When we look at the breadth of technologies involved in automating a machine, no single technology jumps out as a divine, comprehensive control solution. Again this year, we have no magic bullet to offer.
Get used to it. Machine control excellence is a grind-it-out quest to find the right combination of emerging and established technologies that must combine seamlessly and systematically to assure machine automation success.
]The help we offer here is to unearth a few trends that seem to have the momentum to influence the choices you make in machine controls in the coming years.
HMI and Network Connectivity
Every machine needs an operator interface of some type, even if it runs lights-out. Machine size and complexity determine the degree of sophistication required.
“We see a definite trend to services for the HMI on our legacy systems,” says FKI Logistex’s controls engineer, Mark Chrismer. Based in St. Louis, FKI builds a multitude of material handling and sortation machines for all industries (Figure1). “In fact,” says Chrismer, “this is emerging so fast that we’re now consolidating our service activities into one location in Cincinnati. We no longer see machines as self-contained islands of automation. Every machine needs connectivity to other machines and to the enterprise.” He says FKI currently ships a modem embedded on every machine, and that many customers are adding virtual private networks (VPNs) for access-security purposes.
“ODVA standards on EtherNet/IP and DeviceNet now allow connectivity from machine to machine,” says Chrismer. “We find a trend in industrial automation to move to EtherNet/IP for connectivity, including distributed I/O.”
Services is one of three trends Wonderware believes are impacting automation and controls implementation for large machine and system builders such as FKI. “First, OEM business is moving toward a service business because of the large installed base,” agrees Rashesh Mody, vice president of Wonderware’s HMI and SCADA division. “Second, machine builder HMI solutions must be extendable to the degree they must connect machine parameters to sources beyond the machine environment. And third, HMI packages must be unified such that the operator interface portion of the HMI package must be interconnected seamlessly with data-collection software and networking software.”
Wonderware says it takes this further with its Industrial Application Server platform that now includes intelligence and control capabilities operating as a layer between I/O and its HMI software.
When it comes to operator interfaces for small machines, connectivity certainly is a growing requirement.
Operator interfaces have a permanent future in industrial automation because machine builders today are demanding a window into the process,” states Phil Horner, president, Horner APG. “However, this window is going to change to a machine-based operator interface that provides an Ethernet-centric, plant-wide window. Connectivity is a critical piece to the next-generation of solutions.” The company’s OCS products can collect data and store it on compact flash, an indication, says Horner, that the market is enjoying a significant improvement in data collection with this architecture. “SCADA solutions historically filled this market need,” says Horner. “However, for most machines, the PC-based SCADA package has to be connected in some fashion to a PLC. The new architecture doesn’t depend on the network because it’s being collected and stored in a local environment.”
Horner says there’s been large growth in the all-in-one control environment that provides a modest OI capability, some measure of logic control, and expandable onboard I/O. “Most of the players are in the lower end of the market, and I see this continuing for the near future,” says Horner. “Watch for more powerful displays being integrated to allow the customer more options for his applications.”
|Figure 1: HMI Needs to provide more
FKI Logistex sees services availablity as an increasingly important component in the HMI on its legacy material handling and sortation machines for all industries.
Source: FKI Logistex
Over the years, most machine-intelligence platforms centered on the venerable PLC. There are so many flavors of PLC available that many engineers view the traditional PLC hardware platform as a commodity, and have thought so for several years. Just look what’s selling on eBay these days. Going forward, PLCs still will have their place, but as Horner suggests, it’s reasonable to expect more movement to an all-in-one architecture.
DynaPath Systems, Livonia, Mich., implements PC-based controllers for its family of machining centers and its new K3 knee mill (Figure 2). “We needed a control architecture that’s small enough for machine mounting, but fully functional,” says Paul Barnhardt, DynaPath’s vice president. “There’s little room to mount controls on our new K3 knee mill, so we must incorporate the total machine control in a pendant-mounted package.”
For medium and larger machines, PC-based control still draws a level of machine-builder interest. Jacob Pien, president, HA Controls (HAC) states, “PC-based machine control has strong roots in Asia and Europe, so it’s just a matter of time before this global trend will be embraced by machine builders in North America.” Not surprisingly, HAC offers a family of multi-functional, PC-based controllers. It supplied the CNC package on a PC-based platform for Dynapath’s knee mill. It incorporates a soft motion kernel and a machine interface board. The machine interface board includes both motion and I/O interfacing.
Another machine builder places itself squarely in the PC-based controls camp: “With traditional PLC controls, bending tubes that are 3 inches long at the end of the process wastes up to 6 inches of material,” says Cliff Bailey, electrical engineering manager at GWS Tube Forming Solutions, Bothwell, Ontario. The company builds PC-based CNC, hydraulic, and servo-controlled tube-forming machines (Figure 3). “GWS has machines that are specially designed to produce very short tubular parts efficiently, but drastically reduce waste,” says Bailey.
"To sustain this performance, we needed a PC-based platform with the best available processing power.”
Last year, Bailey saw an opportunity to start fresh and move toward a more reliable, higher performing, PC-based control platform. “We’d used PC-based control for a few years, but we were looking for an alternative that was free of rotating parts such as hard drives, which are highly susceptible machine vibration,” says Bailey. Besides a vibration-resistant hardware platform, GWS sought to provide its customers with more production data and online diagnostics.
After analyzing major suppliers’ product lines, Bailey selected Beckhoff Automation’s embedded PCs running TwinCat NC PTP software for logic and motion functions. Bailey says that with the PC-based controls, one GWS machine does the work of two traditional end-forming machines.
|Figure 2: PC-based solution
DynaPath Systems incorporates all machine control in a PC-based pendant on its new knee mill.
“One of the major trends in machine automation right now is pushing ever-higher speed in control processing and networking with less hardware,” says Graham Harris, Beckhoff’s president. “With faster processors and more bandwidth in the I/O network, machine builders will be able to increase throughput with tighter repeatability, reduce waste through tighter control, combine multiple functions in one machine, eliminate auxiliary controllers, and use one network for all device connectivity.” In Harris’ view, as PC processing power advances, so does high-end automation and control. “By implementing more powerful PC-based controllers, machine builders will reduce control cabinet size by eliminating separate motion controllers/cards, network interface cards, and auxiliary control devices,” he adds.
The PCs that GWS uses are connected via SERCOS and IP Link using fiberoptic networking. “Fiber is a great fit for our machines because it’s highly immune to electrical noise interference that can plague other fieldbus cabling,” says Bailey.
More Axes, Please
As machine complexity grows, the need for multi-axis control becomes more prevalent. An application that illustrates this is a gantry mechanism for flat-panel display manufacturing by machine builder, CPS Korea. CPS gantry systems and precision stages are used for flat panel manufacturing, repairs, and inspection (Figure 4). The gantry system does proprietary processes that require high path precision at high speeds using very-high-resolution feedback.
|Figure 3: Idustrial PC needed
For its tube benders, GWS needed a tougher, vibration-resistant PC platform to provide customers with more production data and online diagnostics.
Motion-technology provider ACS Motion Control (ACS) sees the trend to higher axis-count systems in machine control. “Global trends toward the demand for high axis count systems will combine brushless servos and steppers, tighter integration between control logic and motion control, quicker ways to troubleshoot system problems and get back on line, lower risk by reducing development time, offering expert support on-site, providing detailed programming examples, and showing a proven track record of high quality and reliability,” believes Neal Kearney, ACS vice president sales and marketing. “Users want the reassurance that a control system offers the power and flexibility, but is still scalable and won’t require them to continually move to new platforms and learn new development tools. The user wants to leverage the investment made now on future projects.”
Danaher Motion’s senior product line manager for performance controls, Jeff Pike, adds, “Most of today’s machine builders simply don’t have the time or resources to research, mix, match and test potential components in developing their motion system. Now, they look more to leverage the supplier’s engineering expertise and have the supplier take responsibility for system performance. They’ll tell suppliers, ‘This is my system, and this is the performance I need.’ ”
As a result, says Pike, one of the most significant trends is the move toward complete packaged motion system solutions. “These preconfigured and fully integrated packages of exact-fit components include controllers, software, drives, motors, I/O, and mechanics that are tied together with a high-performance motion network, and a single point of fulfillment and support.”
For large machine builders, there’s a move toward distributed I/O, and whether wired or wireless, it’s impacting sensor technology. As distributed I/O installations increase, many sensors will be connected to a secondary or sub-network, but these distributed sub-networks still must be connected back to the machine intelligence for processing. Based on market implementation thus far, Ethernet is steamrolling competition as the most common industrial network.
More sophisticated sensor applications, including machine vision-guided robotics, follow similar trends toward more information gathering and networking to deliver that information. Combined Technologies Group (Com-Tech) implemented vision-guided robots at the Honda Transmission Manufacturing facility in Russell’s Point, Ohio (Figure 5). The project consisted of nine GE Fanuc robots for material handling of various transmission components. Each robot incorporates a Cognex vision camera to locate parts or packaging material. At the start of the process, a robot unloads newly arrived parts from skids and loads them into machining centers. The cameras locate the parts on the skids for pickup. At the end of the machining lines, another robot places the finished parts into heat-treat baskets.
|Figure 4: Fast, multi-axis response
CPS Korea’s need for enhanced multi-axis control is apparent in its gantry mechanism for flat-panel display manufacturing, with proprietary processes that require high path precision, high speeds, and very-high-resolution feedback.
“The challenge in this application was that the baskets deformed over time due to the heat-treat process,” says Tom Stocker, vice president, Com-Tech. To adjust for this deformity, Com-Tech integrated vision into the robot to locate the area of the basket where the part is to be placed. After the heat-treat process, another VGR robot removes the parts from the heat-treat baskets and places them on conveyors that move parts to final processes. “The integration of the cameras reduced labor costs, and also eliminated the chance for part damage from improper handling,” continues Stocker.
“Unlike blind robots, vision-guided robots don’t depend on costly precision fixtures to hold parts, additional labor to load and orient parts, or need upstream actuators, sorters and feeders to separate parts for processing,” says Bryan Boatner, product marketing manager, Cognex. “Consequently, VGRs allow manufacturers to easily process various part types without tooling changeover. Plus, they provide the added benefit of automatic collision avoidance for safer work cells.
Machine vision via so-called smart cameras has become so popular that multiple units, networked together to sense, measure, read and verify are increasing more rapidly than any other machine control technology category.
Boatner sees definite trends toward more machine output inspection. His company indicates that the fastest growing applications are traceability and error proofing for food and drug security, direct part-tracking using image-based ID readers throughout manufacturing and supply chain operations, and vision-guided robotics in automotive and packaging applications.
Other vision trends Com-Tech expects will grow include continual improvement in pattern-recognition software allowing VGR applications to robustly operate in ever-changing environmental conditions, customers being more willing to learn vision by investing in training, and doing multiple operations with one camera other than just locating parts.
“We see similar trends in vision applications and technology,” says Brian MacCleery, senior product manager, National Instruments. “The most intriguing include vision-guided motion, easier installation, high-speed timing/triggering synchronization between vision systems and control systems, and very smart camera technology, enabling embedded complex state-chart logic—the full programming power of a PAC in the vision system, and improved adaptive algorithms to minimize reprogramming.”
Safety Is Trendy, Too
A recent study by Liberty Mutual Institute for Safety shows companies saving millions in general liability and workers’ compensation losses over three years by being proactive in safeguarding machine environments. General liability claims dropped 31% and workers’ compensation claims fell 34%.
“Our site surveys are a rigid study of the entire machine environment,” says Chris Soranno, machine and process safety engineer at Omron STI Services. He sees a definite trend to safety services including on-site safety surveys.
“This process used to be reactionary,” says Soranno. “Now we see a definite trend by machinery users to be proactive in creating a safe machine environment. We see movement toward vertical machine guarding rather than horizontal guarding using floor mats, gates, and the like. Many machines need the flexibility offered by vertical guarding techniques, including safety zone control.”
Even with all the statistics on the virtues of safeguarding machine environments, there remains very little initiative by many machine builders to offer safety equipment with their machine proposals, preferring to leave the safeguarding issue to the user, if they can. Soranno sees the same picture, and says 95% of Omron STI’s business is with end users of machines.
With perimeter safety becoming more important for machine builder and users alike, there appears to be a somewhat relentless trend toward smarter perimeter sensors. However, instead of mechanical barriers, machine safety has moved to perimeter vision sensing to determine if any prohibited section of the machine environment has been invaded. Pilz Automation Safety LP recently launched its SafetyEye 3-D, safe camera system. Developed in conjunction with Daimler-Chrylser, it places an invisible protective cocoon around a work area. This system claims to offer increased safety without barriers, detection zones that are configurable easily on a PC, and fast diagnostics for rapid troubleshooting.
The Missing Link—Wireless Technology
There’s a basic understanding that, comparatively, legacy machines aren’t instrumented very well. There’s also a movement to create efficiencies in energy, productivity, and preventive maintenance. And, factories are moving away from being islands of information.
“I’d add that machine builders will soon start looking to monitor motor parameters, bearings, and power consumption on new machines. Emerging alternative energy markets will require all types of remote monitoring. And, even green trends are driving environmental and energy consumption monitoring on all machines,” says Gary Ambrosino, president and CEO of Sensicast. “We looked at what’s missing in machine control that can be best fulfilled with our technology.” Sensicast is a provider of smart wireless sensors and mesh network solutions.
|Figure 5: Highly sensitive robots
Vision-guided robots for handling transmission components at Honda reduced labor costs, eliminated the chance of part damage from improper handling, and improved work cell safety via automatic collision avoidance.
Wireless might fit nicely into this machine environment, and meet the requirements of delivering information on not only legacy machines and processes, but also on new, larger machines.
A user that agrees with the idea of wireless sensors on legacy machines is Hollinsworth & Vose, East Walpole, Ma. H & V is one of the oldest paper mills in the U.S. and uses compressed air throughout its factory.
By most expert reckonings, the average compressed air system runs at 30-50% inefficiency. National Grid, the utility that services H & V, wants to contain or even lower electricty consumption in this service area through joint programs with customers. The objective at H & V is to improve the efficiency of the paper mill’s compressed air system, lower the electricity expense component of manufacturing, and conserve energy, leading to lowered greenhouse gas emissions. So, National Grid, in conjunction with the U.S. Department of Energy, funded the H & V project. Reportedly, H & V realizes substantial, five-digit savings annually.
“Because of our higher than normal power consumptions, National Grid wanted to make our plant a test case,” says John Krukonis, project engineer at H & V. “Our high usage of compressed air made us a good test.” He reports there are five flow and pressure sensor locations — some battery operated and some powered, depending on location — and power monitors located at each compressor. To avoid extensive wiring to connect monitoring sensors, wireless technology became a natural choice for this application.
“There is a definite savings from wirelessly monitoring flow and pressure at critical locations. Leaks are sensed immediately and fixed shortly thereafter, resulting in far less wasted air,” adds Krukonis.