Robotics Integrate PCs, Networks

Remember the "gaps" of past decades? The Sixties began with a missile gap and ended with a generation gap. The search for more "gaps" was rewarded in the 1980's with the discovery of a "robot gap." American industry was supposedly doomed because Japanese manufacturers had more robots than anywhere else.

By Gary A. Mintchell, CONTROL ENGINEERING January 1, 2000


Machine control


PC-based control

Open systems

Sidebars: Robotics industry enjoying its best year Open systems for robotics Robot safety standard now ANSI standard

Remember the ‘gaps’ of past decades? The Sixties began with a missile gap and ended with a generation gap. The search for more ‘gaps’ was rewarded in the 1980’s with the discovery of a ‘robot gap.’ American industry was supposedly doomed because Japanese manufacturers had more robots than anywhere else. Well, there are still more robots in Japan. American and European manufacturing are still competitive, though, and all areas are expanding robotic applications (see sidebar).

Robots usually come in one of three varieties: articulated arm, SCARA, and gantry. Articulated arm robots are most often seen, for instance, in long automotive assembly spot welding lines. SCARA robots are fast, multi-axis, pick-and-place machines often used for packing and assembly of small parts. Gantry robots sometimes cover large areas and are often capable of precise handling of heavy payloads. These are often found on machining lines handling parts going into and out of automatic mills and grinders. They are also useful for certain part-picking operations.

Robots still underutilized

Do robots have a future? The Robotic Industry Association (Ann Arbor, Mich.) cites analysts, who estimate that only 10% of manufacturing plants that could benefit from robots have installed them. Patricia E. Moody and Richard E. Morley, in their new book The Technology Machine: How Manufacturing Will Look in the Year 2020 (The Free Press, New York, 1999), say robotics is one of the hot technology areas that will continue to be important to manufacturing. Clearly, a control engineer not considering robotics as part of the automation tool set is risking loss of competitive advantage.

The same controls engineer responsible for installing and maintaining PLCs and CNC equipment in a manufacturing process is often also responsible for procuring, installing, and maintaining robotic equipment. This presents a challenge because each controller is programmed differently, with different editors that behave differently, and often use quite different languages. Things are beginning to change, however, as more editors run on Microsoft Windows with the complement of Windows tools, such as multiple windows open, drag and drop, copy and paste, and visual interface. Many programs are either graphic or are very much like Basic, which is familiar to more and more engineers.

Using a common foundation like Windows leads to another benefit-communications. Standards like OPC and tools like COM, DCOM, and ActiveX objects mean robots can now be more easily integrated into the larger factory process. Just as CNCs are now using PC technology to enable better user interface and faster, easier communications (see Control Engineering , Nov. ’98, p. 121), robotic technology is increasingly incorporating PC and networking technology to gain the same advantages.

Dean Elkins, Motoman’s (Dayton, O.) vp, says robots typically have a ‘black box’ part of the system due to the complex kinematic calculations required for precise motion control of the machine. Users have asked for better human-machine interface-something more consistent with other machines on the factory floor. They also want links to data input and output through devices like bar codes.

He also sees increasing efforts to shrink the hardware controller by placing a controller in the motor. ‘Fiber-optic cabling and networks will further shrink hardware and make installation easier and faster. The movement toward consumerization through PC technology and Ethernet and other open device networks will help lower costs and enhance communications. Emergent technologies like Microsoft Windows CE may lead to user benefits like standardized teach pendants.’

Joe Campbell, Adept Technology’s (San Jose, Calif.) vp, points out that a robotic system is not unlike a motion control system with a controller, servo module, drive amplifier, and motors with feedback. Kinematics is the difference. Robotic control usually involves complex movements, coordinating up to 6 or more axes of motion. Sometimes guiding the tool over the workspace is challenging. Integration of vision systems with robotic control has been used for many years, but use is increasing as both technologies become easier to integrate and applications become more challenging. Engineers are familiar with vision systems for inspection, but their use for part location, flexibility in fixturing, as well as inspection make the duo a powerful team. Their power is seen in applications like applying sealant to complex surfaces or packaging soft or flexible products.

Flexibility needed

Mr. Campbell adds that trends in manufacturing-like shorter product life cycle, need for flexible production processes, and the resulting need to keep capital investment low-are driving development of smaller servo systems to replace cams and gears plus distributed control. These trends have prompted Adept to introduce a new product, SmartModules.

This modular, built-to-suit robotic tool features linear motion modules built from standard, off-the-shelf components into 2- and 3-axis robots for pick-and-place and material-handling applications. Each linear motion module has a SmartAmplifier. These contain an on-board servo controller, as well as servo amplifier, power controller, and IEEE 1394 (Firewire) serial data bus. Firewire is hardware deterministic and ideally used for all amplifier-to-controller communications. Fewer wires and connections by using a bus topology yield improved reliability and reduced costs.

Mike Calardo, director of operations, Robotic Products Division of ABB Flexible Automation (Auburn Hills, Mich.), notes, ‘We have been shipping a controller with a fieldbus connection to I/O modules for the last three or four years. This gives integrators and end-users a lot of flexibility in design because they can easily go with our I/O modules or connect to anyone who is compatible with DeviceNet. It’s a seamless operation.’

‘Controllers are much more open than they used to be,’ he adds. ‘Open interfaces can expose the whole robot environment to a PC. With a product like WebWare, users can expose robotic data to any Web-enabled device, which may not be a PC. Being Web-enabled is a two-way street. A technician working at the robot cell could download manuals or troubleshooting guides from a central server to get production moving sooner.’

Mr. Calardo sees future applications expanding. Increasing software power in modeling mechanical movement signatures will enable an exciting future application-robots as accurate as a machine tool capable of much more precision either for cutting or measuring applications.

Software takes charge

Fanuc Robotics’ director of controller software development, Claude Dinsmoor, notes that robotics has always been somewhat software intensive because of complex movements. ‘Where a hardware designer could keep a couple of software designers happy in the past, now it’s more like 10 software designers to one hardware designer. Much design time is devoted to development of graphical user interfaces, especially on teach pendants to give added power and flexibility to operators.’

Mr. Dinsmoor also thinks the future belongs to ‘the wired robot.’ He adds, ‘Currently, connectivity to a PC is a requirement for the factory floor. The issue will become connectivity to the entire suite of Internet tools. The device connecting on the Internet may not be a PC. We have had Ethernet connectivity with FTP and other Internet tools for some time. We have had occasions of engineers helping solve problems from home over an Internet hookup.’

Brian Demoe, Trellis Software and Controls (Rochester Hills, Mich.) marketing manager, suggests that the role of software relative to hardware has increased over the past five years from about a 50:50 to 80:20 ratio. As hardware becomes more standardized less custom hardware is being developed. On the other hand, software advances mean tighter integration of a process from machine control right up to the enterprise information system. ‘Software is the glue that holds things together,’ he adds, ‘from controller to parts and factory to enterprise.’

‘Users and integrators both have an interest in software advances, but each has a different emphasis,’ continues Mr. Demoe. ‘Users want improved ease-of-use. This includes easier and faster training along with interfaces that help guide maintenance and troubleshooting. Since so many people are familiar with the Microsoft Windows interface, industry acceptance of Windows tools like drop-down menus and dialog boxes has met this objective. Meanwhile integrators need to be able to customize the product to add their unique value. Once again, open interfaces built upon Windows architecture allow this added value from integrators to users.’

Jim Degen, president of Kuka North America (Sterling Heights, Mich.), says the strong software emphasis built on Windows platform benefits operators. Visual Basic can be used to develop much more informative screens using graphic elements in addition to text. Kuka’s manuals are stored in the controller as HTML pages reducing troubleshooting time. Building on PC hardware makes networking easier. In fact, integrators and support personnel today use common remote terminal tools to perform diagnostics off-site, keeping customers’ processes running while saving travel expenses. Meanwhile, not only can software control with open interfaces drive a Kuka 6-axis articulated arm robot, it can also control someone else’s gantry or XYZ Cartesian robot.

Commotion Technology (San Francisco, Calif.) is another company emphasizing software for robotic applications. President John Tenney notes, ‘The primary role of software is to reduce lifecycle cost of automation-from development through operation. Flexible, easy-to-use software that relies on industry standards like Windows NT, PC hardware, Java, C++, and web-based interfaces significantly decrease time-to-market, development costs, operational maintenance, and system upgrade costs.

Cup of robotic Java

For instance, Commotion Technology’s control software, Control Factory, runs on a variety of operating systems including Windows NT and VxWorks from Wind River Systems. It has a graphical programming interface to speed development, or programmers can use Java (Mr. Tenney notes that in 2000 Java programmers will outnumber C++ programmers). Control Factory is actually written in Java, running on a ‘black box’ on VxWorks or on a PC with Windows NT.

Mr. Tenney addresses another powerful, new software tool-3D simulation. In Control Factory, a technician brings up the robot in 3D simulation. This is not only ‘virtual reality,’ but can be a view of the machine actually running. It is useful during development, as well as for troubleshooting.

Another company with simulation tools is Deneb Robotics (Troy, Mich.). President Bob Brown advocates using its tools right from the design stage of a project. The process of a project is often described in detail in the motions of the machine and design of mechanical assemblies, which are then passed off to controls for software design and programming. The process is much better if mechanical and software are talking much earlier. By taking CAD drawings into a simulation package, controls engineers have a better view of sequence of operations. Initial sequence programming can actually be done automatically so the programmer can emphasize exception handling routines, communications, etc.

Robots have come a long way from slow but methodical islands of automation. Simulation software, communications, and embedded PCs are certainly in their future.

Robotics industry enjoying its best year

The North American robotics industry is enjoying its best sales year ever in 1999 according to Robotic Industries Association (RIA, Ann Arbor, Mich.).

According to statistics compiled from January through September 1999, a total of 13,368 robots valued at $1.11 billion were ordered. This is 62% above the prior year in units and 40% in dollars. The previous record for orders for a full year was in 1997 with 12,149 orders valued at $1.10 billion.

Don Vincent, RIA executive vice president, attributes some of the growth to customers new to the industry, particularly nonautomotive. ‘For example, the United States Postal Service recently announced orders for some $66 million worth of robots,’ noted Mr. Vincent. ‘There’s also been an increase in use in industries such as food, consumer goods, and plastics, while demand from automotive manufacturers and their suppliers remains strong.’

Material handling applications have emerged as the leading use for robots, followed by spot welding, arc welding, assembly, material removal, coating, dispensing, and inspection.

Shipments are also setting a new pace with 10,755 units valued at $846 million shipped through September. This is a 32% gain in units and 13% in dollars over 1998.

RIA estimates that 98,000 robots are now used in the United States. According to some industry analysts, less than 10% of manufacturing companies that could benefit from robotics have installed them, providing a large potential market.

Mr. Vincent adds, ‘Robotic technology is going to be a powerful factor in helping manufacturing companies of all sizes become more productive, and it’s going to play a much more important role in areas such as space and undersea exploration, surgery, and environmental clean-up. As our 25-year anniversary winds down, we look forward to the next 25.’

Robotic Industries Association-

Open systems for robotics

Open systems can be one subject not to discuss in polite company, like politics and religion. Not only do proponents of open systems often see the market as ‘us versus them’ (them being suppliers of proprietary systems), but often the very definition of ‘open’ is in dispute. (See ‘Open Systems Mean Freedom of Choice,’ CE ,Sept.’99, p. 56, for a longer discussion of open systems.) Meanwhile, suppliers of proprietary systems have moved with market forces and begun making systems more open.

Most people agree that open systems relate to PC technology. Reasons most often cited include taking advantage of ever-increasing power of PC microprocessors and software. Add in economies of scale of the PC market-sales much larger than the industrial market-and these larger markets usually mean lower prices for chips and networking equipment. Another reason lies with enterprise information needs. Managers are demanding accurate manufacturing information as quickly as possible. Of course, the best information comes directly from machine controllers. Since plants generally are now wired with a PC client-server network over Ethernet, machine control connectivity to that network becomes mandatory.

Every manufacturer cited in this article already has added some standard connectivity to its controller-essentially opening it to the greater plant environment.

Some manufacturers cite complexity of kinematic algorithms as a requirement to maintain robot control of its own processor. Advancing technologies that are shrinking chip size and packing more components on a smaller printed circuit board are permitting a complete controller on a PCI board. Look for several companies to have computer plug-in cards that control robot motion while the PC handles all the human-machine interface, data collection, and communication chores.

Kuka (Sterling Heights, Mich.) has refurbished its robotic line with PC-based control. Jim Degen, president, cites the line’s ability to work with third-party software for each specific job and the ability to customize HMI with Visual Basic as major advantages.

Walt Weisel, president of Robotic Workspace Technology (RWT, Fort Meyers Beach, Fla.) is a proponent of PC-based robot control. He states, ‘By adopting an open architecture platform for hardware and software, integration issues have successfully been simplified and implementation costs have been reduced significantly. Most importantly, end users have a wide range of choices in selecting controls, enabling a high degree of ‘customization’ using commercially available products. Finally, controls can easily be upgraded or even replaced on old robots without throwing away the investment in capital equipment.’

Another technology is lurking on the horizon, though. Embedded systems are beginning to appear in manufacturing. Sometimes called ‘applied computing,’ these are application-specific devices built on standard PC hardware and software platforms. Much publicity has surrounded the evolution of Microsoft Windows CE from home users’ ‘set top boxes,’ to industrial control. This operating system leverages such commonly used technologies as Ethernet connectivity, COM and DCOM for data communications, and ability to use ActiveX objects in a small form factor.

Microsoft has released Windows NT in an embedded configuration. CRS Robotics (Vurlington, Ontario, Canada) exhibited a robot running on Windows NTE at the Embedded System Conference in San Jose, Calif., in September.

Expect to see many more developments in embedded computing in the future. This will likely show up first in Windows CE powered intelligent teach pendants.

Robot safety standard now ANSI standard

Although controls engineers build safeties into all control systems, robot safety seems to capture more attention. Intensive effort by a committee of technical and safety experts drawn from users, suppliers, integrators, and technology developers has resulted in a new standard. ANSI/RIA R15.06-1999 Robot Safety Standard is approved as a new American National Standard.

Jeff Fryman, manager of standards development for Robotic Industries Association (RIA,

RIA offers safety training with topics including risk assessment, hazard analysis, R15.06 standard compliance, design in safety, and fundamentals of robotic safety.