Co-simulation Simulink and Gazebo: Gazebo Custom Support block makes it very slow

Hello,

I have a trouble with the simulation speed of the Co-simulation between Simulink and Gazebo.

First of all, the simulation speed is close to the real-time without the Gazebo Custom Support block. However, I need to use this block to read the contact information.

Without the Gazebo Custom Support block: 1 sec simulation takes 3.5 sec (in real-time).

With the Gazebo Custom Support block: 1 sec simulation takes 15 sec (in real-time).

(sampling time = 0.01 sec)

Anyone has ideas or solutions to account for this issue?

Thanks!

Yun

Answer 1

[Gaurav Bhosale]

Hi Yunsik,

We are working on performance improvement. Further, as per our initial findings, if Gazebo and MATLAB/SImulink is running on same machine ( Ubuntu ) then we observed performance improvement. So, if you can install MATLAB on same Gazebo machine then you might get better performance.

Also, try with light version of Contact message. The Contact message has several fields but you might not required all fields, then you can create your own Contact customized message with only those required fields and subscribe that message with Gazebo Subscribe block.

Thanks.

[Yunsik Jung]

Hi, Gaurav. Thank you for reply.

Running them on same machine looks a better option for me. I will try it.

About creating a light version of contact message, can you let me know how to customize the contact message with specific fields only like the following?

contact.position.x

contact.position.y

contact.position.z

I am following the example for the .proto file to create Gazebo custom message as (from https://www.mathworks.com/help/robotics/ref/gazebogenmsg.html):

messageDefinition = {'message MyPose'
                     '{'
                     '   required double x = 1;'
                     '   required double y = 2;'
                     '   required double z = 3;'
                     '}'};
fileID = fopen(fullfile(folderPath,'MyPose.proto'),'w');
fprintf(fileID,'%s\n',messageDefinition{:});
fclose(fileID);

Can you let me know how to write the .proto file to create the customzied contact message with the three fields only?

Or please share any documentation or example related to this.

Thanks.

[Gaurav Bhosale]

Hi Yunsik,

You can create any .proto file or modify existing one. You can get more idea from google protobuf documnetation.

Further, the idea is to add field name, datatype based on your requiements.

e.g. In the above example, 'x', 'y' and 'z' are scalar ( mentioned with 'required' ) of type 'double'. Similary, if you want vector then you need to use 'repeated' instead of 'required'.

Thanks

[Yunsik Jung]

Thank you for the quick response!

I will check the documentation to get an idea who to do it.

Thanks! And I really hope you and your team get the improvement soon.

Thanks.