7/31/2019 Agvs Lecture Viii Sem

1/31

Introduction to Automatic

Guided Vehicles

7/31/2019 Agvs Lecture Viii Sem

2/31

What is an AGV?

A Computer-Controlled, Non-manned, Electric PoweredVehicle Capable of Handling Material

Driverless Vehicle

Electric motors, battery powered

Programming capabilities Destination

Path selection

Positioning

Collision avoidance

System Discipline

7/31/2019 Agvs Lecture Viii Sem

3/31

What is a good use for AGVs?

Repetitive motion

Distances over 150 feet

Multi-shift operationDesire to save costs and improve

efficiency

Modern AGVs are computer-controlledvehicles with onboardmicroprocessors.

Position feedback system to correctpath

Communication between vehicles viasystem controller RF communication Electric signals

System management computers Optimising the AGV utilisation Tracking the material in transfer and

directing the AGV traffic.

7/31/2019 Agvs Lecture Viii Sem

4/31

Why use Guided Vehicles?

Not a permanent obstacle

Paths can be changed easily

System can be expanded easily

Does not represent a single point of failure - system has

built-in redundancy

Favorable cost/benefit compared to other automated material

handling solutions

7/31/2019 Agvs Lecture Viii Sem

5/31

7/31/2019 Agvs Lecture Viii Sem

6/31

7/31/2019 Agvs Lecture Viii Sem

7/31

AGVS towing vehicle

AGVS unit load carriers

AGVS pallet trucks

AGVS forklift trucks

AGVS light-load transporters

AGVS assembly-line vehicles

7/31/2019 Agvs Lecture Viii Sem

8/31

7/31/2019 Agvs Lecture Viii Sem

9/31

AGVS Pallet TrucksNo special device is needed for loadingexcept the loads should be on pallet

Limited to floor level loading and unloading

with palletized load

Widely used in distribution functionsCapacity 1000-2000 lbSpeed > 200ft/min

Pallet truck can be loaded either manually orautomatically

AGVS Forklift TrucksAbility to pickup and drop palletized loadboth at floor level and on stands.

Pickup and drop off heights can be differentVehicle can position its fork according to load

stands with different heights

Very expensive

Selected where complete automation isnecessary/required.

7/31/2019 Agvs Lecture Viii Sem

10/31

AGVS Towing VehiclesFirst type of AGV introduced.

Towing vehicle is called an automated guidedtractor

Flatbed trailers, pallet trucks, custom trailers can beused.

Generally, used for large volumes (>1000 lb) andlong moving distances (>1000 feet).

7/31/2019 Agvs Lecture Viii Sem

11/31

AGVS Unit load CarriersTo transport individual unit load onboard thevehicle.

Equipped with powered or non-powered roller,chain or belt deck, or custom deck.

Loads can be moved by Pallet truck, forklift truck,automatic loading/unloading equipment, etc.

7/31/2019 Agvs Lecture Viii Sem

12/31

7/31/2019 Agvs Lecture Viii Sem

13/31

7/31/2019 Agvs Lecture Viii Sem

14/31

Application

7/31/2019 Agvs Lecture Viii Sem

15/31

7/31/2019 Agvs Lecture Viii Sem

16/31

Important issues for AGVS

Guidance system

Routing

AGVS control systems Load transfer

Interfacing with other subsystems

7/31/2019 Agvs Lecture Viii Sem

17/31

The goal of an AGVS guidance system keep the AGV ontrack/predefined path

One of the major advantage of AGV is ease in modification given bythe guidance system for changing the guide path at low costcompare to conveyors, chains, etc.

Another benefit is: guide path is flexible which means intersectionof path is possible.

Generally, guide path does not obstruct another systems.

The guidance systems can be selected based on the type of AGVselected, its application, requirement and environmentallimitation.

Wire-guided

Optical Inertial

Infrared

Laser

Teaching type

AGVS Guidance system

7/31/2019 Agvs Lecture Viii Sem

18/31

Wire-guided:

An energized wire is rooted along the guide path.

The antenna of the AGV follows the rooted wire.

Optical:

Colorless florescent particles are painted on the

concrete/tiled floor. Photosensors are used to track these particles.

Inertial:

The guide path is programmed on a microprocessorwhich is fixed on the AGV

Sonar system is incorporated for finding obstacles.

7/31/2019 Agvs Lecture Viii Sem

19/31

Infrared: Infrared light transmitters are used to detect the

position of the vehicle. Reflectors are affixed on the top of vehicle to reflect

the light.

Laser: Laser beam is used to scan wall-mounted

bar-coded reflectors.

Accurate positioning can be obtained.

Teaching type: AGV learns the guide path by moving the required

route.

Sends the information to the host computer.

7/31/2019 Agvs Lecture Viii Sem

20/31

Unobstructed movement

Flexibility Locations, path, P/D points can be reprogrammed

Easy to change guide path system

Number of vehicles can be altered depending on requirement

Greater reliability Less environmental problems

AGV can be replaced by another, in case of failure.

Lower investment

Higher operating savings on long run

Minimal labor cost

Easy maintenance

Easy to interface with other systems

Best choice for AS/RS, FMS

Advantages of AGVs

7/31/2019 Agvs Lecture Viii Sem

21/31

7/31/2019 Agvs Lecture Viii Sem

22/31

Motivation

An FMS provides an automated cost effective

manufacturing set up

To facilitate the successful running of an FMS

system, quick and accurate transportation of thefollowing are required,

Parts

Pallets

Fixtures

Tools

Automated Storage and Retrieval Systems

(AS/RS)

7/31/2019 Agvs Lecture Viii Sem

23/31

Combination of

equipment and controls

Which,

Handles

Stores

and Retrieves

materials with

Precision Accuracy

and Speed

With a defined degree of Automation

Definition of AS/RS

7/31/2019 Agvs Lecture Viii Sem

24/31

Automatic removal of an item from a storage

location

Transportation of this item to a specific

processing or interface point

Automatic storage of an item in a

predetermined location

Automatic reception and processing of itemsfrom a processing or interface point

Functions of AS/RS

7/31/2019 Agvs Lecture Viii Sem

25/31

Typical AS/RS systems

7/31/2019 Agvs Lecture Viii Sem

26/31

Storage space

Bay

Row

Aisle/Unit

Racks

S/R machine

Storagemodules

Components and Terminology

7/31/2019 Agvs Lecture Viii Sem

27/31

Some advantages of using AS/RS are:

High space efficiency

Improved inventory management and control

Reduction in labor costs

Better security

Flexibility in design to accommodate various

loads

Increased productivity when interfaced withother manufacturing systems like FMS etc

Helps JIT implementation

Advantages

7/31/2019 Agvs Lecture Viii Sem

28/31

Unit Load AS/RS

Multi Load AS/RS

Person on board AS/RS

Deep Lane AS/RS

Automated item retrieval system

Types of AS/RS

7/31/2019 Agvs Lecture Viii Sem

29/31

Used for

palletized/containerloads with standardsizes

Computerized andAutomated

Uses automated SRmachines

Uses rails forguidance

Unit Load AS/RS

7/31/2019 Agvs Lecture Viii Sem

30/31

Handling of small loads/

individual parts

Ideal for cases where

space is limited

Low volume productions

Smaller investment and

greater flexibility

Mini Load AS/RS

7/31/2019 Agvs Lecture Viii Sem

31/31

Allows storage of

items in less thanload quantities.

Person performs

tasks of selectionand picking

Flexibility and time

reduction

Person on Board AS/RS