All Questions

Filter by
Sorted by
Tagged with
0 votes
1 answer
10 views

What is the difference between callback_group and callback_event when creating a publisher?

The documentation of the Node class defines the create_publisher function as follows: ...
user avatar
0 votes
1 answer
10 views

MoveIt collision checking: when is contact stored vs. not stored

(ROS version is Melodic) I'm using PlanningScene::checkCollision() to check for collisions, and noticed that when there are multiple collisions -- as in more than 1 ...
user avatar
0 votes
1 answer
5 views

how to creating fake Pose

Hello, I am trying to pubuilsh a fake pose in code. I checked the message rules and put the desired value and executed it, but the following error occurs in the subscriber. May i know what mistake i ...
user avatar
0 votes
1 answer
14 views

Understanding JointTrajectoryController of ros_control

Hi, currently, I am trying to understand how the hardware_interface and ros_control work: velocity_controllers/JointTrajectoryController is chosen for the ...
user avatar
0 votes
1 answer
4 views

Is there a ros1 package like demo_nodes_cpp from ros2?

I just need a simple talker/listener pair to use for demo purposes. Yes I could roll my own, but for testing connectivity a standard package is a little easier. Originally posted by rkent on ROS ...
user avatar
0 votes
0 answers
238 views

How to calculate the workspace of a five bar planar parallel robotic manipulator using MATLAB?

I am trying to calculate the workspace of a five bar planar parallel manipulator using MATLAB. Also, I am trying to plot the exact workspace as shown( kindly check the link). For this I guess I need ...
Nanase Tomoe's user avatar
0 votes
1 answer
18 views

LIDAR sensing backwards

Using RPLIDAR A1M8 on ROS2, navigation 2. I am getting very buggy and odd movement and then during SLAM testing I realized that it is detecting backwards. I put my hand in front of the robot/LIDAR and ...
user avatar
0 votes
1 answer
15 views

How to use --headless-rendering on Fortress

I ran this line, ign gazebo -r models/sdf/freenove_smart_car.sdf --headless-rendering and ...
Garrett Fogerlie's user avatar
0 votes
1 answer
21 views

KDL problem with cmake after complete removal

I have removed all the orocos-kdl files from ubuntu by sudo rm -rf $ (locate orocos-kdl), then I have followed the installation instructions and installed orocos-...
user avatar
0 votes
1 answer
7 views

ResizeNode subscribes and publishes camera info on the same topic

Seems like a dumb question, but I can't find the answer. I see that image_proc::ResizeNode subscribes to /camera_info, and then generates a new CameraInfo message with the scaled intrinsics. But it ...
Clyde McQueen's user avatar
0 votes
1 answer
151 views

How to install ROS2 on Ubuntu 20.04 with WSL?

Hello, I am running on windows 10 and I have installed Ubuntu 20.04 through the WSL environment. Now I want to install ROS2 on the Ubuntu. Which of the two processes should I follow? Install ROS2 for ...
user avatar
0 votes
1 answer
5 views

map / navigate on a different axis / plane

Hello everyone, first of all I would like to thank you for such a great forum, it has helped me solve many issues in the past! I have questions that could be caused by my luck of understanding how the ...
user avatar
0 votes
1 answer
10 views

PWM control (Rosbot 2.0)

Hi, I'd like to know how to control the PWM signal directly. The motor is controlled by cmd_vel by using ros node but how to control the PWM without cmd_vel msg? Originally posted by choking on ROS ...
user avatar
0 votes
1 answer
2 views

A nodelet is blocking another nodelet

Hi, I have a package which contains 2 nodelets and I want to run these 2 nodelets in the same manager. The problem is, I can only run 1 nodelets at a time, when I run both of them only the one which ...
user avatar
4 votes
1 answer
331 views

Does a stable library exist for docking robots using images?

I built a mobile base from scratch, and now I am focused on getting the robot to charge. The robot is using an on-board webcam (and PC) to detect a QR barcode on the charger unit. Using OpenCV I find ...
Mike's user avatar
  • 361
0 votes
0 answers
357 views

Outer Position Loop to Control Inner Velocity Loop

I'm trying to control the position of a brushless DC gearmotor. To drive the motor, I have a controller box that provides a velocity that is proportional to a 0 to 5 V input. The motor has it's own ...
bfris's user avatar
  • 109
0 votes
0 answers
11 views

Real-Time, App-Based Tool Tracking and Inventory Management System

For one of my classes, I need to create a sensor system that can connect with an app that will be able to track when specific tools leave a certain area. I do not know which sensor to implement that ...
Payton Aussin's user avatar
0 votes
1 answer
404 views

Derive the system's dynamics function and the Jacobian Matrix G of Extended Kalman Filter of a differential drive robot on a 2D plane

I have found the following answer on the system's dynamics function and what the Jacobian matrix G of the Extended Kalman Filter look like for a 2D robot with a differential drive. Taken from slides ...
Gabriele's user avatar
  • 163
0 votes
2 answers
120 views

moveit setup assistant not working

When i launch moveit setup assistant i receive the following error. ...
user avatar
0 votes
1 answer
15 views

ROS 2 (Foxy Fitzroy) Compatibility with Ubuntu 21.10

Will ros2 (Foxy Fitzroy) work on the latest version of Ubuntu (currently 21.10)? If not, will it be supported in the future? Should I install Ubuntu Focal Fossa (20.04) instead? Originally posted by ...
user avatar
0 votes
2 answers
4 views

Multiple Cmakelist.txt

I have a Cmakelist.txt that looks as follows in my project ...
user avatar
0 votes
1 answer
67 views

prevent teb_local_planner from getting stuck while turning around obstacle (carlike)

I am running teb_local_planner in simulation for a carlike robot. Quite often I see teb_local_planner getting stuck while trying to turn around an obstacle. I guess this is because during the path ...
user avatar
0 votes
1 answer
1 view

Way to modify messages in rostopic without tweaking stuffs in ros driver

This is an example sensor message from my robot topic (/base_imu/data): ...
user avatar
0 votes
1 answer
274 views

Remapping diff drive controller to cmd_vel

Hi! I'm looking to use nav2 with my current diff drive controller setup. My controller is currently subscribed to the /diff_drive_controller/cmd_vel_unstamped topic, while it appears nav is publishing ...
user avatar
0 votes
1 answer
117 views

Moveit2 Octomap Setup

I cannot figure out how to get an octomap to show up in moveit2. I can pass a sensors_3d.yaml as parameters to the move_group and without a transform from the camera to the robot and the move group ...
user avatar
0 votes
1 answer
48 views

Localization using IMU and LiDAR only

I am quite new to particle filters and other localization algorithms. For my project I am using an IMU and 2D LiDAR on a robot for indoor navigation. Is it possible to develop a new (or adapt existing ...
user avatar
0 votes
0 answers
107 views

Trajectory following of 3-wheel omnidirectional robot

I created a three-wheeled omnidirectional robot on omni-wheels, there is also a program in which I can plot a trajectory when plotting a trajectory, such data are obtained (X, Y, Tangent X, Tangent Y, ...
Flex1sh's user avatar
1 vote
1 answer
63 views

Dynamically-stable Motion Planning for Humanoid Robots

I was reading the classical robotics paper Dynamically-stable Motion Planning for Humanoid Robots and I don't understand why the two trees are swapped in line 7 of figure 5 (page 11). Seems like an ...
user30694's user avatar
1 vote
1 answer
429 views

How to calculate operating torque and holding torque of a slew drive for a manipulator arm?

Hope you are doing good and enjoying your weekend. I have a question regarding calculation of torque and tilting moment for a slew drive. Slew drive (motorised) will be used at the base of a ...
techno's user avatar
  • 11
0 votes
1 answer
18 views

Using xacro for robot description does not work

Hi, I defined a model using the urdf and everything works fine. However, when I replace one of the links with a macro, the link is not built to form the tree. the xacro file: links_joints.xacro` ...
user avatar
0 votes
1 answer
101 views

How much weight can this DC motor carry?

I'm trying to make a RC Car with a total weight around 1kg. It will be 4-wheel drive with differential drive algorithm. The count of motors will be 4 DC motors simply. I have chosen the following ...
Karnik Kanojia's user avatar
0 votes
1 answer
63 views

ROS2 Message generation in python package

Hi, I have a python package with multiple nodes and I need to send a message from one node to another. Currently the message type is ...
Darkproduct's user avatar
1 vote
1 answer
240 views

What is the noise in this PWM signal?

I'm in the process of calibrating servos while constructing a new hobbyist robot arm. When testing the base rotation servo I noticed some unexpected noise in the PWM signal while the servo is in ...
RowanP's user avatar
  • 339
0 votes
1 answer
8 views

How to use moveit! to push?

Hello, I wish to use moveit! to command a robot arm to push an object from its current location to another specified location. I'm new to moveit, but I imagine the task may be implemented by ...
user avatar
0 votes
1 answer
57 views

aruco_ros not detecting marker

Hello, I'm trying to detect a marker using aruco_ros. The launch code for the aruco_ros node: ...
user avatar
0 votes
1 answer
1 view

Starting a node twice, with differend parameters

Hallo , I want to start my node twice, but it shoud have differend parameter for my COM-Path. Here is my code: ...
user avatar
0 votes
1 answer
4 views

how to output the OpenCV image out of the callback function?

Hi, I am subscribing a videostream of compressed image and i knew how to convert it into OpenCV image and was able to show it already. But i want to output(like return value) the OpenCV image from the ...
user avatar
0 votes
1 answer
450 views

What does RR stand for in RR-manipulator?

I have memorized RR-manipulator as having 2 arms from Google images but "arm" isn't spelled with "R". I also noticed that RRR-manipulator has 3 links. Does R stand for revolute?
heretoinfinity's user avatar
0 votes
1 answer
13 views

ROS2 generating 'core' file on error, how to disable?

I'm running a simple talker/listener demo, using a Docker image based on ros:galactic-ros-core w/ros-galactic-desktop installed. I'm getting an error about half the time when I run the demo, but my ...
user avatar
0 votes
1 answer
157 views

Better Aruco detection

Hello, I'm using aruco detection to detect a marker at the back of a robot, I'm running simulations in Gazebo and checking the camera feed through Rviz. The problem I'm having is that the detection is ...
user avatar
0 votes
1 answer
5 views

The transition/difference between Citadel and Fortess

Hi there! I wanted to test my current file on Fortress but it seems that there's few ign syntax are not supported on Fortress from Citadel. Is there any doc about this? Originally posted by ...
Garrett Fogerlie's user avatar
0 votes
1 answer
1 view

Unable to publish a message to a predefined topic

Hello, My project is on Linux. I am having an issue with Publisher. I git clone a package in which a node called A1 has a topic named a1. I also installed another package in which a node called B2 has ...
user avatar
0 votes
1 answer
69 views

Convert Time Stamp from rosbag(Topic) to Understandable Format Y/M/D H:M:S

Hi someone would you know what the following TimeStamp means? and how to convert it to seconds or other understable format such year/month/day Hour:Minutes:Seconds? I have a car-robot that has driven ...
user avatar
1 vote
0 answers
43 views

Help prove the following identity (Jacobian)

I have encountered the following identity expression. Can please someone elaborate and explain how this equation is manipulated?
Vladislav Priziment's user avatar
0 votes
1 answer
17 views

ROS2 plugin does not load for clang-tidy

I have a MoveIt2 PR that creates a new plugin. It's working great except CI does not pass for galactic. Strangely, CI does pass for ...
AndyZe's user avatar
  • 853
0 votes
1 answer
49 views

rospy.Time.now() sometimes returns 0

Hello, I'm trying to run this code: ...
user avatar
0 votes
1 answer
25 views

teb_local_planner keeps selecting impossible trajectories for a carlike robot

I am testing teb_local_planner for a carlike vehicle. I am trying to make the robot park backward, for which I would expect the planner to turn in 2-3 times (as a human driver would). However the ...
user avatar
0 votes
1 answer
14 views

Global planner with curvature limit

Hi all, I'm looking for a global path planner (base_global_planner) with a feature of limiting the curvature (or turning radius) of the path. I found teb_local_planner which can configure the minimum ...
user avatar
0 votes
1 answer
232 views

Multiplication of rotation matrix help

I'm Watching Angela Sodemann video on 6DOF robots and am following her example, but I'm getting a different answer for my R3_6 matrix and I'm not sure where I'm going wrong. She uses this as her ...
Joe Jankowiak's user avatar
0 votes
1 answer
63 views

using asio in a ros2 package

I am looking for a sanity check on this idea from more experienced developers. ros2 is installed on an Nnvidia TX1 using a docker container of the ros galactic release. The container runs a c++ ros2 ...
user avatar

15 30 50 per page
1
97 98
99
100 101
906