Design and Application of Optimal Feedback Controller for controlling Active Vibrations

Improved manufacturing methods have become crucial factors in retaining global competitiveness for a wide range of products. This has led to the development of intelligent, compact and lightweight smart machine tools. A great difficulty is faced in the design of such machine tools due to the fact that the reduction in weight results in low rigidity and poor vibration control characteristics. The induced vibrations in the system may destabilize the system and result in complete failure of the system. On the other hand, the successful vibration reduction of the smart machine tools during machining process can improve productivity, increase quality, and reduce tool wear. Also healing the vibration error can reduce industrial waste, save money and improve design flexibility of new cutting tools. Therefore, there is a need to develop machine tools that are equipped with suitable vibration control features. Objective of the present paper is an attempt to design an optimal feedback controller and its application to control the active vibrations. Smart machine tools technology using active control system may provide a solution to this problem. With the optimization of position of closed loop poles of the system, maximum reduction of vibrations has been found. These machine tools use piezoelectric materials, electro-rheological fluids and shape memory alloys as sensors and actuators for providing effective vibration control.