Comparison of Active Control Algorithms for Rotor Unbalance Compensation

Author(s):  
Kari Tammi ◽  
Antti Laiho

This paper shows a short introduction to three unbalance compensation algorithms and an experimental comparison of those algorithms. The algorithms have been tested experimentally on a laboratory-scale test rig equipped with an electromagnetic actuator. So called Convergent Control algorithm has been found the most suitable for the current purpose in terms of performance and simplicity. The algorithms are subjected further tests on rotor unbalance compensation in an electrical machine. This paper shows some initial considerations for those further tests.

2017 ◽  
Vol 140 (2) ◽  
Author(s):  
Wander Gustavo Rocha Vieira ◽  
Fred Nitzsche ◽  
Carlos De Marqui

In recent decades, semi-active control strategies have been investigated for vibration reduction. In general, these techniques provide enhanced control performance when compared to traditional passive techniques and lower energy consumption if compared to active control techniques. In semi-active concepts, vibration attenuation is achieved by modulating inertial, stiffness, or damping properties of a dynamic system. The smart spring is a mechanical device originally employed for the effective modulation of its stiffness through the use of semi-active control strategies. This device has been successfully tested to damp aeroelastic oscillations of fixed and rotary wings. In this paper, the modeling of the smart spring mechanism is presented and two semi-active control algorithms are employed to promote vibration reduction through enhanced damping effects. The first control technique is the smart-spring resetting (SSR), which resembles resetting control techniques developed for vibration reduction of civil structures as well as the piezoelectric synchronized switch damping on short (SSDS) technique. The second control algorithm is referred to as the smart-spring inversion (SSI), which presents some similarities with the synchronized switch damping (SSD) on inductor technique previously presented in the literature of electromechanically coupled systems. The effects of the SSR and SSI control algorithms on the free and forced responses of the smart-spring are investigated in time and frequency domains. An energy flow analysis is also presented in order to explain the enhanced damping behavior when the SSI control algorithm is employed.


Author(s):  
Young-Tai Choi ◽  
Norman M. Wereley ◽  
Gregory J. Hiemenz

Novel semi-active vibration controllers are developed in this study for magnetorheological (MR) fluid-based vibration control systems, including: (1) a band-pass frequency shaped semi-active control algorithm, (2) a narrow-band frequency shaped semi-active control algorithm. These semi-active vibration control algorithms designed without resorting to the implementation of an active vibration control algorithms upon which is superposed the energy dissipation constraint. These new Frequency Shaped Semi-active Control (FSSC) algorithms require neither an accurate damper (or actuator) model, nor system identification of damper model parameters for determining control current input. In the design procedure for the FSSC algorithms, the semi-active MR damper is not treated as an active force producing actuator, but rather is treated in the design process as a semi-active dissipative device. The control signal from the FSSC algorithms is a control current, and not a control force as is typically done for active controllers. In this study, two FSSC algorithms are formulated and performance of each is assessed via simulation. Performance of the FSSC vibration controllers is evaluated using a single-degree-of-freedom (DOF) MR fluid-based engine mount system. To better understand the control characteristics and advantages of the two FSSC algorithms, the vibration mitigation performance of a semi-active skyhook control algorithm, which is the classical semi-active controller used in base excitation problems, is compared to the two FSSC algorithms.


2017 ◽  
Vol 11 (7) ◽  
pp. 922-930 ◽  
Author(s):  
Addy Wahyudie ◽  
Mohammed Jama ◽  
Tri Bagus Susilo ◽  
Bisni Fahad Mon ◽  
Hussein Shaaref ◽  
...  

Author(s):  
Johannes Neukäufer ◽  
Nadin Sarajlic ◽  
Harald Klein ◽  
Sebastian Rehfeldt ◽  
Heiko Hallmann ◽  
...  

Additive manufacturing is increasingly being used to develop innovative packings for absorption and desorption columns. Since distillation has not been in focus so far, this paper aims to fill this gap. The objective is to obtain a miniaturized 3D printed packed column with optimized properties in terms of scalability and reproducibility, which increases process development efficiency. For this purpose, a flexible laboratory scale test rig is presented combining standard laboratory equipment with 3D printed components such as innovative multifunctional trays or the column wall with packing. The test rig offers a particularly wide operating range (F=0.15 Pa…1.0 Pa) for column diameters between 20 mm and 50 mm. First results regarding the time to reach steady-state, operational stability and separation efficiency measurements are presented using a 3D printable version of the Rombopak 9M. Currently, innovative packings are being characterized, which should exhibit a optimized bevavior regarding scalability, reproducibility and separation efficiency.


2008 ◽  
Vol 56 ◽  
pp. 182-187
Author(s):  
Antonio Occhiuzzi

Control algorithms for semi-active structural control system found in the scientific literature often rely on the choice of several parameters included in the control law. The present paper shows the preliminary conclusions of a study aiming to explain the weak dependency of the response reduction associated to semi-active control systems on the particular choice of the control algorithm adopted, provided that the relevant parameters of any control law be properly tuned.


2011 ◽  
Vol 368-373 ◽  
pp. 1152-1155

Removed due to Plagiarism. Original was published by Nicola Caterino, Mariacristina Spizzuoco, Antonio Occhiuzziexperimental Comparison of Control Algorithms for Semi-Active Control Withmagnetorheological Dampersin the Proceedings of ANISIS2009, Bologna


2020 ◽  
Vol 8 (5) ◽  
pp. 304 ◽  
Author(s):  
Jianan Xu ◽  
Yansong Yang ◽  
Yantao Hu ◽  
Tao Xu ◽  
Yong Zhan

Wave energy is a renewable energy source that is green, clean and has huge reserves. In order to develop wave energy resources, an oscillating buoy Wave Energy Converter (WEC) device based on the artificial breakwater is presented in this paper. In order to effectively vent the gas in the hydraulic PTO and to improve the active control capability of the PTO system to guarantee the safety performance of the system under high sea conditions, a hydraulic PTO with an active control circuit is designed. Additionally, for the Power Take-Off (PTO) system, there is a optimal damping point under different sea conditions for PTO system, so the PTO can be controlled by the Maximum-Power-Point-Tracking (MPPT) control algorithms to improve the generated power of the system. At present, the MPPT control algorithms for wave energy are mainly used to control the load of generator. However, a fixed-load storage battery is used for the load of the generator in this paper. Additionally, an MPPT control taken at a hydraulic PTO system is executed to improve the power generated by hydraulic PTO under different sea conditions effectively in this paper. The MPPT control based on the hydraulic system is conducted by controlling the displacement of hydraulic motor to achieve the optimal damping point tracking control. The control flow of the MPPT algorithm is provided. The variable step hill-climbing method is used in MPPT control algorithm in which the big step can reduce the time of tracking and the small step can increase the accuracy of MPPT control algorithm. Due to the slow stability of the hydraulic system, a filter method for hydraulic PTO power is used. In addition, the hydraulic PTO system and MPPT control are verified to be feasible with the simulation. Additionally, MPPT control based on hydraulic variable motor is easier to carry out in practical applications than the traditional control of resistance. Finally, the simulation results demonstrate that it is an effective power control strategy for hydraulic PTO system to improve the generated power.


Algorithms ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 256 ◽  
Author(s):  
Rang-Lin Fan ◽  
Pu Wang ◽  
Chen Han ◽  
Li-Jun Wei ◽  
Zi-Jian Liu ◽  
...  

With the further development of the automotive industry, the traditional vibration isolation method is difficult to meet the requirements for wide frequency bands under multiple operating conditions, the active control mount (ACM) is gradually paid attentions, and the control algorithm plays a decisive role. In this paper, the ACM with oscillating coil actuator (OCA) is taken as the object, and the comparative study of the control algorithms is performed to select the optimal one for ACM. Through the modelling of ACM, the design of controller and the system simulations, the force transmission rate is used to compare the vibration isolation performance of the nine control algorithms, which are least mean square (LMS) adaptive feedforward control, recursive least square (RLS) adaptive feedforward control, filtered reference signal LMS (FxLMS) adaptive control, linear quadratic regulator (LQR) optimal control, H2 control, H∞ control, proportional integral derivative (PID) feedback control, fuzzy control and fuzzy PID control. In summary, the FxLMS adaptive control algorithm has the better performance and the advantage of easier hardware implementation, and it can apply in ACMs.


Energies ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3505
Author(s):  
Salma Benzaria ◽  
Ekaterina Mamontova ◽  
Yannick Guari ◽  
Joulia Larionova ◽  
Jérôme Long ◽  
...  

In view of potential uses in short-term thermochemical heat storage by sorption of water vapor, the capacity to release a sufficient heat amount at the appropriate rate of a Prussian blue analogue (PBA) containing hexacyanocobaltate vacancies has been compared with those of 13X type zeolites possessing Na+, Ce3+, Ce4+, or Tb3+ extra-framework compensating cations. The extended structural and surface characterization demonstrated good reproducibility of the preparation procedures performed on a 10-g scale. The adsorbents were tested under dynamic conditions of gas flow with the aid of either a gas flow calorimeter (120 mL h−1 helium flow) to measure the amount and rate of the integral heat release or a laboratory-scale test rig (15,000 to 22,800 mL h−1 nitrogen flow) to monitor the outlet temperature of nitrogen heated by adsorption. For a regeneration temperature of 353 K and a partial H2O pressure of 2.8 kPa in helium, the PBA sample yielded an integral heat ranging between 900 and 1020 kJ kg−1 with a very slow heat release lasting for even 12–14 h. The zeolite-based materials generated between 350 and 950 kJ kg−1 more rapidly (up to 6–7 h), depending on the nature and the content of compensating cations, as well as on the dehydration state achieved during regeneration. With the laboratory-scale test rig, the efficiency of heat extraction by convection was about 65% for Na-13X and only 38% for PBA, and it diminished with decreasing flow rate.


1988 ◽  
Vol 55 (4) ◽  
pp. 931-938 ◽  
Author(s):  
J. N. Yang ◽  
F. X. Long ◽  
D. Wong

Three optimal control algorithms are proposed for reducing oscillations of flexible nonlinear structures subjected to general stochastic dynamic loads, such as earthquakes, waves, winds, etc. The optimal control forces are determined analytically by minimizing a time-dependent quadratic performance index, and nonlinear equations of motion are solved using the Wilson-θ numerical procedures. The optimal control algorithms developed for applications to nonlinear structures are referred to as the instantaneous optimal control algorithms, including the instantaneous optimal open-loop control algorithm, instantaneous optimal closed-loop control algorithm, and instantaneous optimal closed-open-loop control algorithm. These optimal algorithms are computationally efficient and suitable for on-line implementation of active control systems to realistic nonlinear structures. Numerical examples are worked out to demonstrate the applications of these optimal control algorithms to nonlinear structures. In particular, control of structures undergoing inelastic deformations under strong earthquake excitations are illustrated. The advantage of using combined passive/active control systems is also demonstrated.


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