Adaptive Control of Active Balancing Systems for Speed-Varying Rotors Using Feedforward Gain Adaptation Technique

1999 ◽  
Vol 123 (3) ◽  
pp. 346-352 ◽  
Author(s):  
Kwang-Keun Shin ◽  
Jun Ni
Keyword(s):  
Adaptive Control ◽  
Transfer Function ◽  
Control Method ◽  
Control Area ◽  
Positive Real ◽  
Single Plane ◽  
Active Balancing ◽  
Gain Adaptation ◽  
Jeffcott Rotor ◽  
Classical Technique

This paper presents a new adaptive control method for active balancing of speed-varying rotors. It is developed based on the feedforward gain adaptation problem, which is a classical technique in the continuous-time adaptive control area. The condition for using this technique is the need for strictly positive realness of the transfer function. In this research, the technique is re-examined and modified to be appropriate for the balancing problem. It is also shown that the rotor dynamics of single-plane balancing problem can easily be converted to a strictly positive real transfer function and that, consequently, the feedfoward gain adaptation technique can be applied. This paper demonstrates that the developed method can be applied to a simple Jeffcott rotor and can also be extended to the single-plane balancing problem of general flexible rotor. Simulation studies show that the new method works well as expected.

Adaptive Influence Coefficient Control of Single-Plane Active Balancing Systems for Rotating Machinery

1999 ◽  
Author(s):  
Stephen W. Dyer ◽  
Jun Ni
Keyword(s):  
Adaptive Control ◽  
High Speed ◽  
Control Method ◽  
A Priori ◽  
Weighted Averaging ◽  
Control Law ◽  
Influence Coefficient ◽  
Single Plane ◽  
Line System ◽  
Active Balancing

Abstract Rotating unbalance is a costly source of harmful vibration affecting a wide variety of applications such as high-speed machine tools and turbomachinery. Active balancing technology allows adjustment of a machine’s balance state while conditions change as the machine continues to operate. An adaptive control law for single-plane active balancing is presented here for control of steady-state rotation-synchronous vibration. The adaptive control method, based on the well known “influence coefficient” approach, requires no a priori modeling or estimation of plant dynamics. A control “gain” parameter is introduced and shown to enhance stability robustness of the non-adaptive portion of the control law. A recursive on-line system identification method is presented that uses exponential weighted averaging to mitigate the effects of measurement noise and system nonlinearities. Experimental results establish the efficacy of the adaptive control system even in the face of certain nonlinear and time-varying rotordynamic systems.

Adaptive Influence Coefficient Control of Single-Plane Active Balancing Systems for Rotating Machinery

2000 ◽  
Vol 123 (2) ◽  
pp. 291-298 ◽  
Author(s):  
Stephen W. Dyer ◽  
Jun Ni
Keyword(s):  
Adaptive Control ◽  
High Speed ◽  
Control Method ◽  
A Priori ◽  
Weighted Averaging ◽  
Control Law ◽  
Influence Coefficient ◽  
Single Plane ◽  
Line System ◽  
Active Balancing

Rotating unbalance is a costly source of harmful vibration affecting a wide variety of applications such as high-speed machine tools and turbomachinery. Active balancing technology allows adjustment of a machine’s balance state while conditions change as the machine continues to operate. An adaptive control law for single-plane active balancing is presented here for control of steady-state rotation-synchronous vibration. The adaptive control method, based on the well known “influence coefficient” approach, requires no a priori modeling or estimation of plant dynamics. A control “gain” parameter is introduced and shown to enhance stability robustness of the nonadaptive portion of the control law. A recursive on-line system identification method is presented that uses exponential weighted averaging to mitigate the effects of measurement noise and system nonlinearities. Experimental results establish the efficacy of the adaptive control system even in the face of certain nonlinear and time-varying rotordynamic systems.

scholarly journals Method for Establishing a Traveling Wave Sound Field with Adaptive Control in a Water-Filled Sound Tube

2021 ◽  
Vol 11 (13) ◽  
pp. 5785
Author(s):  
Yan Xiao ◽  
Xuesong Zhang
Keyword(s):  
Adaptive Control ◽  
Transfer Function ◽  
Wave Field ◽  
Transmission Coefficient ◽  
Sound Source ◽  
Traveling Wave ◽  
Control Method ◽  
Sound Field ◽  
Reflection And Transmission ◽  
Reflection And Transmission Coefficient

The transfer function method is a common method for establishing a traveling wave field in a sound tube to measure the reflection and transmission coefficient of underwater material. The voltage applied to the secondary sound source can be calculated in accordance with the transfer matrix between the sound sources and hydrophones, then a traveling wave field can be established in the sound tube. However, the transfer function must be remeasured when the measurement frequency needs to be changed. A checking procedure of the traveling wave field in the sound tube is essential before measuring underwater acoustic material. If it is not an accurate traveling wave field, the secondary sound source signal should be corrected until the traveling wave field meets the requirements. To address these problems, an adaptive control method for generating plane traveling waves is proposed. The phase difference of sound pressures measured using the two hydrophones between the secondary sound source and the sample is used as the objective function in the adaptive algorithm, and the amplitude and phase of the secondary sound source can be obtained using the adaptive control system in the frequency domain. When a traveling wave field is formed, the reflection and transmission coefficient of the sample can be measured at the same time. With this method, the procedure of testing the traveling wave field is omitted. If the state of the primary sound source changes, the signal form of the secondary sound source can be changed immediately. Therefore, the efficiency of material measurement is improved. Theoretically, this method can obtain the most matching signal form of the secondary sound source, such that the accuracy of this method is remarkably high. Simulation and experimental results in this paper show that the measurement accuracy is reliable within the frequency range of 100–2500 Hz.

scholarly journals Disturbance compensation-based output feedback adaptive control for shape memory alloy actuator system

2021 ◽  
Vol 18 (1) ◽  
pp. 172988142199399
Author(s):  
Xiaoguang Li ◽  
Bi Zhang ◽  
Daohui Zhang ◽  
Xingang Zhao ◽  
Jianda Han
Keyword(s):  
Adaptive Control ◽  
Shape Memory Alloy ◽  
Shape Memory ◽  
Control Method ◽  
Control Law ◽  
Reference Trajectory ◽  
Disturbance Compensation ◽  
Comparison Results ◽  
Control Scheme ◽  
Actuator System

Shape memory alloy (SMA) has been utilized as the material of smart actuators due to the miniaturization and lightweight. However, the nonlinearity and hysteresis of SMA material seriously affect the precise control. In this article, a novel disturbance compensation-based adaptive control scheme is developed to improve the control performance of SMA actuator system. Firstly, the nominal model is constructed based on the physical process. Next, an estimator is developed to online update not only the unmeasured system states but also the total disturbance. Then, the novel adaptive controller, which is composed of the nominal control law and the compensation control law, is designed. Finally, the proposed scheme is evaluated in the SMA experimental setup. The comparison results have demonstrated that the proposed control method can track reference trajectory accurately, reject load variations and stochastic disturbances timely, and exhibit satisfactory robust stability. The proposed control scheme is system independent and has some potential in other types of SMA-actuated systems.

scholarly journals A Novel Adaptive Control Approach Based on Available Headroom of the VSC-HVDC for Enhancement of the AC Voltage Stability

Energies ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3222
Author(s):  
Duc Nguyen Huu
Keyword(s):  
Adaptive Control ◽  
Voltage Stability ◽  
Reactive Power ◽  
Control Method ◽  
Offshore Wind ◽  
Voltage Source ◽  
Long Distance ◽  
Control Approach ◽  
Hvdc System ◽  
Voltage Support

Increasing offshore wind farms are rapidly installed and planned. However, this will pose a bottle neck challenge for long-distance transmission as well as inherent variation of their generating power outputs to the existing AC grid. VSC-HVDC links could be an effective and flexible method for this issue. With the growing use of voltage source converter high-voltage direct current (VSC-HVDC) technology, the hybrid VSC-HVDC and AC system will be a next-generation transmission network. This paper analyzes the contribution of the multi VSC-HVDC system on the AC voltage stability of the hybrid system. A key contribution of this research is proposing a novel adaptive control approach of the VSC-HVDC as a so-called dynamic reactive power booster to enhance the voltage stability of the AC system. The core idea is that the novel control system is automatically providing a reactive current based on dynamic frequency of the AC system to maximal AC voltage support. Based on the analysis, an adaptive control method applied to the multi VSC-HVDC system is proposed to realize maximum capacity of VSC for reactive power according to the change of the system frequency during severe faults of the AC grid. A representative hybrid AC-DC network based on Germany is developed. Detailed modeling of the hybrid AC-DC network and its proposed control is derived in PSCAD software. PSCAD simulation results and analysis verify the effective performance of this novel adaptive control of VSC-HVDC for voltage support. Thanks to this control scheme, the hybrid AC-DC network can avoid circumstances that lead to voltage instability.

Anti-noise model-free adaptive control and its application in the circulating fluidized bed boiler

2020 ◽  
pp. 095965182097937
Author(s):  
Na Dong ◽  
Wenjin Lv ◽  
Shuo Zhu ◽  
Donghui Li
Keyword(s):  
Adaptive Control ◽  
Complete Convergence ◽  
Circulating Fluidized Bed ◽  
Control Method ◽  
Noise Model ◽  
Good Resistance ◽  
Industrial Systems ◽  
Noise Interference ◽  
Model Free ◽  
Tracking Differentiator

Model-free adaptive control has been developed greatly since it was proposed. Up to now, model-free adaptive control theory has become mature and tends to be an effective solution for complex unmodeled industrial systems. In practical industrial processes, most control systems are inevitably accompanied by noise that will result in indelible error and may further cause inaccurate feedback to the output. In order to solve this kind of problem with model-free technique, this article incorporates an improved tracking differentiator into model-free adaptive control. After that, the anti-noise model-free adaptive control method with complete convergence analysis is proposed. Meanwhile, numerical simulation proves that the improved control method can quickly track a given signal with good resistance to noise interference. Finally, the effectiveness and practicability of the proposed algorithm are verified by experiments through the control of drum water level of circulating fluidized.

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