Evolutionary rather than revolutionary changes characterize the motion control market. Motors and motor controllers continue to gravitate toward higher performance and functionality as market demands become more stringent. At the same time, higher levels of intelligence — driven largely by software advancements, are giving engineers greater control and flexibility in designing motor-based systems.
The increasing complexity of motion control applications is driving many of the changes in motors and motor controllers. “Clearly, the applications we’re seeing are more complex, and more sophisticated— wireless communications, security, and networking,” said Kirk Barker, electronics product manager for Maxon Precision Motors Inc.
Peter Nachtwey, president of Delta Computer Systems, said, “One trend is the opening up of new markets for motion control technology being made possible by the advancing ease of use of motion controllers. Engineers that couldn’t justify the motion system development learning curve in the past are now able to make use of the technology. An example of this is the great increase in the number of motion controllers that are being used in engineering and production test environments.”
Though considered mature, the motion control market continues to show steady growth. Reported sales of motors, electronic drives, controllers, actuators and other motion control components are up 3.7% from the first quarter of 2007, according to a report by the Motion Control Association (MCA).
The report found that motors—brush and brushless, servomotors with gearings mounted, direct drive, linear motors and steppers, accounted for the largest percentage of motion control sales at 36.5%. “The findings show that the motion control market as a whole is expanding at a healthy rate and therefore represents an important area of vitality within the greater economy,” said Paul Kellett, MCA’s director of market analysis.
One area of progress has been in the electronic components used to create motors and motor controllers, according to Keith Kowalski, vice president of technology for Haydon Switch & Instrument Inc. “These components are smaller, more efficient, lighter, and more powerful,” said Kowalksi. “All this allows designers to use products in ways that were never thought to be possible before, even with the same motor or actuator.”
Component integration has also reduced the number of parts inside motors and controllers, saving space and giving designers more flexibility in designing motion control systems. “As components become smaller, manufacturers are able to integrate controllers and actuators into complete systems,” said Kowalski.
As motors scale up the performance curve, smaller motors are offering the performance of their larger counterparts. “Devices previously using 16-mm-diameter motors are demanding the same performance out of a 13-mm-diameter product,” said Ted Severn, director of sales and marketing for motor manufacturer MicroMo Electronics.
One motor trend is the increasing use of piezo motors for linear actuation. These motors, which replace traditional linear motors used with a ballscrew or leadscrew, provide precise positioning.
According to Scott Jordan, director of Nanopositioning Products for Physik Instrumente LP, piezo-based motors provide centimeters to travel — longer than the few hundred microns previously—and many kilograms of pushing and holding force. Piezo motors also provide sub-nanometer positioning resolution. They are finding use in applications from industrial automation to semiconductor test and metrology equipment, Jordan noted.
Higher performance also characterizes the latest motor controllers. “The technology in motor controllers now provides 10 to 20 times more performance than five years ago,” said Wayne Baron, president and co-founder of Galil Motion Control.
The integrated motor and controller, whose design was pioneered a decade ago by Animatics, also continues to gain usage, noted Mark Feyh, product manager for the Electromechanical Automation Division of Parker Hannifin.
“The most significant development in motion control technology over the past year has been the continuing trend to integrate controllers with brushless dc motors,” said MicroMo’s Severn. “This allows an OEM designer to specify a motion control system rather than having to specify a DC motor or brushless DC motor along with the drive electronics for that particular motor.”
Integrating the motor and controller saves space and reduces the cabling complexity inherent in separate motors and controllers, said Jim Drennan, marketing manager for Tolomatic. “But it introduces safety issues such as heat dissipation. One may have to derate the motor’s performance because of the higher temperatures,” he said.
Another way to increase value has been to integrate the motor with a fan or blower, according to Phil Faluotico, brushless motor engineering manager for Ametek Technical and Industrial Products. “The ability to regulate blower speed as system voltage changes is one advantage. We’re able to regulate system performance as voltage increases.”
Another control option is incorporating a motor control IC in the motor and keeping the drive electronics external, according to Pete Visconti, vice president of sales and marketing for LSI Computer Systems, a fabless supplier of ICs for motor control. “More sophisticated users want the motor control IC in the motor,” Visconti said.
Ethernet Becomes Ubiquitous
In communications protocols, the key trend has been the adoption of Ethernet as the preferred networking interface. Ethernet has already emerged as a de facto standard for factory data networking, communications, and control.
“Ethernet is reliable, and there are plenty of Ethernet cards available,” said Galil’s Baron.
Parker’s Feyh agreed. “We’ve gotten more requests on the Ethernet bus. Bandwidth is high enough, and Ethernet chipsets have come down in price. Ethernet looks like the clear winner.”
Lenze–AC Tech has developed a servo motor drive that not only has an Ethernet port, but does not require any proprietary software or protocol to set up. The engineer can access any motor drive function through an Internet browser.
Older communications buses, such as CANbus, still have their proponents, though. “CANbus is very popular because of its use in automotive applications,” said LSI Computer’s Visconti.”
Feyh added, “CANbus is still viable for lower bandwidth applications. It can send on/off signals to move or jog a motor at a certain speed.”
Software Importance Gaining
The use of software is giving motors and controllers a greater degree of intelligence and flexibility to regulate functions such as motor velocity and positioning.
“As software gets more user-friendly, machine designers are able to program these systems more easily and improve the function of their end product, as well as focus their efforts on the core performance of their machines,” said Haydon’s Kowalski.
Motor controllers are also offering simplified programming. Yasakawa Electric America Inc. released its MotionWorks IEC Mechatronic Control System that is compatible with the IEC61131-3 programming standard, providing function block, ladder program, and structured text languages in a single development package.
But software is not always the best means of dealing with some aspects of motor behavior, said Dave Coutu, president of Intelligent Motion Systems. “We’re offloading some of the control from software to hardware to deal with the idiosyncrasies of the motor, such as stalling and resonance,” he said.
Because software used across various manufacturers’ products is often nonstandard and proprietary, vendors consider software a product differentiator, noted Galil’s Baron. “Software tools are not commodities. For us, we recognize applications support, and getting a product design into an OEM is in many ways a bigger challenge than developing the product.”
Motion control advancements are occurring as cost pressures continue, particularly in parts used for high-volume applications such as consumer electronics.
Stepper motor prices continue to fall as more motors are built in low-cost regions such as China, according to Parker’s Feyh. ”Most of the stepper motor market is looking for lower cost, not high performance,” he said.
The increasing complexity of motion control applications has created opportunities for suppliers to improve the price-performance ratio in their products, and add value.
“Of course, the cost is always near the top of the list, but more importantly, the OEM customer is looking for value,” said Haydon’s Kowalksi.
Part of that value equation is giving the customer design and applications assistance, given increasing time-to-market pressures and smaller engineering departments at many OEMs, noted IMS’ Coutu. “It doesn’t pay for a company to design it himself.”
Galil’s Baron added, “10 to 15 years ago, customers were able to design their own motors and controllers. There’s been a trend away from do-it-yourself motion control.”
The lack of industry standards for motors and communications protocols further necessitates the need for motion control suppliers to get involved in the customer’s application, according to Tolmatic’s Jim Drennan. “There’s acceptance of proprietary solutions. “If the solution is sold to the OEM, the OEM is tied to that solution.”
On the technology side, Physik Instrumente’s Jordan said, “Expect more speed, more intensive linkage to the customer’s automation processes, tighter synchronization, more sophisticated interfacing, more non-Windows-based environments, and more software power in easier-to-use formats. Also, the rapid adoption of multicore processors in PCs is placing new demands on synchronization and concurrency features in all classes of instrumentation.”
Kowalksi said, “There will be increased focus on power density and performance. Designers will be able to use relatively simple products for higher performance applications. This can be widely seen in the stepping motor arena, with stepping motor actuators performing in a way that was only thought to be possible with servo systems just a few years ago.”
The ability to interface with absolute encoder technology will be standard in most future motor drives, according to Mark Langille, BiSS Product Manager for Dynapar. “Even the low-end versions will have absolute encoder interface capability,” Langille said. “The request for motor temperature and vibration feedback integrated into the position feedback seems to be growing in demand.”
On the business side, the wave of consolidation that has occurred in recent years is not likely to subside. For instance, Ametek has acquired rival motor suppliers EG&G Rotron, Pittman, and Extreme Energy.
“It appears that the North American market is slowing down,” said MicroMo’s Severn. “If this happens, then I would expect to see more market consolidation as buying opportunities occur.”