Broad-Band Active Vibration Suppression Using PPF Focused on Industrial Application

Abstract

Due to the demand for higher accuracy and lower acoustic noise levels, there is a growing interest for active vibration suppression in industrial application. Many control concepts have been proposed in this field that are suited to introduce damping in systems with a large number of modes. However tuning is often focussed on reduction of one dominant mode. Such control approaches are less transparent when several dominant modes are involved.A combined loop-shaping and root-locus tuning approach is proposed to reduce several dominant modes with low-order controllers. The tuning approach is experimentally evaluated on a vibrating plate using piezo's for both sensing and actuating. Based on the given tuning rules and trade-offs, a SISO feed-back controller is designed and implemented. This low authority control approach shows that besides local performance, also the global damping of the plate is improved which consequently results in reduction of vibration levels over the whole plate for a broad range of frequencies. As a results, acoustic noise radiation is reduced significantly.

Model Predictive Control Applied to Constraint Handling in Active Noise and Vibration Control

“…In the previous equation, is known as the Kalman gain matrix and is given by (again employing the positive definite solution of a DARE) (11) It is important to note that the previous predictions depend only on future inputs , which are free variables. This is essential because it allows a search for the best (according to the cost ) sequence of future inputs.…”

“…For mechanical systems, a commonly applied method is positive position feedback (PPF) control as proposed by Caughey and co-workers [11], [14], [18], [32]. Other methods, including optimal approaches such as [2] and minimax Linear Quadratic Gaussian (LQG) [37], have also been prominent but are less frequently applied in practice.…”

A Negative Imaginary Approach to Modeling and Control of a Collocated Structure

“…Velocity feedback, [6] and [10], and resonant controllers [21], are two well known examples of controllers that guarantee unconditional closed-loop stability when implemented on collocated structures. Positive position feedback (PPF), [22], [23], and [24], is another technique which is not sensitive to the spill-over effect, and has similar stability properties. Unlike velocity feedback and resonant control, the frequency response of a PPF controller rolls off at high frequencies, thus leaving the unmodeled high-frequency modes of the plant undisturbed.…”

Modeling, identification and control of a force generator for vibration attenuation

“…In [8] the important issue of actuator constraints, crucial for any application and vibration control, is taken into consideration and solved by means of a model predictive approach. In [9], instead, the effectiveness of a positive position feedback compensator in damping several dominant modes of a vibrating structure is demonstrated. It can be noted that while all of the mentioned approaches consider the structural dynamics, this paper assumes the vibrating structure to be ideally stiff, so no vibrating modes have been taken into consideration.…”