Project Title: Integration and Simulation of Custom Mobile Manipulator in ROS 2 Jazzy Project Overview: I am developing a simulation for a custom aquatic/land hybrid robot using ROS 2 Jazzy and Gazebo Harmonic. I have the individual components (a custom chassis and a 6-DOF manipulator arm), but they are not yet functioning correctly as a unified system. I need a ROS 2 expert to properly integrate the manipulator onto the mobile base, fix kinematic/physics issues, and implement a reliable pick-and-place simulation. Technical Stack: OS: Ubuntu 24.04 (Noble) Middleware: ROS 2 Jazzy Jalisco Simulator: Gazebo Harmonic (gz-sim) Modeling: URDF/Xacro Control: ros2_control (DiffDrive, JointTrajectoryController) Planning: MoveIt 2 (optional but preferred) Current Project Status: Mobile Base: Custom CAD mesh (.stl) for the chassis is available. Configured with "Ghost Wheels" (collision spheres) and a Differential Drive plugin. Base successfully drives in Gazebo using teleop. Manipulator: URDF/Xacro files for a 6-DOF arm are available. Controllers (arm_controller, gripper_controller) are defined but need tuning. Current Integration State: A draft master Xacro file exists attempting to combine the Base and Arm. Issues: The arm moves in unexpected/odd ways, the physics interactions are unstable (arm sometimes collapses or jitters), and the pick-and-place logic is not accurate. Scope of Work (Freelancer Tasks): Proper Integration: Correctly mount the Manipulator onto the specific elevated deck of the Mobile Base in the URDF. Ensure the transform tree (TF) between base_link and the arm is correct. Physics & Kinematics Tuning: Fix inertial properties and collision geometries to prevent "exploding" or jittering in Gazebo. Tune joint limits and friction/damping so the arm moves smoothly and holds its position against gravity. Simulation Mission: Refine the Python mission script to spawn random objects. Implement a robust logic for the robot to drive to an object, pick it up (stable grasping), and place it securely on the robot's deck. Deliverables: A working, stable .urdf.xacro file for the combined Mobile Manipulator. A Python launch script that demonstrates the robot successfully picking up a spawned cube and placing it on the deck without physics errors.