Control of an Assembly Line for Airbag Gas Generators with Java
Gas generators for airbag-
and retention systems are mass products with many variants. As a result an assembly line with a
high degree of flexibility is required. On the other hand a highly automated assembly system
consisting of a large number of mechanical and electronic components is required to meet today's
productivity goals. In the end, the extreme consumer safety requirements for gas generators demand
a complete and consequent documentation of all process parameters for every single item
produced.
To meet this opposed requirements software had to be designed supporting flexible assembly
line configurations and documenting all relevant process parameters.
As a result of the project Line 2000 of TRW Airbag Systems and Software Factory a new
software generation has been developed as a 100% Pure Java application to control the assembly
lines for gas generators at TRW Airbag Systems. The software incorporates the following core
components:
controls of the assembly line
communication module to Simatic S7
documentation system for the process parameters
statistical process control SPC
monitoring of the availability of all components
line editor for configuring the assembly line
product editor for the configuration of different product variants
job management
Based on the line configuration the product variants are configured and defined by parameters
and process sequences. The product variants are stored as master data to the products. To start job
on the production line only the product variant is to be selected from the master data and a
quantity is to be defined. In a single assembly line up to four different products can be
manufactured simultaneously.
The cycle time less 5 seconds in the production line leads to high requirements for safety,
availability and quality of the software package. The soft- and hardware components necessary for
running the line are redundant, so the line can be run even if one of the components breaks down.
An important advantage with the Linie 2000 concept is the line editor, which is capable to
model any kind of assembly line configuration to control the sequences of the components required
(modules, stations, material feeds, measuring devices, packaging stations, etc.).
fig. 1: Complex systems rely on quality software
fig. 2: Flexible Cell - Part of an assembly line with 10-15 units
fig. 3: Line editor for the assembly line configuration
More than 20 assembly lines using this software generation will take up production next
year.
