1. ECE 445 Group 20 4/23/2012 Kevin Dluzen Jonathan Hall Diyang Qiu

2. Motivation Current golf ball retrieval systems are… Manually driven Costly Gas powered Our robot is… Autonomous Cheap Solar powered

3. Features  Locates golf balls in front of robot and directs 2 front mounted motors to nearest ball  Picks up golf balls while moving and stores them in container  On board power management system allows for PV charging while operating  Detection system for number of balls collected and manual emergency disable switch

4. Major Modules 1.Mechanics  Pick up wheel  Robot structure 2.Control  Vision processing  Sensors 3.Motors  Motor/ H-bridge design 4.Power  Solar power  Power management

5. Electrical System Overview

6. Evolution of mechanical design 1. Mechanics module

7. Final Mechanical Design 1. Mechanics module 18” x 16” footprint, 20” tall 2 front motors, 2 free castor wheels Sprocket driven pick up wheel

8. Pick up mechanism 1.Golf ball pushed through thin film into 14”D wheel 2.Rides up the wheel via 6 pairs of L-shaped brackets 3.Pushed out through thin film 4.Rolls down incline and into container while triggering push button 1. Mechanics module

9. Pickup wheel in action

10. Vision processing components Camera (Fire-i digital camera)  640 x 480 RGB resolution  30 fps Compact Vision system (NI CVS-1456)  2 TTL inputs/ 10 TTL outputs  3 IEEE 1394 input ports  Configurable FPGA for I/O control  Runs via LabVIEW code 2. Control module

11. Vision Processing Steps 2. Control module 1.Threshold image based on gray scale value of each pixel 2.Complete circles, filter out big/small blobs, identify circles

12. Ball positions to outputs 2. Control module State:1- Halt2- Straight3- Turn right4- Turn Left Left PWM 0%70%40%70% Right PWM 0%70% 40% LabVIEW code: 1) Identify nearest ball based on y coordinates of balls 2) Identify state based on x position of nearest ball 3) Halt state triggered with disable switch or ball counter

13. Vision system in action 2. Control module

14. Golf ball counter  Push button mounted above container  CVS counts number of low to high changes  Disables motors when maximum ball count reached  Count resets via disable switch 2. Control module

15. H-Bridges and Motors o 2 front mounted 12V DC parallel shaft gear motors o Direct shaft drive system o Pick up mechanism driven by chain drive o Axial driven pick up mechanism 3. Motor Module

16. H-Bridges and Motors CONTROL SIGNALS AHIBHIALIBLIDISABLE FORWARD PWM0010 BACKWARD 0PWM100 DISABLE XXXX1 H Bridge Design: o DC Motor Control Using PWM o Concerns about flyback voltage o Concerns about heating (operational frequency) o High side N-type Mosfet bootstrapping o HIP4081 Mosfet Driver 3. Motor Module

17. Progression of H-Bridge Construction o H-bridge Construction from prototype to PCB o PCB creation and Eagle CAD software o Included surface mount components for final design 3. Motor Module

18. PCB DESIGN TOP BOTTOM BOTH 3. Motor Module

19. H-Bridge Testing o Heating to less than 40deg C above ambient o Must operate with 3-12 V logic PWM o Must output proper functions for motor control as defined by Control table 3. Motor Module

20. Power management components Solar Panel  12 Volt 5 Watt Trickle Charger  Charge Controller Lead-Acid rechargeable Battery  12 Volt  5Ah 4. Power module

21. Power management components 4. Power module Battery Management Circuit o SPDT dual relay o BJT (NPN, β=100) o Arduino UNO o Voltage regulator (Vin=12V, Vout =5V) o Current Sensor (Low current sensor )

22. Testing circuit BJT circuit Regulator circuit 4. Power module

23. Arduino Features Power source  The battery powering the system  5 Volts from the voltage regulator Senses system voltage  Implement switching operation when voltage lower than 10.5 Sense the solar panel power condition  Current sensor converts current signal to voltage signal  Voltage sensed by Arduino 4. Power module

24. Power Management Circuit 4. Power module

25. Switching results for different battery situation Relay operation steps B2 LOW B1 HIGH Relay 4 on Relay 3 on Relay 1 on Relay 2 on Relay 4 off B2 HIGH B1 LOW Relay 4 on Relay 2 off Relay 1 off Relay 3 off Relay 4 off B1 LOW Shut down the system and wait for battery to be charged by the solar panel 4. Power module

26. Summary

27. The Green Retriever is… Autonomous Cheap Solar powered Additional Features  Can be charged while operating  Counts number of balls collected  Can turn on a dime

28. Recommendations  More sophisticated search algorithms  Use data from PV panel for maximum power point tracking  More powerful motors for higher collection speeds  Multiple pick up wheels

29. Acknowledgments  Alex Suchko (Amazing TA)  Greg Bennett (Machine Shop)  Skot Wiedmann (Parts Shop)