Implementation of modified positive velocity feedback controller for active vibration control in smart structures

Abstract

This paper introduces the Modified Positive Velocity Feedback (MPVF) controller as an alternative to the conventional Positive Position Feedback (PPF) controller, with the goal of suppressing unwanted resonant vibrations in smart structures. The MPVF controller uses two parallel feedback compensators working on the fundamental modes of the structure. The vibration velocity is measured by a sensor or state estimator and is fed back to the controller as the input. To control n-modes, n sets of parallel compensators are required. MPVF controller gain selection in multimode cases highly affects the control results. This problem is resolved using the Linear Quadratic Regulator (LQR) and the M-norm optimization method, which are selected to form the desired performance of the MPVF controller. First, the controller is simulated for the two optimization approaches, and then, experimental investigation of the vibration suppression is performed. The LQR-optimized MPVF provides a better suppression in terms of vibration displacement. The M-normoptimized MPVF controller focuses on modes with higher magnitudes of velocity and provides a higher level of vibration velocity suppression than LQR-optimized method. Vibration velocity attenuation can be very important in preventing fatigue failures due to the fact that velocity can be directly related to stress.

Nonlinear vibration suppression of flexible structures using nonlinear modified positive position feedback approach

“…To overcome this issue, a first-order compensator was added parallel to the second-order compensator. The results were the Modified Positive Position Feedback (MPPF) [21,22], the Modified Positive Velocity Feedback (MPVF) [23], and the Modified Acceleration Feedback (MAF) [24].…”

Vibration reduction in aerospace structures via an optimized modified positive velocity feedback control

“…The first-order term in the MPVF controller increases the closed-loop damping of the system, and existence of the secondorder term is essential to suppress the resonant harmonic vibrations. The feedback controller is then expressed in form of [16] …”

“…In resonant vibrations of aerospace structures, the fatigue caused in transverse oscillations can become damaging. As it is discussed in [16], a direct approach to prevent fatigue failure is suppressing the vibration velocity. By reducing the vibration velocity, oscillations with higher frequency which also have high displacement amplitudes are better targeted for suppression.…”

“…The designed controller is a resonant frequency controller, which focuses on vibration reduction of tonal excitations. The idea of optimized Modified Positive Velocity Feedback (MPVF) was initially discussed in [16], and in this study, the proposed method is investigated in more detail. Two optimization approaches are used, which are the M-norm and Linear Quadratic Regulator (LQR), to tune the controller gains while considering the dynamics of the structure.…”

Active Vibration Control of Laminated Composite Plates by using External Patches

“…Omidi (2014) [16] proposed that Modified Positive Velocity Feedback(MPVF) control has significant advantage over PPF as it efficiently uses two parallel feedback controllers; one for displacement and the other for velocity. The latest advancements involve several factors to be considered while approaching the technical application of active vibration control.…”