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.

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.

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.

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.

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.