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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Assistance in finding correct LIDAR for short-range object detection task

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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718 views

How to get unix/posix time stamp in header of ROS msg?

I am using two sensors each connected to different machine (each machine separately runs Ubuntu 16.04 and ROS Kinetic). When I echo topic on these two machines, I ...
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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 initial guessing to LiDAR point cloud for ICP processing in Graph SLAM

I am currently in the process of implementing Graph SLAM using ICP and g2o in python 2.7 The data I have are pose data (4 x 4 transformation matrix) and lidar data ( in the format of [x y z 1] with ...
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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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1answer
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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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2answers
69 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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102 views

Sensor model and Inverse sensor model using occupancy grid mapping with lidar for particle filter

I'm a bit confused about how one goes about calculating the sensor model $p(z_t|x_t, m) $ and inverse sensor model for position $p(x_t |z_t,m_{t-1})$. From this answer, it seems like one way for ...
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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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38 views

LEGO-LOAM: Creating and Saving a Map

I have implemented LEGO-LOAM on my system. I have a velodyne VLP16 lidar. I am getting a display like this in the rviz window. I need help in creating and saving a map from this data. What should I do?...
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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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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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How to evaluate the location accuracy of a visual slam algorithm in an indoor enviorment without motion capture system?

I have a ground mobile robot with wheel for indoor applications and I want to develop a vSLAM algorithm for it. So one problem for me is how to know my modifications do really improve the performance ...
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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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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 ...
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Is it common for 3D LiDARs to require thermal management?

My team had a 3D LiDAR sponsored to us and we were expecting to be able to use it with no issues, but in the datasheet it specifies that performance can suffer once the temperature rises above 50C. ...
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Use Realsense camera to get the camera image

I have to use LIDAR in my project. I was searching for some LIDARs with a camera and came across the Intel RealSense d400 series. I know it has a camera but please suggest a way to use that camera ...
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How to obtain live vertical height values using LIDAR

I plan to control the flying height of my drone using a LIDAR (in real-time). Therefore, I would be attaching the LIDAR to my UAV, pointing vertically downwards. However, after looking at some of the ...
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1answer
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Usage of Falkolib(OpenSLAM) for 2D lidar landmark extraction

I am using Falkolib for landmark extraction in a 2D environment. Currently I am using the testKeypointOC executable from the bin directory. I have changed the testKeypointOC.cpp file and the ...
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Fusion multiple LaserScans to PointCloud

I am currently trying to do 3D SLAM with two 2D Lidars and possibly additional IMU in ROS. However, there seems to be no ROS package available to meet my needs. The closest one would be laser_pipeline ...
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RpLIDAR unable to see black objects

I am working on a ROSBOT for a natural navigation project. While working with RpLIDAR A2 version, I found that it does not sense thin black surfaces like black pants/trousers while at close range (...
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1answer
330 views

How to convert PointCloud2 message to a grid?

I'm using a Velodyne sensor which publishes on /velodyne_points topic, and its class type is PointCloud2. Now I want to convert ...
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1answer
94 views

LiDAR Point cloud data reliability/quality

I'm trying to develop a quality measurement (kind of a metric) for the reliability/quality of given point cloud data (coming ...
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1answer
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Hector SLAM in ROS with RPLidar

Trying to set up Hector SLAM with the RPLidar A2. I downloaded both rplidar_ros-master and hector_slam-catkin; extracted them ...
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939 views

Do I need a camera along with LIDAR for SLAM?

Equipment: Pi 3 B Mega 2x Encoder Motor 12VDC 299RPM MPU 6050 12V bat 2000mAh LIDAR or Kinect ? I want to implement EKF SLAM. I have referred bot NOX ROS wandering robot, Hussarian CORE and Robotics ...