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.
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. Structural components: metal braces, wheels, treads, and gears. Sensors: ultra sonic, line tracking, light sensors, bumper switches, and limit switches. Sensors: ultra sonic, line tracking, light sensors, bumper switches, and limit switches. Electrical components: motors, pneumatics, power packs, transmitters, and receivers. 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 end- point location.
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. Evaluate Design Weight Review
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 90 o 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 projects 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 DesignCostOperationTotal Moe 0.5940.6080.11.302 LS Navigator 0.4410.6080.21.249 Flying Wedge 0.2880.4950.20.983 DesignCost Hot Spot0.7350.75 Line Snoop0.5250.75 Maze Runner0.2950.5 Ease of construction Footprint Complexity of Mechanical and Electrical systems Programming complexity Additional base cart costs Additional sensor costs Number of tasks completed Ease of detection Requires prioritization Arena complexity Arena re-usability Difficulty of point location change Uses recycled parts Construction costs Value per dollar spent.
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 Generate prototype designs C-code template C-code template Testing Testing Arena specifications and design Arena specifications and design Instruction Manual outlining building design and tasks to be performed Instruction Manual outlining building design and tasks to be performed