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Twin-model based virtual manufacturing for machine tool-process simulation and control

Periodic Reporting for period 2 - TWIN-CONTROL (Twin-model based virtual manufacturing for machine tool-process simulation and control)

Reporting period: 2017-04-01 to 2018-09-30

Simulation tools are currently a key complement to European machine tool industry expertise to increase competitiveness. In fact, according to Industry 4.0 modelling plays a key role in managing the increasing complexity of technological systems. However, the different available software packages are focused in a single feature related to machine tool or machining process. Due to the fact that machining process performance is related to the combination of the different phenomena, it can be concluded that there is a need to integrate the most important effects in a common simulation environment in which the machine tool, the process and other aspects (life cycle features) are simultaneously analysed.

In Industry 4.0 knowledge of the process obtained through monitoring plays a key role in documenting system and processing status. The combination of models and process monitoring will be useful not only in the development and design stages, but mainly during the production stage to check that production is running smoothly, detect wear and tear without needing to halt production or predict component failure and other disruptions.

The main objective of this project is the development of a simulation and control system that integrates the different aspects that affect machine tool and machining performance. This holistic approach will allow a better estimation of machining performance than single featured simulation packages. In addition, lifecycle concepts like energy consumption and end-life of components will be integrated too.

Apart from estimation purposes, the developed tool will be installed within machine tool CNCs and will allow a direct control of the process through monitoring. The monitored data combined by the model-based estimations will allow an improved performance of the manufacturing process by controlling component degradation and optimize maintenance actions, increase energy efficiency, modify process parameters to increase efficiency or even smoothen it to protect a degraded component until the next planned maintenance stop, etc.
Based on feedback from the end users involved in Twin-Control, the requirements of the projects were determined in detail. After this preliminary work, technical developments were carried out to obtain different features that have been integrated in three main exploitable results of the project.

A new approach to simulate machining processes has been developed based in SAMCEF Mecano FEM solver. A digital representation of machine tools can be developed in this environment by combining structural FEM analysis, specific elements for the feed drives and control loop models. The novelty of this approach consists in the integration of new machining process models that provides the chance to evaluate machine tool performance during manufacturing operations. For process-specific analysis, these models are also available in standalone mode to provide a fast and easy simulation tool. The loads estimated by this integrated simulation can be used by additional modules simulating life cycle performance of the machines.

An advanced local monitoring and control system has been developed, based in ARTIS hardware and integrating new features developed by Twin-Control partners. ARTIS Genior Modular can connect to machine CNC/PLC and get internal signals at a high sample rate. Apart from the complete monitoring capabilities, this system has enhanced features:
- Process monitoring: after a learning stage of a specific process, process related thresholds are defined for all monitored signals that allow detecting anomalous performance. The integration of the new process models developed in Twin-Control will allow the determination of these thresholds without the need of a learning stage.
- Adaptive feedrate control: According to a defined spindle consumption setpoint, the system can adapt machine tool feedrate to increase productivity.
- Component-level energy monitoring: a low-cost energy monitoring concept is proposed, based on the disaggregation of the machine’s total power consumption.
- Collision Avoidance System: a graphical simulation environment that uses real positions of the machine, and I able to predict collisions and stop the machine in advance.

A cloud-based fleet-wide platform for machine tool condition, performance analysis and proactive maintenance has been developed. The KASEM® platform, provides an easy-to-use interface, allowing creation of algorithms and visualization of the evolution of indicators or the generated reports. The solution provides:
- More than 60 KPIs for the health status of machine-tool and its sub-systems
- An accurate and dynamic diagnostic tool thanks to a root-cause analysis and modelling of physics
- Additional indicators obtained by the implementation of the Quick Machine Tool Characterization tests developed in Twin-Control
- Integration of Remaining Useful Life (RUL) calculation of critical components.

In the last year of the project, the different developments have been evaluated in two industrial validation scenarios: aerospace and automotive. The evaluation served to validate the presented features, apply them in an industrial environment and evaluate the impact on end users.

A complete exploitation plan (business model, market and risk analysis) has been defined for the three main results of the project. For each result an exploitation leader has been defined to finalize the work to make these results ready for market.

Twin-Control activities have been disseminated to different audience. The website (http://twincontrol.eu/) and twitter account (@Twin_Control) have been providing updated information about project status and relevant events to the general public. Project developments have been also presented in industrial forums, like machine tool fairs, and specific workshops have been organized in relevant pilot lines by project partners. Regarding scientific dissemination, apart from presentations of project results in several international conferences, a book compiling project activity
The three main project results are beyond the state of the art:
- The Digital Twin integrating a dynamic interaction of machine tool dynamics, machining process and control loops.
- A local monitoring system that integrates advanced features like Collision Avoidance System and Energy Monitoring.
- A fleet platform for machine tools showing relevant cause-effect examples of machine tool and/or process failure.

Regarding wide-scope impacts, the contribution of Twin-Control is:
- Reduction of machine tool design, development and set-up time and costs (10%)
- Reduction of machining process design and set-up time (10-20%)
- Reduction in energy consumption (60%), combining efficient machine design and energy monitoring
- Reduction of scrap parts (10 %)
- Reduction of 30 % in corrective maintenance costs
- Increase in machine up-time (up to 10%)
- Reduction of life-cycle costs by 15%
- Reduction of Operation and Maintenance costs by 25%
KASEM HMI
Digital Twin of the GEPRO 502 machine tool (aerospace use case)
Twin-Control concept diagram
Collision Avoidance System implemented in a SIEMENS CNC