Intelligent Workflows for Gear Grinding – ETG

High volume production requires uncompromising quality with increasingly shorter processing times.

Machines are technically advanced, and significant cost savings are no longer found among the processing techniques. But within upstream and downstream process stages such as set-up, measurement and communication between machine and measurement equipment. The Engineering Technology Group (ETG) has discussed how the Kapp Niles platform can tie together and automate these processes to streamline productivity, thanks further to open standards such as umati and GDE.

There are different approaches to further increase the efficiency of production processes by integrating as many process steps as possible into one machine. However, from a technical point of view, this is very complex and inflexible, and thus unreliable.

This is why KAPP NILES and ETG choose a different path.

“Instead of integrated machines, we rather envision integrated production chains with as little manual handling between individual chain links as possible. We continue to develop from a pure machine manufacturer to a provider of solutions,” says Konstantin Schäfer, Head of Product Management at Kapp Niles.

This becomes apparent in the growing measurement technology sector, Kapp Niles Metrology. Their existing portfolio is being optimised for production systems to communicate with each other. In particular, through the new KN assist platform, Kapp Niles and ETG can support the user with the control system software KN grinding from project planning through to production.

KN grinding, a hands-on control system

As part of the project-related configuration, all required processing options are combined in one workpiece project. With the step-by-step intuitive user interface, concrete project data is collected. In a virtual set-up process, the user selects the gear type and the suitable tools from a component set. Each step is displayed on a conventionalised machine.

Upon request, KN grinding offers technological suggestions. Volker Zenker, Software Development Manager at Kapp Niles explains: “Unlike with previous releases, critical or incorrect values are displayed to the user. A sequential control allows for a straightforward compilation of workflows via drag & drop. This comes in very handy for the complex processing of workpieces with multiple processing positions within one project. These generated sequences can be used for automated processing as well as for set-up sequences. The need for softkeys is replaced by a touch screen control panel display. All new machine generations feature this control system.

No data security compromises

Compared to highly automated production centres, it seems like a relic of the early days of industrialisation if operating personnel have to walk from the measurement room to the machine to carry over measurement reports to type in corrected values manually. However, this is still practised within a high-tech environment due to users’ extremely high safety standards, such as the automotive industry has circumvented simple data integration. Moreover, the use of USB sticks is strictly prohibited.

Another factor has been the lack of consistent data transmission standards to allow for secure data integration. That is why Kapp Niles has developed solutions that no longer require the installation of invasive software and thus allow users to retain control over their data at all times. Konstantin Schäfer: “This concept does not include any cloud services.“ Applications that go beyond direct machine control are programmed in HTML5. This allows the user to apply them on both classic computers and mobile end devices.

KN assist: the bigger picture

The result of the above is the KN assist platform. Thanks to HTML5 programming, KN assist runs without any further software requirements on a PC and mobile devices alike. All the user has to do is to call up a single address on the Intranet and thus is granted access to the system through his browser or an app. The data exchange takes place via the standard interface OPC UA (Open Platform Communications Unified Architecture) facilitating machine-to-machine communication with very little effort. As an overview of the overall system array. KN assist uses the open data exchange format such as GDE (Gear Data Exchange) and umati (universal machine tool interface), developed by VDW in cooperation with project partners.

This allows the exchange of basic gear/toothing data, modifications and assessments among manufacturers. Furthermore, the operating states of all machines in the plant are displayed. This gives each user from every location a production overview. An even more complex application is the data management of all component-specific parts such as clamping, dressing and grinding tools. Until now, component set-up data had to be manually entered into the machine to avoid the possibility of supplier data carriers accessing the production areas.

In future, RFID or 2D codes will be attached to dressing rolls, worms or clamping tools which will be read by the machines. This reduces set-up times considerably and allows components to be identified. Storage locations, service life, clamping cycles or assignments to a project in planning can be conveniently documented this way. In doing so, the response time to service requests and internal processes is reduced.

 Quicker response times to service requests

The customer expects prompt service in the case of a service request or system malfunction. However, the classic chain of messages is comparatively slow. Machine operators detect an error, notify the service department and describe the problem. The service department then contacts the manufacturer – and so on. In following this process chain, information can get lost or displays can be misread. Moreover, the machine manufacturer will have to collect, update and analyse the data first. Conventional data transmission via the internet would be feasible.

However, it is considered insecure by most users. Kapp Niles has taken remedial action for this process where the customer can now initiate the contact in KN grind system. Christian Füger, Manager of Sales Service, describes the option: “The service request can be initiated via a button on the display of the machine or via the web interface of any mobile end device. This allows the service manager, operator or planner alike to respond without delay.”

The service request is sent to Kapp Niles directly via a TÜV-IT-certified VPN connection. Diagnostic data and log files of the relevant machine will be provided to the customer upon explicit release, without losing the royalties over the process and the data. Currently, the response time is around 12 hours. In other time zones without local representation, 24 hours at worst. Christian Füger says: “We strive for end-to-end service with a response time of two to four hours. This can be done, as all information such as commission numbers, error patterns and measurement reports are already provided along with the service request.”

Turbo for the measurement technology

The portfolio now includes machines for production-related measurements, as significant time savings can be achieved for follow-up work of grinding processes.

During the classic process, random workpiece samples were taken from production to be carried to the measuring machine usually located in a different hall. Depending on the workload, the results would usually be available about 15-20 minutes later. Afterwards, the measurement report had to be taken back to the machine to manually type in the corrections. To reduce these times, Kapp Niles is drawing on multiple factors. The measuring machines are also designed for product-related applications and they can do without a climate chamber.

The individual axes and the workpiece are monitored via sensors for temperature compensation purposes. Air springs absorb vibrations to ensure the measurement accuracy meets the highest standards, even in high volume production. Gerhard Mohr, Managing Director of Kapp Niles Metrology, lays out the benefits:

“The machines can be accessed freely by the operator from three sides, and thus is also suitable for automated loading. Flexible positionable counter holders are provided for the measurement of wave-shaped parts. In addition, the machines can be converted into a new workpiece in seconds with a quick change clamping system. Automation also contributes to save time”.

The direct connection between the grinding and measuring machines is known as the ‘closed loop’. The measuring machine provides data not only in form of reports but also as GDE dataset. In the first version, these are the typical correction variables (fHα, fHß, tangent length correction /pitch correction) which will change in the case of a temperature increase or tool wear.

Compared to a manual input, this data can be imported and analysed quicker with fewer errors. If a new measurement result is provided, the operator will be notified and receive correction suggestions. Christian Graf from the Kapp Niles Software Development Team explains: “What happens here is not a pure TARGET/ACTUAL comparison. On the contrary, the operator receives the prepared measured values, which allows him to decide whether and how he will intervene. Based on the project, automated tracking is another option.”

Overall, the described measures will significantly speed up and simplify the workflow. The user gains a better overview of the production process while taking advantage of the many benefits of the new software platform, even on a multi-vendor basis.