Need advices for a project with a robot arm

Question

Hi,

I start working with gazebo and ask you for some advices. I need to set up a simulation of a very simple robot arm trying to grab things around itself. The idea is to use this simulation to try some learning algorithm. (the task to learn is to grap things). This simulation must respect some rules:

• it must be computationally light (few degrees of freedom, no heavy rendering...)
• the code must be as simple as possible

These are the questions I faced this last month:

• Do I need to use ROS ? It sounds convenient for simulating a PID controller but I fear that I could not handle everything happening in the simulation if I use it.
• Is it possible to simulate a PID controller in Gazebo just using a Model or Joint Plugins ?
• Where can I find a good documentation about the physic engine (which might be ODE in my case) ? I often wonder where I can find the default parameters used by gazebo when I load a simple model.

I would be grateful if you could share your experience with me.

EDIT: Up to now I could build an arm and make it grab a box using PID in a controller. My question is pretty simple, if I had to use ROS for any reason, would be the implementation of this arm grabbing things very different ? What would be roughly the architecture of this project using ROS ?

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Originally posted by debz on Gazebo Answers with karma: 198 on 2015-08-17

Post score: 1

Answer 1

Hi,

I hope I can help with some information.

1. You don't need to use ROS to work with Gazebo or even for simulating a PID.

2. Yes, you can use a Model Plugin. Actually, they already have a plugin for this: https://bitbucket.org/osrf/gazebo/src/d5b03a8150fb0f730565bcc41fd9b916dd3e174c/gazebo/physics/JointController.cc?at=default

3. Here, http://sdformat.org/spec?elem=sdf , you can find information about the default parameters used in Gazebo. Maybe, you can check http://www.ode.org/ for more information about ODE engine.

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Originally posted by Eduardo Albuquerque with karma: 89 on 2015-08-17

This answer was ACCEPTED on the original site

Post score: 1

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Original comments

Comment by debz on 2015-08-17:
Wow your second link is great. It's simply amazing that after two weeks of research I could not find this. (I read many questions on this forum and no answer is linked with this JointController). I'll also check the ODE documentation. Thanks for your answer !

Comment by Eduardo Albuquerque on 2015-08-18:
Thanks hehe it took me a long time to discover the existence of this plugin too. It comes in handy! Hope it helps.