodes at the same time and position for reinforcement learning. I would like the vehicles to not interact with each other (collision and LIDAR) but still have ...
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Minimum distance that can be measured using Rplidar A1M8
can you please explain what is the minimum distance that can be measured using RPliadr A1M8
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Object racking on conveyor belt using low cost Lidar or similar non-camera options
The requirement is that movement of products right from the start to end of the conveyor belt (of length around 2.5 m) need to be tracked. The same can be easily done using any IP Camera and OpenCV ...
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velodyne LiDAR, which driver or lib give the timestamp of each point?
I am looking for a VLP-16 driver lib or code that gives a point time stamp instead of per scan time stamp.
I know their official manual show how to calculate the timestamp of each point but I was ...
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Transform problem with rviz map display when using the SLAMTEC Mapper M2M2 with ROS
I am working on a project using the SLAMTEC Mapper M2M2 with ROS to map an area of interest. I am using Oracle Virtualbox to run ROS Noetic with Ubuntu 20.04, and my host machine is running on Windows ...
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Simulating Velodyne Puck Lite
I am trying to simulate a Velodyne puck Lite on Gazebo Garden but I am not sure how to go about the rotation speed of the lidar.
Does adjusting the update rate and making the angle of the rays of the ...
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Gazebo Garden Lidar Visualization
I am trying to visualize a point cloud of the lidar so I used the file in the Gazebo Garden tutorials (link: https://gazebosim.org/docs/garden/sen...) and I added these two lines for the Vsiualize ...
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Question about getting global coordinates of lidar point cloud from relative in Webots
I need to do custom mapping of surroundings with lidar using mobile robot in Webots. What I use for that:
GPS for getting robot position.
Compass for getting direction robot.
Lidar for getting info ...
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Lookup would require extrapolation into the future on the same machine
I get this error when trying to view my RPLidar A2 scan in rviz2. It’s on a differential drive robot controlled using arduino using Articulated Robotics’ code that I quickly ported to Humble, ...
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Motion/System Model for range finder
I have a 1D Time-of-Flight based range finder that returns distance in mm. I am trying to implement a Kalman filter to get outlier-free estimation. The sensor measures the distance to the ground below ...
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Lidar data and map misaligned after rotation
I am working with the telepresence robot of the Ohmnilabs (here a picture of the robot). I setup the navigation stack and I tuned the parameters and everything worked fine for the map creation phase.
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Is there regulation of LiDAR in the public space?
Are there any regulations (in the US or the EU), plans to regulate or initiatives that think about the "pollution" with or amounts of laser emission in urban spaces in general and the impact ...
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How to deal with inexact pointcloud matching?
When running ICP(for example with SLAM) it's possible your next position does not have a point cloud which matches up with the prior point cloud due to resolution limits. How is this dealt with it? ...
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Dynamic mapping without localization in ROS
I have a /scan topic coming from a 2D lidar scanner.
The task is to receive a mapping of the dynamic environment. It is assumed that the position of the scanner is always known, so localization is not ...
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Custom sensors and materials simulation in Gazebo: how to simulate specific sensors behaviors for heterogenous materials / buildings
We are currently working on a simulation for a drone that would evolve in an urban environment. It would flight in front of facades and thus must avoid collision into walls, balconies, windows, etc. ...
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A short-range alternative to LiDAR
LiDAR is a very popular choice for long distance applications such as autonomous vehicles. I'm looking for a device that can give me a 3-dimensional representation of a close proximity environment (e....
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Merging multiple LIDARs real time
Is there a standard practice for merging the pointclouds generated by several LIDARs when there is overlap?
For example, if my vehicle has two LIDARS (front and back) I'd rather fuse and deal with a ...
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How to make a synchronized LiDAR/Camera rig for Autonomous Driving research?
I am just starting a research project at my university involving sensor fusion between a Camera and a LiDAR device to detect and localize cars around our vehicle (bounded boxes around cars in 3D point-...
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3D LiDAR synchronization with RGB Camera
There's a general procedure for estimating projection transformation between camera and 3d LiDAR but there's a secondary problem which is associating pixels with depths in a grid which isn't uniformly ...
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What is the most cost effective yet still reliable outdoor boundary system?
I am working on a robot that will operate outside in people's lawns in a predefined space. The issue that I am having right now is figuring out what kind of boundary system I should implement in order ...
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How do I identify the different wires on RPLidar?
I bought an RPLidar A1M8-R6 from the following site: https://www.dfrobot.com/product-1125.html?tracking=585c2ddea9c83
I am trying to connect RPLidar to Arduino so I could get information on the ...
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How does Lidar penetrate jungle canopy for archeological surveys?
I've read articles like these https://www.nationalgeographic.com/history/article/maya-laser-lidar-guatemala-pacunam and wanted to understand what's going on here. My understanding is the lidar would ...
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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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Reflective surface
Have you encountered the problem of reflective surfaces for realsense camera (d435 or t265) and lidar (A1 or A2). I would like to know what are the ways to solve problems with reflective surfaces for ...
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Vulnerability of LiDAR systems for autonomous drones
I will soon be working on an autonomous drone project and we're planning to use LIDAR systems for localization & mapping.
However, at the same time, we are looking into how to make drones safer ...
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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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does lidar sensor output data have spatial locality?
i have a question about the output of lidar sendor (like velodyne vlp-16, etc)
Is there any spatial or temporal locality for output data which is from lidar sensor?
Does the produced output data from ...
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LiDAR rig that scans within a projection window
I had an idea for a LiDAR scanner but am having trouble locking in the feasibility of it.
First of all - I know stereo matching would be way more efficient - this is more of a thought experiment at ...
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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 ...
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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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Is Lidar SLAM with only lidar sensor and no loop closure detection just a odometry?
I'm a newbee to SLAM. I have a question that in Lidar SLAM(including 2D lidar and 3D lidar), if I only use a single lidar without any other sensors like IMU and no loop closure in the mapping process, ...
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How to keep a sensor pointed downward
I am using LIDAR to measure a robot's altitude. The robot's orientation relative to the ground is dynamic; i.e. the XY plane tilts relative to the Z axis. I would like the LIDAR to remain pointed ...
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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 ...
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How to use data collect from lidar to generate a 2d map with
I'm new to robotics and I'm using ros noetic with the package rp_lidar. I want to use the data collected from my a1m8 slamteck lidar and generate a 2d map for my rover to navigate and avoid collision. ...
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Which scan matching algorithm can be used to extract the moving objects (in 2D lidar scanner)?
There are different types of scan matching algorithms to match consecutive 2D lidar scans, see https://youtu.be/nvFcN2-NqRc?t=421 (ICP, correlative matching, RANSAC). Most of the algorithms return the ...
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Res-Scaling method beats PID controller. How?
Scenario:
I have a robotic arm that has a (1D) lidar on its end, to orient itself with respect to the slant table in front of it. The lidar returns pretty accurate distance values in mm. The motor ...
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Is Kalman filter really desired here?
I am trying to use Kalman Filter in my project to eliminate outliers that go beyond certain limit.
I am use 1D lidar to get the distance between the robot and an object. I get pretty accurate values ...
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Not getting expected performance from kalman filter+mahalanobis distance
I am using a 1D lidar in one of my projects and it returns the distance it measures, in millimeters (mm). At some point in time, it gives garbage values that go as high as 10,000 or higher, when the ...
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What is the state-of-the-art approach to detect moving objects from mobile robot with 2D Lidar only?
Having a setup of a mobile robot with a 360° 2D lidar (1 plane). What is the current easiest approach to detect moving object with a high reliability from a moving robot? To make it simple, we ...
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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 ...
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ROS Laser Scan rotates with the robot in RVIZ
I am currently working on developing a ROS application for autonomous navigation using AMCl. I am first trying to get move_base to work before continuing with AMCL. ...
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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 ...
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Assistance in finding correct LIDAR for short-range object detection task [closed]
I am working on a task that involves finding a distance of a moving object going a static linear object, e.g a long pole. After trying some approaches (mostly involving stereo vision), I have come up ...
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