Effects of Piezoceramic Actuator in Quasistatic Use

2014 ◽  
Author(s):  
Johannes Riemenschneider ◽  
Oliver Huxdorf ◽  
Steffen Opitz
Keyword(s):  
High Speed ◽  
Open Loop ◽  
Rotor Blades ◽  
Special Importance ◽  
Low Frequencies ◽  
Patch Type ◽  
Loop Control ◽  
Dc Voltage ◽  
Piezoceramic Actuator ◽  
Static Conditions

In the field of smart structures, piezoceramic actuators are wildly used for vibration reduction and acoustic manipulation of structures. Those applications typically run at frequencies between 10 Hz and 10k Hz. Prominent examples are the piezoceramic actuators implemented in helicopter rotor blades to twist them dynamically for higher harmonic control (HHC) or individual blade control (IBC). Once the actuators are implemented it would be a great benefit to also use them to statically change the blade twist (higher twist for take-off and landing — for higher lift; lower twist for high speed forward flight — for reduced drag). Staying with this example it can be found that sensing the twist displacement is not an easy task at all (see [1, 2]), so it would be most desirable, to use open loop control. In order to do that, the transfer function has to be known accurately. Unfortunately measurements show that the amplitudes for such very low frequencies behavior behave strongly non linear. This paper presents experimental results investigating the influence of the frequency on the amplitude — especially going for frequencies in the lower mHz region. A variety of piezoceramic actuators has been investigated: from stacks to patch type, d33 as well as d31 effect actuators. A second focus of this paper is the reaction of piezoceramic actuators on the application of a constant DC voltage. The drift that occurs has to be taken into consideration. A third focus of this paper is the dependency of a displacement output of such an actuator at a constant applied DC voltage on the voltages that the actuator had seen before. This topic is of special importance for aerodynamically effective surfaces that are driven by piezoceramic actuators and should be analyzed (generation of polars) in static conditions.

scholarly journals The Modelling, Simulation and FPGA-Based Implementation for Stepper Motor Wide Range Speed Closed-Loop Drive System Design

Machines ◽  
2018 ◽  
Vol 6 (4) ◽  
pp. 56 ◽  
Author(s):  
Chiu-Keng Lai ◽  
Jhang-Shan Ciou ◽  
Chia-Che Tsai
Keyword(s):  
Embedded System ◽  
High Speed ◽  
Closed Loop ◽  
Open Loop ◽  
Drive System ◽  
Stepper Motor ◽  
Motor Drive ◽  
Digital Controllers ◽  
Loop Control ◽  
Wide Range

Owing to the benefits of programmable and parallel processing of field programmable gate arrays (FPGAs), they have been widely used for the realization of digital controllers and motor drive systems. Furthermore, they can be used to integrate several functions as an embedded system. In this paper, based on Matrix Laboratory (Matlab)/Simulink and the FPGA chip, we design and implement a stepper motor drive. Generally, motion control systems driven by a stepper motor can be in open-loop or closed-loop form, and pulse generators are used to generate a series of pulse commands, according to the desired acceleration/run/deceleration, in order to the drive system to rotate the motor. In this paper, the speed and position are designed in closed-loop control, and a vector control strategy is applied to the obtained rotor angle to regulate the phase current of the stepper motor to achieve the performance of operating it in low, medium, and high speed situations. The results of simulations and practical experiments based on the FPGA implemented control system are given to show the performances for wide range speed control.

scholarly journals Modal Engineering for MEMS Devices: Application to Galvos and Scanners

2020 ◽  
Author(s):  
Lawrence Barrett ◽  
Matthias Imboden ◽  
Josh Javor ◽  
David K. Campbell ◽  
David J. Bishop
Keyword(s):  
High Speed ◽  
Open Loop ◽  
Optical Systems ◽  
Control Algorithms ◽  
Mems Devices ◽  
Open Loop Control ◽  
Optical Elements ◽  
Loop Control ◽  
High Q ◽  
Change Position

Optical systems typically use galvanometers (aka galvos) and scanners. Galvos move optical elements such as mirrors, quasi-statically, from one static position to another, and an important figure of merit is their step-settle relaxation time. Scanners move in an oscillatory fashion, typically at the device resonant frequency. MEMS devices, which have many advantages and are often used in such optical systems, are typically high Q devices. Moving from one position to another for a galvo or one frequency/amplitude to another for scanners, can take many periods to settle following the ring down. During these transitions, the optical system is inactive and the time is not being efficiently used. In this article we show how a novel class of open loop control algorithms can be used to rapidly change position, frequency and amplitude, typically in well under the period of the device. We show how the MEMS designer can excite, with complete, high-speed control, a vibrational mode of the system. We call this modal engineering, the ability to control the modes of the system in a practical, fast way. This control of the modes is accomplished with open loop control algorithms.

Research on Novel Self-Spinning High Speed On/Off Valve Based on Fuzzy-Logic Parameter Self-Tuning PID Controller

2012 ◽  
Vol 468-471 ◽  
pp. 1448-1452 ◽  
Author(s):  
Jian Chen ◽  
Jian Ping Shu ◽  
Mian Li ◽  
Qi Zhou ◽  
Zhu Ming Su
Keyword(s):  
Fuzzy Logic ◽  
Control System ◽  
Pid Controller ◽  
High Speed ◽  
Position Control ◽  
Open Loop ◽  
Axial Position ◽  
Valve Body ◽  
Loop Control ◽  
Self Tuning

The flow rate of a novel self-spinning high speed hydraulic on/off valve is regulated by changing the relative axial position (the duty cycle) of the valve spool to the nozzles located on the valve body through driving a gerotor pump using brushless direct current motor. The closed loop axial position control system of the valve spool with feedback of the axial displacement of the valve spool has shorter response time, and not more ripple of output pressure than corresponding open loop control system. A fuzzy logic parameter self-tuning PID controller is investigated to overcome nonlinearity of the control system. The simulation results show that the overshoot is decreased greatly than conventional PID controller.

Open Loop Control of Combustion Instability With a High-Momentum Air-Jet

2004 ◽  
Author(s):  
Jong Ho Uhm ◽  
Sumanta Acharya
Keyword(s):  
Low Frequency ◽  
Sine Wave ◽  
Open Loop ◽  
Effective Control ◽  
High Momentum ◽  
Open Loop Control ◽  
Low Frequencies ◽  
Loop Control ◽  
Wave Modulation ◽  
Air Jet

A new strategy for open-loop control of combustion oscillations using a high-momentum air-jet modulated at low frequencies is presented in this paper. The oscillations in the swirl-stabilized spray combustor of interest are dominated by an acoustic mode (235 Hz) with a low frequency (13 Hz) bulkmode (of the upstream cavity) oscillation superimposed. The most effective strategy for control is shown to be achieved through the use of a new concept which utilizes a high-momentum air-jet injected directly into the region of flame dynamics. It is shown that with a low frequency modulation (15 Hz) of the high momentum air-jet, the pressure oscillations can be reduced significantly (by a factor of nearly 10). Square wave modulation is shown to be considerably more effective than sine-wave modulation. These results are extremely promising since high bandwidth actuation is not required for effective control.

scholarly journals Turbulent boundary layer under the control of different schemes

2017 ◽  
Vol 473 (2202) ◽  
pp. 20170038 ◽  
Author(s):  
Z. X. Qiao ◽  
Y. Zhou ◽  
Z. Wu
Keyword(s):  
Boundary Layer ◽  
Turbulent Boundary Layer ◽  
High Speed ◽  
Control Strategies ◽  
Local Maximum ◽  
Open Loop ◽  
Open Loop Control ◽  
Feed Forward ◽  
Loop Control ◽  
Combined Feed

This work explores experimentally the control of a turbulent boundary layer over a flat plate based on wall perturbation generated by piezo-ceramic actuators. Different schemes are investigated, including the feed-forward, the feedback, and the combined feed-forward and feedback strategies, with a view to suppressing the near-wall high-speed events and hence reducing skin friction drag. While the strategies may achieve a local maximum drag reduction slightly less than their counterpart of the open-loop control, the corresponding duty cycles are substantially reduced when compared with that of the open-loop control. The results suggest a good potential to cut down the input energy under these control strategies. The fluctuating velocity, spectra, Taylor microscale and mean energy dissipation are measured across the boundary layer with and without control and, based on the measurements, the flow mechanism behind the control is proposed.

Pressure control of a pneumatic valve system using a piezoceramic flapper

2004 ◽  
Vol 218 (1) ◽  
pp. 83-91 ◽  
Author(s):  
S B Choi ◽  
J K Yoo
Keyword(s):  
Tracking Control ◽  
Control Method ◽  
Sliding Mode ◽  
Pressure Control ◽  
Open Loop ◽  
Flexible Beam ◽  
Loop Control ◽  
Piezoceramic Actuator ◽  
Valve System ◽  
Pneumatic Valve

This paper presents a robust pressure control of a pneumatic valve system driven by piezoceramic actuators. The piezoceramic actuator bonded to both sides of a flexible beam makes a movement required to control the pressure at the flapper nozzle of a pneumatic system. After deriving the governing equation of motion, an appropriate size of the valve system is constructed. A sliding mode controller that is known to be robust to system uncertainties is then formulated in order to achieve accurate tracking control of a set of desired pressure trajectories. The closed-loop control bandwidth of the proposed valve system is empirically evaluated with respect to the supplying pressure and desired pressure. Tracking control performances for various pressure trajectories are presented in the time domain. In addition, the pressure control response achieved from the proposed feedback control method is compared with the response obtained from the open-loop control method.

Turbocharger rotor vibration reduction methodology with an active control scheme

2021 ◽  
pp. 095745652110307
Author(s):  
Rajasekhara Reddy Mutra ◽  
J Srinivas ◽  
Jakeer Hussain Shaik ◽  
Maddela Chinna Obaiah ◽  
Gunji Balamurali ◽  
...  
Keyword(s):  
High Speed ◽  
Active Vibration Control ◽  
Vibration Reduction ◽  
Open Loop ◽  
Rotor System ◽  
Dynamic Responses ◽  
Experimental Result ◽  
Loop Control ◽  
Highly Nonlinear ◽  
Control Configuration

The turbocharger rotors are often supported on the dual film floating ring bearings that are meant for high-speed applications. The damping ability of these bearings is relatively high. However, due to highly nonlinear bearing forces, often system instability occurs. The present work focuses on the dynamic analysis and active vibration control studies of a practical turbocharger rotor system with the use electromagnetic actuator (EMA) system. Initially, the system is analyzed using the finite element approach. The inner and outer film forces are considered along with rotor imbalance forces. The dynamic responses at the critical operating speeds are obtained numerically. To minimize the vibration amplitudes, a tiny EMA system is installed at one of the nodes along the shaft. The effect of the EMA parameters such as the number of turns of winding coil around a pole ( N c) and pole-face area ( A a) on the response of the system is studied. Further, an open-loop control configuration is practically studied by using a vibration shaker at the bearing node under different operating speeds, and the percentage reduction in critical vibration amplitudes is recorded. The EMA system is effectively controlling the high-speed rotor system vibrations. The EMA parameters N c and A a are influencing the system vibration response. Further, an experimental result has given considerable vibration reduction with the present approach.

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