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.
68HC11 IR Sensors 1 Motor 1 IR Sensors 2 Motor 2 Block Diagram
Schematic H-Bridge circuit for head movement.
Schematic Main Power circuit
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 STAA distance1 STAA distance2 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) $120.00 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 01/13/03-01/29/03 Researching various components for the IR robot. 01/20/03-02/09/03 Discussion of the features that robot will have. Designing the Robot. 02/10/03 Ordering the basic components for the robot. 02/23/03 Receiving the majority of the components of the robot. 02/25/03-03/17/03 Testing of the various components of the robots. 03/19/03-03/28/03 Re-discussion of the features of the robot and redesigning the robot based on the tests of the components. 04/10/03-04/15/03 Integration of the majority of the components into the basic designs of the robot. 04/17/03-05/14/03 Programming. Troubleshooting. Basic features of the robot are incorporated. Buggy. 05/17/03-05/29/03 Majority of the programming done. Refining the design of the robot. Adding and fixing some features of the robot. 05/30/03 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