Project Overview

1
Project Overview

• Dirt BOT
• Team Members Jeff Chalmers
• Jason Jellin
• Edward Aluede

2
Schedule

• Review of high-level schedule milestones

Phase 1
Phase 2
Phase 3
Phase 4
Sep
Oct
Nov
Dec
Jan
Feb
Mar
Apr
May
FOR MORE INFO...
Go to http//home.att.net/turbo.jeff/robot/timel
ine.xls
3
Schedule (cont.)

• Phase 3
• Modify mechanical design (as needed)
• Integrate Vacuum
• Acquire and assemble documentation

4
Hardware (cont.)

• DC Motor Controlling Unit

• H-Bridge Motor Controller
• Unit that will be used for the DirtBOT will
  control two DC motors
• Independent control of motor speeds using PWM
  embedded in software
• Input Voltage 5 Volts
• Output Voltage 3 Volts per motor
• Output Current 300mA continuous
• Power 500mW total per motor

5
Hardware (cont.)

• DC Motor Controlling Unit (cont)

• H-Bridge Motor Controller
• Bill of Materials
• Item Qty. Location Description
• 1 4 R1-4 Resistor, 1.3 kOhm, 1/4W, 5
• 2 8 D1-8 Signal Diode, 1N4148
• 3 8 Q1-4, Q9-12 Transistor, PN2907A, PNP
• 4 8 Q5-8, Q13-16 Transistor, PN2222A, NPN
• 5 1 J1 Header, Male, 0.100, 1 x 7
• 6 1 - PCB, Mini Dual H-Bridge

6
Hardware (cont.)

• DC Motor Controlling Unit (cont)

• PCB Layout

7
Hardware (cont.)

• DC Motor Controlling Unit (cont)

• H-Bridge Schematic

8
Hardware (cont.)

• DC Motor Controlling Unit (cont)

• H-Bridge Motor Connection

9
Hardware (cont.)

• Batteries - NiCd

• Typically can handle over 500 charging cycles
• Typical life of 5 years
• Battery Packs contain (7) 1.2 Volt Cells
  connected in series
• Total 8.4 Volt 1000mAh

10
Hardware (cont.)

• Batteries Charging System - NiCd

11
Hardware (cont.)

• Batteries Charging System - NiCd

• Theory When the battery cells are fully charged,
  current will drop to zero.
• Ich (Vo Vb) / R

12
Progress

• Completed
• Determined Key Hardware Components
• Obtained Hardware Components for Testing
• Debugged Certain Software Issues
• Issues/Problems
• Battery Charging Circuit
• Circuit to Limit Voltage/Current to Motors

13
Whats Next

• Sensors
• Dead Reckoning Positioning Sensors
• Mouse as Distance Sensor
• Wheel Encoder (Distance)
• Compass/Gyroscope (Theta)
• Software
• Develop Motor Speed Control
• Continue to Optimize Program
• Design
• More 3-D Modeling and 2-D Drawings
• Begin Building Prototype
• Determine Required Gear Ratio for Motor
• Design Electronics/Electrical