ManyMove C++ Trees

This manymove_cpp_trees package is part of the manymove project for ROS 2 Humble. It offers a BehaviorTree.CPP-based framework for composing motion sequences, object manipulation, and I/O signal handling, using the action servers and messages defined throughout manymove packages.

Use at your own risk; this repository is experimental and does not provide safety features.

Overview

Key Functionalities

• BehaviorTree.CPP Integration
  Provides a set of custom BT nodes (planner, object manipulation, signals, etc.) that can be used to build modular robotic behaviors.

• MoveIt 2 & Action Server Bridges
  Easily plan and execute motions, manage collision objects, attach/detach objects, and send/receive I/O signals by leveraging the action servers in manymove_planner and manymove_object_manager.

• Reconfigurable at Runtime
  Much of the tree logic (target poses, velocities, attach operations, etc.) is dynamically drawn from the Blackboard, allowing for flexible updates without recompiling.

• HMI Service Node
  A dedicated node that exposes services for controlling behavior execution (start, stop, reset) and publishes Blackboard status.

Architecture

1. Behavior Tree Nodes
   • action_nodes_planner.hpp: Nodes for planning/executing manipulator motions (PlanningAction, ExecuteTrajectory, etc.).
   • action_nodes_objects.hpp: Nodes for adding/removing collision objects and checking or attaching them.
   • action_nodes_signals.hpp: Nodes for sending/reading digital I/O signals and checking robot state.
   • action_nodes_logic.hpp: Custom decorator/condition nodes for controlling execution flow (e.g., pausing, aborting, blackboard key checks).
2. bt_client_node
   • A reference implementation (in bt_client.cpp) that programmatically constructs a complex Behavior Tree.
   • Demonstrates combining the above custom BT nodes (e.g., for scanning the environment, picking/dropping objects, checking signals, etc.).
   • Uses a MultiThreadedExecutor to spin the tree logic in parallel with the HMI service node.
3. HMI Service Node
   • HMIServiceNode provides services to start/stop/reset execution.
   • Publishes execution status (e.g., stop_execution, reset, etc.) at a fixed interval.

Installation & Dependencies

Please refer to the main ManyMove README for overall setup instructions, build steps, and prerequisites.

Usage

Running the bt_client_node

The bt_client_node is an example node that programmatically creates a Behavior Tree:

ros2 run manymove_cpp_trees bt_client_node

Parameters (can be set via the command line or a launch file):

• robot_model (default: “lite6”)
• robot_prefix (default: “”)
• tcp_frame (default: “”)
• is_robot_real (default: false), determines if real I/O signals are used or mocked.

Defining Your Own Trees

• Include the desired node headers (action_nodes_*) in your custom .cpp.
• Register them with BehaviorTree.CPP (see tree_helper.hpp and action_nodes_planner.cpp for examples).
• Construct an XML tree (or build it programmatically) referencing these node types.
• Create a BT::Tree from the factory and tick it in a loop or an executor.

Example Features

• Motion Planning & Execution
  PlanningAction and ExecuteTrajectory nodes for MoveIt 2-based motion.

• Collision Object Management
  AddCollisionObjectAction, RemoveCollisionObjectAction, AttachDetachObjectAction, etc.

• I/O Signals & Robot State
  SetOutputAction, GetInputAction, CheckRobotStateAction, and so on.

Notes & Disclaimer

• Experimental: This package is under development; no warranty of stability.
• No Safety Features: Robot safety must be handled externally.
• Check Main README: For detailed disclaimers, licensing, and more information.

Contributing

Feedback and pull requests are welcome. If you discover any issues or have suggestions, please open an issue or PR in the main manymove repository.