MES in Vehicle Manufacturing - Punch & PMC

Building a vehicle requires lots of money. To develop a new type of vehicle, almost needs 500 million RMB for development and 2 billion RMB for manufacturing. Development cost include: model design, prototyping, process design, component design, vehicle calibration, vehicle testing, component testing. Manufacturing cost include: facility building, device buying and setup, production preparation. During manufacturing cost, device buying and setup take almost 3/4, and Punch Shop takes 35% of device cost in whole plant. Suppose one type of vehicle is very welcomed by customers, its sales number is beyond plant’s building capacity, in that case, is it possible to expand plant and buy more devices to build more vehicles? From point of view of Punch Shop, it’s very difficult. Because punch machine has very high requirement to ground flatness and stability, so it’ll take very long time to build punch facility. Besides that, punch models also need long time to build. So in order to improve plant capacity, it’s most likely to use current devices effectively as possible. Punch process includes: Unpack, get material, transfer material, positioning, feed material, cleaning, punch, test. Most processes are done by punch machine automatically, operators assist machine accordingly. So, production and devices and systems need to support devices: - Operators need to assist devices to ensure daily work continuously. - Device engineers need to maintain devices, and fix problems ASAP. - Systems need to find out any errors or alerts, and to notify engineers accordingly. So in Punch Shop, the main functions of MES is PMC. PMS is short of Production Monitoring and Control, in MES field, it’s focus on devices. PMC collects below information: 1) Devices’ running state. 2) Device abnormal information, such as alert code, error code. 3) Number counters, such as shift production counter, buffer zone counter. 4) Time counters, such as accumulated down time. 5) Devices’ key process parameters. 6) Working-in-process product information, such as serial number, material number, model type. 7) Production rate information, such as assembly time, waiting time, blocked time. 8) Line speed. Technically speaking, MES is mainly collecting device data via PLC. PLC is short of Programmable Logic Controller, is the logic layer and application interface of devices. PLC stores PMC related business data into specific Data Blocks, and then MES get data from PLC via OPC. OPC is short of OLE for Process Control, can map PLC data into OPC Server memory tags. MES communicates with OPC via OPC client or IIoT gateway. Below diagram shows PMC data flow:

Diagram 2.1-1: PMC Data Flow We can see that, after OPC collected devices data from PLC, it uses data for 2 purpose: 1) OPC sends data to SCADA Server, and then output data in real time via SCADA client. 2) OPC sends data to MES Server, archives in Database, then outputs as report. In lineside, operators and engineers are checking real time data. SCADA is short of Supervisory Control And Data Acquisition. Production department can monitor and control devices remotely, and IT uses SCADA for collecting and displaying data. Popular SCADA products include: Siemens WinCC, Rockwell FTView, GE Cimplicity. SCADA server can synchronize data from OPC server quickly, its rate frequency is 250ms~1000ms, and then SCADA client gets data from SCADA Server, and then output data into TV or LED board.