How do I enter a string into a ROS message in Simulink?

Question

Harry Parsons 2020-9-21

0
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此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/597328-how-do-i-enter-a-string-into-a-ros-message-in-simulink

回答： Josh Chen 2020-10-26

I'm attempting to send a path message to a ROS system. However, in order for this to be correctly published to RVIZ it requires a reference frame ID (FrameId in the header). I have attempted to complete this in multiple ways- First I attempted to enter a String Constant into a bus assignment block:

This has come up with the following error:

I then attempted in the shown matlab block to create a 128x1 uint8 array of the ASCII values of "odom", and blank characters (ASCII 32) making up the remaining 124 characters, using the following code:

frameid = zeros(128,1, 'uint8');

string = ['o', 'd', 'o', 'm'];

frameid(1:4) = uint8(string);

frameid(5:128) = 32;

frameid = uint8(frameid);

globalplannermessage.Header.FrameId = frameid;

This, however, simply ended up with RVIZ showing that the reference frame was blank (For frame []: Frame [] does not exist)

What is the recommended method to complete this?

This is my first question on here, so if I have missed any important information please let me know and I'll change whatever needs to be changed!