ROS message filter

1. Reason In robot applications, the sensing frequency of sensors can rarely be consistent, For example, the odometer data can reach 50Hz, the image frequency can reach 30Hz, and the lidar data acquisition can reach 10Hz Then the time must be out of synchronization, and some fusion algorithms need to synchronize the sensor data before f ...

Posted on Sat, 04 Dec 2021 22:40:22 -0500 by provision

ros image processing correlation

1. image_transport ros specifies a variety of basic data structures for transmission between node s. Image is also a commonly used data, image_transport package is used to process image data transmission. It is a framework that only provides the most basic raw image data. If you need to reduce the bandwidth during transmission, you also need to ...

Posted on Sat, 04 Dec 2021 14:09:01 -0500 by stndrdsnz

ROS learning - write a simple Publisher and Subscriber

Write a Publisher node "Node" is a term for executable files in ROS, which is connected to the network of ROS. Here, we will create a Publisher node (talker) to continuously broadcast the message. First, switch to begin_ The location of the tutorials package. roscd beginner_tutorials Create an src folder to store the source code. ...

Posted on Tue, 16 Nov 2021 10:01:51 -0500 by surion

Multisensor splicing of 2D lidar

0. Introduction In order to ensure the 360 ° environmental coverage of the lidar, we often need to use multi-sensor splicing. If we simply take and read the information of the lidar, as shown in the figure below, the two lidars will overlap, which requires us to calibrate the lidar. <arg name="device_ip1" default="192.168.1.200" /> ...

Posted on Sat, 30 Oct 2021 21:44:36 -0400 by gingerboy101

ROS-3DSLAM: Radar Part AC analysis A

2021@SDUSC Tuesday, October 26, 2021 - Saturday, October 30, 2021 1, Program introduction: Through previous studies, I have mastered the information flow, structure and function of LVI Sam package, and also focused on the analysis of the feature extracted code. This week, I decided to learn the research results of other students in the group ...

Posted on Fri, 29 Oct 2021 21:43:02 -0400 by benny_g

ROS introduction topic communication learning notes

Reference link: Gu Yueju introduction to ROS lecture 21 Lecture 7 8 10 11 12 1. Topic communication 1.1 Topic - asynchronous communication mechanism An important bus used to transmit data between nodesUsing the publish / subscribe model, data is transmitted from the publisher to the subscriber. Subscribers or publishers of the same topi ...

Posted on Sun, 24 Oct 2021 15:36:00 -0400 by hubardz

Run through ORB-SLAM2 with opencv4.5.2 + melody + USB binocular camera

Run through ORB-SLAM2 with opencv4.5.2 + melody + USB binocular camera preface Getting started with SLAM requires basic hardware such as depth camera and lidar, but considering their own economic strength, they start with the following camera. The specific length of this camera is like this. I bought it on Taobao for 35 yuan to prac ...

Posted on Sun, 24 Oct 2021 03:56:15 -0400 by XxDeadmanxX

ROS learning: defining complex service message types and passing images

1 Introduction:   there are many blogs on the Internet about creating client and server and defining service data types, but the service data types are generally simple. When the service data types include complex data types, such as images and point clouds, there are few relevant introductions. This blog post describes in detail how to u ...

Posted on Wed, 06 Oct 2021 21:53:32 -0400 by kidbrax

About the two kinds of ROS Time that will appear in ROS

During the experiment, it is found that ROS actually counts two ROS times One is the simulation time: sim time, which should be calculated only when the program is startedOne is the system time: system time, which should match the system time Many people may not know much about these two times. It should be considered in many places. The syst ...

Posted on Sun, 19 Sep 2021 12:02:41 -0400 by jonah