Tag Bot: A Robotic Game of Tag

Jonathan Rupe

Wai Yip Leung

Project Objectives

Simulate a game of one-way “tag” using two RC vehicles

User controlled target RC vehicle Self-Automated Seeker RC vehicle

Infinite games of “tag”

Project Description

Signal Detection accomplished by modulated IR Emitters and Detectors

Tag simulated by a predefined distance detected by IR Range Sensors

No obstacle avoidance If there is no signal detected, seeker vehicle

will run a predetermined search pattern

Design Specifications

Target will be able to be detected within 8 feet from the seeker vehicle

To tag the target, the seeker must be within 24cm of the target

Target RC Vehicle

User Controlled via RF Remote Control Circular array of 8 Modulated IR Emitter LED’s

Batteries

IR LED Emitters

Seeker RC Vehicle

360 degree stand-still turning achieved by 2 independently controlled motors

Seeker RC Vehicle

Circular Array of 8 IR LED Detectors 3 IR Range Detectors mounted in the front of the

vehicleIR range sensors

Circular array of 8 IR detectors

Front

rear

User Interface

Target RC Vehicle– On / Off power switch(es)– RF Remote Control

Seeker RC Vehicle– Self-Automated– On / Off power switch(es)– 3 status LED’s

User Interface – Seeker RC Vehicle

Status LED’s

Signal Present is “on” if the seeker has detected the presence of the target signal, “off” otherwise.

Tagged is “on” if the seeker vehicle has tagged the target vehicle, “off” otherwise.

ERROR is “on” if an error has occurred. (i.e. hit an object other than target). “Off” otherwise.

Signal Present Tagged ERROR

Analytical Components

IR Detector Sensors– 8 sensors, mounted equally around 3”- 4” diameter

tube– Will detect signal up to 8’ away– Non-modified detection beam width is ±60º

Will be shrunk down using tubing to obtain desired beam width based on testing

Analytical Components (cont’d)

IR Range Sensors– 3 mounted on front as shown in

an earlier slide– Detection distance of target or

object is 24 cm– Uses triangulation to detect

obstacle

Analytical Components (cont’d)

HC12 Microcontroller

PORTA PORTB PORTP

8 bitsIR Detectors

3 bitsIR Range Sensors

3 bits/5 bitsLED’s/Motors

Port Mapping

Analytical Components (cont’d)

PORTB Bit IR Range Sensor Mapping

B0 (LSB) IRR0B1 IRR1B2 IRR2B3 Not UsedB4 Not UsedB5 Not UsedB6 Not UsedB7 (MSB) Not Used

IR Range Sensor Mapping

Front

rear

0 12

PORTA Bit Mapping to IR Detector

A0 (LSB) IRD0A1 IRD1A2 IRD2A3 IRD3A4 IRD4A5 IRD5A6 IRD6A7 (MSB) IRD7

IR Detector Mapping

0

4

26

1

35

7

PORTP Bit MappingP0 (LSB) Status LED0P1 Status LED1P2 Status LED2

P3 H-bridge P1 & P9 (enable)

P4 H-bridge P2P5 H-bridge P7P6 H-bridge P15P7 (MSB) H-bridge P10

Output Port Mappings

Front

rear

HC12

Status LED0

Status LED1

Status LED2

Motor 1

Motor 2

Analytical Components (cont’d)

Seeker Vehicle Analysis– Speed of seeker vehicle will be adjusted to suitable

speed determined upon testing– Vehicle will continuously turn to ensure that the

signal is always detected from the front-most detector

Non-signal based turning will be done on a timed basis

Test Plan

Test each segment separately– Modulated IR emitter and detector circuits

Complete 360º emission of IR signal Proper directional detection of IR signal

– IR range sensors– DC motor control– HC12 code w/out sensors attached

Proper execution of search pattern

– HC12 code w/sensors attached Proper execution of search pattern & interaction w/sensors

Test Plan (cont’d)

Fully assembled testing of seeker and target vehicles– Non-mobile detection of IR signal from target

vehicle– Mobile detection of IR signal from target vehicle– Successful searching, tracking, and tagging of

target vehicle

Power Consumption

PartDissipation

Current (mA)Quantity

Total Current Dissipation (mA)

Power Consumption (W)

HC12 300 1 300 1.5IR LEDs 45 10 450 2.25IR Detectors 0.2 8 1.6 0.008IR Range Sensors 50 3 150 0.75DC Motors 300 2 600 3

7.508Total Power Consumption:

Division Of Work

Task Description Person AssignedCoding JonDC Motor Drive Circuitry & Testing JonModulated IR Emitter and Detector Assembly & Testing WaiIR Range Sensor Assembly & Testing WaiPower Circuitry Design, Construction, and Testing WaiWeb Site WaiSeeker RC sensor and hardware mounting BothTarget RC IR emitting beacon mounting BothProject Testing Both

Work Completed

Task Description % CompleteCoding 6.78%DC Motor Drive Circuitry & Testing 100%IR Range Sensor Assembly & Testing 50%Power Circuitry Design, Construction, and Testing 0%Web Site 2%Seeker RC sensor and hardware mounting 0%Target RC IR emitting beacon mounting 0%Final Project Testing 0%Modulated IR Emitter and Detector Assembly & Testing 90%

Work Completed (cont’d)

Modulated IR Emitter Circuit

Component Value/DescriptionU1 555 Timer ICR1 47 ohm resistorR2 470 ohm resistorR3 5k variable resistorC1 0.0047uf ceramic capacitorRLED 82 - 150 ohm resistor

Work Completed (cont’d)

Modulated IR Detector Test Circuit

Work Completed (cont’d)

IR Range Sensor Circuit

Work to be done

Complete IR emitter/detector sensor testing HC12 coding Web page IR range sensor mounting Vehicle construction and hardware mounting Project Testing

Total System Cost

Item Description Qty. Unit Price Actual Cost Our CostRC Car (Seeker) 1 $29.95 $29.95 $29.95RC Car (target) 1 $29.95 $29.95 $29.95HC12 Micro Controller 1 $159.00 $159.00 $0.00IR Range Sensors 3 $13.50 $40.50 $0.00IR LEDs 8 $0.26 $2.08 $2.08IR Receivers 8 $0.83 $6.64 $6.64Motor Batteries 2 $8.00 $16.00 $16.00Other Expenses N/A N/A $50.00 $50.00

$334.12 $134.62Total:

Potential Safety Problems

Stubbed toe

Questions?