Lenna Mobile Robot ONE

Lenna Autonomous Mobile Robot is designed for educational and research purposes. It is built upon a robust hardware architecture that combines an ARM-based embedded microcontroller and a Jetson Nano single-board computer (SBC) to provide both low-level and high-level control capabilities.

Lenna Mobile Robot ONE	LMRO Revised Model

Repository Structure

.
├── hardware/                # Design & implementation
│   ├── mechanics/           # CAD, 3D models, assembly instructions
│   └── electronics/         # Schematics, PCB layouts, wiring
│
├── software/
│   ├── embedded/            # Microcontroller code (C/C++)
│   └──  ros/                 # ROS packages, launch files, nodes
│
├── docs/
│   ├── user_manual/         # Setup, architecture, coding style
│   └── figures/             # Images, diagrams, plots
│
└── README.md                # Entry point, quick start

List of Contents

• System Overview
• Mechanical Design
• Electronics Design
• Control Architecture
• Plug and Play

System Overview

The current design is a differential-drive Wheeled Mobile Robot (WMR) that employs a two-layer hierarchical architecture consisting of a High-level Controller Board (HCB) and a Low-level Controller Board (LCB). The HCB, which is either an Nvidia Jetson Nano B01 or an Nvidia Jetson Orin Nano depending on the target ROS version, handles high-level processing, runs ROS, and interfaces with the Light Detection and Ranging (LiDAR) sensor. The LCB is a custom-designed microcontroller-based embedded board built, responsible for sensor interfacing and motor control. Communication between the two boards is established via Universal Asynchronous Receiver/Transmitter (UART) serial communication and a custom protocol.

LMRO Physical Architecture

Mechanical Design

In this work, a differential drive mobile robot was developed following the unicycle kinematic model, which is one of the most widely adopted models for wheeled robotic systems. The design process was carried out in SolidWorks, with an emphasis on modularity, simplicity, and ease of future expansion. The proposed robot architecture follows a three-level stacked structure, where each layer hosts a distinct set of components. This modular design allows rapid prototyping and straightforward replacement or modification of subsystems without interfering with the core mechanical or electrical functionalities.

LMRO Revised Model Exploded View and Components

Electronics Design

As mentioned earlier, the Lenna Robotics team has designed a custom PCB for the LCB, referred to as the Bardia Board. The complete design is available on the Lenna Robotics GitHub page, and the following sections provide details on the design choices, the considerations that shaped them, and the resulting component selection.

LMRO Low-level Controller Board

Control Architecture

As previously mentioned, this robot employs a distributed architecture. In this architecture, robot control is divided into two layers: the hardware control layer (LCB) and the robot control layer (HCB). The hardware control layer is responsible for reading and filtering sensor data as well as controlling the motor dynamics. In contrast, the robot control layer handles more complex computations and high-level decision-making. This hierarchical structure decouples the robot control from its governing dynamic equations and allows motion control to focus on kinematics at the velocity layer.

LMRO Hierarchical Control Architecture

Plug and Play

This section provides step-by-step procedures to create your own ROS workspace and run the nodes required to work with the Lenna Mobile Robot (LMRO).

Always source your ROS distribution:

source /opt/ros/<distro>/setup.bash

Create your ROS workspace and add the mentioned lenna packages to the /src directory:

mkdir -p ~/lenna_ws/src
cd ~/lenna_ws
catkin build

Source the compiled workspace:

source ~/lenna_ws/devel/setup.bash

Teleoperation

You can use the ROS package teleop_twist_keyboard to control LMRO using the lenna_teleop_keyboard launch file inside the lenna_bringup package:

roslaunch lenna_bringup lenna_teleop_keyboard.launch

SLAM

Both slam_toolbox and hector_slam can be used for LMRO:

roslaunch lenna_bringup lenna_slam_toolbox.launch

or

roslaunch lenna_bringup lenna_slam_hector.launch

Navigation

Using the lenna_navigation_stack launch file, you can use the ROS NavStack (move_base and amcl packages) to implement autonomous navigation:

roslaunch lenna_bringup lenna_navigation_stack.launch

Citation

If you use this code or build upon this work, please cite:

@INPROCEEDINGS{11213761,
  author={Riazati, Erfan and Hajizadeh, Arian and Esmaeilzadeh, Seyed Majid},
  booktitle={2025 33rd International Conference on Electrical Engineering (ICEE)}, 
  title={Design and Implementation of a Modular ROS-Based Mobile Robot with Hierarchical Control}, 
  year={2025},
  volume={},
  number={},
  pages={1038-1043},
  keywords={Visualization;Simultaneous localization and mapping;Navigation;Computer architecture;Real-time systems;Hardware;Mobile robots;Synchronization;Tuning;Testing;mobile robot;hierarchical control;distributed control;navigation;SLAM;ROS},
  doi={10.1109/ICEE67339.2025.11213761}}