Final project

An omnidirectional autonomous mobile robot will be developed, capable of detecting and avoiding obstacles. The system is designed to operate on solid, flat, and stable surfaces. Figure 1 presents the initial conceptual design of the autonomous mobile robot.

Main Design Sketch — Figure 1. Initial conceptual design of the omnidirectional autonomous mobile robot.

Background Idea

The motivation for this project arises from a strong personal interest in robotics, particularly in the field of space robotics. This work is conceived as an opportunity to consolidate fundamental knowledge in mechanics, electronics, and programming, as well as to apply these skills in the design and construction of a functional autonomous vehicle.

Sketch of the Final Project

The robot will be equipped with four mecanum wheels, which enable movement in any direction depending on the motion applied to each individual wheel. These wheels will be coupled to TT DC motors and complemented with sensor systems located on the lateral, frontal, and rear sections of the autonomous vehicle. Figure 2 shows the overall robot design with the main components integrated. Figure 3 presents a top view of the robot chassis, while Figure 4 illustrates an exploded view highlighting the central components of the system.

Finally, Figure 5 shows the operation of the robot's movement according to the type of motion imparted to its wheels. This information was obtained from Motion Dynamics.

Expected Challenges

One of the main challenges anticipated during the development of this project is the programming and electronic design of the robot. This is primarily due to the fact that my academic background is not directly focused on these areas, resulting in limited prior experience with the programming languages, development environments, and electronic architectures required for the system. Nevertheless, this project represents an ideal opportunity to acquire and strengthen skills that are not typically addressed within my field of study, contributing significantly to my professional development.

General Schedule of Activities for the Final Project

I wrote a general schedule of activities to organize myself better

Fablab Week	Main Tasks	Estimated Time
Week 1. Project management	Project description Creation of the Wheel of Achievements Establishment of the activity schedule Identification of fundamental concepts Conceptual sketching Identification of required project components Website design and programming	2-3 days
Week 2. Computer Aided Design	Design of the robot chassis using CAD software Design of required mechanical parts Design of sensor supports	2-3 days
Week 3. Computer Controlled Cutting	Cutting of the chassis and necessary components for robot assembly Implementation of adaptations if required	2-3 days
Week 4. Electronic Production	Design and fabrication of a PCB to integrate the ESP32 microcontroller, sensor module sockets, and motor connectors	3-5 days
Week 5. 3D Scanning and printing	3D printing of an adjustable support for the MQ-135 sensor 3D printing of a PCB enclosure	2-3 days
Week 6. Embedded Programming	Development of a basic motion control program including motor control, sensor data acquisition, and obstacle avoidance logic	3-5 days
Week 7. Computer Controlled Machining	Refinement of mechanical components and chassis	3-4 days
Week 8. Electronics Design	Development of a basic electronic schematic PCB design including additional protections and status LEDs	3-4 days
Week 9. Output Devices	Motor control implementation	2-3 days
Week 10. Mechanical Design	Design of a basic drivetrain system Definition of guides for rapid assembly Implementation of active or passive ventilation	2-3 days
Week 11. Input Devices	Integration of sensor systems Functional testing and validation of sensor operation	3-4 days
Week 12. Molding and Casting	Fabrication of a basic protective enclosure	3-4 days
Week 13. Embedded Nettworking and Communications	Establishment of basic WiFi communication	4-5 days
Week 14. Interface and Application Programming	Development of a web-based interface	4-5 days

Preliminary Bill of Materials

Componente	Quantity	Cost (MXN)	Application
TT DC Motor	4	$59	Robot locomotion
L298N H-Bridge Motor Driver	1	$90	Control of motor speed and rotation direction
Rotary Encoders	4	$43	Controlled measurement of vehicle motion
ESP32 DevKit V1	1	$124	Main microcontroller
HC-SR04 Ultrasonic Sensor	3	$53	Obstacle detection
LM7805 Voltage Regulator	1	$48	Voltage regulation for motors and sensors
AMS1117-3.3 Voltage Regulator	1	$12	Voltage regulation for sensors
Male/Female Headers	1 set	$350	Electrical connections
Dupont Cables (MM, MF, FF)	Various	$59	Electrical connections
Rechargeable Battery (2500 mAh)	2	$189	Power supply
Power Switch	1	$29	System power on/off
Double-sided Copper Board	10x10cm	$392	PCB fabrication
SMD Resistors 0805	Various	$0.24	PCB components
SMD Capacitors 0805	Various	$129	PCB components

Future Work

Based on the initial design, a potential project extension is proposed, focused on the development of a gas-mapping robot operating within a controlled environment. This extension is conceived as an enhancement and expansion of the base system, with potential applications in environmental monitoring and the analysis of current real-world problems.

Design for the Gas-Mapping Robot

The gas-mapping robot will be based on the initial autonomous vehicle design, with modifications to integrate additional sensors and functionalities. The main components of the system will include:

Chassis: Adapted to accommodate additional sensors and ensure stability during operation.
Microcontroller: ESP32 or similar, capable of handling multiple sensor inputs and data processing.
Sensors: Integration of gas sensors such as MQ-135 (smoke), SGP30 (CO₂/VOCs), and DHT22 (temperature and humidity) for comprehensive environmental monitoring.
Data Storage: Implementation of local data storage using an SD card module, with potential WiFi connectivity for real-time data transmission.
Power Supply: Enhanced battery system to support additional components and ensure extended operation time.

Schedule for Future Work: Robot Upgrade to Gas-Mapping System

Fablab Week	Main Tasks	Estimated Time
Week 1. Project management	Definition of project extension proposal	1 day
Week 2. Computer Aided Design	Design of a chassis with modular slots for adding or removing components	2-3 days
Week 3. Computer Controlled Cutting	Exploration of alternative materials such as MDF and acrylic Design of a logo or project name on structural materials	1-2 days
Week 4. Electronic Production	Design and fabrication of a PCB integrating the ESP32 microcontroller, power regulators, and RGB status LEDs	4-5 days
Week 5. 3D Scanning and printing	Design and printing of TPU shock absorbers and a sealed enclosure	2-3 days
Week 6. Embedded Programming	Implementation of an exploration algorithm Programming of integrated sensor data acquisition Data storage programming in CSV format via SD card or WiFi	5-6 days
Week 7. Computer Controlled Machining	Milling of an aluminum base plate for structural support, weight distribution, and heat dissipation	2-3 days
Week 8. Electronics Design	Design of a circuit including battery backup port, overvoltage protection, and real-time power consumption monitoring	4-6 days
Week 9. Output Devices	Implementation of a telemetry system using an OLED display to show battery level, operating mode, and system status	3-5 days
Week 10. Mechanical Design	Improvement of the traction system using high-grip wheels Implementation of a self-leveling mechanism	3-5 days
Week 11. Input Devices	Integration of MQ-135 (smoke), SGP30 (CO₂/VOCs), and DHT22 (temperature and humidity) sensors Data collection through a training mode in which the robot navigates a defined space to generate a dataset	3-5 days
Week 12. Molding and Casting	Fabrication of protective enclosures for components	2-5 days
Week 13. Embedded Nettworking and Communications	Creation of a local SD card backup database Transfer of datasets to a PC for offline processing	3-7 days
Week 14. Interface and Application Programming	Development of a 3D heat map Dashboard creation with real-time graphs Prediction of areas with high smoke concentration within 5 to 10 minutes Display of model confidence	4-5 days

Bill of Materials for Future Work

Componente	Quantity	Cost (MXN)	Application
MQ-135 Gas Sensor	1	$53	Gas and smoke detection
SGP30 Sensor	1	$199	CO2 and VOC detection
DHT22 Sensor	1	$135	Temperature and humidity measurement
SD Card Module	1	$49	Local data storage
OLED Display 0.96”	3*	$103	Visualization of robot data
Motor Rotary Encoders	2*	$165	Estimation of traveled distance
SD Card Reader Module	1	$245	Local data storage
MicroSD Card 16 GB	1 set	$57	Data storage
Acrylic Sheets	Various	$91	Enclosure for controlled environment

Spiral development

As previously discussed, this autonomous mobile robot presents multiple opportunities for future improvement and expansion. Based on this perspective, a Spiral Development is proposed as a visual tool to outline potential milestones and long term development goals, assuming the successful completion of the core project objectives.