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Microcontroller Robot
Design
Spring 2003
Advisor : Prof. Hayler
Engineering Team:
Mark Vo
Jing Hua Zhong
Abbas Ziadi
Have you seen the Terminator?
Well, this is the beginning…
Introduction

The need for
intelligence

Trends in
robotics
Features of the Robot

Roaming
Will roam around until it detects an object.

Observing
Will observe the object to determine if it is a
moving object or not.

Avoiding
Will avoid objects and walls to prevent crashing.
Features of the Robot

Following
Will follow moving objects.

Stopping
Will stop at a specified range to the object.

Retreating
Will turn around an run if it senses that the object is too
close.
Servo Motors

Original unmodified servo motor only rotate
60 degree non-continuous rotation.

Modification allows for 360 degree continuous
rotation.

Removing the “stop” on the drive gear and
disengaging of the drive gear from the
feedback potentiometer.
Block Diagram
IR Sensors 1
IR Sensors 2
68HC11
Motor 1
Motor 2
Block Diagram Detailed
Schematic
H-Bridge circuit for head movement.
H Bridge Motor Controller
Schematic
Main Power circuit
Program/Flow Chart
Programming/Concepts

Assembly Language Programming
Assembly and C

Global Variables
Access of variables

Modular subroutines
Subroutines can be used by other subroutines
Programming/Concepts

Free Running Counters

Use of Interrupts
Motor control
PWM generation

Output Compare
Output Waveform

Analog to Digital
Convert sensor signal to digital signal
Partial Code
TURNA3
JSR
BACKUP
JSR
FORWARD3
JSR
BACKWARD2
LDD
#$EFFF
STD
dtime
JSR
DELAY
LDAA
#$00
STAAdistance1
STAAdistance2
RTS
Specification of the Robot

Maximum Velocity of Robot is 0.15 m/s.

Robot consumes about 2650 mA/hr.

Last approximately 40 minutes on a fully charged battery.

Maximum infrared range is 150 cm.

Incorrect Infrared readings occur at distances less than 15 cm.

Total mass of 4 kg.
Application of the Robot

Exploration
Space Probe
Hazardous Area

Entertainment
Robotic Pet
Toy

Military
Spy Drone
Death Machine
Development/Troubleshooting

Researching various components.

Listing features that the robot should have.

Designing the robot.

Obtaining all the components for the robot.

Testing each components.
Development/Troubleshoot

Integrating all the
components

Programming

Debugging

Add features
Problems Encountered

Power Supply
Unstable Power.
Components such as IR sensors and motors would not function
correctly.
Battery voltage was too high.
Burning out some components.

Program Language
Difficult to implement complex features such as tracking.
Time consuming in debugging.
Problems Encounter

Infrared Sensors
Limited Range of 1.5 m.
Incorrect readings will occur when object is less than 15
cm from the IR detector.

68HC11
Could not use some of its feature due to limited
documentation of the board such as booting.
Limitations of Robot

The robot is unable to see any farther than 1.5
meter due to the IR sensors.

It could run into thin upright object such as a
leg of a chair due to the placement of the IR
Sensors.

Reaction to moving object is slow due to the
speed of the motors.
Budget
68HC11 Microcontroller(1)
Servo Motors(2)
Infrared Sensors(2)
Capacitors, Resistors, etc..
Decks(2)
Batteries(2)
Screws, nuts, bolts, etc…
Misc.
Total
$120.00
$30.00
$25.00
$2.00
$15.00
$50.00
$5.00
$10.00
$257.00
Timeline
01/13/03-01/29/03
01/20/03-02/09/03
02/10/03
02/23/03
02/25/03-03/17/03
03/19/03-03/28/03
04/10/03-04/15/03
04/17/03-05/14/03
05/17/03-05/29/03
05/30/03
Researching various components for the IR robot.
Discussion of the features that robot will have.
Designing the Robot.
Ordering the basic components for the robot.
Receiving the majority of the components of the
robot.
Testing of the various components of the robots.
Re-discussion of the features of the robot and
redesigning the robot based on the tests of the
components.
Integration of the majority of the components into
the basic designs of the robot.
Programming. Troubleshooting. Basic features of
the robot are incorporated. Buggy.
Majority of the programming done. Refining the
design of the robot. Adding and fixing some
features of the robot.
Demonstration
Conclusion

Accomplished the majority of the goals we
have set for ourselves.

We have encountered numerous problems
along the way.

The robot can be used as a basis for other
projects.
Thank You
If you are interested, our hardware
demonstration will begin in 5 minutes
downstairs