Holistic standardisation approach for tyre industry
A holistic standardisation approach for tyre industry focused on reusable and modular objects is essential to get the best benefits for end users. Therefore the use of international standards such as ISA S88 (IEC 61512) is the basic to be successful. This standardisation approach has to cover both batch and continuous processes. Siemens is able to provide standardised solution for mixing areas and the whole tyre factory as well.
Currently, if a plant manufacturer is buying machines from different suppliers, the structure of the application software is always different. This prevents a smart horizontal and vertical integration and the integration effort is increased. Additionally, the end user has much higher training efforts of its operator and maintenance peoples and troubleshooting is more complex and time-consuming. Therefore the use and implementation of an industry standard focused on modularisation, reusability, and clear definition of data interfaces is needed. Based on the knowledge and experience from mixing areas, Siemens is able to offer a holistic approach for a standardised solution for the whole tyre factory.
Open and flexible approach
As basic for a technological engineering the ISA S88 technological hierarchy standard is used. Based on this standard, each part of a tyre manufacturing can be split into areas, production cells, units, equipment modules, and control modules. Within each level the user is able to take care about reusability and between the different levels about the needed data interfaces for logistics, supervisory control and data acquisition solution and MES system solution.
Example of the mixing area and the adaption of the ISA S88 standard:
Mode-/ State model according to ISA S88 & Weihenstephaner standard
From the perspective of an end user it is very important, that each machine follows a unique mode-/ state model. This helps the operator to understand the behavior of each machine independent of the supplier of the machine. He recognise the state of the machine and if there is the need to activate the next step (e.g. via “start” command). Typically, there could be several different state models according to the program (e.g. production, start up, maintenance, etc.) available. One possible solution for that is the use of the mode-/ state model according to ISA S88 & Weihenstephan.
Reusable and modular library objects
According to a clear structuring according to ISA S88 the engineer is able to define a holistic approach for a software object model, which has the clear focus on reusability.
Each reusable object at control module level (such as motor, valve, inverter, etc.) or each equipment module (such as conveyor, cylinder, etc.) or units and production cells consists of several data aspects. Typical data aspects are software blocks, hardware, tags, alarms and messages, diagnostics, visualization faceplates and screens, simulation data, circuit diagrams, state model, simulation model, etc.
All these data aspects are available within the screen windows for the visualization part at operator panel to get the needed information just in time.
Support of virtual commissioning
More and more users are using solutions for virtual commissioning to get in an early phase of the development a higher quality, before the real commission phase will start. Therefore for each reusable technological object a virtual data aspect is provided as well. Within this data aspect the physical behaviour of this object is described and the user is able to manipulate the I/O interface manually or connect them with a simulation framework. This offers the users the possibility to start a realistic simulation scenario for any part of a tyre site with software and hardware in the loop.
First step of virtual commissioning
In the first step of virtual commissioning each part is still virtually. The production line with process is represented in a simulation framework and/or the machine behavior is available as simulation model as well. The test is done without any interaction with real automation components
In the second step a first automation component (e.g. developed software) is added to these simulation scenarios. The production line and the machines are still virtually. The PLC is still virtually and may be represented by a simulation tool. It controls and drives the virtual process of the machine. By connecting the simulation model of the machine with the simulation model of the PLC the user is able to test his developed software driven by the mechanics model.
In the third step the developed software is running at the real PLC. This PLC is controlling and interacting with the simulated process, usually by exchanging I/O signals through OPC. Another possibility is using a specific simulation system which is able to simulate the environment of I/O-signals and field bus devices in real time. This virtual commissioning phase is much closer to the real world. The real behaviour of the automation components becomes increasingly significant
The human machine interface or operator panel may also be real. The visualization part which represents the human interaction with the process is modulated or part of the process simulation as well. This phase can be used to train in an early phase the operator of the machines. The machine itself is still virtually.
Benefits of virtual commissioning
- Quite a lot of errors can be discovered before the real commissioning
- Reduces down times in the shop floor
- Early training of the operator personals
- Factory acceptance test before the real commissioning
Application example for mixer lines
Siemens presents at the Tyre Technology Expo in Hannover an application example of a mixer line based on reusable library objects for tyre industry. The user is able to create very fast a first approach for a mixer line by using these library objects and sample solutions. The visualization part is generated according to the call up structure of the PLC program automatically. Each object has a connection to the circuit diagram to get detailed information about the wiring or hardware cabinets.
Benefits of standardisation
- Unique data and control structures focused on horizontal (machine-to-machine) and vertical (machine-to-SCADA/MES) integration.
- Reduction of the total cost of ownership for end-users
- Simplification of the machines modularization
- Re-use of objects at each level of modularization (e.g. control modules, equipment modules, units)
The consistent use of reusable and standardised objects for PLC programing, visualization and simulation simplify and accelerate the engineering. Thereby the user is able to create sample solutions which are adaptable very fast to the needed solution. Siemens has a lot of experience within tyre industry, offers solutions for standardisation and knows very well the needs of end users, OEMs and system integrators.