Improvements in servomotor and motor drive technology widen its scope of application

ControlDesign.com
10/20/2005

THE SUBSTANTIAL development in servomotor and motor drive technology, both in industry and academia, can greatly enhance the quality of control across a wide range of applications, according to the findings of a recent study conducted by Frost & Sullivan. Improvements in control techniques and algorithms, backed by greater processing power in motor drives are increasing the functionality, capability and appeal of servo-based control systems, the report stated. The development and availability of greater functionality, especially at attractive costs, provides important potential benefits for application developers of servo systems technology.

"Integration at lower levels within the controller itself increases the number of features and functions that can be integrated into a single chip," says Frost & Sullivan Research Analyst Rahul Nayar. "In some controllers, this can occur to a considerable degree, absorbing many of the functions of the servo drive into a single microchip."

Such integration has a huge impact at the application level. It enables designers building servo applications around the controller to add and develop more features in the applications. Enhanced and greater numbers of features enable technology developers to differentiate their applications, giving them a significant advantage in a competitive market. This practice has also increasingly solved problems at the motor level, resulting in better control of drives.

The features and functionalities have been improved to such an extent that this technology is now being considered in areas where its use was once restricted.

Linear motors, in particular, are seeing increasing application in fields once dominated by traditional and low-cost technologies. The latter are increasingly yielding to drive technology, due to its natural advantages in important operating parameters.

Some enhancements in drive technology include improvements in some of the core technologies around which developers build drives, greater digital processing power, performance and resolution. In Europe, there has been focused research on three major technologies -- a high force density linear motor, a nanoposition controller and a high-speed torque motor. A liquid metal plasma (LMP) linear motor, supposedly having the highest force density in the industry, was designed for both high efficiency and cold interface.

"Meanwhile, a drive-based solution for motion control consisting of two closed-loop control modules has been developed in North America," observes Nayar. "European companies have also developed a new, intelligent servo motor, integrated standard servomotor components with controllers and drives into a compact package that runs on a software system, enabling flexible control."

Apart from these advancements, another crucial factor that drives adoption of servo technologies is the cheaper costs of processing power. This has helped servo technologies match rising demands from end-user industries and applications such as packaging.

"Servo technology, which found application only in high-cost, advanced, fly-by-wire systems in military aircraft, now replaces hydraulics and pneumatics in applications as commonplace as automobile power steering," notes Nayar. "For a technology that has been labelled an expensive control technology, this is a significant step."

The rapid advancement of this technology has outpaced the awareness campaigns about the significance of new research among engineers and other personnel. Moreover, the engineers' original training in digital technology would have been limited to theory due to the expense and limited availability of hardware. Some industry participants prefer to stick to 'tried and tested' techniques and technologies such as proportional-integral controllers, which are considered reliable, stable and 'safe'. Providing better training and conducting awareness programs to keep engineers informed about the latest technologies and their potential advantages in application can correct this trend.