Pictures of the Future    Fall 2007

Factory Data Democracy

Let’s say you want to buy a new sports car. How would you order it? In black with light-colored seats, or maybe white with a silver side frame, or red with a manual transmission? The variety of consumer tastes has a major impact on industrial production, as it forces manufacturers to become more flexible and react to the growing demand for different designs. A state-of-the-art automotive paint shop today paints one body green, the next blue, and a third white. Bumpers and seats matching the vehicle color also need to be mounted.

Such individualization is just one trend that’s changing production processes. "The time from original idea to finished product is getting shorter," says Dr. Heiner Röhrl, head of Industrial Communication at Siemens Automation and Drives (A&D) in Nuremberg, Germany. This is having an impact on everyone in the production process—from product designers to production managers, suppliers, and distributors, all of whom need to access relevant product data more quickly than ever before.

"That’s why all production-related data should be collected only once, and then stored in a database accessible to everyone," says Röhrl, referring to merchandise management systems, development, production control, and accounting (see  Factories of the Future—Trends and UGS and Siemens). Production floors and offices are thus set to converge globally. "That’s the vision of the seamless factory," says Röhrl. "It’s a vision of a a common data library that allows production processes to be configured more rapidly and flexibly."

It is, in short, a vision of a virtual world of communication in which data flows from the factory paint shop to the executive suite. But for this vision to be translated into reality, local partner networks need to be able to exchange data—something they can’t do now because most networks have separate standards. What is needed, therefore, is a medium that communicates information across all local interfaces. "This medium will be Ethernet," says Röhrl. Ethernet is nothing new. It’s been used for more than 30 years to link office computers, while Industrial Ethernet has been networking production control systems for over 20 years. Now, however, Ethernet is set to take control of individual machines in factories.

Data that’s Always There. Yet significant challenges remain to be overcome. "The big issue is real-time data transmission," says Ewald Kuk, head of Product Management at Industrial Communication. "In office Ethernet systems, if a data packet has to wait a couple of seconds because the information highway is occupied, no one will notice." But that can’t be allowed to happen with production machines, the control processes for which often occur in the space of milliseconds or even microseconds. "Imagine a printing machine with several rollers," says Kuk. "If just one roller fails to operate completely in synch with the others, you can throw away the result. That’s why we’ve developed an Industrial Ethernet system that always keeps a high-priority lane open for time-critical data." (see Pictures of the Future, Fall 2005,  Wireless Wizardry). Because Industrial Ethernet is based on the office network standard, it has no problems with interface linkage.

But not all production areas can be connected via cables, which is why wireless solutions should be employed in difficult-to-reach areas, not to mention when it comes to driverless transport systems and rotating components. Audi, for example, uses IWLAN (Industrial Wireless Local Area Network) in the production of its R8 sports car. Here, the vehicle body is mounted on a device that can rotate 360 °, enabling bolting robots to reach every corner. Because IWLAN is based on the WLAN standard, it can easily be integrated into existing networks and Ethernet systems, whereby the wireless connection presents a challenge in addition to the real-time issue in that it needs to be reliable at all times. "If your cell phone drops a call, you can redial, but an interruption to the radio signal in a factory will result in expensive losses after just a few minutes," Kuk explains. IWLAN therefore uses redundant antennas, reserved data transfer packets, a time-monitored signal transmission system and a roaming function to ensure continuous connections. "Thanks to its patented innovations, Siemens has a lead of at least one-and-a-half years on the competition when it comes to reliable wireless data communications," says Kuk.

IWLAN technology is very complex because factories contain a lot of equipment that can interfere with signals. There are metal machines, devices that emit electromagnetic waves, and areas with very high temperatures and vibrations. Uninterrupted connections can be ensured by using special materials for receiver housings and secure installations for circuit boards from Siemens’ Scalance W product family. In addition, encryption and access control systems do their part to protect against external computer attacks. At the 2007 Hannover trade fair, Siemens presented a new wireless emergency cut-off security feature. "Our IWLAN system makes it possible for the first time to not only securely monitor a facility but also securely operate it," says Kuk. Emergency shut-down circuit breakers are usually triggered via separate cables. With Siemens’ IWLAN system, however, the emergency signal is securely transmitted within fractions of a second in the reserved data transfer packet.

Thanks to the increasing performance capability of a broad range of components, industrial communication systems are becoming ever more seamless—all the way down to the level of sensors and actuators. Sensors register parameters such as proximity, speed and ambient conditions, thus making it possible to monitor equipment. They also contribute to the effectiveness of control processes through their connection with actuators.

Intelligent algorithms and growing computing power on chips open up completely new application possibilities for these sensor networks, as they are now capable of self-organization. Individual sensors can start themselves up, recognize neighboring sensors, and communicate with them, meaning that if one sensor fails, another can pass on the information that would otherwise have been lost.

Such systems are known as mesh networks because they link sensors like a lattice, which is what distinguishes them from previous star-shaped architectures in which each node could only communicate with neighboring devices. "Self-organization makes wireless systems more flexible and robust, and also significantly lowers planning and operating costs," says Dr. Rainer Sauerwein, a self-organization researcher at Siemens Corporate Technology. "This is especially helpful when the network topology cannot be planned in advance." This would be the case, for example, if a truck driving between two oil tanks at a refinery had its wireless connection interrupted.

Sauerwein and his colleagues are developing new wireless technologies to ensure that sensors can be utilized as flexibly as possible in production. But such systems need to be immune to disturbances from other radio fields in the factory environment. "The most interesting standard here at the moment is ultra-wide band, or UWB," Sauerwein says. "Unlike narrow-band IWLAN, UWB operates on a very broad frequency, is suitable for use with mesh networks, and provides for more precise localization." With UWB, sensor network data can be sent to an IWLAN receiver or directly to an Ethernet system via a gateway that pre-processes the information. It can then be forwarded to all downstream systems and, if necessary, even to the accounting department.

RFIDs for Eggs. Information like supplier data would definitely be of interest to accounting departments, however. And radio frequency identification (RFID) technology can provide exactly such data. Tiny RFID transponders, which can be affixed to goods or components, store production and identification data, which can be sent to reading devices (see Pictures of the Future, Fall 2005,  RFID). Up until recently, RFID technology was used mainly in closed factory cycles. Now, however, it’s moving into other areas. Spanish company Grupo Leche Pascual, for example, which processes around two million eggs per day into dairy and pasta products, has been using RFID technology from Siemens for its supplier chain since mid-2006. The vehicles that transport the eggs are equipped with RFID transponder systems that register the origin, amount, and weight of each truck shipment. The system has sensors that record temperature, and it also utilizes the Global Positioning System (GPS) to track trucks. When a shipment arrives at the factory, the data is checked for irregularities in order to avoid any loss of quality or materials. The origin of the ingredients is thus thoroughly documented, and the plant accounting department receives supplier data in real time for its accounts payable system.

Standardization measures need to be implemented before this type of system can be used across national borders and in different industrial sectors. "Ultimately, there’ll be a mix of wireless and wired technologies that we’ll be able to select from to create an optimal communication system for a given production process," Röhrl explains.

The seamless integration of these media will lead to ever more tightly knit global production networks. Repairing your car in the future might then involve having an RFID transponder telling mechanics when and where the vehicle was made and what’s wrong with it on the basis of sensor data. Spare parts will be ordered automatically, and suppliers will know when to plan component shipments. All the repair shop will have to do is install the replacement parts.
                                                                                                                  Dagmar Braun