New arms. A new control. And in all cases new approaches: application-specific robots and a controller that not only employs a PC architecture, but which has the ability to control up to 36 axes. These are the sorts of things that aren't commodities.
"They're just commodities now." That's a common remark made by people in advanced manufacturing engineering and purchasing departments when the subject is industrial robots. That remark is a testament to how well equipment manufacturers have done in transforming devices that were considered to be unreliable, difficult, troublesome, and just this side of a necessary evil (after all, they were doing the dirty, dangerous and difficult jobs) just 20 or so years ago into something that is essentially bought by the pound (or at least pounds of payload capacity). This commodity status is good news for those who are specing robots for purchase—in some ways it is as simple as filling in the cells on an Excel spreadsheet. It is not particularly good news for those who are robot vendors. Like producers of any other product—including cars and trucks and the components that go into making them—the robot producers are faced with a handful of alternatives to address this situation: They could reduce prices and cut margins. They could make incremental improvements in things like speed and accuracy and hold their prices. They could perform some serious, significant innovation and take their products right out of the commodity category. Which is what the people at Motoman Inc. (www.motoman.com; West Carrolton, OH) decided to do. Company president and COO Craig Jennings states quite clearly: "We're trying to de-commoditize the robot. What we're saying is that we can deliver more performance and meet the price threshold by coming up with a better mousetrap."
Yes, this is a story about a new approach to robots. But it is just as much a story about how to compete in an environment when the customer—for cars, trucks, components, robots, what-have-you—is oftentimes driven by spreadsheet thinking unless there is a significant, discernable difference. What Jennings and his colleagues both in the U.S. and Japan (Motoman's parent company is Yaskawa Electric Corp. of Kitakyushu, Japan) have been working on for the past several years is the development of what they describe as "application-specific robots." As Yaskawa has a worldwide installed base of over 105,000 robots, it is evident that they know more than a little about manipulator design and control. So they have taken that knowledge in the pursuit of providing what Jennings calls "HyperProductivity®" (yes, they've registered the term).
What's notable about their approach—notable for those who are interested in new robotic systems; notable for those who are interested in being competitive in their own markets—is that they have decided to go beyond the incremental improvement that is typical of many companies when they try to compete. In the robot world, this incremental improvement has typically taken the form of providing robotic equipment that is a little faster, a little stronger, a little more accurate. Not that all of those things aren't helpful. But they may not be enough to be truly competitive. So, as Jennings put it, "We decided to design a robot around a process—the entire manipulator. This isn't just a few features in the controller"—yes, and they have a new one of those, the NX100— "and a few add-ons for the manipulator. Literally: We redesigned the robot around the process. Everything is different." And the differences of the new robots—the EA and ES Series—have a variety of benefits, including reduced integration costs; reduced life-cycle costs; reduced floor-space requirements; increased uptime; improved maintenance; and more-accurate off-line programming.
Essentially, robots for arc welding and spot welding applications (in this case, the EA and ES Series, respectively) have tended to be general-purpose manipulators modified with the equipment necessary to do the tasks. After all, one of the necessities in the robot business is to achieve the kinds of economies of scale that can lead to reduced costs, and in order to achieve those economies, it has generally been necessary to deploy the general-purpose products in a number of applications. But to differentiate their product (which they believe will lead to more business, and consequently to economies), the Motoman engineers have designed these new robots to do the tasks. For example, in the case of the EA arc welding robot, they've designed the package so that the torch cable is run through the arm, not over it, and the torch itself goes through the wrist. Consequently, this design provides direct wire feed that can lead to better welding, and reduced cable interference that can provide improved off-line programming. Similarly, the ES spot welding robot design routes all of the utilities through the upper arm so that the dress-out is not dangling as is ordinarily the case, permitting improved access into parts for welding and higher-robot density within a work area, and significantly reducing worn cable (with significantly signifying a replacement interval of about 24,000 hours rather than the 2,000 to 4,000 hours as is typical for a general-purpose robot).
They worked on some fundamentals, such as using a new grease with low viscosity to eliminate leakage. They put zeroing devices on each of the axes to minimize the time necessary to do a motor change and to get the robot back in operation. But they also did some things that were changes to normal practices. For example, in order to achieve cabling through the arm it was necessary to have an entirely new motor reducer developed, one that's donut shaped. In order to achieve arms with lighter mass, they're employing lost-foam casting. It takes a full approach to improvement in order to create better products.
Like many producers of industrial products, Motoman has been pursing the PC control approach. According to Jennings, they now have a commercially viable product. One that employs Windows CE and VxWorks as the real-time OS. This approach has a variety of benefits for control, from the ability to quickly create custom HMIs to the availability of the various communications protocols that it supports. The teach pendant for the NX100 control serves as the user-interface device; the familiar Windows-format makes working with the pendant all the easier. But unlike many producers of robot controllers, Motoman has been relentless in its pursuit of a single controller that can handle multiple robots. With the NX100 there is the ability to control four robots—and analog processes at the same time. So, for example, four robots could be used for arc welding and there's one controller handling the entire operation.
According to Erik Nieves, senior manager, Technology Advancement at Motoman, they have a patent on the way that programming is handled. He explains that each robot can be programmed individually yet can run in a parallel manner. That is, in other approaches it is necessary for each robot to have the same number of steps in their programs, which can necessitate "phantom" steps for robots that don't need to perform as many moves as others. So programming can be faster. Because there is a central controller for four robots, there is a considerable reduction in integration costs. And because the arms are fully modeled in the control (remember: there is the integration of cables and dressing, which is unlike most other robot arms, so the models of the arm in the controller are closer to the actual arms than is the case when the cabling and dress-out are appendages, which can't be modeled), robots can be programmed to work as closely as possible, which can contribute to reduced cycle times.
Jennings says that they've shown the new arms and the new controller to people who have heretofore not used Motoman equipment in any significant way. And that the responses have been positive. When you look at the ES and EA arms, it seems as though they represent what should have been all along. Perhaps the obviousness of it all—in retrospect, at least—truly marks how significantly they've changed the game.