1. AGV / ASRS April 12 th, 2005 Student Names: Trevor Skipp and Albert Chung Instructor: A. A Arroyo University of Florida Department of Electrical and Computer Engineering EEL 5666: Intelligent Machine Design Laboratory

2. Summary Concept Behaviors Implementation Communication protocol Conclusions Suggestions for future study

3. Inspiration Current StandardDesired Attributes Poor warehouse utilization Dynamic storage Warehousing is a “middle-man” business Lower labor and insurance overhead Safety drawbacksReduce the risk of personal injury

4. Designers’Approach Divide tasks among two automated vehicles –AGV (Automated Guided Vehicle) Inexpensive, small, fast, and nimble –ASRS (Automated Storage and Retrieval System) Expensive, tall, slow, and bulky

5. Behaviors

6. Design Specifications Operate in a 4’x8’ model warehouse Navigation Obstacle detection Queue Communication Mechanical fork lift

7. Model Warehouse Shipping and receiving docks Transition dock Storage shelves

8. Navigation Follow a high contrast line Cartesian coordinate system Knowledge of current location, destination, and direction

9. Queue FIFO job processing Incoming pallets are marked with an age Outgoing pallets are delivered oldest first Application to food and other products that can expire

10. Communication User input –Notify that a pallet is entering the warehouse –Request a pallet to be shipped out Data link between vehicles –Assign tasks –Determine transition dock –Notify when a task is completed

11. IN OUT Simulation DOCKS

12. Purpose ♦Transfer products safely on and off shelf space Summary DOCKSHELVES

13. Implementation

14. Required Modules Fork Lift Power Motor Driver L.C.D. Sensors RF Transceiver

15. Fork Lift (ASRS) Capable of lifting pallets onto a 3 tier shelf Screw type powered by a 200 RPM motor Expensive

16. Fork Lift (AGV) One height Tilt type powered by a servo Cheap

17. Interrupts Low Priority 1.Remote control 2.RF data link High Priority Fork RF Timer overflow

18. Power Required voltage levels: –3.3V: Logic –5V: Motor driver, LCD, servo –12V: Gear head motors

19. Backbone Sensors Line follower: Optek OPB745 Reflective Object Sensors Obstacle detection: Sharp GPD2D12 infrared range finders Obstacle collision: Bump sensors

20. Line Follower Module

21. IR Detector Sony television remote (code #202)

22. Decoding Technique

23. Remote Button “3” 10000110000011 10000110000011 00011 00011 11100 Initial Sample Mask Reverse First Signal Subsequent samples

24. Results Remote Button Algorithm Result 00x0A 10x01 20x02 30x03 40x04 50x05 60x06 Remote Button Algorithm Result 70x07 80x08 90x09 CH UP0x11 CH DWN0x12 VOL UP0x14 VOL DWN0x15

25. RF Transceivers Laipac TRF-2.4G –1Mbps –Hardware CRC –Dual channel, full duplex –Two operating modes: Direct Mode and Shockburst

26. Communication Protocol

27. Stop and Wait ARQ Error detection Positive acknowledgment Retransmission after timeout Negative acknowledgement and retransmission

28. Header Error Control Purpose: lost or damaged frames |----------Header------------||-----------Data-------------| Frame #Check #I/ODock # 1 bit3 bits1 bit3 bits

29. Alternating Frame Numbers

30. Special Considerations Dynamic resynchronization Stations have different timeout lengths Lost connection Duplicate transmissions

31. Example ASRS –Places a command from the remote control onto the queue –Sends command to the AGV through RF –Sets timer and waits for an ACK AGV –ACKs packet –Echoes packet back after the job is completed –Sets timer and waits for an ACK ASRS –ACKs packet –Updates queue

32. Conclusions Navigation Communication –Remote control –RF protocol Experience –Debugging –Design software: Eagle & AutoCAD

33. Suggestions for Future Study Sliding Window ARQ Larger warehouse with more shelves Swarm Approach: Multiple AGVs for every ASRS “Conveyor Belt” robot