Active Vibration Control Of Piezo Stack Actuator With Consideration To Hysteresis And Saturation Effects

Tindak balas penggerak piezo bertindih dari segi daya-sesaran-pecutan sebagai fungsi pengujaan voltan dan frekuensi diukur bagi menentukan ciri-ciri histeresis dan ketepuan yang boleh diwakili oleh persamaan kuadratik polinomial. Ketepuan daya, sesaran dan pecutan berlaku daripada 400 Hz sehingga 500 Hz untuk 400 V voltan pengujaan. Ciri-ciri histeresis dan ketepuan ini kemudiannya digunakan di dalam sistem kawalan getaran aktif dan mengakibatkan pengurangan ralat sebanyak 50 - 67 %. Ini membuktikan kepentingan memasukkan histeresis dan ketepuan penggerak di dalam reka bentuk sistem kawalan getaran aktif. Pengukuran kebolehpindahan menunjukkan julat frekuensi berkesan pada 250 - 450 Hz. Kebolehgunaan secara praktikal sistem kawalan getaran aktif telah disiasat dengan menggunakannya pada mesin pencanai elektrik yang berkelajuan nominal 25000 rpm dan kebolehpindahan getaran berkurangan sebanyak 91 %. Penambahbaikan telah dicapai menggunakan model histeresis lelurus bersama-sama tiga skim anti-gegulung (pengapitan, pengiraan-belakang dan mod jejakan) untuk mengelakkan ketepuan voltan pantas pada penggerak piezo bertindih dan prestasinya telah dibandingkan dengan skim kawalan daya aktif. Hasil kajian menunjukkan sistem PID-kawalan daya aktif adalah lebih baik daripada PID-anti-gegulung dengan jumlah pengurangan kebolehpindahan getaran sebanyak 97.7 %. Getaran struktur boleh dihadkan supaya kurang daripada nilai tepu sesaran penggerak di dalam sistem kawalan getaran aktif dengan melakukan pengubahsuaian struktur dinamik dan ini telah menyebabkan perlebaran julat frekuensi berkesan kepada 200 - 510 Hz dengan pengurangan kebolehpindahan getaran sebanyak 96 % berbanding dengan reka bentuk asal. Di dalam penyelidikan ini, sumbangan utama adalah penentuan lengkungan histeresis dan ketepuan bagi penggerak piezo bertindih dari segi daya-sesaran-voltan sebagai fungsi pengujaan frekuensi. ________________________________________________________________________________________________________________________ The piezo stack actuator response in terms of force-displacement-acceleration as a function of the excitation voltage and frequency are measured to determine the hysteresis and saturation characteristics which are represented using quadratic polynomial equations. Saturation of force, displacement and acceleration occurred from 400 Hz to 500 Hz for the 400 V excitation voltages. These hysteresis and saturation characteristics are used in the active vibration control (AVC) system which resulted in error reduction of 50 - 67 %. This proves the importance of including the hysteresis and saturation of the actuator in the design of the AVC system. Transmissibility measurement showed the effective frequency range of 250 - 450 Hz. The practical applicability of the AVC system was investigated using an electric die grinder with a nominal speed of 25000 rpm and the vibration transmissibility was reduced by 91 %. Further improvement was achieved using the linearized hysteresis model together with three anti-windup schemes (clamping, back-calculation and tracking mode) to avoid fast voltage saturation of the piezo stack actuator and the performance was compared with the active force control (AFC) scheme. The results showed that the PID-AFC was superior to the PID-anti-windup schemes with a total vibration transmissibility reduction of 97.7 %. The vibration of the structure can be limited to be less than the saturation displacement of the actuator in the AVC system using the structural dynamic modification (SDM) and this has resulted in a wider effective frequency range of 200 - 510 Hz with the vibration transmissibility reduction of 96 % when compared with the initial design. In this research, the main contribution is the determination of the hysteresis and saturation curves of the piezo stack actuator in terms of force-displacement-voltage relationship as a function of excitation frequencies

Active Vibration Control To Attenuate Hand-Arm Vibration For Orbital Sander

Dynamic analysis of the orbital sander is carried out using coupled orbital sander-hand-arm model subjected to the active vibration control (AVC) pad. Analisis dinamik bagi mesin penggilap orbit telah dilakukan dengan menggunakan model pasangan mesin penggilap orbit dan tangan tertakluk kepada pad kawalan getaran akti

Modelling of the Coupled Beam-Piezoelectric Material With Hysteresis Non-Linerity Effect

Hysteresis is one of the non-linearity characteristics of the piezoelectric material. This characteristic is important to be characterized since it can affect the performance of the piezoelectric material as sensor or actuator in many applications. In this study, the model of the coupled aluminium beam with single piezoelectric patch material is constructed to investigate the hysteresis effect of the piezoelectric material to the whole beam structure. A P-876 DuraActTM type piezoelectric patch material is used in modelling of the piezoelectric actuator. Firstly, the modal analysis of the coupled beam-piezoelectric actuator is determined to get the natural frequencies and mode shapes. Then, the piezoelectric patch material is investigated in terms of actuator by given a sinusoidal voltage excitation and output in terms of deflection, stress and strain of the piezoelectric actuator are investigated. From the results, it is clear that, the coupled beam-piezoelectric material is affected by the hysteresis of the piezoelectric material and the natural frequencies of the beam structure. This characteristic is important for the piezoelectric actuator manufacturer and by providing the correction algorithm, it can improve the performance of the piezoelectric actuator for many applications

Vibration Analysis of Kenyir Dam Power Station Structure Using a Real Scale 3D Model

In this paper, the vibration analysis in terms of modal and harmonic responses are investigated for the power station structure of Kenyir Dam in Terengganu, Malaysia. Modal analysis is carried out to provide the dynamic characteristics of the power station which includes the natural frequencies and mode shapes. Meanwhile, the harmonic response analysis is performed by applying the force to the structure to obtain the Frequency Response Function (FRF) in certain range of frequencies. A real scale three-dimensional (3D) model of the Kenyir Dam power station is constructed using SolidWorks software and imported to ANSYS software for the Finite Element (FE) analysis. A proper boundary condition is taken into consideration to demonstrate the real behaviour of the power station structure. From the results, six most significant natural frequencies and mode shapes including the FRF in all three axes are selected. The highest natural frequency value occurred at 5.4 Hz with the maximum deflection of 0.90361 m in the z axis direction. This value is important in order to verify whether the structure can overcome the resonance phenomenon from the external disturbance forces in the future

Vibration analysis of Kenyir Dam power station structure using a real scale 3D model

In this paper, the vibration analysis in terms of modal and harmonic responses are investigated for the power station structure of Kenyir Dam in Terengganu, Malaysia. Modal analysis is carried out to provide the dynamic characteristics of the power station which includes the natural frequencies and mode shapes. Meanwhile, the harmonic response analysis is performed by applying the force to the structure to obtain the Frequency Response Function (FRF) in certain range of frequencies. A real scale threedimensional (3D) model of the Kenyir Dam power station is constructed using Solid Works software and imported to ANSYS software for the Finite Element (FE) analysis. A proper boundary condition is taken into consideration to demonstrate the real behaviour of the power station structure. From the results, six most significant natural frequencies and mode shapes including the FRF in all three axes are selected. The highest natural frequency value occurred at 5.4 Hz with the maximum deflection of 0.90361 m in the z axis direction. This value is important in order to verify whether the structure can overcome the resonance phenomenon from the external disturbance forces in the future

Attenuation of Humming-Type Noise and Vibration in Vehicle HVAC System Using a Tuneable Dynamic Vibration Absorber

Heating, ventilation, air conditioning (HVAC) is one of crucial system in a vehicle. Unfortunately, its performance can be affected by the vibration of HVAC components, which subsequently produced unwanted noises. This paper presents an innovative design solution which called as tuneable dynamic vibration absorber (TDVA) to reduce the humming-type noise and vibration in the HVAC system. A detail investigation is carried by developing a lab-scale HVAC model that has the capability to imitate the real HVAC operation in a vehicle. An alternated air-condition (AC) with a fixed blower speed is implied in the study. The analysis of humming-type noise and vibration induced from the HVAC components are performed, and the TDVA is designed and tuned according to the natural frequency of the AC pipe before the attachment. The humming-type noise and vibration characteristics of the HVAC components are compared before and after the implementation of the TDVA. The findings shown that the HVAC model data compares well with the vehicle data, whereby the implementation of TDVA is found to reduce the vibration of the AC pipe by 79% and 61% in both idle and operating conditions and this subsequently improved the humming-type noise of the HVAC system. It also been observed that the TDVA has an effective frequency range around 75–255 Hz and 100–500 Hz for the HVAC model and vehicle systems, respectively

Calculating the Moduli Elasticity For Reinforced Concrete Using New Rule of Mixtures Approach for the Dam Structure

Dam is the important structure use for water domestic store, electricity power supply, irrigation and flood control. Dam deal with reinforced concrete as a main material in construction. the material considerable safe when ability to support external and internal load. the capability of dam material due to safety is effect by degradation. Prevention monitoring must be conducted for high risk structure. Thus, moduli elastic is a mechanical property to measure stiffness and had relationship between stress and strain of material. While non-destructive and destructive testing in site inspection does not include reinforce and give incorrect moduli elasticity. New approach rule of mixture (Rom) with solid work software refer to United States Department of the Interior Bureau of Reclamation (USBR) standard design for small dam, give reliability monitoring with true sustain modulus elasticity of dam structure time by time. the concrete properties for sustain of moduli elasticity standard type gravity concrete dam value is 20.684 GPa. If the value decreases drastically from the standard, high precaution must be taken

Experimental Validation of the HVAC Humming-type Noise and Vibration in Model and Vehicle System Levels

The presence of noises in the vehicle cabin is an annoyance phenomenon which is significantly affected by the heating, ventilation, and air conditioning (HVAC) system. There are very limited studies reported on the specific type of noise characterisation and validation for both model and vehicle system levels. The present study developed a model of HVAC system that reflects the operation as in real vehicle, and the investigation of the HVAC components were carried out individually to determine which component contributes to the humming-type noise and vibration. The study was conducted under two conditions; idle speed of engine (850 rpm) and operating condition (850-1400 rpm). A ixed blower speed and full-face setting were applied throughout the experimental process. Three different sensors were used for the experiment, which are: accelerometer, tachometer, and microphone. From the results, the compressor and AC pipe components have contributed the most in generating the noise and vibration for both the model and vehicle systems. The findings also highlight that the humming-type noise and vibration were produced in the same operating frequency of 300-400 Hz and 100-300 Hz for idle and operating conditions, respectively, and this result was validated for both model and vehicle system levels

A Lab-scale HVAC Hissing-type Noise and Vibration Characterization with Vehicle System Validation

Heating, ventilation and air conditional (HVAC) system provides a cold ventilation for the comfort of the driver and passengers in a vehicle. However, the vibration induced by the HVAC contributes to a reasonable level of noise emission, and hissing is one of the critical noises. So far, the characterization of hissing noise from the vehicle is least to be reported compared to other type of noises. Hence, this paper investigates the occurrence of hissing noise from several HVAC components. A lab-scale HVAC system was developed to imitate the real-time operations of the vehicle HVAC system. Two engine conditions, namely as ambient and operating conditions, were tested at speed of 850 rpm and 850-1400 rpm, with the blower speed maintained constantly at one level. The result shows that the hissing noise from the labscale HVAC was produced at frequency range of 4000-6000 Hz. The finding also highlights that the main component contributors of noise emission are an evaporator and a thermal expansion valve. The validation with a real vehicle system showed a good consensus whereby the hissing noise was produced at the similar operating frequency ranges. Also, the hissing noise was found to be louder when in an operating condition which could be taken into consideration by the vehicle manufacturers to improve the HVAC design

Measurement of the Hissing-Type Noise and Vibration of the Automotive HVAC System

Noises such as hissing, humming, air-rush and compressor engagement are the common type of noises that can be induced from the automotive heating and ventilating air conditional (HVAC) system. These noises are basically generated from the effects of vibrational HVAC components. Due to this, the root cause of the noises has to be investigated for any implementation of solution. In this study, the hissing-type of noise is taken into consideration whereby the noise and vibration are measured from various HVAC components such as Evaporator Inlet and Outlet and Thermal Expansion Valve (TXV). Three types of measurement sensors are used in this study which is tri-axial accelerometer for the vibration, tachometer for the engine rpm tracking and microphone for the noise measurement. Two types of operating conditions are taken into consideration, when engine running at 850 rpm (idle) and 850-3000 rpm (tracking) conditions and a constant blower speed is applied for both conditions. the result shows that, the hissing type of noise is determined at the frequency range of 4500-5000 Hz for the both idle and running conditions, whereby the vibration at the Evaporator Inlet is the most significant compared to the Evaporator Core and TVX components. the vibration of the Evaporator Inlet shows the drastic vibration increment between 1000-1500 rpm and getting worse towards 3000 rpm. This result is validated with the 3D colour of noise waterfall analysis, whereby the hissing noise shows the dominant result in the frequency range of 4500-5000 Hz