Smart design and best practice of vehicle manufacturing
1. Smart Designs and
Best Practices
of Vehicle Manufacturing
Tallrain Zhang, Jul 2015
tallrain@gmail.com
2. Data
• 4 Processes: Stamping, Welding, Painting, Assembly.
• A car body is made of 300-500 pieces of steel plates.
• A car contains 5000-6000 welding points, 90% of them are welded by
Robots.
• A car will be covered by 4-6 layers of paint, 90% of operations are
done by Robots.
• A car goes through 200+ assembly stations before it’s completed.
3. Systems
• Scheduling System: which car to build, how to build it, how to
communicate with Plan Layer and Device Layer.
• Kanban & Andon.
• Error Proofing: of material rack, of tools.
• Quality System: Defect, Short Build, Scrap, Quality Gate.
• Key material genealogy.
• Kitting System.
• Call Material System.
• Measuring System.
4. Cooperation
• ERP to deliver Work Order information.
• PLM to deliver BOM data.
• WMS to deliver material and warehouse information.
• MES to schedule work orders, to define BOM into station level, and
then to define Error Proofing. MES to talk with PLC via OPC.
• PLC defines logic level of all devices which need to talk to upper level
systems.
• Device/Robots/Tools/Sensors to execute physical control operations.
5. Scheduling – Get New Order
• Business: at one welding station, after
completing current vehicle, Robot
requests to Scheduling System to get
next order. Then Scheduling System
deliver next order with vehicle
configuration data, into PLC data blocks.
• Logic: Scheduling System to query and
get next available order according to
order sequence, and then to get vehicle
configuration data from system, and then
write all data into PLC data blocks.
Robot
PLC
MES Server
MES DB
Return Next
Vehicle
Request Next
Vehicle
6. Scheduling – Read Order
• Business: when vehicle arrives, PLC
reads vehicle ID from RFID, and then
request to get vehicle configuration
data from Scheduling System.
• Logic: Scheduling System reads vehicle
ID from PLC, and then to query vehicle
configuration data from Database, and
then write all data into PLC data blocks.
Robot
PLC
MES Server
MES DB
Returns vehicle
configuration data
Input Current
Vehicle ID
7. Scheduling - Holding
• Business: Planner or Quality Engineer holds a vehicle in system, and
then in the shop, vehicle bypasses some manufacturing stations,
then comes to Line Off point via Turn Table.
• Logic: When receiving Read Order Request from PLC, Scheduling
System returns vehicle order status and quality status together with
vehicle configuration data. If its order status is Hold, then PLC will
bypass manufacturing stations and put it into Line Off via Turn
Table.
Turn Table
Bypass
Station
Line Off
Bypass
Station
8. Scheduling – Turn Table
• Business: when vehicle comes through Turn Table, PLC checks its order status and
quality status, and then route it into next manufacturing station, or Repair Zone, or
Line Off.
• Logic: Scheduling System checks order status and quality status with vehicle ID, and
then write data into PLC. PLC routes vehicle according to the data value of PLC data
blocks.
Turn Table
Line Off
Repair Zone
Manufacturing
Station
Manufacturing
Station
Manufacturing
Station
Manufacturing
Station
9. Scheduling – Secured Gates
• Business: when vehicle
comes through a Secured
Gate, Traffic Light shows
route direction, and release
gate if it’s allowed.
• Logic: Scheduling System
writes order status and
quality status into PLC, then
based on the combination of
these 2 values, PLC decides
to route vehicle into
different directions, and
controls Traffic Light and
Gate Releasing accordingly.
10. Control - Robot
• In Roof welding station, Robot locates,
moves, and welds based on type of Roof.
• Logic: Scheduling system writes vehicle
configuration data into PLC, then PLC
controls Robots to call according profile
for the vehicle.
Robot
PLC
MES Server
MES DB
Returns vehicle
configuration data
Input Current
Vehicle ID
11. Control – Device with PLC
• Business: at Engine assembly shop, Filling
Machine fills according volume of gas for
each coming Engine.
• Logic: PLC sends out Engine ID, then
Scheduling System queries product BOM and
gets item number of Gas Tank, and then
converts it into mapping value according to
MES/PLC protocol. Then PLC controls
machine to fill gas accordingly.
Filling
Machine
PLC
MES Server
MES DB
Returns vehicle
configuration data
Input Current
Vehicle ID
12. Control – Device with PC
• Business: In Nameplate Laser
Scribing station, Laser Machine
scribes vehicle ID and its
configuration data for each
vehicle.
• Logic: Scheduling System shares
remote view to PC, which
controls Laser Machine. So this
PC can get all data for each
coming vehicle.
MES DB
Control PC
Laser
Machine
Remote View
14. Error Proofing – Get Vehicle ID
• Business: In the midst of some Conveyor controlled area, where no RFID or
Label is available, but Error Proofing needs to know the vehicle ID when it
comes to station.
• Logic: 1. Installs Encoder into Conveyor, and connects it into PLC, so now
PLC knows speed of Conveyor. 2. When vehicle comes to head of this area,
PLC gets vehicle ID via RFID or Label. Base on 1 & 2, we can get how long
will it for a vehicle between line head and a specific station. In return, we
can get vehicle ID only if we know the passing time and the station number.
15. Error Proofing – for Rack
• Business: When vehicle or engine comes to
station, system turns on Rack Light, tells
operators which items need to be assembled.
Only after operator picked item from exact
Rack location, Error Proofing is completed for
that item.
• Logic: after loading BOM from PLM,
manufacturing engineer defines item into
station and Rack locations. And each time a
new product comes, Error Proofing get Rack
location data and write it into PLC. When
operator picks an item from Rack, sensor
sends signal to PLC and completes Error
Proofing for this item.
Error
Proofing
Server
PLM BOM
BOM with
Rack info
PLC
Rack Light
Vehicle ID
16. Error Proofing – for Tool
• Business: when vehicle or engine comes to
station, system tells PLC which Torque
Guns need to be used. Only after clicking
these Guns, Error Proofing is completed.
• Logic: after loading BOM from PLM,
manufacturing engineer defines item into
station and Tool numbers. And each time a
new product comes, Error Proofing get
Tool number data and write it into PLC.
When operator clicks a Torque Gun, PLC
tells Error Proofing that Gun is completed.
Error
Proofing
Server
PLM BOM
BOM with
Tool info
PLC
Torque Gun
Vehicle ID
17. Quality - Defect
• Business: at assembly or
quality check stations,
operator could input Quality
Defects. And in Turn Tables or
Quality Gate, products with
Defects will be identified and
sent to Repair Zone.
• Logic: After defect input,
system updates vehicle’s
quality status. And in Turn
Table or Quality Gate, PLC gets
quality status from system and
controls routes accordingly.
Have Defect?Quality Status
Turn Table
Quality Gate
Repair Zone
18. Quality – Short Build
• Business: at quality control
points, system detects if any
parts are short built, and then
alert operators for it.
• Logic: manufacturing
engineer defines BOM into
station level as To-build BOM,
and system records all parts
already assembled as Built
BOM. To-build BOM – Built
BOM = Short Build BOM.
MES Server
PLM BOM
To Build BOM
Finding Short Build?
Built BOM
Quality Status
19. Quality Gate
• Business: at Quality Gate, system checks
all quality information, and returns
Quality Gate result.
• Logic: system will check if there’s any
hold, scrap, defect, short build, test
failure, and then make it as a Quality
Gate report, and then update quality
status and write it into PLC.
Hold or Scrap?
Defect?
Short Build?
Test Failed?
Quality Gate Result
20. Testing – Device with PLC
• Business: when vehicle comes into test
device, system sends test profiles,
parameters into device, and collect data
and result from it.
• Logic: based on vehicle ID, system
queries database and gets test
parameters for the station and writes
into PLC. PLC controls device to test and
then sends data and result back into
system.
Test Device
PLC
MES Server
MES DB
Return Test
Parameters
Input Vehicle
ID
Test
Parameters Test Result
Upload Test
Result
21. Testing – Device with PC
• Business: when vehicle comes into test
device, system sends test profiles,
parameters into device, and collect data and
result from it.
• Logic: PC sends request to system via Web
Service to get test parameters, and uses
them for test, and then uploads data and
result into system via Web Service.
Test Device
PC
MES Server
MES DB
Test Result
Vehicle ID
Test
Parameters
Test
Parameters
Test Result
22. Material – Kitting by Sequence
• Business: Kitting according to vehicle sequence, delivery according to sequence.
• Logic: when vehicle passes trigger point, Scheduling System calls Kitting station for
that vehicle with Kitting BOM configured for the Kitting station, and when Kitting is
completed, Kitting box will be delivered into assembly station by sequence.
Trigger Point
Call Material
Deliver
Material
Kitting
Station
Assembly
Station
23. Material – Go with Conveyor moving
• Business: at some assembly area, materials are put
together inside a box, and moving with vehicle
together, so operator can assemble with vehicle
and conveyor moving.
• Logic: the box is Kitting box, which means the
materials are suit for that vehicle at that station.
Material Handling operations have been divided
into 3 sub-operation: Kitting, Delivery, Assembly,
with 3 different teams accordingly.
Delivery
Kitting
Assembly
Kitting Box