Components of FMS

Basic components

• Workstations

• Material Handling Systems

• Storage Systems

• Computer Control Systems

• Human resources

Workstations• Load/unload

stations– It act as the physical

interface between the FMS and the rest of the factory

– Raw workparts enter the system at load station, while finished work parts exit at unload station

– Manual loading/unloading is more prevalent

Workstations – contd.

• Load/unload stations – contd.– A certain level of cleanliness should be maintained at

this workplace and hence air hoses/washing facilities are often required to flush away chips

– Generally, these stations are raised slightly above the floor level using an open ground platform for permitting the chips and cutting fluid to drop through the openings

– It may have a data entry unit and monitor to communicate between the operator and computer system which includes which parts are to be loaded, which pallet is required, etc.

Workstations – contd.

• Machining centre– Most common

application of FMS are for machining operation

– Workstations are predominantly CNC machine tools – especially, horizontal machining centers

Workstations – contd.• Machining centre – contd.

– CNC machining centres will have the following features

• Automatic tool changer• Tool magazine• Use of palletized work parts• CNC machine• Capability of distributed numerical control

– Machining centres are used for non-rotational parts (or for milling, drilling, etc.)

– Turning centres are used for rotational parts– Certain machining centres will have horizontal,

vertical and multiple spindles, while in certain turning centres, single point cutting tool can be rotated around the work part

Workstations – contd.

Workstations – contd.

• Other processing stations– FMS can also be

applied for carrying out other processing operations such as sheet metal fabrication

– Workstations will perform different processes such as punching, shearing, bending, etc.

Workstations – contd.

Assembly• Flexible automated assembly systems are developed to

replaced manual assembly systems• Industrial robots are used as workstations in the flexible

assembly• It can be programmed to perform tasks with variation in

sequence and motion pattern to accommodate various product styles

Other workstations• Cleaning stations • Inspection systems

Other workstations – contd.• Automatic chip

removal system • Central coolant

delivery system

Material Handling Equipment

• The material handling function in a FMS is often shared between two systems– Primary handling system

• Establishes the basis layout of the system

• Responsible for moving parts between workstations

• Eg. Conveyor, AGVs, etc.

Material Handling – contd.

– Secondary handling system• Consists of transfer devices, automatic pallet

changers etc.• Main functions are

– Transfer work from the primary system to the machine tool

– Position the parts with significant accuracy and repeatability to perform processing/assembly operation

– Reorientation of the part if necessary to present the surface to be processed

– Buffer storage of parts to minimize work change time and maximize station utilization

Material Handling – contd.

• MHS determines the layout configuration of FMS

• Different configurations of layout are:– In-line layout– Loop layout– Ladder layout– Open field layout– Robot centered layout

Material Handling – contd.

• In-line layout– Machines and MHS are arranged in straight line– Parts moves from one machine to another in

sequence and there is no backflow– Work moves in one direction only, which is similar to

transfer line (FML)– Has only a primary MHS– If greater flexibility is required, a linear transfer system

that permits movement in 2 directions can be installed• In this case, a secondary MHS is provided along with primary

MHS

Material Handling – contd.

• In-line layout

Material Handling – contd.• Loop layout

– Workstations are organized in a loop, which is served by a MHS

– Parts usually flow in one direction around the loop, with the capability to stop and be transferred to any station

– A secondary handling system is used at each workstation to permit parts to move without obstruction around the loop

– Load/unload stations are located at one end of the loop

– Alternative term of loop layout is rectangular layout• This arrangement is used to return pallets to the starting

position in a straight line machine arrangement

Material Handling – contd.

• Loop layout

Material Handling – contd.

• Ladder layout– Consists of a loop with rings between the

straight sections of the loop on which workstations are located

– Rings increases the possible ways of getting from one machine to another and removes the need for secondary MHS

– Reduces average travel distance and congestion in the handling system, which will lead to reduction in transport time

Material Handling – contd.

• Ladder layout

Material Handling – contd.

• Open field layout– Consists of multiple loops and ladders and

may include sidings– Is used for processing a large family of parts– Number of different machine types may be

limited and parts are routed to different workstations depending on which one becomes available first

Material Handling – contd.

• Robot centred cell – Uses one or more

robots as the MHS– Industrial robots can

be equipped with grippers that make them suited for the handling of rotational parts

– They are often used for processing cylindrical or disc shaped parts