sen's profile - activity

Thanks Dornhege. I like your suggestions and I intend to follow the second suggestion. I will let you know how it turns out.

Hello,

I want to develop an application in Qt that can run nodes in ROS. I know one can run the CMakeList.txt of the package in Qt as per the necessary changes shown in http://answers.ros.org/question/12790/ros-qt-creator-gui/.

I already have a developed application that has the normal .pro files. The application has loads of other algorithm codes in it and I intend to integrate this application with some Qt code to run ROS nodes. But I can not understand how to do so, as the ROS package can be run using the CMakeList.txt. I may not have enough expertise on ROS+Qt, so any help will be highly appreciated.

Thanks, Sen

Just like you, I was new to ROS just 3 months ago. So my idea of "programming a robot" was to write codes that will run on a microcontroller (that pretty much runs everything from the motor control to the sensors and communication).

How I finally got my two wheel robot running using ROS:

1. The tutorials (the publishing/subscribing one that Dimitar pointed out was very useful)
2. Looking at the codes for turtlebotsim and turtlebot
3. Using the tutorials to see how the turtlebot codes are related (in particular what each node publishes, and which nodes subscribe to that topic)
4. The easiest was the 'cmd_vel' topic where you can see the result in both turtlebotsim and turtlebot (if you have it). So this was the starting point to get my own robot working.
5. With the turtlebot_teleop node/code already there, I started writing my own subscriber to printout what was on 'cmd_vel' while running the teleop program, and then progressing to pushing the 'cmd_vel' values out onto my robot motors.
6. Once I got the basic idea of how the nodes run separately, yet are connected through ROS topics, I progressed to writing publishers/subscribers for sensor data.

I think the crucial step for me while learning ROS was the understanding that there is no longer a need for a central brain/control to tell the robot to 'do this at this time'. Instead, each robot module (sensors, motors) would just do what they do best when they see something published. Eg. motors subscribe to a robot velocity command and convert that into wheel velocity; sensors just keep reading and publishing their readings, without the need to know what the readings are used for.

@All ... So after going through all the ROS tutorials on their Wiki, now I wrote my own package which can run the turtle in the turtlesim the way I want.

Having that, can anyone tell me how can such a code be translated into a real working robot.Like running real wheels on a robot(forward / backwards / turn).

Thanks a lot.

Sen

Thanks a lot Dimitar & Welin. I am going through those tutorials now.

Hi All,

I am new to ROS. I have been programming Pioneer and Coroware robots using Player for a while now. But now I have to venture into ROS.

I went through more or less the whole ROS tutorials on ROS-Wiki, but could not find any convincing place where it explains how to write an application in ROS to run a robot.

Any help will be highly appreciated.

Thanks, Sen