Grassinator1300 Senior Design Mid-Semester Design Presentation 2014

Julie White (Team Leader) WebsiteWebsite SensorsSensors Autonomous ImplementationAutonomous Implementation Glen Luker Remote Control ImplementationRemote Control Implementation Autonomous ImplementationAutonomous Implementation Hardware ImplementationHardware Implementation Grassinator1300 Team

Aaron Ray Power System DesignPower System Design Electrical Subsystem TestingElectrical Subsystem Testing CAD DesignCAD Design Perry Clark Hardware ImplementationHardware Implementation Hardware Components TestingHardware Components Testing Hardware DebuggingHardware Debugging Timothy Mange Lead DocumentationLead Documentation Electrical Subsystem DesignElectrical Subsystem Design Power System TestingPower System Testing

Faculty Advisor Dr. Raymond Winton

Overview System Overview Problem and Solution Technical and Practical Constraints Changes and Refinements Packaging Test Plan Future Goals

System Overview Power System Microcontroller Drive System Sensors Remote Control

Problem and Solution

Problem Current lawn mowers require prolonged physical labor and sun exposure. Riding mowers can create additional cleanup work because of their size. Push mowers do not create cleanup work but still require physical work and sun exposure.

Combine the usability of a riding mower with the size of a push mower, while further reducing the sun exposure with autonomous features. Solution

The Grassinator1300 intends to solve these problems by providing a small gas-powered push mower platform that is radio-controlled (RC). Use RC mode to record and execute movementsUse RC mode to record and execute movements Operate in autonomous modeOperate in autonomous mode Allow user to supervise from a nearby shady areaAllow user to supervise from a nearby shady area Limited physical labor.Limited physical labor. Solution

Technical and Practical Constraints

NameDescription Battery RequirementsThe Grassinator1300 must be powered by a 24 VDC battery supply. Obstacle DetectionObstacles must be detected at a minimum of 6-inch range. Remote ControlThe remote control must be able to communicate with transmitter up to 150 feet without any obstructions. Cutting HeightThe Grassinator1300 must have an adjustable cutting height between inches. Speed/ServosThe Grassinator1300 must be able to maintain a speed of about 3 MPH. Technical Constraints

Proper safety measures and shut off features should be implemented to keep people and animals safe. System will shutoff if: Microprocessor malfunctionsMicroprocessor malfunctions Motor stops workingMotor stops working Sensor failsSensor fails Practical Constraints Health & Safety

The Grassinator1300 will not be designed to work in stormy or inclement weather. Practical Constraints Environmental [1]

Changes and Refinements

Kill Switch Allows the microcontroller to control the blade motor PCB Relay Circuit (original design) Arduino could not supply enough current to activate. Time delay too large if power was lost. Relay Module(new) Integrated circuit Arduino compatible [2]

Battery Monitor Allows user to actively monitor the battery level. Voltage divider maps voltage into safe range. Keeps device from becoming unstable. [3]

SD Card Reader EEPROM onboard Arduino (Original) Limited memory Expensive Stored directly in memory SD card reader (New) Interchangeable memory cards Inexpensive Stored as a character in a file[4]

Arduino Uno to Arduino Mega Added features require more digital I/O pins Mega: 54 digital I/O pins Uno: 14 digital I/O pins Minimum code change requirements. [5]

Packaging

Schematic

PCB 3 inches 3.85 inches

PCB Enclosure

Packaging

Test Plan

PROJECTED TIMELINE DescriptionDate Order PCBASAP PCB Trace Testing3-28 PCB Population3-31 Overall System Test4-4 Projected Timeline

Test Plans part 1 The PCB will be trace tested and populated within a week of arrival from manufacturer Then PCB will be powered and checked for expected voltages Subsystems will then be tested using the PCB to ensure functionality

Test Plans part 2 Subsystems will be secured inside enclosure and constraints testing will begin on overall system. Field testing of entire system. Retesting of any corrections made due to failed tests.

Jan.Feb.MarchAprilMay PCB Design Prototype Refinement PCB Population/ Packaging Testing & Debugging Future Goals

[1] “How to Mow Now That it has Stopped Raining”, Purdue, Accessed: Sept. 28, has-stopped.htmlhttp://purdueturftips.blogspot.com/2013/04/how-to-mow-now-that-it- has-stopped.html [2] “Relay Module (Arduino compatible)”, DFRobot, Accessed: March 3, xUdt_ldXni xUdt_ldXni [3] “How Well Do Ipad Batteries Compare to Other Tablets? Ipads Smoke the Competition”, Iphone Hacks, Accessed: March 3, [4] “SD Card Reading Writing Module for Arduino”, DX, Accessed: March 3, [5] “Arduino Mega 2560”, Arduino, Accessed: March 3,

Grassinator1300 Senior Design Mid-Semester Design Presentation 2014