Digital I/O signal activation

[pala5]

Helo @mhubii.

I have a question that came up while using your packages (lbr_frI_ros2_stack and fri).
I have the LBR Iiwa 14 820R with the Sunrise.OS 1.16.1.9 (FRI 1.16), and I am working with Ubuntu 22.04 and ROS2 Humble distro.

We have installed an external digital I/O card, configurable from Sunrise.Workvisual, required to control some external devices.
I have seen, that in the FRIClientSDK, for the FRI 1.16 version, in the frilLBRCommand class, there is the function setDigitalIOValue, but I did not found this functionality in this package.

I am missing something or it was not considered?
Could you provide some help regarding this issue?

[mhubii]

Hi @pala5 , thanks for raising this issue. This is indeed missing right now

[pala5]

Hi @mhubii, are you planning to work on it soon?

[mhubii]

well this is an important feature that should be supported. How urgent is it on your end?

[pala5]

Well, I could say it is a matter of life and death.

[pala5]

Hey @mhubii!
Do you have time to work on that?
Thanks

[mhubii]

really occupied these days :(, I will give it a quick look tomorrow, hope this get you unstuck. Genuinely sorry

[pala5]

Hey @mhubii, do not worry! Thank you very much for your effort.

[pala5]

Hey @mhubii!
I don't want to be a bore, but do you have any update?
Thanks

[mhubii]

@mhubii Hello, in my previous work, I implemented the connection between the motorized spindle -Beckhoff- robot control cabinet, which enabled me to control the start and stop of the motorized spindle and the speed through the sunrise workbench. Start-stop is achieved by sending a digital signal of DC+24V, and the speed is achieved by sending a continuous DC 0-10V analog signal. Now I want to realize the control of ROS2 and motorized spindle through FRI-1.15, but I have no clue. Could you please give me some advice, so that I can understand how I should modify fri to achieve my goal?

Originally posted by @TalentLeshen-DLUT in #231 (comment)

I looked through the KUKA Fast Robot Interface C++ SDK (version 1.15), I think I can by setting

1. void KUKA: : FRI: : LBRCommand: : setBooleanIOValue (const char *, const bool),
2. void KUKA: : FRI: : LBRCommand: : setDigitalIOValue (const char , const unsigned long long),
3. void KUKA: : FRI: : LBRCommand: : setAnalogIOValue (const char , const double)

to make robot sent to receive ROS2 bool as well as the simulation, to control the start-stop of the motorized spindle and speed,
But I have no idea how to get ROS2 to send msgs.

Originally posted by @TalentLeshen-DLUT in #231 (comment)

[mhubii]

here is a list of things that would need to be done

• Add I/O to IDL messages: https://github.com/lbr-stack/lbr_fri_idl (this could be a starting point)
• Add I/O to lbr_fri_ros2: https://github.com/lbr-stack/lbr_fri_ros2_stack/tree/rolling/lbr_fri_ros2/src/interfaces
• Add I/O to lbr_ros2_control: https://github.com/lbr-stack/lbr_fri_ros2_stack/tree/rolling/lbr_ros2_control
• Add I/O to robot_description: https://github.com/lbr-stack/lbr_fri_ros2_stack/blob/rolling/lbr_description/ros2_control/lbr_system_interface.xacro
• Potentially modify the LBRServer.java

[TalentLeshen-DLUT]

@mhubii Hello, I have modified the project according to your method this week, you can see these changes in the fork below.
https://github.com/TalentLeshen-DLUT/lbr_fri_ros2_stack/tree/dev-humble-io
After I finished the modification, the project could be built with normal colcon, but when I connected the hardware, I found that I could not connect with it. I've tried for a long time, but I can't solve the problem. I think I need your help.

[mhubii]

hi @TalentLeshen-DLUT. Apologize the late response. Seems you've been putting quite some effort! I am back online now. Would you mind working this through together?

[TalentLeshen-DLUT]

@mhubii First let me wish you a belated Merry Christmas and a happy New Year. I can't imagine how happy I would be if I could get your help. I think I'd love for you to configure io with me. During your absence, I tried to modify lbr_fri_idl,lbr_fri_ros2 and lbr_ros2_control according to the method you gave. I created msg for analog io and digital io, and tried both modifying and creating analog_command files directly in position_command, which you can see in the following pages. (Correspondingly, I modified part of ros2_control)
https://github.com/TalentLeshen-DLUT/lbr_fri_ros2_stack/tree/dev-humble-io (In this project, I make changes directly in position_command,wrench_command, and torque_command)
https://github.com/TalentLeshen-DLUT/lbr_fri_ros2_stack/tree/dev-humble-io-2 (In this project, I created analog_command and modified digital_command)
In addition, I modified async_client, but the result is not satisfactory, they both have the same problem: miss state interfaces and miss command interfaces. I don't know what caused this problem, I guess it is that the hardware of lbr_bringup needs to be modified.

[TalentLeshen-DLUT]

@mhubii I'm sorry that the above may confuse you because I used machine translation and didn't check it. In fact, in Project 1, I tried to configure IO directly in the position,wrench, and torque commands. In Project 2, I tried to configure IO files (analog command and digital command) . But they ran into the same problem :miss state interface and miss command interface. I guess I need to change the hardware part of lbr bringup, but I'm not sure.