First Year Robotics
Platform
By: Andria Farnham, Adam Selinger, Curtis Langley
Topics of Discussion
Introduction
The First Year Robotics Platform project involves the
development of a design project for first year ENGR 120
students involving a simple robot platform. The
platform will provide students with a starting point
and leave room for further expansion and students
input.
ENGR 120 Project Outline
Each group will be provided with a Vex Robotics Design
Kit which will be used in the design of a Robot to perform
a variety of outlined tasks which may include:
Vex Robotics
Design System
The Vex Robotics Design System is a robotic kit designed as an
introduction into the world of robotics. The system offers programming
in RobotC for simplified user interface, and comes with a number of
building parts and sensors including:
•
Structural components: metal braces, wheels, treads, and gears.
•
Sensors: ultra sonic, line tracking, light sensors, bumper switches, and
limit switches.
•
Electrical components: motors, pneumatics, power packs, transmitters,
and receivers.
ENGR 120 Project Motivation
This project is designed to give first year students exposure
to Electrical and Computer Engineering to give them a better
idea which area of Engineering they would like to major in.
Project Goals
Come up with a design for a robot cart that will be constructed
with VEX robotics pieces that students will be able to use with
provided sensors in order for the robot to locate a specific endpoint location.
Project Goals
• Robot should be able to perform 2 -3 different tasks
• Electronic complexity should not be too high, uses 1-2 sensors
• Mechanical complexity should be low, the cart should be easy to build and
fit within the provided tool box.
Project Goals
• Uses packed sensors provided to the students from the department
• Sensor should preferably be able to have a varying view independent
of cart movement
• New sensors that are not currently in department inventory can be
used in design
• Cart design should be able to be easily modified by the students in
order for project expansion
Project Goals
• All parts provided by the departments, no costs should be acquired
by students
• Reclaimed sensors can be used if the complexity of using them is not
too high
• Preferably no new VEX components should be acquired
• Sensors used should be quite low in cost
Project Overview
Considering all design criteria, each team
member independently generated 3 ideas for
the cart design and type of target-point
utilizing the 5-3-5 design method.
The list of initial designs were individually and
independently ranked by each team member
against the outlined design constraints and
project goals.
The individual team member rankings for the 9
cart and point-locater designs were combined
and averaged. The resulting averages were
ordered from lowest to highest with the top
ranking 3 being selected for further analysis.
Design
Review
Evaluate
Weight
Cart Designs
Design 1: “Moe”
• Modeled after standard VEX “Tumbler” Design.
• Four wheels, four drive motors:
• One per each wheel
• Fixed Front-Facing Sensor Array
Design 2 : “LS Navigator”
• Modeled after standard VEX “Tumbler” Design.
• Four wheels, three drive motors:
• One per front wheel
• Single rear-drive via differential
• Rotating Sensor Mount for 360° field of view
Design 3 : “Flying Wedge”
• Triangular shaped
• Three Wheels, one drive motor:
• Single rear drive via differential
• Single direction controlled front wheel.
• Rotating Sensor Mount for 360° field of view
Task Designs
Design 1: “Hot-Spot”
• Robot finds a definite point.
• Possible challenges:
• Radiation (Heat) source.
• Intersection of two lasers.
• Light intensity (high/low) detection.
Design 2: “Line Snooper”
• Robot tracks a solid colour line
• Possible challenges:
• Manages broken lines.
• Manages 90o turns.
• Determines correct path between varying shades of grey.
Design 3 : “Maze Runner”
• Robot Completes a non pre-defined maze.
• Possible Methods of attack:
• Trial and error (Try-Bump-Stop).
• Sonar.
Design Evaluation
A standard weighting scheme was generated through close analysis of the
proposed design goals and criteria. To further refine the weighting metrics, a Criteria
Prioritization Questionnaire was completed by the project’s acting supervisor: Dr. M.
McGuire.
Each of the top 3 designs for both the cart and task categories were then
individually and independently evaluated by each team member. These
independent evaluations were summed, averaged and had the appropriate category
weighting metric applied.
The final weighted rankings were compared with the highest being taken
as the design which best fits both the assumed and department defined project
goals and objectives.
Evaluation Results
Design
Cost
Operation
Total
Moe
0.594
0.608
0.1
1.302
LS
Navigator
0.441
0.608
0.2
1.249
Flying
Wedge
0.288
0.495
0.2
0.983
• Ease of detection
• Requires prioritization
• Arena complexity
• Arena re-usability
• Difficulty of point location
change
•Uses recycled parts
• Construction costs
• Value per dollar spent.
• Ease of construction
• Footprint
• Complexity of Mechanical and
Electrical systems
• Programming complexity
• Additional base cart costs
• Additional sensor costs
• Number of tasks completed
Design
Cost
Hot Spot
0.735
0.75
Line Snoop
0.525
0.75
Maze Runner
0.295
0.5
Final Cart Design
Modified version of the LS Navigator.
• Offers good balance between mechanical
electrical complexity and experience
• Moderate build time – Between 1 and 2
hours
• Zero additional VEX parts required for cart
construction
• Small form factor fits inside provided
equipment case
• Versatile design based off of an existing
standardized VEX robot.
Final Point of Interest
Design
Hot Spot Locator
• Low cost
• Simplistic design
• Offers a range of complexity
• Low costs associated with task changes
• Varying levels of system complexity available
Summary
Three leading designs were created for cart design and
point detection. Based on a weighting algorithm that
incorporated a number of aspects such as cost, feasibility,
and function, a final decision was made for cart design and
point detection method.
Future Works
(499 continuation)
• Generate prototype designs
• C-code template
• Testing
• Arena specifications and design
• Instruction Manual outlining building design and tasks to
be performed
?
Questions