FRI 2.6

[matija9]

As per readme, please create branch for FRI version 2.6.

[mhubii]

hi @matija9 and thank you for creating this issue. Apologize the late response, I wasn't notified. Please do feel free to tag me! There is now a branch fri-2.6

[matija9]

Hi @mhubii thanks for the response and for opening the branch.
I have created pull request for it.

[mhubii]

I'll keep this open until this is added to tests etc

[matija9]

I have just now gotten to installing lbr_fri_ros2_stack with fri 2.6 and I get an error that file:
https://raw.githubusercontent.com/lbr-stack/lbr_fri_ros2_stack/rolling/lbr_fri_ros2_stack/repos-fri-${FRI_CLIENT_VERSION}.yaml rosdep install --from-paths src -i -r -y
is not found.
Should I then install lbr_fri_ros2_stack with some other version of fri and then build this new version after stack is installed or are there supposed to be some changes on the stack as well?

I didn't tag you so as not to disturb you during the holidays and there is no big rush with it.

[mhubii]

hi @matija9 and apologize the late response. Please do feel free to tag. Could you post your installation steps?

[matija9]

hi @mhubii, now i have to apologize for the late response.
I have tried to install lbr_fri_ros2_stack exactly like it is described in the documentation.

I had ros-dev-tools installed previously, then i tried running following set of commands:

source /opt/ros/humble/setup.bash
export FRI_CLIENT_VERSION=2.6
mkdir -p lbr-stack-26/src && cd lbr-stack-26
vcs import src --input https://raw.githubusercontent.com/lbr-stack/lbr_fri_ros2_stack/humble/lbr_fri_ros2_stack/repos-fri-${FRI_CLIENT_VERSION}.yaml
rosdep install --from-paths src -i -r -y

While executing these commands i get HTTP Error 404: Not Found and nothing gets downloaded. As i have seen there is not .yaml config file for this version, so i get that is the problem.

Then i have tried to manually clone all of the required repos, but when i tried building the workspace i got the error stating there s wrong version of FRI and that it expected version 1.15, but that was easily fixed by adjusting CMakeLists.

So now it have all been installed , but sadly my robot has some hardware issues so it will be a few weeks before i can test if it all works for real.

[mhubii]

hi @matija9, the issue is the following: The repos-fri-2.6.yaml does currently not exist (hence the error): https://github.com/lbr-stack/lbr_fri_ros2_stack/tree/rolling/lbr_fri_ros2_stack

Here are steps you can do manually:

1. Clone repositories

source /opt/ros/humble/setup.bash
export FRI_CLIENT_VERSION=1.15
mkdir -p lbr-stack-26/src && cd lbr-stack-26
vcs import src --input https://raw.githubusercontent.com/lbr-stack/lbr_fri_ros2_stack/humble/lbr_fri_ros2_stack/repos-fri-${FRI_CLIENT_VERSION}.yaml

2. Manually checkout

git --git-dir=src/fri/.git --work-tree=src/fri checkout fri-2.6

3. Install dependencies and build

rosdep install --from-paths src -i -r -y
colcon build --symlink-install

I hope this fixes your issue. If you could create a pull request that adds the repos-fri-2.6.yaml, that would be awesome! The pull request should be aimed at the rolling branch.

Please note that vcs is just a utility tool around git. vcs is quite popular in the ROS community as it lets you run several git commands in parallel / specify several repositories etc

[matija9]

@mhubii thanks for the response. I have managed to download and install everything, but as i mentioned in previous comment there was also a problem with CMakeLists.txt in fri repo where i got an error that provided SKD is not of right version which i have at first solved by commenting out that part. But after a bit of digging i saw that files in SDK list their version as 2.5. I have checked again but both my robot and my sunrise workbench are on version 2.6.
Do you think that maybe there were no changs in FRI between versions and KUKA just didn't bother to change version numbers within SKD client?
And again as I said robot I was working on has some issues and it will be at service for some time so it will be probably over a month before i can test 2.6 version.

And i can create a pull request for repos-fri-2.6.yaml, no problem. I will also try and fix CMakeLists.txt in fri to make it build without problems and make a pull request for that too.

[mhubii]

hi @matija9, yes, KUKA is a little sloppy with their versioning. As a client, it is hard to track what or whether something changed, that's why we decided to just treat the FRI SDK as a black box. If your files list 2.5, you are likely fine compiling using 2.5.

[mhubii]

Hi @matija9, sorry for the delay. I've now had the chance to have a look at the fri-2.6 branch. As you mentioned, the SDK mentions version 2.5, this is checked through a regular expression in the CMake file, see e.g.:

fri/CMakeLists.txt

Line 62 in 5811942

if (NOT FRI_CLIENT_VERSION STREQUAL "1.15")

You can quickly verify this through

git clone git@github.com:lbr-stack/fri.git -b fri-2.6 && \
cd fri && \
cmake -B build

This will throw

CMake Error at CMakeLists.txt:63 (message):
  Expected FRIClient version 1.15, found: 2.5

Since this is a client to the SDK, it might not be ideal to support KUKA's shortcoming here.

Let me know what you think. Maybe in your PR here lbr-stack/lbr_fri_ros2_stack#248, one may just point to fri-2.5 instead.

[matija9]

Hi @mhubii, in #36 i have changed that regular expression to look for version 2.5 so it can build properly. I know that is not the best solution but it works with KUKA's broken versioning.

one may just point to fri-2.5 instead.

You mean just use SDK from 2.5 for 2.6 as well? I am not that sure about it because there still could be some meaningful changes even tho version number in the file is same. I can test running the robot with "wrong" version of FRI. I can get back to you next week with the results.

Also i will try to get a hold of someone else with the robot running version 2.6 if i can to check if i maybe got a broken version of FRI on my robot.

[mhubii]

thanks for investigating all this! I just compared the contents of the zip files in fri-2.5 and fri-2.6 branch (just using git). They are exactly the same. It is pretty safe to say you can control the robot using the fri-2.5 branch just fine.

I agree that this is very confusing to users, and wonder how one could avoid the confusion.