ISE 115 Material Handling Automation

1. ISE 115Material Handling Automation

2. Material Handling System • MH must be An integral part of a mfg. system’s design. • A CIM system consists of a network of fabrication cells, assembly lines and an overlay of MH and Mfg. Info. system. • Strategy: Limit on-site MH to non-storage functions - load/unload, on/off line transport, and packaging. Do not handle materials. Flow them. • No on-site parts, WIP, and FG storage. • No parts kitting and staging. • Parts delivered in bulk to points of use by suppliers. • Pack out at the end of line.

3. Equipment Used • Storage –AS/RS, carousels, shelf stackers, in-process buffer lines, die/cutting tool magazines • Loading/unloading (or Pick & Place) – MH (or assembly) robots • Transporting – Conveyors, AGVs, indexing mechanism (linear, rotary), elevators, robots • Special equipment: • Slug loader (Slug – A collection of tote stacks) • Palletizer

4. Storage Systems • Carousels – Most economical method for storing parts. • Horizontal: Single/double stack, multi-layer (rotary). • Vertical: Serves as elevator & buffer in conveyor highway. • Bidirectional, with or w/o a robotic inserter/extractor. • AS/RS – High-rise, narrow-aisle with robotic retrievers. • Mini-Load for small parts stored in tray compartments. • Unit Load for larger, bulky items stacked on pallets. • Deep Lane for high-volume, bulky materials (LIFO).

5. Storage Systems • Stackers – Variable configuration. Made of shelves and a robotic stacker. Often used for POU storage of tools, dies, and small pallets. • Buffer lines – For moving parts in asynchronous mode. Horizontal (FIFO), vertical (LIFO), overhead bridge (FIFO) Ex: Buffer conveyor for linking S/A lines and F/A lines. • WIP AS/RS – Low height, single aisle AS/RS or multi-level carousel used for storing S/A’s or partially completed parts.

6. Load/Unload, Pick & Place • Jointed (articulated) arm for loading, unloading, and indexing (stationary or on-track) • SCARA for small parts picking and placing. • Linear modules for feeding and short distance move. • Special purpose robots Modular assembly machines, Screwbots, AS/RS inserter/extractor, PCB component inserter . • Vision Control for parts ID, gauging, and random orientation of incoming parts.

7. Transporting CONVEYOR Roller, belt, skate wheel, power & free, tow line. Work is performed along a conveyor line. AGVS Continuous routing or On-call dispatching. Often used as end-of-line linkage for conveyors. Consist of AGV fleet, tracks, P&D stations, charging stations, and a dispatch control system.

8. Conveyor System • Belt – Sliding, pulley, bulk-mover • Roller – Gravity flow, Powered (drive shaft, friction belt), Self-powered (short section application) • Skate wheel – Bedding material: Wheels, tubes, beads. Fixed length vs. Extendable • Slat – Light to heavy load. Slats are linked and pulled. • Chain – Sub-floor tow line • Overhead – Hanger loop (coating line) Power & free trolley (Large part transport) Components Conveyor highway, oval loops, ramps, spurs, diverters, elevators, accumulators, carriers (pallets), tote stackers, slug loaders. Traffic control - Supervisory computer and distributed PLC system

9. Belt Conveyor

10. Skate Wheel Conveyor

11. Roller Conveyor

12. Slat Conveyor

13. Power & Free Conveyor

14. Conveyor Selection Criteria • Move distance – Belt is best in distance. Self-powered roller for short distance. • Speed – Belt is fastest. • Load weight – Slat for heavy metal transfer. • Load type - Box, pallet, container, bulk, loose • Traction requirement – Belt for incline/decline - Roller for zero pressure accumulation • Portability – Skate wheel. • Noise – Rollers are noisy. • Cost – Skate wheel is most economical.

15. Automated Guided Vehicle System Industrial application Moving flats, pallets, boxes, containers, paper rolls, metal coils, ingots, tool magazine, .. Main components • Drive/steering motor mechanism & guidance track • Battery & charging system (opportunity & overnight) • On-board shuttle mechanism & P&D stations • On-board controller & central supervisory computer • IR communication system (on-board & P&D stations) • Sonar scanner for obstruction detection • Radio transceiver

16. AGVS

17. AGV Driving & Tracking System • Typically one front drive wheel, two rear wheels, and a tracking system on the belly. • Front wheel – Large & wide. Steering and Driving. Fitted with two high resolution encoder mechanisms. • Rear wheels – Small. Idlingand distance tracking. Each wheel is fitted with a precision encoder. • Guidance sensors, lasers, or cameras tracing floor track or targets, or scanning perimeter markers.

18. AGV Guidance System Guidance types • Buried wire • Retro-reflective tape • UV paint line • Grid system – optical (markers or color tiles) or inertial (magnetic) • Laser perimeter scan • GPS (emergent technology)

19. AGV System Control Traffic control Zoning – Only one AGV may enter the route segment. Application: Blind alley No zoning – On-board sonar detection to avoid pile up. Application: Circular route Route intersection – Normally allowed. Right of way yield. Communication Central Dispatch – Radio Frequency P&D station I/F – Infra-red binary code

20. Design Modeling and Analysis Published analytical models for designing conveyor sections, AS/RS, and AGVS. Simulation – Required for large conveyor system installation. Queuing models – Time tested. Works for small systems. Analytical storage (line buffer) models. Quest- Given inflow & outflow characteristics, what must be the buffer capacity such that Pr[overflow] ≤ p.