Holonomic drive messages

[dlan]

Hi,

I’m trying to do holonomic navigation in warehouse.

I replaced Kaya_REB instead of Carter_REB in “Warehouse Navigation with carter” sample.

added a lidar topic in Kaya_REB/base_link and added a REB_Lidar in Kaya_REB related to the lidar topic.

When play and create Application from Robot Engine Bridge, the lidar works and moves with the Kaya, then I ran the Isaac SDK part for holonomic navigation, the goal pose and path generated accordingly, but Kaya moved in wrong path.

screenshots:

I am not sure if it is the right steps to simulate holonomic navigation with Kaya.

1. I didn’t modify the Kaya model to attach a lidar on it, I just added a lidar topic and REB_lidar and it can detect obstacles.

2. Is that possible to check REB_HolonomicBase result? input/output messages? or the speed message that send from IsaacSDK and received by IsaacSim omniverse?

Appreciate for any helps!

[ltorabi]

Unfortunately, Kaya is not yet supported in Isaac Sim. Kaya’s holonomic drive base simulation scripts have not yet been implemented

[eliabntt94]

Hi @ltorabi any news on this?

[ltorabi]

Hi @eliabntt94 ,

We have this basic example with joystick for Kaya: https://docs.omniverse.nvidia.com/app_isaacsim/app_isaacsim/sample_kaya.html

Please see if this is helpful for you.

Kindly,
Liila

[eliabntt94]

Hey, thanks for the fast response.

I’ve seen that. But I was looking more at a ROS component (like ROS_DifferentialBase) or at a REB component so that I can control that through code.
I’ve seen the REB_holonomic base but it’s not clear to me if it is also omnidirectional. I’ve experimented a lot today so I have a bunch of question that maybe you can answer:

• Can I develop a custom ROS component to move my robot? smth like ROS_DifferentialBase but for my omnidirectional robot. If so is there any tip?
• Is the REB_HolonomicBase also usable in a omnidirectional way?
• Is it possible to send command to the REB_DifferentialBase (or any other component) through ros? For this I think I have to dig into rosbridge and the tutorials but I didn’t had time today ;)
• Maybe, you can also check my other question regarding the rendering layers for the camera if you have time

Much appreciated,
Elia

[Hammad_M]

One option is to do something like: How to set velocities of a mobile robot with /cmd_vel? - #4 by Hammad_M
along with the dynamic control extension to receive a custom ROS message in your extension, and then use set_articulation_dof_velocity_targets Dynamic Control [omni.isaac.dynamic_control] — isaac_sim 2022.1.1-release.1 documentation for the driven joints.

Note that the drive should be set up for velocity control similar to this example: https://docs.omniverse.nvidia.com/app_isaacsim/app_isaacsim/sample_ros_turtlebot.html#velocity-control-setup

This is the most general solution as you can use any standard ROS message to pass the data around and write a controller either on the ROS side, or inside isaac sim with full access to physics state information through dynamic control.

[eliabntt94]

Yeah, I’ve done something similar in Gazebo since I didn’t model all the rollers as you’ve done with kaya. The only difference is that I used three virtual joints in that case :) I’ve to understand better how to use the REB_holonomicbase and how to expose that through ros though since I think that should solve the problem since it seems that it’s omnidirectional.
BTW, as a suggestion, exposing that to ROS would be great. Also, would be nice if we could code plugins/custom components following a blueprint to give a bit more flexibility :)

[1365351984]

Have you succeeded? I’m also trying to navigate the complete controller.