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This paper presents a design, development and experimental verification of an active vibration control system of aluminum plate. The active structure consists of an aluminum rectangular plate as the host structure, strain gages as the sensor element and a piezoceramic patch as the actuation element. Based on characteristics of the integrated elements with use of the fuzzy optimization strategy based on the pseudogoal function the optimal orientation of piezoelectric actuator is found, and the whole active vibration control system is designed and developed. The active vibration control system is controlled by proportional-integral-derivative (PID) control strategy. Control algorithm was implemented on the PIC32MX440F256H microcontroller platform. In order to prevent it from negative occurrences from derivative and integral terms in a PID controller, the first-order low-pass filters are implemented in the derivative action and in the feedback of integral action. The experiment considers active damping control under periodic excitation. Experiments are conducted to verify the effectiveness of the vibration suppression and to compare the damping effect with different adjustment of PID gains. Experimental results corresponding to the developed active vibration control system are presented. The system suppresses more than 90% of vibration amplitude, which confirms the high level of effectiveness in vibration active damping at the proposed active structure.

U radu je prezentovan praktičan primer merenja i analize vibracija na prva dva stepena aksijalnog kompresora sa namerom da se proceni povezanost između poremećene ulazne struje vazduha i pojave otcepljenja strujnica od lopatica kompresora. Poremećenost ulazne struje vazduha je ispitivana tokom različitih režima leta aviona sa maksimalnim potiskom, pod pretpostavkom da postoji nesimetrično strujanje vazduha kroz dvostruki uvodnik i da ono ima uticaj na pojavu vibracija kompresora. Prikazano je merenje vibracija na avionu Galeb G-2 sa motorom Rolls Royce Viper Mk22-6 sa ciljem da se prepozna i definiše minimum neophodnih podataka koji bi ukazali na potencijalnu poremećenu struju vazduha kroz kompresor, kao posledicu nejednake raspodele vazdušne struje u uvodniku. Efikasnost ove metodologije merenja predstavljena je korišćenjem Furijeovih transformacija. Predložena metodologija merenja i analize može se sprovoditi na različitim tipovima aviona u cilju istraživanja pojave otcepljenja strujnica i pumpanja kompresora., This paper presents a practical example of the measurement and analysis of vibrations in the first two stages of the axial-flow compressor with intention to estimate a connection between inlet air flow distortions and appearance of stalling of the compressor blades. The inlet air flow distortions were tested during different regimes of the aircraft flight with a maximum thrust, with an assumption that the asymmetry of air flow through the twin-inlets existed and had effect on vibrations of the compressor. The paper shows the measurement of vibrations on the Galeb G-2 aircraft powered by the Rolls Royce Viper Mk22-6 engine with the aim to recognize and define the minimum necessary data for detection of the potential distorted air flow through the compressor, as consequences of an unequal air flow distribution in the inlets. The detection capability of this methodology of measurement is presented using the fast Fourier transform (FFT). The proposed methodology of measurement and analysis can be implemented in different types of aircraft in order to research the occurrence of stall and surge.

Piezoelektrični aktuatori se uveliko primenjuju za aktivno upravljanje vibracijama na raznim strukturama sa ciljem povećanja performansi sistema. Razvijeni sistem aktivnog upravljanja vibracijama se sastoji od aktivnije strukture, kontrolera i visokonaponskih pojačivača. U ovom radu, kompozitna greda predstavlja osnovnu strukturu za senzorsku (merne trake) i aktuatorsku (dvoslojni PZT piezoelektrični aktuator) platformu. U cilju unapređenja dinamičkih karakteristika aktivnog sistema vršena je promena koeficijenata PID regulatora. Efikasnost sistema aktivnog upravljanja vibracijama za posmatrani mod oscilovanja se može povećati promenom koeficijenata PID regulatora, ali u isto vreme moguće je narušiti stabilnost sistema. Nestabilnost sistema je najčešće uslovljena pojavom 'spillover' efekta. U ovom radu predstavljen je značaj 'spillover' efekta u zatvorenim petljama piezoelektričnih aktivnih struktura, kao i značaj promene koeficijenata PID regulatora na stabilnost sistema. Eksperimentalni rezultati sistema aktivnog prigušenja vibracija su predstavljeni u radu i daju jednu od mogućnosti za povećanje stabilnosti upravljanih struktura., Piezoelectric actuators are widely used in structural systems for active vibration control with the aim to enhance the performance of systems. The developed system of active vibration control consists of active structure, controller and high voltage amplifier. In this paper, the composite beam is host structure for sensor platform (strain gages) and actuator platform (dual layer PZT piezoelectric actuator). In order to improve the dynamic characteristics of active system, the coefficients of PID controller are changed. The effectiveness of active vibration control system at mode of interest can be improved with change of PID coefficients, but the stability of system can be reduced. The instability of the active structure is often perturbed by spillover effect. In this paper the importance of considering spillover effects in closed loop of piezoelectric active structures is demonstrated and shown the importance of change the PID coefficients in stability of active vibration control system. Experimental results which correspond to the developed active vibration control system are presented and affirmed stability on proposed active structure.

Određivanje veličine i položaja piezoelektričnih aktuatora i senzora za aktivno upravljanje vibracijama savitljivih struktura obično je bazirano na maksimalnoj efikasnosti upravljanja i postizanja maksimalnog izlaza za modove vibracija od interesa. Integracija piezoelektričnih delova utiče na masu i dinamičke performanse bazične strukutre. Ovo je prvi deo istraživanja koje predstavlja teorijski razvoj višeciljne fazi optimizacione tehnike za određivanje položaja i veličine piezoelektričnih aktuatora i senzora na tankozidnoj kompozitnoj gredi. Kriterijumi optimizacije za određivanje optimalne veličine i položaja piezoelektričnih aktuatora i senzora zasnivaju se na stepenu upravljivosti upravljanih modova. Procedura optimizacije obuhvata ograničenje promene prvobitnih dinamičkih karakteristika i ograničenje u porastu mase. Pseudociljna funkcija, zasnovana na teoriji fazi skupova, daje izraz za globalnu ciljnu funkciju eliminišući upotrebu težinskih koeficijenata i kaznenih funkcija. Optimizacija rojem čestica je upotrebljena za nalaženje optimalne konfiguracije., Sizing and location of the piezoelectric actuators and sensors for vibration control of flexible structures is usually based on maximum control effectiveness and achieving the maximum output for the vibration in the modes of interests. Integration of piezoelectric patches affects the mass and the original dynamic properties of the parent structure. This is the first part of the two-paper research which presents the theoretical development of the multi-objective fuzzy optimization technique of sizing and location of the collocated piezoelectric actuators and sensors on the thin-walled composite beam. The optimization criteria for the optimal size and location of piezoelectric A/Ss are based on the degree of controllability (DC) for controlled modes. The optimization procedure implies the constraining of the original dynamic properties change and the limitation of the mass increase. A pseudogoal function, derived based on the fuzzy set theory, gives an expression for global objective functions eliminating the use of weighting coefficients and penalty functions. the particle swarm optimization technique is used to find the optimal configuration..

Ovo je drugi deo istraživanja višeciljne fazi optimizacije veličine i položaja piezoelektričnih aktuatora i senzora na tankozidnoj kompozitnoj gredi. Prvi rad je fokusiran na teorijskom modelu optimizacione tehnike za optimalno dimenzionisanje i postavljanje piezoelektičnih aktuatora i senzora na pametnu strukturu za aktivno upravljanje vibracijama. U ovom delu, biće prikazana numerička analiza predstavljene optimizacione tehnike za kompozitnu konzolu sa i bez ograničenja u pogledu stepena upravljivosti za rezidualne modove., This is the second part of a two-paper research of the multi-objective fuzzy optimization of sizing and location of the collocated piezoelectric actuators and sensors on the thin-walled composite beam. The first paper is focussed on the theoretical model of a optimization techique for optimal sizing and location of piezoelectric actuators and sensors on a smart structure for active vibration control. In this part, the numerical analysis of the presented optimization technique will be presented for the cantilever composite beam with and without limitations in degrees of controllability (DCs) for residual modes.

This paper deals with active free vibrations control of smart composite beams using particle-swarm optimized self-tuning fuzzy logic controller. In order to improve the performance and robustness of the fuzzy logic controller, this paper proposes integration of self-tuning method, where scaling factors of the input variables in the fuzzy logic controller are adjusted via peak observer, with optimization of membership functions using the particle swarm optimization algorithm. The Mamdani and zero-order Takagi-Sugeno-Kang fuzzy inference methods are employed. In order to overcome stability problem, at the same time keeping advantages of the proposed self-tuning fuzzy logic controller, this controller is combined with the LQR making composite controller. Several numerical studies are provided for the cantilever composite beam for both single mode and multimodal cases. In the multimodal case, a large-scale system is decomposed into smaller subsystems in a parallel structure. In order to represent the efficiency of the proposed controller, obtained results are compared with the corresponding results in the cases of the optimized fuzzy logic controllers with constant scaling factors and linear quadratic regulator.

This paper presents experimental verification of the active vibration control of a smart cantilever composite beam using a PID controller. In order to prevent negative occurrences in the derivative and integral terms in a PID controller, first-order low-pass filters are implemented in the derivative action and in the feedback of the integral action. The proposed application setup consists of a composite cantilever beam with a fiber-reinforced piezoelectric actuator and strain gage sensors. The beam is modeled using a finite element method based on third-order shear deformation theory. The experiment considers vibration control under periodic excitation and an initial static deflection. A control algorithm was implemented on a PIC32MX440F256H microcontroller. Experimental results corresponding to the proposed PID controller are compared with corresponding results using proportional (P) control, proportional-integral (PI) control and proportional-derivative (PD) control. Experimental results indicate that the proposed PID controller provides 8.93% more damping compared to a PD controller, 14.41% more damping compared to a PI controller and 19.04% more damping compared to a P controller in the case of vibration under periodic excitation. In the case of free vibration control, the proposed PID controller shows better performance (settling time 1.2 s) compared to the PD controller (settling time 1.5 s) and PI controller (settling time 2.5 s).