Assessment of the Effectiveness of a Polar Fuzzy Approach for the Control of Centrifugal Compressors

2014 ◽  
Vol 136 (4) ◽  
Author(s):  
Benjamin Defoy ◽  
Thomas Alban ◽  
Jarir Mahfoud
Keyword(s):  
Fuzzy Controller ◽  
Magnetic Bearing ◽  
Polar Coordinates ◽  
Active Magnetic Bearings ◽  
Flexible Rotor ◽  
Control Approach ◽  
Rotor Design ◽  
Physical Quantities ◽  
Insight Into ◽  
Academic Test

The aim of this study is to assess the possibility to apply a new control approach dedicated to turbomachinery. The controller is fuzzy based using inputs expressed in polar coordinates. The advantage is that it manages two significant physical quantities, namely tangential and radial velocities that are related to steady state and transient behaviors, respectively. A synchronous filter is associated to the controller in order to enhance the ratio command force/bearing dynamic capacity. The approach was previously applied experimentally with success for the control of an academic test rig. It is adapted here for the control of an industrial compressor whose flexible rotor is supported by active magnetic bearings (AMB). At this stage, only numerical investigations are performed. The controller has to satisfy the standards and the end users requirements. In addition, it should be easy to implement. The behavior of the machine studied is assessed for several configurations of unbalances. A test that corresponds to usual industrial excitations (subsynchronous excitations at nominal speed) is also carried out. Results obtained are satisfactory and give insight into the potential of the approach. In addition, and as the fuzzy controller parameters are independent from the rotor design, the approach is a first step for the standardization of magnetic bearing controller synthesis.

Experimental Assessment of a New Fuzzy Controller Applied to a Flexible Rotor Supported by Active Magnetic Bearings

2014 ◽  
Vol 136 (5) ◽  
Author(s):  
Benjamin Defoy ◽  
Thomas Alban ◽  
Jarir Mahfoud
Keyword(s):  
Fuzzy Controller ◽  
Magnetic Bearings ◽  
Polar Coordinates ◽  
Active Magnetic Bearings ◽  
Flexible Rotor ◽  
Control Approach ◽  
Single Output ◽  
Single Input ◽  
Physical Quantities ◽  
Academic Test

The aim of this study was to develop and implement a new control approach dedicated to turbomachinery. The new, fuzzy based controller utilizes inputs expressed in polar coordinates. Its originality is that it manages two significant physical quantities, namely, tangential and radial velocities, associated with steady-state and transient behaviors, respectively. Three controllers are compared for the control of a flexible rotor supported by active magnetic bearings (AMBs): proportional-integral-derivative (PID), single-input and single-output (SISO) fuzzy and the new controller. The assessment was performed using an academic test rig and the results obtained with the new controller show that performances were enhanced with equivalent levels of stability and robustness.

scholarly journals Improvement of flexible rotor/active magnetic bearings system performance using pi-d control

2020 ◽  
Vol 40 (2) ◽  
pp. 112-123
Author(s):  
Adis Muminovic ◽  
Sanjin Braut ◽  
Adil Muminovic ◽  
Isad Saric ◽  
Goranka Štimac Rončević
Keyword(s):  
Pid Control ◽  
Real Life ◽  
Magnetic Bearing ◽  
Magnetic Bearings ◽  
Active Magnetic Bearing ◽  
System Response ◽  
Active Magnetic Bearings ◽  
Flexible Rotor ◽  
Notch Filters ◽  
Common Control

Proportional–integral–derivative (PID) control is the most common control approach used to control active magnetic bearings system, especially in the case of supporting rigid rotors. In the case of flexible rotor support, the most common control is again PID control in combination with notch filters. Other control approaches, known as modern control theory, are still in development process and cannot be commonly found in real life industrial application. Right now, they are mostly used in research applications. In comparison to PID control, PI-D control implies that derivate element is in feedback loop instead in main branch of the system. In this paper, performances of flexible rotor/active magnetic bearing system were investigated in the case of PID and PI-D control, both in combination with notch filters. The performances of the system were analysed using an analysis in time domain by observing system response to step input and in frequency domain by observing a frequency response of sensitivity function.

Modeling, Motion and Vibration Control for Flexible Rotor Supported by Active Magnetic Bearings

2005 ◽  
Author(s):  
Yuichi Nakajima ◽  
Takahito Sagane ◽  
Hiroshi Tajima ◽  
Toru Watanabe ◽  
Kazuto Seto
Keyword(s):  
High Speed ◽  
Magnetic Bearings ◽  
Active Magnetic Bearings ◽  
Flexible Rotor ◽  
Bending Vibration ◽  
Modeling And Control ◽  
Control Approach ◽  
Flexible Rotors ◽  
Pass Through ◽  
And Control

This paper proposes a new modeling technique and control system design for flexible rotors using active magnetic bearings (AMB) to pass through many critical speeds and fulfill high-speed rotation. To achieve this purpose, it is necessary to control not only motion but also many modes of bending vibration. For the purpose, an extended reduced order physical model that is able to express simultaneously the motion and bending vibration of the flexible rotor, is proposed. Furthermore, a new controller combined PID with LQ control is adapted to control the flexible rotor. Effectiveness of the proposed modeling and control approach for the flexible rotor is verified through simulations and experiments.

Fuzzy robust control applied to rotor supported by active magnetic bearing

2020 ◽  
pp. 107754632093373
Author(s):  
Felipe Carmo Carvalho ◽  
Marcus V Fernandes de Oliveira ◽  
Fabian A Lara-Molina ◽  
Aldemir A Cavalini ◽  
Valder Steffen
Keyword(s):  
Fuzzy Controller ◽  
Design Procedure ◽  
Magnetic Bearing ◽  
Magnetic Bearings ◽  
Active Magnetic Bearing ◽  
System Stability ◽  
Active Magnetic Bearings ◽  
Mechatronic Systems ◽  
Neuro Fuzzy ◽  
Vibration Attenuation

The technology associated with active magnetic bearings has been widely used in the last years and can be considered as being one of the most promising solutions for several applications in rotating machinery. Lubricants are not necessary, and high rotation speeds are reached without any relevant heating. Active magnetic bearings are classified as mechatronic systems because they are composed of mechanical and electronic parts that are controlled by using dedicated software. In this context, the present work is devoted to the design of robust controllers applied to supercritical rotors supported by active magnetic bearings. For this aim, numerical and experimental tests were carried out. Different from previous studies reported in the literature, the present contribution proposes a novel design procedure to robustify the neuro-fuzzy controller of a rotor supported by active magnetic bearings based on optimal robust design. This optimal design procedure tunes the robust neuro-fuzzy controller taking into account the optimal balance between vibration attenuation performance and robustness, that is the increase in vibration attenuation implies the reduction in the robustness. The first stage of the controller synthesis is dedicated to the specification of all design requirements. Then, the adaptative neuro-fuzzy controller was obtained, starting from the determination of the plant dominant poles and finally performing the model-based analysis of the system stability and performance. Finally, the vibration control performance and robustness are optimally balanced by using a robust optimization procedure. The behavior of the controller was evaluated by investigating the unbalance response of the rotating system. The obtained results demonstrated the effectiveness of the conveyed approach.

The Pulse Power Amplifier for the Magnetic Bearing

2009 ◽  
Vol 147-149 ◽  
pp. 161-166
Author(s):  
Stanisław Jalbrzykowski ◽  
Marek Brański ◽  
Krzysztof Falkowski
Keyword(s):  
Power Amplifier ◽  
Magnetic Bearing ◽  
Pulse Power ◽  
Magnetic Bearings ◽  
Experimental Result ◽  
Active Magnetic Bearings ◽  
Flexible Rotor ◽  
Construction Principle

There is presented PWM power amplifier for the inductance load. The PWM amplifier assigns to supply the active magnetic bearings which support shaft and flexible rotor. The power amplifier has got ten channels. The channels have got pulse bridge inverter with modulation PWM. There is showed construction, principle of operation, simulation and experimental result the PWM power amplifier.

Robust control of active magnetic bearing systems with an add-on controller to cancel gyroscopic effects: Is it worth it?

2020 ◽  
pp. 107754632096619
Author(s):  
Alican Sahinkaya ◽  
Jerzy T Sawicki
Keyword(s):  
Rotational Speed ◽  
Computational Cost ◽  
Magnetic Bearing ◽  
Active Magnetic Bearing ◽  
Limiting Factors ◽  
Flexible Rotor ◽  
Control Approach ◽  
Run Up ◽  
Gyroscopic Effects ◽  
The Cost

One of the performance-limiting factors in the design of robust controllers for active magnetic bearing systems is the fact that the controller needs to be robust to the gyroscopic effects, that is rotational speed-dependent dynamics of the system. Studies in the literature show that better performance and stability can be achieved when gyroscopic effects are explicitly handled by a cross-feedback control for rigid rotor-active magnetic bearing systems. For flexible rotor-active magnetic bearing systems, gyroscopic effects are mainly dealt by defining the rotational speed as an uncertain parameter of the model or with linear parameter-varying controllers. This study explores the novel idea of compensating gyroscopic effects of a flexible rotor-active magnetic bearing system with an add-on controller and investigates its effects on the achieved performance of μ-controllers. The study is carried out on an experimental active magnetic bearing test rig with relatively high gyroscopic effects. An add-on controller is designed to compensate the gyroscopic effects of the first and second flexible modes of the rotor. Two μ-controllers are designed for the system: (1) benchmark controller that is designed using a standard control approach for active magnetic bearing systems and (2) controller designed with a modified model of the system in which the gyroscopic effects for the first and second flexible modes are reduced because of the presence of the add-on controller. Both controllers are implemented, and their performances are compared for initial levitation, run-up test from 0 to 10,000 r/min, orbit sizes at various speeds, and the computational cost of implementing each controller. The results suggest that better performance is potentially possible at the cost of significant increase in the computational complexity of the controller.

scholarly journals A Vibration Sensor-Based Method for Generating the Precise Rotor Orbit Shape with General Notch Filter Method for New Rotor Seal Design Testing and Diagnostics

Sensors ◽  
2021 ◽  
Vol 21 (15) ◽  
pp. 5249
Author(s):  
Karel Kalista ◽  
Jindrich Liska ◽  
Jan Jakl
Keyword(s):  
Notch Filter ◽  
Magnetic Bearing ◽  
Magnetic Bearings ◽  
Harmonic Vibration ◽  
Filter Method ◽  
Vibration Exciter ◽  
Active Magnetic Bearings ◽  
Rotor Vibration ◽  
Seal Design ◽  
Exact Shape

Verification of the behaviour of new designs of rotor seals is a crucial phase necessary for their use in rotary machines. Therefore, experimental equipment for the verification of properties that have an effect on rotor dynamics is being developed in the test laboratories of the manufacturers of these components all over the world. In order to be able to compare the analytically derived and experimentally identified values of the seal parameters, specific requirements for the rotor vibration pattern during experiments are usually set. The rotor vibration signal must contain the specified dominant components, while the others, usually caused by unbalance, must be attenuated. Technological advances have made it possible to use magnetic bearings in test equipment to support the rotor and as a rotor vibration exciter. Active magnetic bearings allow control of the vibrations of the rotor and generate the desired shape of the rotor orbit. This article presents a solution developed for a real test rig equipped with active magnetic bearings and rotor vibration sensors, which is to be used for testing a new design of rotor seals. Generating the exact shape of the orbit is challenging. The exact shape of the rotor orbit is necessary to compare the experimentally and numerically identified properties of the seal. The generalized notch filter method is used to compensate for the undesired harmonic vibrations. In addition, a novel modified generalized notch filter is introduced, which is used for harmonic vibration generation. The excitation of harmonic vibration of the rotor in an AMB system is generally done by injecting the harmonic current into the control loop of each AMB axis. The motion of the rotor in the AMB axis is coupled, therefore adjustment of the amplitudes and phases of the injected signals may be tedious. The novel general notch filter algorithm achieves the desired harmonic vibration of the rotor automatically. At first, the general notch filter algorithm is simulated and the functionality is confirmed. Finally, an experimental test device with an active magnetic bearing is used for verification of the algorithm. The measured data are presented to demonstrate that this approach can be used for precise rotor orbit shape generation by active magnetic bearings.

scholarly journals An Adaptive Neuro-Fuzzy Control of Pneumatic Mechanical Ventilator

Actuators ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 51
Author(s):  
Jozef Živčák ◽  
Michal Kelemen ◽  
Ivan Virgala ◽  
Peter Marcinko ◽  
Peter Tuleja ◽  
...  
Keyword(s):  
Control System ◽  
Control Algorithm ◽  
Fuzzy Inference ◽  
Fuzzy Controller ◽  
Mechanical Design ◽  
Mechanical Ventilator ◽  
Mechanical Ventilators ◽  
Inference System ◽  
Control Approach ◽  
Neuro Fuzzy

COVID-19 was first identified in December 2019 in Wuhan, China. It mainly affects the respiratory system and can lead to the death of the patient. The motivation for this study was the current pandemic situation and general deficiency of emergency mechanical ventilators. The paper presents the development of a mechanical ventilator and its control algorithm. The main feature of the developed mechanical ventilator is AmbuBag compressed by a pneumatic actuator. The control algorithm is based on an adaptive neuro-fuzzy inference system (ANFIS), which integrates both neural networks and fuzzy logic principles. Mechanical design and hardware design are presented in the paper. Subsequently, there is a description of the process of data collecting and training of the fuzzy controller. The paper also presents a simulation model for verification of the designed control approach. The experimental results provide the verification of the designed control system. The novelty of the paper is, on the one hand, an implementation of the ANFIS controller for AmbuBag pressure control, with a description of training process. On other hand, the paper presents a novel design of a mechanical ventilator, with a detailed description of the hardware and control system. The last contribution of the paper lies in the mathematical and experimental description of AmbuBag for ventilation purposes.

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