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The problem of active vibration control of weakly damped mechanical structures is potentially unstable modes of vibrations due to the positive feedback for some vibration modes. The paper will discuss the change of positive feedback on the negative one using all-pass discrete-time filters which are arranged in a cascade. The piezoelectric actuator as a source of force is used to damp vibration. It...
This article deals with automatically tunable bandpass second-order IIR filter. Filter is applied on the test stand which is used for active vibration control of sliding bearings with the use of piezoactuators. Control algorithm of vibration control was realized in Simulink and applied in dSPACE control system.
This article is focused on comparison a quality of control processes between closed-loop control systems with standard and 2 DOF controllers. The article is also dealing with analysis and applications standard and two degree of freedom controllers, which are tuned by multiple dominant pole method. Pneumatic actuators are typical for integral character and this method is suitable for integral system...
The paper deals with the mathematical model of the simply supported and fixed beam whose vibrations are actively damped with the use of linear piezoactuators. The model in the form of equations of motion to analyze assumes collocated and noncollocated arrangement of a sensor and an actuator. It is assumed that a piezoactuators output force depends on the supply voltage and the piezoactuator track...
This paper describes application of Kalman filter on revolutions measurement of the shaft. The shaft is a part of a device which is used for active vibration control of sliding bearings with the use of piezoactuators. Control algorithm of Kalman filter was realized in Simulink and applied in dSPACE control system.
The paper discusses the results of modeling and testing the prototype of an active vibration control of sliding bearings with the use of piezoactuators. The main goal of the active vibration control is to prevent instability due to the oil film and to extend the operating speed range of sliding bearings. The paper focuses on the analysis of the effect of the feedback controller gain on the operating...
This paper describes a laboratory model for experiments with an active vibration control. This test rig is consisting of steel cantilever beam connected to aluminium frame in vertical position; stack piezoactuator fixed near clamped end of the cantilever beam and a piezoelectric accelerometer positioned at the free end of the beam. Control algorithm is implemented into digital signal processing system...
Statistical process control (SPC) is an approach to process control that has been widely used in any industrial or non-industrial fields. SPC is based on so called Shewhart's conception of the process variability. This conception distinguishes variability caused by obviously effected common causes from variability caused by abnormal assignable causes. New manufacturing technologies and concepts strongly...
Paper describes the creation of mathematical model for active damped mechanical structure. The model is consisting of differential equations for structure's motion and an equation of the control loop. This model is used to design and examination the control loop algorithm and for testing the behaviour of the whole system before applying it on the real structure.
The effect of parametric vibration damping is theoretically well described and the first experiments are published. The paper focuses on the design and verification of the system functionality which is based on the use of piezoactuators as an element of the controlled stiffness which varies periodically in time according to a sinusoidal function. The principle of governing the piezoactuator stiffness...
Two dimensional Fourier transform is a powerful tool for image processing, especially in the field of image restoration and filtration. But also it is useful for detection of periodicities at any angle with respect to the image edge. This paper describes the use of two dimensional Fourier transform in the MATLAB environment to compute the length of a wave and the angle between the line that connects...
This paper deals with a system for active rotor's vibration control. A test stand Rotor-kit for testing of the effect of rotors instability has been assembled. This system enables to control journal bearings for suppressing instability caused by an oil film actively. As actuators the piezoactuators have been used. The system of Rotor-kit has been designed in order to test different types of shafts...
Laboratory model for an active vibration control was developed at the Department of Control System and Instrumentation, Technical University Ostrava. The decaying rate of a steel cantilever beam was considerably reduced on this model due to the usage of the piezoactuators as a feedback from vibration. The modal analysis of the model, which consists of the cantilever beam and the aluminium frame, was...
Antialiasing filter belongs to professional converters of analog signals to digital signals. This filter is either built in the circuit of sigma-delta converters or a separate part of the circuit of the successive approximation convertors. The paper will deal with a simple measurement of RMS at the output of A/D conversion while at the input of the converters is a harmonic signal with frequency which...
Nowadays the power supply of electronic circuits which are beyond a reach of main power supply is relatively complicated problem. In our case, if we consider that wireless sensor network of IEEE 802.15.4 standard is not limited to the interior we rely on an alternative power source for the power supply of intelligent wireless modules. Leaving aside the purely alternative power source supplying energy...
The application is created in program environment of Matlab - GUIDE is described in this paper. It enables a digital simulation of control system. The control system with 1 degree of controller freedom (1DOF) or with 2 degrees of controller freedom (2DOF) and plant with a time delay is considered for digital simulation. The application is shown in the examples.
An intelligent wireless smart sensors leak into many branches in technical diagnostics recently. Need of measurement a record various quantities is still rising. Main focus is aimed to energy saving houses, to large complex with many air conditioning units, to industry, where is need of simple action intervention on many places. Problem coming up, when the building has no sufficient cable infrastructure...
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