Queries about sensors in simulation

Question

Hi. I am a new user to ROS and have some questions regarding the use of sensors in simulation.

I undrstand that in order to simulate a sensors, you need to write the gazebo extension for it in the robot's URDF file My doubts are mainly about the elements in the gazebo's extension block.

First of all, am I right to said that the controllers are what that operate the sensors in gazebo? So do I need to install drivers for sensors at all?

To use the controller, you need to choose the correct plugins, but where do we download the plugins from? The sensor's wiki page?

Lastly, how do we know what to include in the elements within the element? So far what I did is just refer the code block from robots like turtlebot without understanding what each part is for.

I checked this website, but it is still work in process.

Thank you.Pardon me if my questions sounds amatuerish.

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Originally posted by ChengXiang on ROS Answers with karma: 201 on 2012-10-17

Post score: 2

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Original comments

Comment by SL Remy on 2012-10-17:
What type(s) of sensors are you interested in learning more about?

Comment by ChengXiang on 2012-10-17:
Hi. Right now I am trying to learn more about camera sensor. But as my project progress, I might also need to incorporate IMU and GPS.

Answer 1

The site is still being developed but keep your eye on the sensors page.

All the sensors that you've mentioned (camera, gps, imu) do already exist.

Some are provided by gazebo, and others are provided as plugins by the ROS community.

(gazebo "native" examples include include CameraSensor, ContactSensor, DepthCameraSensor, ImuSensor, RaySensor, RFIDSensor, RFIDTag) and check out Team Hector's ROS gazebo plugins.

An example of how they use their camera can be seen in quadrotor_with_cam.urdf.xacro.

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Originally posted by SL Remy with karma: 2022 on 2012-10-18

This answer was ACCEPTED on the original site

Post score: 2

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Original comments

Comment by ChengXiang on 2012-10-18:
Thanks trinighost. The team Hector's site answers my doubt on the XML's parameter. So I will not need to install sensors' drivers for simulation? Just the plugin will do?

Comment by SL Remy on 2012-10-18:
I think it's safe to consider a gazebo plugin as the equivalent of a sensor driver..

Comment by SL Remy on 2012-10-18:
And you will need to "install" (i.e. download/checkout/rosinstall then rosmake) the packages that have the plugins that you need.

Comment by ChengXiang on 2012-10-18:
I see. That is what I think too. Just that I wasn't too sure about that. Thanks for clarifying.

Comment by Johannes Meyer on 2012-10-19:
Note that the hector_gazebo stack is released since a couple of weeks at least for ROS fuerte, so you can simply run "sudo apt-get install ros-fuerte-hector-gazebo" to make the sensor plugins available.

Comment by ChengXiang on 2012-10-20:
I see. Thank you.