Rethinking Robotic Deployment
Put away your spreadsheets of specifications and start thinking about process advantages that can be realized through the application of robots.
Those who write advertising for a living learn one thing early in their careers: The difference between "features" and "benefits." "Features" are those things that a product has. Say, for example, a refrigerator with a built-in TV set right next to the water and ice cube dispenser. The ostensible "benefit" is: "it allows you to watch the Food Network while cooking dinner." This is really a case of what's known as "specsmanship." For example, you go to a website like that of Best Buy and do a comparison of refrigerators from various suppliers. But there is a third leg to the stool, which is "customer value." You don't find that on a spreadsheet. Which probably explains why there aren't a whole lot of refrigerators with TV sets out there.
What, you might wonder, does this have to do with robots? It's this: Erik Nieves, technology director, Motoman Inc., speaking of robot technology, says, "Specsmanship is dead." Meaning that while robots have pretty much been about features and benefits, the technology has matured such that he suggests that unless there is "a sea-change in materials," such as the development of composite manipulators (and he candidly admits that "materials scientists have proven me wrong any n-number of times"), the real issue is about the value that can be derived, beyond that which is presently achieved through the deployment of the technology.
Neil Dueweke, general manager, New Domestics and Body Structures Group, Fanuc Robotics America (www.fanucrobotics.com/)
, essentially echoes this by pointing out that in the 20+ years he's been in the robotics industry, he's seen a maturation of the technology. For example, while there were once concerns regarding robot failures so that there was redundancy built into lines, Dueweke says that the mean time between failure (MTBF) for robots is "off the Richter-scale good," that some plants have had robots running for eight to 10 years without replacement.
Sure, there will continue to be incremental improvements. But they are only part of it. It is how they are used and what they can do that matter most. Beyond specsmanship, it is about what the robots can do, either (1) differently than has been possible in the past or (2) different things.
For example, take spot welding. This is one of the original applications for robots in automotive applications. Dueweke says that there are tens, or hundreds, of thousands of weld tips used each year. Depending on the price of copper, these tips could range in price from 30 cents to over $1. Typically, he explains, the method is for operators to monitor the tip wear on robotic spot welding guns by looking at the welds produced. The robot controllers for Fanuc robots have a vision capability. So the company's engineers have developed a system whereby with a simple camera, weld tips can be inspected after every x-number of welds. Dressing or replacement can be performed when required.
This is not radically changing anything. The spot welding is done as the spot welding has been done. It is, however, a value enhancer, not only as regards saving on the cost of tips, but on assuring product quality.
A different approach to spot welding is being facilitated via new technology. Nieves cites the Motoman-VS50, a newly developed robot with a seventh rotational axis (E-axis). It has a 50-kg payload and Yaskawa, Motoman's parent company, has developed a small, lightweight spot welding gun that has welding pressure comparable to a standard gun (i.e., maximum pressure of 5,880 N). The seventh axis, essentially an elbow, allows the spot welding gun to maintain the best orientation even in places that might seem otherwise too constrained for robotic application—or would be too constrained for the typical six-axis arm.
Nieves says, "We're trying to maximize the density in a work cell, and the seventh axis allows us to do that. We anticipate that it will be working in conjunction with the big arms, but it will work tucked in and beneath the other robots. This allows doing hem lines and rocker panels with a robot that people might not even be aware is there."
He explains that at Motoman they're using the acronym ERP, but not in the sense of enterprise resource planning, but "efficient robot production." "Efficient," he says, "means more in less—more process in less space is greater throughput."
Then there's the doing of something that hasn't previously been possible. An example of this that Dueweke cites is using a heavy-duty robot (their M-2000iA), which is available in versions that can handle payloads of 900 or 1,200 kg. He explains that as more body shops are dealing with multiple platforms and multiple models built from those platforms, there can be "a tooling mess in terms of the lifter mechanisms that you need. This robot allows you to clean up those rats' nests of tooling." That is, the robot has the capacity to lift and transfer a car body. Heretofore, even if there was a robotic solution deployed, it would have required a couple of robots. But given the capacity of the M-2000iA, that's not necessary. So here is a case where robotic flexibility can provide a solution that otherwise might not have been achievable.