Robotic Navigation Distance Control Platform By: Scott Sendra Advisors: Dr. Donald R. Schertz Dr. Aleksander Malinowski April 29, 2004

Overview Objective Objective Functional Description Functional Description System Block Diagrams System Block Diagrams Lab Work Lab Work Results Results Future Development and Research Future Development and Research Equipment / Part List Equipment / Part List Sources Sources Questions Questions

Objective Design and Build a Robotic Platform Design and Build a Robotic Platform Maintain a fixed safety distanceMaintain a fixed safety distance Fixed steeringFixed steering Small and economical systemSmall and economical system Applications Applications RoboticsRobotics Slow speed moving vehiclesSlow speed moving vehicles AutomotiveAutomotive

Functional Description Modes of Operation Modes of Operation System I/O System I/O System Diagrams System Diagrams

Modes of Operation Fixed Navigation Mode User enters fixed safety distance in feetUser enters fixed safety distance in feet User enters User or Auto Out of Range ModeUser enters User or Auto Out of Range Mode User presses activation buttonUser presses activation button Increment / Decrement Mode User is able to (increment / decrement) motor speed by one unit manuallyUser is able to (increment / decrement) motor speed by one unit manually

Modes of Operation User Out of Range Mode Followed object is out of range of sensorFollowed object is out of range of sensor Robotic platform stopsRobotic platform stops “Out of Range” displayed on LCD“Out of Range” displayed on LCD User reactivates navigation controls by pressing 0User reactivates navigation controls by pressing 0 “Following” displayed on LCD“Following” displayed on LCD Auto Out of Range Mode EMAC reactivates navigation controls when object is detectedEMAC reactivates navigation controls when object is detected

Modes of Operation Stop / Reload Mode User is able to (stop / reload) motor speed manuallyUser is able to (stop / reload) motor speed manually Navigation Control Mode User is able control Navigation ModeUser is able control Navigation Mode

System Inputs to EMAC User Input  Keypad Sensor Input  Ultrasonic sensors 1 sensor for distance control1 sensor for distance control Robotic Platfor m Motor EMAC Microcontroller Distance Control Sensor Robotic Platfor m Steering LCD Display Keypad (User Input)

System Outputs from EMAC LCD Display LCD Display Current mode of operationCurrent mode of operation User required input informationUser required input information Robotic Platform Motor Robotic Platform Motor Robotic Platform Steering Robotic Platform Steering Trigger Pulse for Sensor Trigger Pulse for Sensor Robotic Platfor m Motor EMAC Microcontroller Distance Control Sensor Robotic Platfor m Steering LCD Display Keypad (User Input)

System Sensor Diagram Robotic Platform (R/C Car) Distance Sensor Moving Object (Similar size to robotic platform)

System Block Diagrams System Block Diagrams Hardware Subsystem FunctionSubsystem Function I/O of SubsystemI/O of SubsystemSoftware Modes of Operation FlowchartsModes of Operation Flowcharts

Sensor Subsystem SRF04 Ultrasonic Pulse Sensor SRF04 Ultrasonic Pulse Sensor Sensor Input Signal Sensor Input Signal Trigger Pulse of 1.5 msTrigger Pulse of 1.5 ms Sensor Output Signals Sensor Output Signals Output signal related to distanceOutput signal related to distance PWM at 33 HzPWM at 33 Hz

Electric Motor Subsystem ESC and Electric Motor ESC and Electric Motor Input signal Input signal PWM signal from 1.0 ms to 1.7 ms positive pulse width at 33 HzPWM signal from 1.0 ms to 1.7 ms positive pulse width at 33 Hz Output speed Output speed Motor’s shaft speed variesMotor’s shaft speed varies Full forward speed with 1.7 ms pulse widthFull forward speed with 1.7 ms pulse width Stop with 1.0 ms pulse widthStop with 1.0 ms pulse width

Steering Subsystem Input signal PWM signal from 1.1 ms to 1.9 ms positive pulse width at 33 Hz with 1.5 ms as neutralPWM signal from 1.1 ms to 1.9 ms positive pulse width at 33 Hz with 1.5 ms as neutralOutput Rotational servo horn to translational movement of steering rodRotational servo horn to translational movement of steering rod

Hardware Subsystem Block Diagram Robotic Platform Steering Subsystem PWM Signal Translates Steering Rod EMAC Microcontroller Robotic Platform Motor Subsyste m PWM Signal Power to Drive Wheels on R/C Car Distance Control Sensor Subsystem PWM Signal Trigger Pulse

Main Software Flowchart Out of Range Mode Display Prompt: Press 1 for User Press 2 for Auto Keypad: User Enters Out of Range Mode EMAC Initialization LCD Initialization Keypad Initialization Keypad: User enters fixed distance Fixed Steering Control Display Prompt: Press 0 to Activate Keypad: User Enters 0 Fixed Distance Display Prompt: Enter 1-9 feet: Control = 0

Main Software Flowchart (Fixed Navigation Mode) Fixed Distance Control Check if signal from sensor Enter User/Auto Out of Range Mode No Yes Increment Motor Speed Decrement Motor Speed Measure > DesiredMeasure < Desired Measure = Desired Check Control Variable Check Keypad 1 0 No Yes Call Software Mode Pressed

User/Auto Flowchart User/Auto Out of Range Mode Display: Out of Range User Out of Range Mode Auto Out of Range Mode Stop Electric Motor Display: Wait for object Display: Press 0 to Activate Display: Following Return Waits for User to Press 0

Increment / Decrement Motor Speed Flowcharts Call IncMotorSpeed () Keypad: User Presses Increment Motor Speed Button C Display Prompt: Manual Inc Speed Press 0 to Activate Call DecMotorSpeed () Keypad: User Presses Decrement Motor Speed Button E Display Prompt: Manual Dec Speed Press 0 to Activate Return

Stop / Reload Flowcharts Stop Electric Motor Keypad: User Presses Stop Button B Display Prompt: Manual Stop Press 0 to Activate Loads Last Motor Speed Keypad: User Presses Reload Motor Speed Button D Display Prompt: Reload Last Speed Press 0 to Activate Save Current Motor Speed Return

Navigation Control Return Check Control Variable 10 Stop Electric Motor Keypad: User Presses Control Button 0 Toggle Control Bit Display: Following Display: Deactivated Return

Lab Work Ultrasonic trigger pulse and servo input signals with 1.5 ms at 33 Hz being neutral using Timer 2 Ultrasonic trigger pulse and servo input signals with 1.5 ms at 33 Hz being neutral using Timer 2 ESC reprogrammed ESC reprogrammed Reprogrammed :1.0 ms stopReprogrammed :1.0 ms stop 1.7 ms full forward Ultrasonic PWM signal measurements using interrupts Ultrasonic PWM signal measurements using interrupts Output PWM signal using Timer 2 on EMAC to control motor speed Output PWM signal using Timer 2 on EMAC to control motor speed

Lab Work Control Strategy Current distance is smaller than user-defined distanceCurrent distance is smaller than user-defined distance -Decrease PWM signal to motor by fixed number Current distance is larger than user-defined distanceCurrent distance is larger than user-defined distance - Increase PWM signal to motor by fixed number

Lab Work Circuit Diagram

Results All software modes are complete All software modes are complete EMAC on the robotic platform triggers ultrasonic sensor and measures PWM signal from sensor EMAC on the robotic platform triggers ultrasonic sensor and measures PWM signal from sensor EMAC increases or decreases motor speed EMAC increases or decreases motor speed Robotic platform maintains the entered safety distance from object Robotic platform maintains the entered safety distance from object

Results

Results

Future Development and Research Model and determine transfer function of robotic platform Model and determine transfer function of robotic platform Implement a better control strategy Implement a better control strategy Incorporate steering of platform using more sensors Incorporate steering of platform using more sensors Using fuzzy logic steering to allow platform to steer non-linearly around corners Using fuzzy logic steering to allow platform to steer non-linearly around corners

Equipment and Parts List Hitec HS-303 Servo Hitec HS-303 Servo Kyosho Hoppin Mad RTR R/C Car Kyosho Hoppin Mad RTR R/C Car Team Novak Rooster electronic speed controller Team Novak Rooster electronic speed controller HP 8011A Pulse Generator HP 8011A Pulse Generator SRF04 Ultrasonic pulse sensors SRF04 Ultrasonic pulse sensors EMAC Microcontroller EMAC Microcontroller

Sources electronics.co.uk/shop/Ultrasonic_Ranger_SRF htm electronics.co.uk/shop/Ultrasonic_Ranger_SRF htm car.com/html_pages/about_icar/current_events_news/advantage/advantage_on line_archives/2004/ html car.com/html_pages/about_icar/current_events_news/advantage/advantage_on line_archives/2004/ html ectrum.pdf ectrum.pdf

QUESTIONS ? Project Website: