The overall objective of the project is to demonstrate the potential for using magnetostrictive materials in industrial processes, such as high-speed machinery, robotics, acoustic devices and anti-vibration control systems.
In the frame of this project, a low weight (< 1.5 kg) actuator was designed and built using magnetostrictif material, Terfenol-D. Results have shown that high forces (> 800 N ms), can be generated on a wide frequency range (200 - 2000 Hz), with low voltage (< 100 V) and power requirements, at temperature from 20 C to 80 C.
Based on these values an electronic controller and a digital control algorithm were designed and developed.
After a brief overview of works found in the literature on the subject, the consortium has decided to develop an optimal Linear Quadratic Gaussian (LQG) control algorithm.
This algorithm has been developed in C-Code and implemented in machine code, including the management of the I/O signals.
Vibration cancellation tests on a real structure using the pure feedback LQG algorithm have demonstrated the capability to achieve significant damping effect up to 20 dB reduction for the more significant frequency peaks.
However we can note, that when the system is under control the vibrating structure generates a noise due to the high frequency component which are not filtered. Further studies could be made in order to reduce this kind of noise.
For comparison, the consortium has tested an adaptive feed forward control algorithm. The noise reduction using this type of controller is less significant (less than 15 dB reduction for the more significant peak) and needs optimization. However this adaptive feed forward control has the advantage that it doesn't need a redesign when the set-up changes.
These experimentations have shown the obvious interest of the magnetostrictive actuator in active vibration control problems.
The Terfenol actuator is a real alternative in this field since control can be achieved with much lower voltages than piezo-ceramic actuators usually require.
This will be achieved by designing and optimising a high-energy system to demonstrate active anti-vibration control over a wide frequency band-width. Actuators will be designed around highly magnetostrictive materials. In order to assess vibrations, sensors and high-speed control systems will also be built and included in an experimental facility fitted with sensors. The project will produce a fully documented demonstration device which will illustrate the capability of anti-vibration systems.
The enabling technology which is developed in actuation and control will be applicable to the other industrial processes mentioned above. Companies working in these fields will be involved in project working parties to ensure the early utilization of the technology within Europe.