Project One
Arduino Autonomous Rover Design
Project Objective
Design a rover with complete mechanical structure that able to navigate to a loading zone in a given maze, pick up a block and return to a random drop-off zone
Project Overview
The course MIE444 Mechatronics Principles stands out as one of the most demanding and memorable experiences during my university career. It revolved around a captivating design project, where a team of four individuals, including myself, was tasked with creating an Arduino autonomous rover capable of navigating a maze, detecting blocks within it, and transporting them to a designated location. In this project, I held the dual role of electrical engineer and project manager.
As the electrical engineer, my responsibilities encompassed configuring motors and sensors, collaborating closely with the mechanical engineer, and coordinating efforts with the algorithm engineer to ensure seamless integration of the rover's functionalities. Simultaneously, as the project manager, I oversaw the overall progress of the project, coordinated tasks, managed the design prototyping process, and maintained regular communication and updates with the teaching team.
While other groups in the course opted for the conventional approach of utilizing Omni wheels and individual DC motors for each wheel to achieve movement and turning, I sought to embrace a unique challenge by building something distinct — a rover that operated akin to a real car.
Our team aimed to construct a 3D-printed autonomous car with rear-wheel drive. To achieve this, I employed a stepper motor to power the rear axle, effectively driving both rear wheels simultaneously through a pair of dog bone drive shafts. Additionally, we mounted a servo motor at the front, connected to the front wheels through linkages, enabling them to steer up to 45 degrees. The incorporation of upper and lower suspension arms with independent suspensions connected the chassis to both the front and rear wheels, achieving an authentic car-like experience.
Challenge & Solution: Turning Issue
Upon completing the programming of the steering and driving systems, we proceeded to test our rover in the maze. We realized the size of the rover posed a significant challenge —every time we attempted a turn, it would collide with the corners due to under-steering. Moreover, during the obstacle avoidance test, it frequently collided with obstacles. Recognizing the difficulties in optimizing the turning algorithm, the team brainstormed alternative solutions that would enhance both the rover's maneuverability and its ability to navigate tight spaces.
After careful consideration, I conceived the idea of employing extra electrical components to address the turning issue and improve the rover's agility. Since mechanical modifications, such as reinforcing the steering linkage or using a more powerful servo motor, would certainly enhance the turning radius, but not to the extent we desired. I sought a solution that would allow the rover to execute sharp turns or even U-turns within extremely confined areas. With less than a week at hand to implement these changes, I delved into the design and integration process.
My concept centered around lifting the rover and enabling it to rotate directly around its center. To bring this idea to fruition, I carefully selected a pair of mini linear actuators as the lifting mechanism. These actuators possessed the ideal dimensions to fit within the existing chassis, and their lifting capacity of 90N proved more than sufficient for our intended application. Additionally, in collaboration with another servo motor, a turning plate was incorporated, enabling precise rotation. As the turning plate made contact with the floor, the rotational motion was effectively transferred to the rover. Through this ingenious modification, our rover achieved zero-radius turning with remarkable precision.
After
Before
Challenge & Solution: Voltage Requirement
Due to the distinct power requirements of the rover's components, such as the Stepper motor necessitating a 12V input and the servos requiring a 5V input, I took on the task of designing a power supply system capable of accommodating these variations. To achieve this, I implemented both a voltage regulator system and a current divider system to effectively differentiate the power supply into separate bands for 12V and 5V.
The voltage regulator system played a crucial role in maintaining a stable 12V output, ensuring the Stepper motor received the appropriate power it required for optimal performance. This system effectively regulated the voltage input, preventing fluctuations and safeguarding against potential damage to the motor.
Simultaneously, the current divider system managed the power supply for the servos, providing them with a steady 5V input. This system divided the available current among the servos, enabling them to function reliably without surpassing their specified voltage threshold.
By implementing these sophisticated power supply mechanisms, we successfully catered to the diverse energy requirements of the rover's components, ensuring each received the necessary voltage while maintaining stability and safeguarding against potential damage or malfunctions caused by incompatible power inputs.
Final Result
"I thought they would fail their project when I first saw their rover stuck in the corners, but they figured out a very creative and effective solution, being able to integrate everything in the end and showed a perfect performance."
— Professor Sinisa Colic, MIE444 Mechatronics Principles Instructor
Our team emerged victorious in the final contest, showcasing the remarkable capabilities of our rover. With flawless execution, it adeptly detected and retrieved the block, navigating through the maze with precision and avoiding any contact with obstacles. The successful drop-off of the block at the designated location further exemplified the rover's proficiency. Our impeccable performance earned us full marks for the project.
The experience of designing, building, and fine-tuning the rover not only showcased the practical application of the principles we learned but also fostered a deeper understanding of the intricate interplay between mechanical, electrical, and algorithmic components. This project served as a significant milestone, laying the groundwork for our future endeavors in the field of Mechatronics, fueling our passion for innovation, and igniting our curiosity to explore further possibilities.