Palletizing exercise: add SKU-based UR10 palletizing exercise

[Ashwani1330]

Summary

This PR adds the RoboticsInfrastructure side of a new SKU-based Palletizing exercise for RoboticsAcademy.

The exercise uses:

• Gazebo Harmonic
• ROS 2 Humble
• a UR10 arm with a simulated suction gripper
• MoveIt with OMPL and Pilz motion planning
• a moving conveyor with dynamically generated SKU boxes
• an online feeder lifecycle
• browser tools for Gazebo, RViz, and the console

Runtime architecture

Runtime ownership is intentionally separated:

Palletizing scene launcher
→ Gazebo, conveyor bridge, feeder, and /clock

UR10 suction launcher
→ robot, controllers, MoveIt, action servers, and planning scene

RAM tool orchestration
→ Gazebo GUI, RViz, and console browser tools

Main changes

Palletizing workcell

• Add the Gazebo Harmonic palletizing scene.
• Add conveyor and pallet models.
• Add the palletizing scene launcher.
• Add the browser RViz launcher.
• Add database mappings for:
  • world 81
  • scene 77
  • robot 34
  • world-robot row 58

SKU feeder

• Add configurable SMALL, MEDIUM, and LONG box SKUs.
• Add an 18-box mixed sequence.
• Dynamically generate box SDF files from task metadata.
• Track the active box through Gazebo Transport.
• Stop the conveyor using the observed pickup pose rather than only timing.
• Publish:
  • /box_ready
  • /box_info
  • /pallet_info
• Consume /box_done to advance the feeder.

UR10 suction robot

• Add the UR10 suction URDF/xacro.
• Add isolated controllers, joint limits, kinematics, SRDF, OMPL, and MoveIt controller configuration.
• Add Move/RobMove/RobPose action servers for group ur10_arm.
• Keep the robot launcher headless; browser RViz is owned by RAM tool orchestration.
• Generate one ros2_control system.

Suction attachment

• Extend gz_link_attacher with configurable:
  • robot model name
  • gripper link name
  • contact topic
• Preserve existing Pick and Place defaults when these parameters are absent.
• Resolve dynamically generated box model names from contact collision data.

Planning-scene reliability

Static conveyor and pallet collision objects are applied using MoveIt's acknowledged /apply_planning_scene service.

The scene node:

1. waits for MoveIt;
2. applies conveyor and pallet;
3. requires response.success;
4. exits normally after confirmation;
5. fails with a bounded timeout if MoveIt is unavailable.

Clock ownership

The Palletizing scene launcher is the single owner of the Gazebo-to-ROS /clock bridge.

Database integration note

This PR updates database/worlds.sql on the feature branch.

The official RoboticsAcademy application image uses Infrastructure humble-devel, while the official database image currently uses the separate RoboticsInfrastructure database branch.

Before release, the Palletizing world/scene/robot rows must also be synchronized into the database branch:

world 81
scene 77
robot 34
world-robot row 58

Please advise on the preferred database-branch update workflow.

Validation performed

Build and configuration

• custom_robots builds successfully with colcon.
• Palletizing Python/launch files parse successfully.
• The expanded UR10 suction xacro contains exactly one <ros2_control> element.
• Direct Python runtime dependencies are declared:
  • rclpy
  • moveit_msgs
  • shape_msgs

Native runtime

• Gazebo Harmonic world starts.
• UR10 spawns.
• Joint state broadcaster becomes active.
• Joint trajectory controller becomes active.
• Move/RobMove action servers become available.
• Feeder publishes box and pallet metadata.
• Suction attach/lift lifecycle works.

MoveIt planning scene

• /apply_planning_scene reports success.
• /get_planning_scene contains:
  • conveyor
  • pallet
• Scene node exits cleanly after successful application.
• Missing MoveIt service produces a bounded 30-second fatal error.

RoboticsAcademy browser integration

Using matching custom Academy/Infrastructure/database images:

• RAM 5.6.13 launches the gz scene.
• RAM launches the gz robot.
• Gazebo renders in the browser.
• RViz renders in the browser.
• Console tool starts.
• Browser reaches world_ready.
• Browser reaches tools_ready.
• One complete Palletizing box pick, lift, feeder acknowledgment, and pallet placement cycle succeeds.
• Existing Pick and Place default UR5/Robotiq attachment and lift path remains operational after the shared gz_link_attacher changes.

Follow-up work

• Feeder recovery logic is not yet implemented for box-spawn failures or boxes that fail to reach the pickup point.
• The MoveIt planning scene currently models the static conveyor and pallet; dynamic, carried, and placed boxes are not modeled yet.
• Reset and entity-cleanup behavior across repeated exercise runs needs additional validation and hardening.

Media

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