Applications of AGVs

1
Applications of AGVs

• Prasad Weerakoon
• 10/29/2008

2
Current State

• First AGV was introduced to market in the 1950s
  by Barrett Electronics of Illinois.
• First ones used were simple tow trucks that
  followed a wire in the floor instead of a rail.
• Presently, most AGVs are laser navigated (LGV
  Laser Guided Vehicle).
• Extensively used in a growing number and a
  variety of applications (FMS)

3
Who/Where Used

• Automotive
• Aerospace
• Clean Room
• Food Beverage
• Manufacturing
• Mining
• Law Enforcement
• Military
• Mail Processing
• Newsprint/Roll handling
• Pharmaceutical
• Warehousing

Bomb Detection and Disposal AGV Source
http//www.a-m-c.com/content/m101/industry_highlig
ht/agv.html
AGVs at work in a warehouse Source
http//www.hksystems.com/agv/index.cfm?m2s1
4
Principal Applications

• Four(4) Main Applications
• Driverless train operations
• Storage and distribution
• Assembly line applications
• Flexible Manufacturing Systems (FMS)

5
Driverless Train Operations

• First type of AGVs to be introduced and still
  widely used.
• Move heavy payloads over long distances in
  warehouses or factories with or without
  intermediate pickup and drop-off points.
• An efficient transportation system.
• Similar technology is used in RT (Rapid Transit)
  systems around the world to transport people (Ex
  MRT Singapore, Vancouver Sky Train, Driverless
  shuttles between airport terminals)

Cockpit of an ATO (Automatic Train Operation)
train Source http//en.wikipedia.org/wiki/Image
KCRSP1950panel.jpg
6
Storage Distribution

• Unit load carriers and pallet trucks are
  typically used.
• Involves materials in unit loads.
• AGVs are often interfaced with an automated
  storage and retrieval system (AS/RS) in a
  distribution center.
• Includes light manufacturing and assembly plants
  

Source http//www.bastiansolutions.com/products/a
utomated-guided-vehicles/
Pallet Truck Video http//video.google.com/googlep
layer.swf?docid-8181783328690702890hlenfstrue

Unit Load Carrier Source http//www.agvsystems.co
m/types/dc40.htm
Automated Pallet Truck Source http//www.egeminus
a.com/pages/agvs/agvs_flv.html
7
Assembly Line Applications

• Unit load carriers and light load carriers are
  used.
• Usually slow production rate (product spends 4-10
  min per station).
• Several different product models made on the
  line, each requiring a different processing time.
  
• Work stations are arranged generally in
  parallel-this allows the assembly line to deal
  with differences in the assembly cycle time for
  different products.
• Assembly Line Video http//video.google.com/google
  player.swf?docid8038361680199985622hlenfstru

8
Flexible Manufacturing Systems (FMS)

• An FMS is a manufacturing system in which there
  is some amount of flexibility that allows the
  system to react in the case of changes, whether
  predicted or unpredicted.
• AGVs provide a versatile material handling system
  to complement the flexibility of an FMS.
• Starting workparts are placed onto pallet
  fixtures by human workers.
• AGVs deliver the parts to the individual
  workstations in the system.
• The pallet is then transferred from the AGV for
  processing.
• After completion of processing, an AGV returns to
  pick up the part.
• The part is then transferred to the next
  workstation for processing and so forth.

9
Cost

• Ranges from a couple of thousand dollars to
  hundreds of thousands of dollars.
• Have to pay extra for the software.
• Depends on the type of AGV.

10
Supporting Technology

• Needs a guidance system (Navigation).
• Types of guidance systems available
• Wired
• Guide Tape
• Laser Target Navigation
• Gyroscopic Navigation
• Natural Features Navigation
• Steering control
• AGVs employ a lot of technology to ensure they do
  not hit one another and to make sure they get to
  their destination.
• Most AGVs run on Microsoft Windows platform.
• More Info http//www.egeminusa.com/pages/software
  /ensor.html

11
Pros

• No margin for human error.
• Human factor is virtually eliminated.
• Continuous labor.
• Faster and more efficient.
• Multi-tasking ability.
• With the high demand, prices of AGVs are going
  down.

12
Cons

• High initial cost.
• High maintenance costs.
• Should recharge the batteries (idle time)
• Lost jobs.
• Evolving technology requires upgrades/replacements
  -high cost.

13
Primary Vendors
14
Existing/Evolving Standards

• Technology is still developing.
• New systems to respond to new application
  requirements.
• Use of a robotic manipulator mounted on an AGV
  (mobile Robot).
• Wireless laser guidance technology.

15
Technical Paper

• SIMULATION OF AN EVOLUTIONARY TUNED FUZZY
  DISPATCHING SYSTEM FOR AUTOMATED GUIDED VEHICLES
• Authors K.K. Tan
• K.Z. Tang
• Department of Electrical Engineering
• National University of Singapore
• As a solution to vehicle dispatching scheduling
  problems.
• A simulation study was conducted based on a
  flexible vehicle dispatching system developed,
  using a self-adapting fuzzy prioritizing approach
  for a fleet of AGVs operating in a multiple
  workcenters manufacturing environment.
• A fuzzy control system is a control system based
  on fuzzy logic- a mathematical system that
  analyzes analog input values in terms of logical
  variables that take on continuous values between
  0 and 1.
• Concluded that tuned fuzzy dispatching system
  outperformed two industry standards.

16
Summary

• AGVs have been in operation for more than half a
  century.
• Used in a variety of places ranging from law
  enforcement to newspaper handling.
• 4 principal applications (driverless train
  operations, storage distribution, assembly
  line, FMS)
• Cost can vary from a few thousands to millions of
  dollars depending on the application.
• Supporting Technology Navigation and software.
• Laser guidance, robot arm combination are few
  developing technologies.

17
Problem

• An AGV has an average empty travel distance 80
  ft. The distance the vehicle travel between load
  unload station 400 ft. Load and unload times
  are each 0.6 min and the speed is 125 ft/min.
  Find the delivery cycle time Lc.

18
Answer

• Tc TL (Ld / vc) TU (Le / vo) (eq 10.1 pg
  296)
• Ld 400 ft Le 80 TL TU 0.6 min
• vc vo 125 ft/min
• Tc 0.6 3.2 0.6 0.64
• Tc 5.04 min/vehicle

19
References

• http//www.a-m-c.com
• http//www.hksystems.com
• http//www.wikipedia.org
• http//www.agvsystems.com
• http//www.egeminusa.com
• http//www.bastiansolutions.com
• Groover, Mikell P. Automation, Production Systems
  and Computer- Integrated Manufacturing. New
  Jersey Pearson Education, 2008