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 68HC11 IR Sensors 1 IR Sensors 2 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 TURNA3JSRBACKUP JSRFORWARD3 JSRBACKWARD2 LDD#$EFFF STDdtime JSRDELAY 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)$30.00 Infrared Sensors(2)$25.00 Capacitors, Resistors, etc..$2.00 Decks(2)$15.00 Batteries(2)$50.00 Screws, nuts, bolts, etc…$5.00 Misc.$10.00 Total$257.00

Timeline 01/13/03-01/29/03Researching various components for the IR robot. 01/20/03-02/09/03Discussion of the features that robot will have. Designing the Robot. 02/10/03Ordering the basic components for the robot. 02/23/03Receiving the majority of the components of the robot. 02/25/03-03/17/03Testing of the various components of the robots. 03/19/03-03/28/03Re-discussion of the features of the robot and redesigning the robot based on the tests of the components. 04/10/03-04/15/03Integration of the majority of the components into the basic designs of the robot. 04/17/03-05/14/03Programming. Troubleshooting. Basic features of the robot are incorporated. Buggy. 05/17/03-05/29/03Majority of the programming done. Refining the design of the robot. Adding and fixing some features of the robot. 05/30/03Demonstration

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