Test MC_11 - Companion Computer (ROS 2 External Mode)

Objective

To test autonomous flight commanded from a companion computer using the PX4 ROS 2 Interface Library over the uXRCE-DDS or Zenoh bridge.

The test runs the library's go-to example, which registers an external flight mode named Go-to Example and flies a fixed triangular pattern (about 20 m x 30 m) relative to the position where the mode is engaged, at constant altitude. This exercises external mode registration, setpoint configuration, go-to setpoint streaming, and mode completion signalling across the bridge.

Preflight

Companion computer setup (once):

• Connect a companion computer to the flight controller and start the bridge:
  • uXRCE-DDS: run the micro XRCE-DDS agent on the companion computer, or
  • Zenoh: follow the ROS 2 Zenoh bring-up on the companion computer
• Set up a ROS 2 workspace on the companion computer with px4_msgs and the interface library, following steps 1 to 3 of PX4 ROS 2 Control Interface > Installation and First Test (skip the SITL steps). The go-to example is built as part of the workspace (package example_mode_goto_cpp).
• Use a recent QGroundControl (Daily), which supports dynamically updating the list of flight modes.

Before flight:

• Start the example on the companion computer:

  ros2 run example_mode_goto_cpp example_mode_goto

• Confirm the console shows the registration succeeding (Registering 'Go-to Example' followed by Got RegisterExtComponentReply)

• Confirm Go-to Example shows up in the QGC flight mode list

• Confirm the airspace is clear roughly 20 m north and 30 m east of the planned engage position (the pattern is flown from wherever the mode is engaged)

Flight Tests

❏ Mode registration

    ❏ With the vehicle disarmed, stop and restart the example node

    ❏ Go-to Example disappears from and reappears in the QGC mode list

❏ Go-to Example mode

    ❏ Arm and take off in Position mode, climb to a safe altitude (10 m or more)

    ❏ Select Go-to Example in QGC (mode must engage on first attempt, no rejection message)

    ❏ Vehicle settles at the engage position, then flies north facing the direction of travel

    ❏ Vehicle flies the east leg while spinning around yaw, slowing down as it approaches the corner

    ❏ Vehicle returns to the engage position with the heading fixed on the first corner

    ❏ On completion the vehicle holds position; switch back to Position or Hold mode

❏ Re-engagement

    ❏ Fly to a different location and engage Go-to Example again

    ❏ The same pattern is flown relative to the new engage position

❏ Companion loss failsafe

    ❏ Engage Go-to Example once more and stop the example node (Ctrl-C) mid-pattern

    ❏ Vehicle triggers a failsafe and switches to Hold; QGC shows a corresponding warning

❏ Land and disarm

Expected Results

• The external mode appears in QGC while the node is running and can be engaged on the first attempt
• Transitions into and out of the mode are smooth, with no twitches or setpoint jumps
• The triangular pattern is tracked accurately at constant altitude
• Stopping the node while the mode is active triggers a failsafe into Hold
• The log shows the pattern portion of the flight in the external mode (check in Flight Review)
• Attach the flight log and the example's console output to the test report