Machine Control and Shutdown via Radio

2008-Mar-08 | Siemens has developed a system for precisely operating industrial equipment on the basis of the wireless WLAN radio standard, which makes it possible to control factory machinery via radio signals, for example. The system’s unique feature is an emergency shutdown function that can be activated via mobile devices. The solution opens up new possibilities in production, such as the establishment of rotating production equipment or the operation of driverless transport systems. Due to its cutting-edge technology several carmakers including Audi and VW are using the system.
Until now, radio networks have been used mainly for home and office communication, despite the fact that their fast data transfer rates make them suitable for controlling industrial machines. The risk was too great that precisely aligned industrial processes carried out by individual machines could be interrupted if commands arrive too late. In the case of a WLAN network, for example, data packages are placed on hold, so to speak, if the network becomes overloaded — which means they are ultimately sent to receivers later than intended. The problem is that even a delay lasting only milliseconds can cause severe disturbances to a production process. The wired systems that industrial companies have used so far, however, require expensive special coverings in dusty and damp areas like paint shops. Wires and cables also place limits on production options, because they are not suitable for things like rotating production equipment.

Now, with Industrial WLAN (IWLAN), Siemens Industry Automation has developed a radio network that achieves the necessary reliability by reserving data transfer rates especially for machine commands. At the same time, “redundant” antennas and time-monitored signal transmission ensure permanent wireless connections. Special casings for receivers also make the system resistant to disruptions such as those caused by electro-magnetic machines, and encryption and access control systems protect against external computer attacks. Separate wiring used to be required for emergency shutdown functions — but this feature can now be implemented wirelessly via the reserved data transfer rates, as was reported by the Pictures of the Future research magazine.

Because IWLAN is based on the WLAN standard, it can easily be integrated into existing networks and Ethernet systems. Audi, for example, uses it in production of its R8 sports car. Here, the vehicle body is mounted on a device that can rotate 360 degrees, enabling bolting robots to easily reach every corner.