Nereo Controller Node

This repository provides a ROS 2 node for controlling the Nereo underwater vehicle (ROV).
The node reuses core control logic from the nereo_firmware repository and acts as a "middleman" between ROS 2 and the low-level controller code.
This design allows you to work on and tune the controllers at runtime using ROS 2 parameters, without the need to recompile the firmware or restart the node.

Main Features

• Receives velocity commands (/nereo_cmd_vel_no_fb) and publishes controlled commands to /nereo_cmd_vel
• Sensor feedback: uses IMU data (/imu_data) and pressure sensor (/barometer_pressure)
• Automatic setpoints: maintains depth and orientation when no active commands are present
• Runtime parameters: all controller parameters (PID and CS) can be changed via the ROS 2 parameter server without recompiling
• Dynamic tuning support: controller gains and limits can be adjusted in real time
• Graphical tuner UI: desktop interface to read/write all controller parameters directly

Control Modes

• 0: DIRECT_PASSTHROUGH
  Commands are forwarded directly without feedback.
• 1: PID_CONTROL
  Uses PID controllers for depth, roll, pitch, and yaw.
• 2: PID_ANTI_WINDUP
  PID with anti-windup on integrators.
• 3: CS_CONTROLLER
  State-space controllers for depth, roll, and pitch; PID for yaw.

Main Parameters

• control_mode: selects the control mode (0-3)
• kp, ki, kd: PID gains (arrays)
• cs_kx0, cs_kx1, cs_kx2: state feedback gains for CS controller (heave, roll, pitch)
• cs_ki0, cs_ki1, cs_ki2: integral gains for CS controller
• cs_heave_min, cs_heave_max, cs_angle_min, cs_angle_max: saturation limits for CS controllers

Usage

1. Launch the node (see test_commands.md for examples)
2. Publish test data to /barometer_pressure, /imu_data, and /nereo_cmd_vel_no_fb
3. Change parameters at runtime using ros2 param set for dynamic tuning
4. Monitor output on /nereo_cmd_vel

PID Tuner GUI

You can tune all available parameters with a graphical interface.

• Launch controller + GUI together:

ros2 launch nereo_controller_node nereo_controller_with_gui.launch.py

• Or run GUI against an already-running node:

ros2 run nereo_controller_node pid_tuner_gui.py --ros-args -p target_node:=/nereo_controller_node

The GUI includes:

• control_mode selector
• kp, ki, kd arrays for depth/roll/pitch/yaw
• manual setpoint toggles and values for depth/roll/pitch/yaw
• full CS controller section: cs_kx0/1/2, cs_ki0/1/2, cs_heave_min/max, cs_angle_min/max

Notes

• The core control algorithms are reused from the nereo_firmware project.
• For test and command details, see test_commands.md.