Auto-Driven Vehicle By Jason Gajowski Nathan Schmarje 9/11/2003

Contents Project Description User Interface Component Description Progress Thus Far Remaining Work/Test Plan Power Usage System Costs Safety Issues Conclusion Questions

Project Description

Abstract –The objective of this project is to design and create an Auto-Driven Vehicle that will be able to navigate itself through an abstract highway system. The vehicle will be able to travel to predefined destinations, which will be preloaded into tables as sample routes (recipes). There will be a minimum of two destinations that the user will be able to select.

Abstract Operational Objectives –Travel Down a programmed route in a single- lane/two-way highway Stay On Path Make Turns Based on Location and Route –Make Left Turns, Right Turns, and Go Straight –Fork Left and Fork Right Make Stops –Stop at Traffic Light –Stop for Stop Sign –Arrive At Destination –Object Detection

User Interface

CommandBinary or String Equivalent Description ST010Instructs the vehicle to follow the path LT110Makes the vehicle take a left turn at an intersection RT011Makes the vehicle take a right turn at an intersection LF000Makes the vehicle fork to the left RF101Makes the vehicle fork to the right LD100Makes the vehicle do its final left turn, ending the recipe RD001Makes the vehicle do its final right turn, ending the recipe Note 1: Commands are based on road indicator sensor pattern, except for forks, which are not by, design (see Figure 2) Note 2: Leading zeros are left off the binary values

Device or CommandBinary StateDescription Power switches(s)0/1Simple power toggle off/on from 7.2V batteries regulated to 5V “Go” switch / “Restart/Reset” 0/1Push button to quickly strobe the “Restart/Reset” command to the MCU Route Select DIP switch package 0/1There are between 2 and 8 available routes to be selected by the user. The binary value selects a particular route and is captured by the MCU upon startup, and when the Reset/Restart switch is triggered. Red LED0/1Indicates an error while the vehicle was driving the path. Also used in conjunction with the yellow LED to indicate a recipe error. Yellow LED0/1Indicates an object was detected in the vehicle’s roadway path. Also lit in conjunction with the red LED to indicate a recipe syntax error. Green LED0/1Indicates the vehicle is ready to begin a new route. This LED is off the vehicle is currently traveling a route.

Component Description

Highway System –The roadway consists of reflective tape that will be laid wide enough to cover the chassis of the car but not the end of the 2 road detection sensors on the sides of the vehicle. –Road indicators consist of rectangular blocks of gaff tape that do not reflect the IR light

Vehicle Description –Dimensions – 17.5 x inches –Motor – 20 Turn DC Motor –Mechanical Speed Control Controlled by Servo Motor –Servo-Motor Drive System One Servo for Speed Control One Servo for Steering

Micro-Controller Description –Rabbitcore RCM2100 –Flash Memory – 512k –Static RAM – 512k –General Purpose I/0 34 –Power Supply – 4.75 ~ 5.25 VDC (140 mA) –Size – 2.0 x 3.5 x.8 inches (51 x 89 x 20 mm) –Clock Speed – 22.1 MHz –Programming Language – Dynamic C

PWM Characteristics –2 modules –2 servo motors – 5V at 500mA –555 Timer ~ 25.6kHz (39us) –Dual 4-bit binary counter (8-bits) ~ 100Hz (10ms) –2, dual 4-bit binary comparators –1.47uF Capacitor –1 1k potentiometer –2 sets of 8-bit binary inputs from micro- controller

Opto-Reflectors –Road Indicator + Path Detection Sensors

Object Detection Sensor –Sharp GP2D12 infrared ranger

ParameterSymbolRatingUnitRemark Operating Supply VoltageV CC 4.5 to 5.5V ParameterSymbolConditions Min. Typ. Max. Uni t Measuring distance range Delta L *1*110-80cm Output Terminal Voltage VOVO L = 80 cm * V Output voltage difference delta V O Output change at L change (80 cm -> 10 cm) * V Average supply currentI cc L = 80 cm, * 1, * mA

Red Light Sensor –TAOS TSLR257 red light photodiode

Progress Thus Far

Vehicle Obtained and Constructed Micro-controller Obtained and Familiarized Prototype Board Constructed and Tested Interface Designed and implemented Drive Control System Designed and Implemented (PWM Modules) Completed Sensor Scoping Completed Sensor Module Preliminary Map Constructed

Remaining Work/Test Plan

Code Design/Implementation (Block Sections) –Structural Layout of Code State Machine Implementation –Path Detection Get Vehicle to Drive Straight Stable –Road Indicator Detection Get vehicle to make all necessary turns –Destination Detection Get vehicle to successfully reach destination –Object Detection –Red Light Detection

Sensors –Final Physical Adjustment of sensors –Verify if road sensors work successfully with micro-controller –Verify Object Detection Sensors works successfully with micro-controller –Implement Red Light Fixture on vehicle –Test Red Light Sensors on vehicle with micro- controller

Map –Make adjustments to preliminary map –Complete circuitry for Red Light Signals

Power Usage

DC Motor –20W Nominal Micro-Controller –Power Supply – 4.75 ~ 5.25 VDC (140 mA) –.7 W Servo Motors –2 servo motors – 5V at 500mA –2.5 W Road Indicator Sensors –25mW Object Detector –165mW nominal –250mW max Red Light Sensor Array –30mW

System Costs

Vehicle - $198 Signal System - $13.60 Driving Area – $84 Miscellaneous – $52 Total - $347.60

Safety Issues

Batteries cannot be overcharged –3hr charge time –Must be fully discharged Small children and babies should NOT handle or play around vehicle

Conclusion

?Questions?