lightweight-cobot/doc/lwc-doc/docs/troubleshooting/open-issues.en.md

Open issues after workstation test

Recorded: 2026-09-15

1. cobot update error

On another computer, cobot update failed while installing Python libraries. The full output was not captured, so the cause is unknown. The next investigation needs the Python version, distribution/environment, and the complete log starting at the first error.

2. Drive knocking in the controller branch

While testing branch controller on the real KUKA iiwa, motion to known target points became jerky and the drives audibly knocked/struck internally. A beep was also heard at the end of the motion.

Observed conditions:

• motion to work, speed 0.1: knocking continued throughout the motion and a beep occurred at the end;
• motion to home, speed 0.5: drive knocking was also present;
• branch dev did not show knocking under these conditions; it appeared only rarely in earlier tests;
• earlier position plots showed isolated short-lived outliers after which the drive could not reach the target in time.

The issue may be related to the FRI/ros2_control implementation in controller. Investigation should check the seven-value position format and order, FRI timestamps and rate, COMMANDING_WAIT/COMMANDING_ACTIVE synchronization, rate limiting, and the source of short-lived outliers. Until investigated, repeat real-robot tests only with operator supervision and a ready emergency-stop procedure.

No fix is intentionally included in this record.