When tools learn how to communicate
The fourth industrial revolution isn’t the result of an innovative thunderbolt that drew the industry into a new era overnight. Rather, it is an interplay of several developments and innovations that together lead to ever closer networking of machines, production methods and people.
Even before Industry 4.0 became a buzzword in the media, Schubert had looked well beyond pure mechanics when engineering its packaging machines. The VMS packaging machine control system has already been in use for over 20 years now, connecting packaging line components and sub-machines to each other. Reliable mechanics, intelligent control and easily interchangeable robot tools have always been intrinsic to Schubert’s TLM machines.
Reduction to the essentials
The most recent example of these developments is the first packaging machine without an electrical cabinet. This innovation was made possible, among other things, by reducing wiring within the aggregates. Schubert System Elektronik (SSE), a Schubert subsidiary, made a vital contribution to this with the development of the latest generation of the WK5 tool control. This gateway links the control level to the sensors and actuators of the lowest field level – i.e. the tools on the individual robots.
The tool control mounted on a robot is directly connected to the VMS packaging machine control (on this image).
Managing director Ralf Schubert, who was annoyed at how difficult it was to clearly identify the source of errors in sensors and actuators, was the driver behind the latest generation of tool control. Until then, it had not been possible to assign individual error messages to a specific actuator or sensor on the robot. The experts from Schubert System Elektronik found the solution to this problem through the use of a much more versatile sensor/actuator bus system – via IO-Link. “By using IO-Link, it is possible to transmit various types of data and more complex data to actuators or sensors with a single cable,” explains Werner Sauter, Head of Development at SSE. “Since each wiring can be a potential source of error, our new control prevents errors and, with its exceptional flexibility when exchanging data, it expands the development possibilities of Schubert’s robotic tools,” adds Harald Gehring, Head of Hardware Development.
The tool control WK5 has been developed by Schubert System Elektronik (SSE), a subsidiary of Gerhard Schubert GmbH Verpackungsmaschinen.
Clear error messages
One VMS module is responsible for controlling the functions of each sub-machine. Robots with their tools, Transmoduls, NC axes, frequency converters, actuating drives, scanners, cameras, user guidance, error visualisation, PLC functionality, the integration of third-party devices and the connection to higher-level software systems are all integrated with the packaging machine control system – via a single software. Via IO-Link, it is now possible to not only transmit digital switching information from and to VMS control, but to also make available further phases of a sensor/actuator. “With the WK5, we are bridging the IO-based, modern bus systems and a physically straightforward IO signal. This enables error messages to be clearly assigned,” says Tobias Ott, Head of Embedded Software at Schubert System Elektronik. The WK5 is designed such that every IO-Link-enabled component can be controlled. The new control technology opens the door for the development of further applications for Schubert’s robot tools. And, over the next few years, it will entail further innovations in the field of automated packaging applications.
Operation of the gateway
The WK-5 functions as a gateway for the connection of intelligent sensors and actuators on the robot arm, or on the changeable tool of a Schubert packaging machine, with the control level – i.e. the VMS packaging machine control. The WK5 collects sensor data and makes it available to the Sercos bus, or vice versa with actuator data. The connection between the VMS module and the automation components within the sub-machine takes place via a local Sercos ring. Each sub-machine has a local Sercos ring which allows the connections between the sub-machine’s VMS module and the bus users in the sub-machine such as drives or digital input-output nodes. In turn, the global Sercos ring connects all VMS modules and enables communication between the modules and with their peripherals.
In this case, the WK5 is mounted on a F2 packaging robot.
Since the WK5 is essentially a bus enabling data to be exchanged between several users within a connection, additional information can also be transmitted – such as user-specific parameters, additional information or even maintenance information, depending on the type of sensor. For example, a light barrier can convey information on the degree of contamination or aging phenomena. This means that data on the probability of failure will be transmitted before it actually happens. In the context of normally planned maintenance, this exchange of information can take place without causing downtime. And this wear warning is defined and programmed for all components in detail.
During day-to-day operations, customers benefit from reduced downtime and reliable machine operation through clear error messages and reduced error sources. The WK5 also opens up entirely new development possibilities and, together with automatic tool exchange, it represents a further step towards fully automatic machine maintenance.