Overview

Project Overview

This project focuses on developing an unmanned omnidirectional robot using a magnetically coupled ball drive (MCBD) to support the mobile remote presence robot (MRP) being developed by the ARGOS team. Our task is to refine the MCBD, a long-term project that has evolved over previous senior designs, aiming to create a functional prototype for applications like warehouse automation, manufacturing, and disaster response. With the MRP being integrated onto the unmanned ground vehicle (UGV) for the first time, new constraints and logistics need to be addressed.

MCBD Robot

As robotics advances, the demand for omnidirectional mobility increases in fields such as autonomous vehicles, healthcare, and supply chain processes. Conventional wheel designs often struggle with complex terrains and rapid direction changes. The MCBD offers true omnidirectional motion, enhancing maneuverability, adaptability, and efficiency compared to traditional solutions like mecanum or omni-wheels. By integrating magnetic coupling and terrain-adaptive suspension, the MCBD enables the MRP to navigate diverse environments smoothly.

Our Key Challenges

Developing the Magnetically Coupled Ball Drive (MCBD) system involves addressing key challenges in magnetic coupling, suspension design, holonomic movement, energy efficiency, and system cost and complexity. Overcoming these issues is essential to creating a functional prototype for the Mobile Remote Presence (MRP) robot.

Magnetic Coupling: The project aims to optimize magnetic coupling without using ferrofluids, ensuring reliable force transfer and minimizing wear. Real-time magnetic force adjustment is crucial for control, particularly on uneven terrain.
Suspension Design: The suspension must maintain ball contact, absorb shocks, and adapt to terrain changes, ensuring stability and smooth movement. Balancing load distribution and responsiveness is key for optimal performance.
Holonomic Movement: The system requires precise kinematic control for true omnidirectional movement. Accurate models and control algorithms are needed to prevent misalignment and ensure agility.
Energy Efficiency: The project must balance power consumption with performance. Effective power management will ensure sufficient torque and speed while conserving energy, critical for diverse applications like search and rescue.
Cost and Complexity: Material selection must align with budget constraints, and the integration of magnetic forces, suspension, and control systems adds complexity. Trade-offs between advanced materials and cost are carefully considered.
Iterative Prototyping and Testing: The project will focus on refining the MCBD through iterative prototyping, including material selection, magnetic calibration, and control algorithm integration to ensure reliable performance across various terrains.

Our Concept Design

Concept A

This concept uses an omni wheel drive system with a rubber x-hatch spherical wheel, optimizing for traction and control. The crown chassis design enhances flexibility and adaptability, ideal for navigation on various surfaces. Additionally, the four wheels provide extra support and power. This concept prioritizes grip and maneuverability in confined spaces or a complex terrain.

Concept B

This configuration combines the mecanum drive system with a wire core spherical wheel, resulting in a lightweight design. The box chassis provides stability and protects the inner components. This concept would be well-suited for environments requiring both stability and versatility, where a balance between weight and maneuverability is essential.

Concept C

Concept C focuses on an omni wheel drive paired with a durable cast ball spherical wheel for high-load scenarios. The crown chassis allows flexibility while maintaining a robust frame for heavier applications. This design could perform well in rugged environments or where heavier payloads need to be handled with precision.

Concept D

A mecanum wheel setup combined with a wire core spherical wheel and crown chassis aims for maximum versatility and agility. The wire core reduces weight while the mecanum wheels enable omnidirectional movement. The crown design adds flexibility, making this concept ideal for agile robots that need to traverse both confined spaces and open environments with varying terrain.

Concept E

Concept E introduces a robust and flexible system that combines omnidirectional movement with a durable and adaptable spherical wheel. The motor-powered omniwheel with rollers provides excellent maneuverability, while the cast ball ensures strength and the rubber covering enhances grip and performance on various terrains. The linear actuator adds a degree of precision control, allowing the robot to adjust its position dynamically, which is useful in environments where surface conditions change frequently or where the robot must navigate obstacles.

Why we chose Concept E?

After the concept selection process, Concept E was chosen as the final design, with supporting selection and matrix tables in the appendix. The team evaluated Concepts C, D, and E based on criteria like magnetic coupling force, center of mass, and maximum acceleration. Concept C scored 187, D scored 184, and E scored 215, making it the top choice.

Concept E’s selection was due to its superior magnetic coupling force, which is crucial for navigating obstacles, and its optimal center of mass for stability on uneven surfaces. It also excelled in maximum acceleration, grip, and maneuverability. Despite the competitiveness of Concepts C and D, Concept E’s advantages and highest score of 215 made it the best fit for the project’s goals.

How will we accomplish this?

Our goal is to optimize the MCBD system to enhance omnidirectional mobility, traction, energy efficiency, and versatility. The project follows a four-step approach:

Design: Develop a design that meets functional and performance criteria.
Prototype: Create a functional prototype using detailed drawings, part ordering, and custom 3D printing or laser cutting.
Testing Setup: Develop a testing setup to assess design effectiveness, including performance metrics and safety.
Evaluation: Test the prototype and conduct a performance evaluation, ensuring a structured flow from concept to a tested prototype while collaborating with other teams.

Page updated

Report abuse