ECE 485: Electrical ECE 485: Electrical Engineering Design I Engineering Design I

ProjectProjectBy Group 2: Joel Marcia,By Group 2: Joel Marcia,

Paul Rosensteel,Paul Rosensteel,Scott Laminack,Scott Laminack,

and Justin Lanhamand Justin Lanham

Overview: The ProblemOverview: The Problem

To design and implement the hardware To design and implement the hardware and software to control the Trekker and software to control the Trekker Robot in three competitions:Robot in three competitions:

1.1. Go around outside loop 3 times.Go around outside loop 3 times.2.2. Go around outside loop at least once, Go around outside loop at least once,

then take the inside loop twice.then take the inside loop twice.3.3. Evade an obstacle on the track and Evade an obstacle on the track and

follow the guidelines from competition 2.follow the guidelines from competition 2.

Overview: SpecificationsOverview: Specifications

OOPic R with a OOPic R with a L7806 – 6V L7806 – 6V Voltage Regulator Voltage Regulator (TO220 Package) (TO220 Package)

OOPic R OOPic R Expansion BoardExpansion Board

Pictures from http://www.superdroidrobots.com/shop/category.asp?catid=25

Overview: SpecificationsOverview: Specifications

A Sharp A Sharp GP2D12 IR GP2D12 IR SensorSensor

A Devantech A Devantech SRF04 SRF04 Ultrasonic Ultrasonic RangerRanger

IR1.Value vs. Dy = 6.1979x - 1.1019

R2 = 0.9984

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IR1.

Valu

e

IR1.Value vs D

Linear (IR1.Value vs D)

U2.Value vs D

y = 5.2785x + 12.763

R2 = 0.9996

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Overview: SpecificationsOverview: Specifications

4 QRB1134 4 QRB1134 Phototransistors Phototransistors with mounting with mounting bracketbracket

2 HiTec HS-422 2 HiTec HS-422 servos to control servos to control the wheels the wheels

1 HiTec HS-311 1 HiTec HS-311 servo to control servo to control the ranger or IR the ranger or IR sensorsensor

Pictures from http://www.superdroidrobots.com/shop/category.asp?catid=25

Optimizing Software andOptimizing Software andAlgorithmsAlgorithms

Game PlanGame Plan

No “If … Then” statementsNo “If … Then” statements Might be easier getting stated, but more Might be easier getting stated, but more

work in the long runwork in the long run

Use object codes to create a virtual Use object codes to create a virtual circuitcircuit Simplify the codeSimplify the code Easier to debugEasier to debug Changes are easier to makeChanges are easier to make

Key Object Codes UsedKey Object Codes Used

oServoSP1 oServoSP1

oTrackeroTracker

oNavConoNavCon

oCompare2oCompare2

oServoSP1oServoSP1 Designed to control servos or to interface Designed to control servos or to interface

servos with different objectsservos with different objects

Specifically used with hacked servosSpecifically used with hacked servos

Supports URCP values (positive and negative Supports URCP values (positive and negative values)values)

Unique property – set Value property to 0, no Unique property – set Value property to 0, no pulses are sent to the servo (wheels stop pulses are sent to the servo (wheels stop completely)completely)

*Key Points using *Key Points using oServoSP1oServoSP1

Set the left servo Set the left servo InvertOutInvertOut property property to “1” – sets wheels turning in the to “1” – sets wheels turning in the same directionsame direction

Set Set RefreshRefresh property to “1” – doubles property to “1” – doubles the pulses sent to servos (increases the pulses sent to servos (increases torque)torque) Tested using o’scope: 36.2 Hz to 73.53 Tested using o’scope: 36.2 Hz to 73.53

HzHz

oTrackeroTracker Designed to use digital sensor inputs Designed to use digital sensor inputs

(line followers) to determine the (line followers) to determine the location of a black line on a white location of a black line on a white backgroundbackground

Formats URCP readings to express how Formats URCP readings to express how much it needs turn much it needs turn Range of values +/-8, +/-16, +/-24, +/-32Range of values +/-8, +/-16, +/-24, +/-32

Maximum of four sensor inputs Maximum of four sensor inputs

*Key Points using oTracker*Key Points using oTracker

Setting the Setting the WidthWidth property to “1” property to “1” allows the use of only three sensors allows the use of only three sensors Range of values Range of values +/-8, +/-24, +/-32 (no +/-8, +/-24, +/-32 (no

+/-16)+/-16) The fourth sensor was used to detect The fourth sensor was used to detect

the “inner circle” with an oEventthe “inner circle” with an oEvent

oNavConoNavCon

Coverts the information received from Coverts the information received from oTracker into motor control speed for the oTracker into motor control speed for the servosservos

Takes the predetermined “Speed” value then Takes the predetermined “Speed” value then adds or subtracts the values received from adds or subtracts the values received from oTracker (URCP values) and send them to the oTracker (URCP values) and send them to the servosservos

*Key Point using oNavCon*Key Point using oNavCon

Set oNavCon to ”0” to turn off the Set oNavCon to ”0” to turn off the line following subroutineline following subroutine This allowed us to turn off or override This allowed us to turn off or override

the line following subroutine to make the line following subroutine to make adjustments for a special “event” adjustments for a special “event”

oCompare2oCompare2

Used with the sonar sensorUsed with the sonar sensor

Triggered depending on distanceTriggered depending on distance

Compares two numbers Compares two numbers (predetermined upper and lower (predetermined upper and lower limits) and sets the servo speed limits) and sets the servo speed values to follow a along a wall or go values to follow a along a wall or go around a “box”around a “box”

Basic Flow DiagramBasic Flow Diagram

Line following(oTracker)

oNavCon

Inner Circle(oEvent)

Go around box(oCompare2)

oNavCon on

Wheels(oServoSP1)

oNavCon off

oNavCon off

Competitions 1 & 2Competitions 1 & 2

Round #1 of Line Round #1 of Line Following CompetitionFollowing Competition

Objective: To complete three laps Objective: To complete three laps around the black line track where around the black line track where one lap must be around the outer one lap must be around the outer

loop of the track.loop of the track.

The Line Following SensorsThe Line Following Sensors

The Line Following CircuitThe Line Following Circuit The circuit for an individual line-followerThe circuit for an individual line-follower

• Pull-Up Resistor = 10 kPull-Up Resistor = 10 k• Rf Resistor = 220 Rf Resistor = 220 • Line follower Capacitor = 0.1 Line follower Capacitor = 0.1 FF

Complete Line Following CircuitComplete Line Following Circuit

The Line Following Printed Circuit The Line Following Printed Circuit BoardBoard

Capacitors Used in Line Following Capacitors Used in Line Following Circuit BoardCircuit Board

We found documentation explaining We found documentation explaining how capacitors could be included in how capacitors could be included in the line following circuit to reduce the line following circuit to reduce noise that the line followers may pick noise that the line followers may pick up.up.

The capacitors are connected to the The capacitors are connected to the line followers in hopes of leveling out line followers in hopes of leveling out the ripple in the signal out.the ripple in the signal out.

No Significant DifferenceNo Significant Difference We tested the Trekker with, and without We tested the Trekker with, and without

the capacitors in the circuitthe capacitors in the circuit No significant difference was found.No significant difference was found. Therefore we chose to remove the Therefore we chose to remove the

capacitors from the line following circuit capacitors from the line following circuit board.board.

Our design of the circuit board made Our design of the circuit board made removal of the capacitors easy, as they removal of the capacitors easy, as they were connected from behind using free were connected from behind using free wireswires

These wires were cut, electronically These wires were cut, electronically removing the capacitors from the circuitremoving the capacitors from the circuit

Direction of Travel Around the Direction of Travel Around the TrackTrack

Servo Values S4 and S5Servo Values S4 and S5

The coded values of S4 and S5 refer The coded values of S4 and S5 refer to server rotational speedsto server rotational speeds

S4’s value directly corresponds with S4’s value directly corresponds with the Right Wheel’s rotational speedthe Right Wheel’s rotational speed

S5’s value directly corresponds with S5’s value directly corresponds with the Left Wheel’s rotational speedthe Left Wheel’s rotational speed

Finding the center of the servos Finding the center of the servos rotational speed valuesrotational speed values

From Trekker Experiment #3From Trekker Experiment #3 S4 and S5 relationship with the rotational S4 and S5 relationship with the rotational

speed of the wheel was foundspeed of the wheel was found

Wheel Speed vs. SX.Value

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Left and Right Wheel Speeds are Left and Right Wheel Speeds are not the samenot the same

Wheel Speed vs. SX.Value

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Reversal of Direction Reversal of Direction

Because the left servo and the right Because the left servo and the right servo are opposite of each other, servo are opposite of each other, they each travel in opposite they each travel in opposite directions relative to one anotherdirections relative to one another

To remedy this, one of the servo’s To remedy this, one of the servo’s values is invertedvalues is inverted

Now both wheels will move the Now both wheels will move the Trekker forward at the same time.Trekker forward at the same time.

First Competition Program Works!!First Competition Program Works!!

The initial line following program was The initial line following program was uploaded to the OOPic R.uploaded to the OOPic R.

The Trekker successfully went The Trekker successfully went around the outer loop of the trackaround the outer loop of the track

First run around the track was very First run around the track was very slowslow

Improvements to ProgramImprovements to Program

Had to find a good value for the servo Had to find a good value for the servo speedsspeeds• Not too slow, or the Trekker would take too Not too slow, or the Trekker would take too

long around the turns. It would have a very long around the turns. It would have a very “jerky” stop and go manuever.“jerky” stop and go manuever.

• Not too fast, or the Trekker would leave the Not too fast, or the Trekker would leave the black line on the turns and not return.black line on the turns and not return.

A speed value of 31 was found to be the A speed value of 31 was found to be the best for what we neededbest for what we needed

Number of Line Following SensorsNumber of Line Following Sensors

The more line following sensors employed The more line following sensors employed in the design, the faster the Trekker in the design, the faster the Trekker should be able to traverse the courseshould be able to traverse the course

Using Four SensorsUsing Four Sensors• Time around track = 1 min 6 secTime around track = 1 min 6 sec

Using Three SensorsUsing Three Sensors• Time around track = 1 min 5 secTime around track = 1 min 5 sec

Three sensors are used in the final design Three sensors are used in the final design of the Line Following programof the Line Following program

Three Outer Loops, no Inner LoopsThree Outer Loops, no Inner Loops

Our Trekker made it successfully Our Trekker made it successfully around the outer loop of the track around the outer loop of the track three times.three times.

No inner loop attempt was madeNo inner loop attempt was made

Round #1 Line Following Round #1 Line Following Competition ResultsCompetition Results

Best time around the track:Best time around the track:• 01:00.75 01:00.75

Competition Ranking:Competition Ranking:• 44thth Place overall Place overall• 8 Points awarded8 Points awarded

Round #2 of Line Following Round #2 of Line Following CompetitionCompetition

Competition Objectives:Competition Objectives: To complete three laps around the black To complete three laps around the black

line trackline track One lap around track must be upon the One lap around track must be upon the

outside loopoutside loop

Group Objectives:Group Objectives: To complete two laps around the inner To complete two laps around the inner

loop of the trackloop of the track Make a better time around the track three Make a better time around the track three

times than in Round #1 of the Line times than in Round #1 of the Line Following Competition Following Competition

Line Following and Inner Track Line Following and Inner Track SensorsSensors

Line Following SensorsLine Following Sensors• Three used, as were used in the Round Three used, as were used in the Round

#1 of the competition#1 of the competition Inner Track SensorsInner Track Sensors

• One was used away from the three Line One was used away from the three Line Following SensorsFollowing Sensors

Direction of Travel and Inner Loop Direction of Travel and Inner Loop Sensor PlacementSensor Placement

Direction of Direction of Travel around Travel around tracktrack• ClockwiseClockwise

Placement of Placement of Inner Loops Inner Loops SensorSensor• On the left side of On the left side of

the Trekker when the Trekker when facing the Trekker facing the Trekker front first.front first.

Line Following and Inner Loop Line Following and Inner Loop Sensor PlacementSensor Placement

Outer Loop BehaviorOuter Loop Behavior

For the first lap, the Inner Loop For the first lap, the Inner Loop Sensor will record each time it Sensor will record each time it passes over the inner loop.passes over the inner loop.

Inner Loop BehaviorInner Loop Behavior

After the first lap, and the inner sensors After the first lap, and the inner sensors having noted the inner loop twice.having noted the inner loop twice.• Every time the inner loop sensor notices a Every time the inner loop sensor notices a

black line the Trekker will turn to the right, and black line the Trekker will turn to the right, and take the Inner Loop around until it finds the take the Inner Loop around until it finds the opposite side of the track on the Outer Loopopposite side of the track on the Outer Loop

Testing and ImprovementsTesting and Improvements

We needed to make the Trekker We needed to make the Trekker have smoother turns around the have smoother turns around the corners of both the outer and inner corners of both the outer and inner loops of the trackloops of the track• This was done by changing the coded This was done by changing the coded

values for the right servo’s center, the values for the right servo’s center, the left servo’s center, the oNav.Center, the left servo’s center, the oNav.Center, the LeftServo.Value, the RightServo.Value, LeftServo.Value, the RightServo.Value, and the overall speed of the Trekkerand the overall speed of the Trekker

Results of Testing and Round #2 of Results of Testing and Round #2 of the Line Following Competitionthe Line Following Competition

Round #2 Line Following Round #2 Line Following Competition ResultsCompetition Results

Best time around Best time around track:track:• 0:50.510:50.51

Competition Competition Ranking:Ranking:• 33rdrd Place Overall Place Overall• 18 Points Awarded18 Points Awarded

Competition 3Competition 3

Round #3 of Line Following Round #3 of Line Following CompetitionCompetition

A familiar problem:A familiar problem: Recognize Inner Recognize Inner

Loop Loop Recognize Tool BoxRecognize Tool Box Line Follow: once Line Follow: once

outer Loop, and outer Loop, and twice inner Looptwice inner Loop

Oh, and navigate Oh, and navigate at most 8.5 inches at most 8.5 inches from Tool Boxfrom Tool Box

Tool Box Solution Tool Box Solution

Hardware:Hardware: Devantech SRF04 Devantech SRF04

Ultrasonic Range Ultrasonic Range Finder Finder

HiTec HS-311 HiTec HS-311 ServoServo

Objects to utilize Objects to utilize hardware:hardware:

oSonarDVoSonarDV oServoSP1oServoSP1 oCompare2: oCompare2:

Properties Properties (Above, Below and (Above, Below and Between) Between)

The Set UpThe Set Up

11stst oCompare2.Input set oCompare2.Input set to oSonar.Valueto oSonar.Value

22ndnd ReferenceIn1 set to ReferenceIn1 set to Lower oSonar.Value = Lower oSonar.Value = 53 and ReferenceIn2 53 and ReferenceIn2 set to Upper set to Upper oSonar.Value = 58oSonar.Value = 58

33rdrd Allow oCompare to Allow oCompare to call Sub Routines to call Sub Routines to maintain 8.5 inches maintain 8.5 inches from tool boxfrom tool box

SonarSonar

Operation of Sonar Operation of Sonar device device

Maximize sample Maximize sample rate. How? (Link rate. How? (Link Sonar.Operate to Sonar.Operate to OOPIC.HZ60)OOPIC.HZ60)

SRF04 TimingSRF04 Timing

Need to toggle at a rate that sonar needs to monitorNeed to toggle at a rate that sonar needs to monitor

SRF04 GraphSRF04 GraphVE(t) vs D

y = 0.144x + 0.1348

R2 = 0.9988

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Function of Sub RoutinesFunction of Sub Routines

We had Four Sub Routines:We had Four Sub Routines: Flag Inner – Used differently than previous Flag Inner – Used differently than previous

competitions.competitions. Above - Servo control to turn left.Above - Servo control to turn left. Below – Servo control to turn right.Below – Servo control to turn right. Between – Servo control to go StraightBetween – Servo control to go Straight Note: Each Sub controlled operation of Note: Each Sub controlled operation of

oNavcon oNavcon

Competition DayCompetition Day

What Happened? A) What Happened? A) Failed to detect object consistently B) Failed to detect object consistently B) When oCompare operated, Sonar Servo When oCompare operated, Sonar Servo lost sight of object and Our Left Turn Sub lost sight of object and Our Left Turn Sub routine was called.routine was called.

Possible Solution:Possible Solution: A) First Right Turn was a hard turn, we A) First Right Turn was a hard turn, we

needed a set up sub routine and a means needed a set up sub routine and a means to return to line follower. to return to line follower.

B) Improve Sonar Performance.B) Improve Sonar Performance.

Overall ResultsOverall Results

Completed two of Completed two of the three the three competitions.competitions.

Placed 2Placed 2ndnd in the in the class overall.class overall.

Project was a Project was a success overallsuccess overall

ConclusionsConclusions

What we learned:What we learned: The importance of working as a The importance of working as a

team.team. Using indicators in a circuit to help Using indicators in a circuit to help

with troubleshooting.with troubleshooting. Integration of external devices with Integration of external devices with

a microcontroller.a microcontroller. Data sheets are helpful in design Data sheets are helpful in design

and implementation.and implementation.

Conclusions ContinuedConclusions Continued

What we learned:What we learned: How an infrared sensor, a sonar How an infrared sensor, a sonar

sensor, and optical sensor work.sensor, and optical sensor work. Utilization of these devices to Utilization of these devices to

accomplish an objective.accomplish an objective.

ReferencesReferences

““OOPic Manual.” Retrieved from OOPic Manual.” Retrieved from http://www.oopic.com/http://www.oopic.com/..

““Trekker Robot. Retrieved from Trekker Robot. Retrieved from ”http://www.superdroidrobots.com/sh”http://www.superdroidrobots.com/shop/.op/.