Santa Clara, CA--In Silicon Valley, as in most regions, many engineers cite motion control as the most crucial factor in the design of their new machines.
Responding to their customers' demands for machines that deliver higher throughput and greater precision, design engineers in this high-tech Mecca are on a constant quest for better motion control systems. That was evident from a recent focus group sponsored by Design News, which drew engineers from such companies as Applied Materials (semiconductor manufacturing equipment), Coherent (medical lasers), and Schlumberger Technologies (test equipment). Together, these engineers gave their wish list for the "ideal motion controller."
Not surprisingly, they wanted simple, easy-to-integrate, off-the-shelf systems. The engineers said they should be able to buy such controllers for under $1,000 for a 3-axis system.
Often, however, off-the-shelf systems fall short, and custom solutions are needed. That typically can take four months or more--far too long for most engineers. "We really need to have vendors provide us with custom products in a week," said Gregg Teaby, a senior design engineer with Advanced Cardiovascular Systems. For most engineers, getting suppliers to trim lead times is more of a priority than ever, particularly in the product development stage.
Among the prime features engineers desire most in controllers:
Superior reliability to minimize application support needs. The quality of a controller was cited as the number one concern--clearly more important than price.
Flexibility and ease of use. Too often, different controllers are needed for stepper and servo motors.
Automatic tuning, and other diagnostic and debugging features.
Compatibility with the voltage requirements of the machine's diverse components.
Modularity, to allow for changes and expansion in customer applications.
Engineers are far more concerned that the controller meet these and other performance requirements than they are with the controller's own architecture, such as integration of DSPs, ASICs, and the like. And when it comes to network protocols for motion control, the engineers were reluctant to try new bus systems--fearing a backlash from their customers.
Nor do design engineers have the time to do lengthy benchmarks of various motion control products. Most rely on two or three known vendors and demand a high level of applications support. At least among the engineers at our focus group, the field of possible vendors was wide open. Few of the engineers we interviewed had built their own motion controllers. Instead, they depend on vendors to keep them up-to-date on new motion control technology.
"Speed is what is driving everything," said engineer Stuart Davis of Applied Materials. In many instances, a motion control vendor's ability to meet the engineer's tighter development schedules outweighs the price of the controller.
As vital as the contoller is, however, the engineers pointed out that it is only one part of the performance equation. Motor performance, as well as the proper functioning of such feedback components as sensors and encoders, also play a major role in the accuracy of a motion control system.
For the future, engineers want to see more intelligence built into the controllers they buy--and more debugging capability. They expect to deal with vendors that can provide a greater range of solutions. And they plan to adopt more PC-based motion control so-lutions. Most of all, with the increased pressures they face in product design, engineers want supplier partners they can trust.