Control the base with the trajectory of MoveIt?

Question

Hi,

I am working with Iiwa(7 DoF) + Omnirob(Omnidirectional platform). My task is making them fullfill mobile manipulation tasks, this means making the platform and arm move synchronously for a certain task.

In order to plan the trajectory I am using moveit. For the planning of the platform trajectory we have two options:

1. Creating a P,P,R joints to define the movement of the platform. Each prismatic joint would refer to X and Y and the revolute would be the theta movement.

2. Define a virtual planar joint from base to /odom_combined.

In my case I used the {P,P,R} joints to plan the trajectory. So basically I am planning for 3(base) + 7(arm) joints group in Moveit.

Once the plan is done I would have a trajectory in {X,Y;Theta; T} for the base, and a similar one for the arm with each Joint.

My problem comes now.

As far as I know, there is no any controller for the base of the robot that allows you to provide a trajectory(vector of positions with time stamp), but only we can provide a path, as move_base does.

I wonder if anybody knows any controller for omnidirectional platforms in order to provide a trajectory created in moveit {X,Y,Theta,T}. In case not, whats the usual approach for omnidirectional mobile manipulators for synchronous base-arm manipulation?

Thanks alot!

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Originally posted by TheCamusean on ROS Answers with karma: 51 on 2018-03-08

Post score: 2

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Original comments

Comment by joaocabogon on 2018-07-17:
Can you please share your URDF? How do you relate the base with the 3 PPR joints?

Answer 1

Hi again,

I found an easy solution in the base of ROS.

Basically, I considered my base joints(PPR) as aregular joint and then use this information to send it to my specific robot through a custom Hardware Interface.

http://wiki.ros.org/hardware_interface

In my personal case, I based my HW interface in David Coleman's ros_control boilerplate. Here Github link:

https://github.com/davetcoleman/ros_control_boilerplate

I hope this could be useful for those people willing to do mobile manipulation.

Bye!

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Originally posted by TheCamusean with karma: 51 on 2018-04-11

This answer was ACCEPTED on the original site

Post score: 0