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By integrating more functions into the central logic, machine builders are finding it easier to expand their universe — introducing new machines to new markets with faster leadtimes and lower costs.
In the case of Thalmann Maschinenbau in Frauenfeld, Switzerland, integrated automation helps get the machine builder into different sized markets without having to reinvent the control system each time. Thalmann serves small craft businesses as well as large industrial operations with its standard and special machines for forming sheet metal.
The machines employ a complex process to produce edge bends on flat sheet metal. A bending beam rolls upward around a pivot point and on the material, without damaging the surface of the sheet. A bending machine usually consists of a bottom beam on which the sheet lies, a top beam that clamps the sheet on the bending edge against the lower beam, and a bending beam that is moved up to bend the sheet metal to the required angle. Thalmann's double benders have two bending beams so that the sheets are bent upwards and downwards without being turned or swiveled during the bending process. This speeds up the bending process considerably, but requires the control of nine axes.
Regatron, based in Rorschach, Switzerland, manages the automation of the Thalmann machines, and switched a couple years ago to an integrated and more-open PC-based technology. "The increased complexity of modern machines necessitated a generational change in the control system," says Felix Lanter, head of development, control and drive technology, for Regatron.
The first control systems that Regatron built were based on a hardware PLC. The integrator employed its first PC-based system with DOS computers in 1991, and its first industrial PC with Windows and Ethernet in 2003. However, the previous PC systems were not as open as the Beckhoff Automation system they switched to, according to Patrick Ruf, software programmer for Regatron. "All the hardware blocks that we added for an additional function were blocks by their own," he says. "Maintenance and diagnostics were therefore very difficult. With the Beckhoff system, all the modules communicate through one bus (in our case EtherCAT), and therefore the information of every module is available in the software."
Figure 1: Interchangeable gripper fingers in Thalmann's bending machines are adapted to customer needs or to the bending programs. This shows a stop finger for a very small contact area on the sheet.
The programming of the control system must reflect the range of the machine requirements. "On the other hand, we intend to maintain uniform design as much as possible," Ruf says. "We have taken some care to design the structure of the control solution in such a way that we can easily expand the area of any individual function."
Ruf adds that the servo drive is easier to integrate because it is connected to the EtherCAT. "In the old solution, the drive was attached to the controller using analog and digital signals," he says. "The new solution offers more possibilities for diagnostics. Also, the integration of proportional hydraulic valves was easier as we needed an additional box from Bosch in the old solution. In the future, it is even possible to connect the valves directly to EtherCAT."
In addition to servo drives and hydraulic valves, numerous monitoring functions are incorporated into the machine programming. For the hydraulic oil, temperature is monitored, flow rate is measured, and oil filters are checked.
"Of course, an important aspect of the control solution for bending machines is operator safety," Kern says. Thalmann uses Beckhoff's safety PLC terminal, which integrates into the EtherCAT terminal system. Safety functions such as e-stop, safety door monitoring and two-hand control can be easily selected and combined. They are configured in Beckhoff's standard TwinCAT System Manager, and run on the same PC platform as the machine program.
Integrated automation can even help machine builders break into entirely new markets. For example, Fives Cinetic Automation in Farmington Hills, Mich., has its main business in automotive powertrain, where companies such as Ford, GM and Chrysler use Cinetic's manufacturing equipment and system integration. With integrated automation, the machine builder has been able to more easily develop solutions to go after the aerospace assembly market, according to Paul Ruland, OEM program manager, factory automation, for Siemens Industry.
"Aerospace assembly requires a lot of hand assembly, with unique sophistication," Ruland says. However, a lot of airplane providers are pushed on delivery times, and need to automate their assembly process. "Cinetic is in automotive, but they're getting into aircraft assembly. They're reusing IP, with integrated solutions, to apply to aircraft assembly."
Machine builders in the semiconductor industry have taken their know-how into solar photovoltaics production, and are looking at lithium ion battery production as an emerging market. "Pre-defined software blocks and architecture systems can already be used, so it reduces entry to that market," Ruland says.
Integration Is Platform-Agnostic
Beckhoff's integration scheme uses a PC platform with TwinCAT control software and EtherCAT as the fieldbus system. "From Beckhoff's perspective, the whole value of integration is combining elements into one," says Graham Harris, president of Beckhoff North America. "The fewer parts you have to do a job, the better."
Integrated automation isn't particular to any given platform. But from Beckhoff's perspective, the PC makes perfect sense as an integration platform. Integrating more functions with the I/O reduces the amount of devices needed to put a system together. "More and more functions are going into software," Harris notes. "Now we can do sequencing or logic and motion control and HMI in one software package, on one PC, one controller. We can have one processor running all these multiple pieces of the architecture."
Multicore processors enable increased functionality from the lowest-level PLC (or smart relay) up through high-end industrial PCs, notes Mike Rothwell, director of control and industry solutions for Phoenix Contact. Industry draws from consumer applications — from cellphones, for example, for the low end; and from consumer PCs for the high end. "Moore's Law benefits even the lowest technologies," Rothwell adds. Quad-core processors ultimately will take those capabilities even further.
In the demo center at its new facility in Ann Arbor, Mich., Phoenix Contact has on display a conveyor system targeted at the automotive industry, running Comau's RecogniSense camera combined with Phoenix Contact's industrial PC. With a dual-core processor, the main controls can run on one core while the other core controls vision, database connectivity and other functions, Rothwell says.
Schneider Electric calls its architecture MachineStruxure. It's a flexible control platform that typically includes a PLC, HMI controller, drive controller and motion controller. "Each one of the controller families, which are under the MachineStruxure umbrella, are all capable of being programmed by one software, SoMachine," says Ed Sandlin, marketing manager. "Everything can be seen from one cable from the PC through, for example, the PLC."
SEE ALSO: Let's Call Them Machine Controllers
There are varying degrees of integration, and this is one place where the definition gets a little fuzzy. For some folks, the safety controller, though tightly integrated with the discrete controller, might still be a separate card. Rockwell Automation takes care of a variety of control functions directly on one piece of hardware (its Logix PLC), notes Mike Burrows, director, market development, integrated architecture, for Rockwell Automaton.
"In many systems today, discrete control, safety control, and motion and servo control are done by three different brains on the machine," Burrows says. "On ours, it's done with one brain. There's much better coordination; your safety decisions are directly in line with the robotics control, and there's a lot less manual synchronization."
Rockwell created its coordinated machine functionality about eight years ago, then started to create a smaller footprint about five years ago, making the amount of control more scalable. "You can buy a little brain, or you can buy a big brain," Burrows says. "If you don't want safety, you don't have to pay for safety — or motion, if you don't want it. But if you want it, you don't have to add separate hardware."
Burrows says there are five basic elements of control that can be incorporated: controller, network, power (actuation, induction or servo drive), operator interface, and I/O function. "As we expand the function of the controller, it'll start taking over the brain that is currently in the other devices," he says. "The first thing is for the servo drive to relinquish control planning functions to the controller. The next is the network — bringing time synchronization, redundancy into the controller. Visualization, we're releasing in the next year."
Figure 2: Ferrum's can seaming machines must accommodate a range of can materials and sizes for various markets while improving delivery and setup times.
Ferrum is also under pressure to reduce delivery time — from 12–18 weeks down to just eight weeks. The machine builder has also worked to accommodate a variety of can sizes with faster setup times. On one can seaming machine, Ferrum was able to reduce the time for a complete format change from six hours down to two hours.
In a pilot project for the American market, Ferrum is using Compact GuardLogix for integrated safety and standard control. As part of the Integrated Architecture solution from Rockwell, the controllers use the same configuration, network and visualization environment as the larger ControlLogix systems.
"Using the Compact GuardLogix controllers with our medium-sized applications, we can create an integrated control architecture," says Martin Schürmann, manager of electrical development at Ferrum. "The architecture is so scalable that we can design our applications with a single control engine and a single development environment, irrespective of the size and complexity."
Another Rockwell customer, Cyan Tec, which makes direct-to-product inkjet printing systems in its facility in Barrow-upon-Soar, U.K., also needed a medium-range integrated solution that would let it react to an array of product needs from a diverse set of industries. "Every single item can be different, varying in terms of shape, size, surface form and materials," says Clayton Sampson, managing director at Cyan Tec. "Therefore, the core technology at the heart of the machines must be flexible enough to achieve top-quality customizable printing on a huge variety of products."
In this case, the machine builder also needed tight integration with motion to precisely pass components to be printed under the static print heads. The core module is a CompactLogix PAC, coupled with a linear motor stage and electric cylinder (Figure 3). "This movement has to be very smooth," Sampson says. "We need precise control and consistent motion system behavior, as we are depositing ink to micron accuracy, and any unwanted movement would be immediately apparent in the quality of the print."
Figure 3: The integrated architecture in Cyan Tec's direct-to-product inkjet printing systems includes motion control in order to keep motion stages running smoothly and seamlessly.
Source: Cyan Tec
Integrated, Still Distributed
The idea of "one brain" does not mean that intelligence cannot still be distributed throughout the plant. For example, Kuka Assembly and Test in Saginaw, Mich., built a modular assembly line for Ford Motor that uses both integrated and distributed automation.
Kuka AT designed a turnkey manufacturing system that produces two types of front-wheel drive transaxles — one a traditional clutch/planetary front-wheel drive unit, and the other a transaxle for hybrid vehicles. The transaxles are assembled on a dry line consisting of 35 manual stations and five automatic stations. Every line segment and every station has its own automation as part of a distributed architecture scheme. But they also all integrate real-time control, safety and communication, communicating on an Ethernet network.
The controls for a typical manual station include a PLC, HMI, managed Ethernet switch and an RFID read/write station, according to Dave Heyman, controls engineering manager for Kuka AT. The controls for a typical automated station include the same components, as well as automatic assembly tools and gauges, and servo drives and motors that operate automatically positioned measurement devices.
The system built for Ford uses segment controllers to control the transport system, which moves the pallets along the conveyor. The segment controllers control pallet motion, keep track of pallet location, and communicate with adjacent segments. In addition to the same control components included in manual stations, the segment controllers have components that control the conveyor transport system elements, including disconnect switches, motor starters and variable-frequency drives (VFDs).
Siemens' Totally Integrated Automation (TIA) enables the various automation and control components that are designed to work together within a distributed architecture. So even though components are physically distributed, multiple control functions still can be integrated within the same system.
"In the past, all safety would go through hardwired Pilz relays," Heyman says. With the new system, safety components such as switches, machine guards and light curtains can be integrated into the main controller, and safety I/O can communicate to the controller via the same Profinet cable used by standard I/O. "Instead of all that dual-relay reliability, it's all built into the PLC. You don't have to grab an electrician to rewire things if there are changes. You just rewrite some code."
Integrating safety onto the distributed control also enabled control of one machine segment rather than a whole line, Heyman notes. "Now an e-stop can stop one conveyor motor. Before, it was all hardwired together under one thing."
Much of the change in automation was initiated by Kuka's customer. "We worked really close with Ford, and gradually moved closer and closer to what we have now," Heyman says. "They've seen the best launch times ever on these two lines. And they don't see the maintenance issues they had in the past."
The Value Proposition
There are several benefits to integrated automation, which will expand further as more functions are able to be added to the main controller. "Every time you can collapse separate functionality of other hardware, that's good," Beckhoff's Harris says. "It's less material — you don't have to buy it, you don't have to store it, you don't have to wire it up; it simplifies everything."
Time to market is a considerable benefit. "Because of the degree of integration between the Allen-Bradley components, a lot of the hassle is removed from combining and building the automation infrastructure, so we can use more of our focus on the print technology," says Cyan Tec's Sampson.
Integrated automation reduces not only development time, but also installation and maintenance time, notes Siemens' Ruland. "It provides faster time to market, with increased flexibility so they can meet the unique requirements for their customers without increasing overhead," he says.
Much credit for the ever-increasing array of functions goes to the semiconductor industry's ability to pack more and more transistors on a single chip. Integrated development environments have been around in commerce — in IT and embedded worlds — for some time, and is surfacing more often in industrial environments, Ruland notes. "We combine logic controllers, distributed I/O configurations, HMI screen configurations, safety network, SCADA — all in one development environment; one development software, one user project for the whole automation system," he says, adding that the ability to put functions in libraries so that they're reusable has become available for automation.
Automation providers are applying what companies like Cisco have already developed — using blade servers in the IT world to share processing power across a network, for example — into the manufacturing space, Burrows says. "Virtualization allows for much higher processing power," he adds. "We're learning and having key partners that help us to take iPad or blade server type functionality and bring it into automation technologies."
Pick a Common Language
Regardless of the hardware platform used, a key aspect of integrated automation is the sharing of a common language. Traditional automation systems include multiple devices, each with their own separate programs, which increases engineering time and costs. Integrated automation simplifies design largely because each device or function uses just one language, one set of tags and standards, to program everything.
"In the past, when you built a machine, you would have a different software for the PLC, for the drive, for the HMI — and have to program each one of those separately and then tie them together when they're on the machine," Sandlin says. "Now you can program it with one software, one project file. It makes it easier for servicing later on down the road, too."
Sam Banerjee, product manager for Schneider Electric, adds, "With everything talking the same language, nothing is lost in translation; there's pretty much seamless communication between devices."
Programming everything in a common language enables machine builders to create function blocks that they can transfer from machine to machine. This has enabled Savage Bros. in Elk Grove Village, Ill., to produce candy-making machines to the exacting requirements of each customer without having to reinvent each system.
"One of the real issues they had was, every time they tried to make a new machine for a new chocolate manufacturer, every machine that they made was a custom machine," says Ashish Patwardhan, also a product manager for Schneider Electric. "They developed their own code and function blocks that now could be transferred to larger machines. Multiple controls are using the same programming, and they're just cutting and pasting. Every new machine is just a modification of the smaller machine."
Frame of Mind
In many ways, working toward a common language is as much a frame of mind as it is a software package. Heyman began years ago trying to get his team members to think in terms of commonizing more functions. "We got tired of customizing HMIs to a station," he says. "An assembly line in this business can have 60–100 stations on it."
Heyman and his engineers try to use the same function blocks for as many devices as possible. For the most part, they try to stick with ladder logic as a common language. "We try to keep it simple, but try to keep it common, so you don't have to know multiple languages."
Kuka has whittled its function blocks down to just a "handful," which Heyman defines as around 60, compared with a couple hundred before. "A lot of that is just discipline in your programming," he says. "Here's a motion block — do as many different motions as possible, vs. writing one for this cylinder with this particular type of valve."