The Experts below are selected from a list of 1830 Experts worldwide ranked by ideXlab platform
Stephan Rinderknecht - One of the best experts on this subject based on the ideXlab platform.
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Active Vibration Isolation of a Flexible Rotor Being Subject to Unbalance Excitation and Gyroscopic Effect Using {\boldsymbol{\mathcal{H}}}_{\boldsymbol{\infty}}-Optimal Control
Proceedings of the 9th IFToMM International Conference on Rotor Dynamics, 2015Co-Authors: Fabian Becker, Stefan Heindel, Stephan RinderknechtAbstract:This contribution deals with active vibration isolation of unbalance induced vibrations of a rotating shaft using \({\mathcal{H}}_{\infty }\)-optimal control and piezoelectric actuators. Controller design for the considered system is challenging and requires a high demand in robustness due to speed-dependent system behavior in consequence of the Gyroscopic Effect. Recent studies in the field of active control of rotor systems, especially at the Institute for Mechatronic Systems in Mechanical Engineering at TU Darmstadt, mainly focus on the attenuation of rotor displacements. For many applications, like aircraft engines, not only the rotor’s deformation itself is of high interest, but also its interaction with the environment. Former works on active vibration attenuation show that active reduction of rotor displacements can be attended by an undesirable increase of bearing forces. In addition to these works, this article deals with the decoupling of a rotating shaft from the surrounding structure, which is also known as vibration isolation. The investigations are based on a rotor test rig with a statically determined bearing configuration. One of the two bearing supports is active and consists of two piezoelectric stack actuators as well as two collocated piezoelectric load washers. The operating range of the test rig includes two unbalance induced resonances. Since the control performance strongly depends on the accuracy of the description of the system dynamics, a finite element model of the rotor is determined and extended by discrete piezoelectric elements. The obtained parametric model is capable of capturing the system’s speed-dependent dynamics. The \({\mathcal{H}}_{\infty }\)-optimal controller will be derived using the parametric finite element model. Finally, the feasibility of the described approach will be validated by testing the control performance by means of vibration isolation in simulation and experiment.
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active vibration isolation of a flexible rotor being subject to unbalance excitation and Gyroscopic Effect using boldsymbol mathcal h _ boldsymbol infty optimal control
2015Co-Authors: Fabian Becker, Stefan Heindel, Stephan RinderknechtAbstract:This contribution deals with active vibration isolation of unbalance induced vibrations of a rotating shaft using \({\mathcal{H}}_{\infty }\)-optimal control and piezoelectric actuators. Controller design for the considered system is challenging and requires a high demand in robustness due to speed-dependent system behavior in consequence of the Gyroscopic Effect. Recent studies in the field of active control of rotor systems, especially at the Institute for Mechatronic Systems in Mechanical Engineering at TU Darmstadt, mainly focus on the attenuation of rotor displacements. For many applications, like aircraft engines, not only the rotor’s deformation itself is of high interest, but also its interaction with the environment. Former works on active vibration attenuation show that active reduction of rotor displacements can be attended by an undesirable increase of bearing forces. In addition to these works, this article deals with the decoupling of a rotating shaft from the surrounding structure, which is also known as vibration isolation. The investigations are based on a rotor test rig with a statically determined bearing configuration. One of the two bearing supports is active and consists of two piezoelectric stack actuators as well as two collocated piezoelectric load washers. The operating range of the test rig includes two unbalance induced resonances. Since the control performance strongly depends on the accuracy of the description of the system dynamics, a finite element model of the rotor is determined and extended by discrete piezoelectric elements. The obtained parametric model is capable of capturing the system’s speed-dependent dynamics. The \({\mathcal{H}}_{\infty }\)-optimal controller will be derived using the parametric finite element model. Finally, the feasibility of the described approach will be validated by testing the control performance by means of vibration isolation in simulation and experiment.
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model based unbalance monitoring using augmented observer in rotor systems under the consideration of Gyroscopic Effect
Conference on Automation Science and Engineering, 2013Co-Authors: Zhentao Wang, Matthias Borsdorf, Stephan RinderknechtAbstract:Unbalance forces are a crucial issue in rotor systems. Often it is of interest to monitor the states of unbalances while the rotor is running in order to prevent damages to the rotor system. For the model based unbalance monitoring a rotor model is required to represent the behavior of the rotor system and the influences of the unbalances. The feasibilities of the methods are often limited by the accuracy of the system model. Accurate physical model is often hard to build especially for large scale rotor systems with unknown physical properties. In case of rotor systems with large discs, the Gyroscopic Effect is not negligible. It results in a rotary frequency dependent system behavior and thus makes the modeling problem more complicated. Besides the modeling problems, disturbances from initial unbalances and rotor bow are also issues to be considered in the unbalance monitoring. In this paper we formulate the disturbances and Gyroscopic Effect as unknown inputs, which are widely investigated in the fault detection processes and use the model of non-rotating rotor as basis for the unbalance monitoring. Augmented observer, which takes sinusoidal vibrations into consideration is used for the unbalance monitoring. The application of the method on a rotor test rig is presented in this paper.
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Linear Quadratic Regulation of a Rotating Shaft Being Subject to Gyroscopic Effect Using a Genetic Optimization Algorithm
Lecture Notes in Electrical Engineering, 2013Co-Authors: Rudolf Sebastian Schittenhelm, Zhentao Wang, Matthias Borsdorf, Stephan RinderknechtAbstract:A Linear Quadratic Regulator and a Kalman Filter are designed for a rotor test rig being subject to unbalance excitation and Gyroscopic Effect. Rotor vibration is controlled by means of two piezoelectric stack actuators installed at one of the two supports of the rotor. The presence of Gyroscopic Effect leads to an undesirable dependence of the system dynamics on rotational frequency of the shaft. As a result, there is a need for high robustness and furthermore, the separation principle does not hold. Due to the latter aspect, controller and observer design become a coupled problem in the case of the rig. In a first step, the number of free design parameters of the controller-observer combination is reduced to a manageable number of 5. Subsequently, these parameters are determined by means of a genetic optimization algorithm on the basis of a Finite Element model of the test rig. It is shown, that it is possible in this way to determine a controller-observer combination leading to robust stability and excellent performance in the whole operating range which contains two unbalance induced resonances. Control performance is validated in simulation as well as experiments at the test rig.
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modal h control in the context of a rotor being subject to unbalance excitation and Gyroscopic Effect
Volume 4: Ceramics; Concentrating Solar Power Plants; Controls Diagnostics and Instrumentation; Education; Electric Power; Fans and Blowers, 2013Co-Authors: Rudolf Sebastian Schittenhelm, Bernd Riemann, Stephan RinderknechtAbstract:H∞-optimal controllers are designed for a rotor being subject to unbalance excitation and Gyroscopic Effect. The system possesses two unbalance-induced resonances within its operating range. The presence of Gyroscopic Effect is challenging for linear time invariant controller design because of the associated dependence of the system dynamics on the rotational frequency of the rotor. Controllers thus have to be robust against deviation of the actual system behavior from the controller design point model.For vibration control purposes, there are two piezoelectric actuators installed in one of the two supports of the rotor. The signals of four inductive sensors measuring the displacements of the two discs of the rotor are used for controller design.In this article, H∞-optimal controllers are designed on the basis of input and output weighting as well as weighting of modal degrees of freedom and modal excitations. It is shown that superior control performance is achieved using modal weighting since a more accurate problem description of rotors excited by unbalance is incorporated in controller design. Results in this article show furthermore that it is possible to design well performing H∞-optimal controllers for a Gyroscopic rotor by means of iterative controller design without taking model uncertainty directly into account via weighting of certain FRFs of the system to be controlled.Copyright © 2013 by ASME
Xiao-guang Lin - One of the best experts on this subject based on the ideXlab platform.
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Theory and experimental verification of spiral flow tube-type valveless piezoelectric pump with Gyroscopic Effect
Sensors and Actuators A: Physical, 2013Co-Authors: Xuefei Leng, Jianhui Zhang, Yan Jiang, Jin-yuan Zhang, Xue-cheng Sun, Xiao-guang LinAbstract:Abstract Valveless piezoelectric pump has low-cost and easy miniaturization characteristics, and its important development trend is multi-function integration. The current paper reports a new phenomenon that the flow in a spiral tube element is sensitive to the element attitude caused by the Coriolis force, and that a valveless piezoelectric pump is designed by applying this phenomenon. The valveless piezoelectric pump has both the actuator function of fluid transfer and the sensor function, which can obtain the angular velocity variation when its attitude changes. First, the present paper analyzes the principle of the pump and the flow characteristics in the tube. The calculation formula for the pump flow is also obtained. Second, the relationship between pump attitude and flow is identified, which theoretically verifies the Gyroscopic Effect of the pump. Finally, a pump is fabricated for experimental testing of the relationship between pump attitude and flow. Experimental results show that when Archimedes spiral θ = 4 π is selected for the tube design, the pump is most efficient, and the pressure differential between pump inlet and outlet is 29 mm H2O, which achieves a one-way mean flow. On the other hand, when the rotation speed of the plate is 70 r/min, the pressure differential is 9 mm H2O, which is 1.5 times that of 0 rpm rotation speed. The spiral tube valveless piezoelectric pump can turn the element attitude into a form of pressure output, which is important for the multi-function integration of the valveless piezoelectric pump and for the development of civil gyroscope in the future.
Xuefei Leng - One of the best experts on this subject based on the ideXlab platform.
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Simulation Analysis and Experimental Verification of Spiral-tube-type Valveless Piezoelectric Pump with Gyroscopic Effect
Chinese Journal of Mechanical Engineering, 2014Co-Authors: Xuefei Leng, Zhang Jianhui, Yan Jiang, Shouyin Wang, Chunsheng ZhaoAbstract:The current research of the valveless piezoelectric pump focuses on increasing the flow rate and pressure differential. Compared with the valve piezoelectric pump, the valveless one has excellent performances in simple structure, low cost, and easy miniaturization. So, their important development trend is the mitigation of their weakness, and the multi-function integration. The flow in a spiral tube element is sensitive to the element attitude caused by the Coriolis force, and that a valveless piezoelectric pump is designed by applying this phenomenon. The pump has Gyroscopic Effect, and has both the actuator function of fluid transfer and the sensor function, which can obtain the angular velocity when its attitude changes. First, the present paper analyzes the flow characteristics in the tube, obtains the calculation formula for the pump flow, and identifies the relationship between pump attitude and flow, which clarifies the impact of flow and driving voltage, frequency, spiral line type and element attitude, and verifies the Gyroscopic Effect of the pump. Then, the finite element simulation is used to verify the theory. Finally, a pump is fabricated for experimental testing of the relationship between pump attitude and pressure differential. Experimental results show that when Archimedes spiral θ=4π is selected for the tube design, and the rotation speed of the plate is 70 r/min, the pressure differential is 88.2 Pa, which is 1.5 times that of 0 r/min rotation speed. The spiral-tube-type valveless piezoelectric pump proposed can turn the element attitude into a form of pressure output, which is important for the multi-function integration of the valveless piezoelectric pump and for the development of civil gyroscope in the future.
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A spiral-tube-type valveless piezoelectric pump with Gyroscopic Effect
Chinese Science Bulletin, 2014Co-Authors: Jianhui Zhang, Xuefei Leng, Chunsheng ZhaoAbstract:The valveless piezoelectric pump integrates driving and transmitting into one operating element, and characterizes easy micro-miniaturization. But, there is the original sin of low pressure and low flow. Thus, it must avoid weakness to choose applications field. This paper analyzes the flow characteristics in the rotary spiral-tube, which will cause the Coriolis force, and subsequently influence the fluid moving. The principle of the pump is deduced, and the spiral-tube-type valveless piezoelectric pump is invented. The angular velocity variation can be obtained when the pump attitude changes, which theoretically verifies the Gyroscopic Effect of the pump. A pump is fabricated for experimental testing. Experiments has shown that when Archimedes spiral $$ \theta = 4\uppi $$ is selected for the tube design, and the rotation speed of the plate is 70 r/min, the pressure differential is 9 mm H2O, which is 1.5 times that of 0 r/min rotation speed. If introduced the low-cost and miniaturized gyroscope, then this may promise potential application in these areas such as smart cars, robots, and home health care.
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Theory and experimental verification of spiral flow tube-type valveless piezoelectric pump with Gyroscopic Effect
Sensors and Actuators A: Physical, 2013Co-Authors: Xuefei Leng, Jianhui Zhang, Yan Jiang, Jin-yuan Zhang, Xue-cheng Sun, Xiao-guang LinAbstract:Abstract Valveless piezoelectric pump has low-cost and easy miniaturization characteristics, and its important development trend is multi-function integration. The current paper reports a new phenomenon that the flow in a spiral tube element is sensitive to the element attitude caused by the Coriolis force, and that a valveless piezoelectric pump is designed by applying this phenomenon. The valveless piezoelectric pump has both the actuator function of fluid transfer and the sensor function, which can obtain the angular velocity variation when its attitude changes. First, the present paper analyzes the principle of the pump and the flow characteristics in the tube. The calculation formula for the pump flow is also obtained. Second, the relationship between pump attitude and flow is identified, which theoretically verifies the Gyroscopic Effect of the pump. Finally, a pump is fabricated for experimental testing of the relationship between pump attitude and flow. Experimental results show that when Archimedes spiral θ = 4 π is selected for the tube design, the pump is most efficient, and the pressure differential between pump inlet and outlet is 29 mm H2O, which achieves a one-way mean flow. On the other hand, when the rotation speed of the plate is 70 r/min, the pressure differential is 9 mm H2O, which is 1.5 times that of 0 rpm rotation speed. The spiral tube valveless piezoelectric pump can turn the element attitude into a form of pressure output, which is important for the multi-function integration of the valveless piezoelectric pump and for the development of civil gyroscope in the future.
Jianhui Zhang - One of the best experts on this subject based on the ideXlab platform.
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A spiral-tube-type valveless piezoelectric pump with Gyroscopic Effect
Chinese Science Bulletin, 2014Co-Authors: Jianhui Zhang, Xuefei Leng, Chunsheng ZhaoAbstract:The valveless piezoelectric pump integrates driving and transmitting into one operating element, and characterizes easy micro-miniaturization. But, there is the original sin of low pressure and low flow. Thus, it must avoid weakness to choose applications field. This paper analyzes the flow characteristics in the rotary spiral-tube, which will cause the Coriolis force, and subsequently influence the fluid moving. The principle of the pump is deduced, and the spiral-tube-type valveless piezoelectric pump is invented. The angular velocity variation can be obtained when the pump attitude changes, which theoretically verifies the Gyroscopic Effect of the pump. A pump is fabricated for experimental testing. Experiments has shown that when Archimedes spiral $$ \theta = 4\uppi $$ is selected for the tube design, and the rotation speed of the plate is 70 r/min, the pressure differential is 9 mm H2O, which is 1.5 times that of 0 r/min rotation speed. If introduced the low-cost and miniaturized gyroscope, then this may promise potential application in these areas such as smart cars, robots, and home health care.
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Theory and experimental verification of spiral flow tube-type valveless piezoelectric pump with Gyroscopic Effect
Sensors and Actuators A: Physical, 2013Co-Authors: Xuefei Leng, Jianhui Zhang, Yan Jiang, Jin-yuan Zhang, Xue-cheng Sun, Xiao-guang LinAbstract:Abstract Valveless piezoelectric pump has low-cost and easy miniaturization characteristics, and its important development trend is multi-function integration. The current paper reports a new phenomenon that the flow in a spiral tube element is sensitive to the element attitude caused by the Coriolis force, and that a valveless piezoelectric pump is designed by applying this phenomenon. The valveless piezoelectric pump has both the actuator function of fluid transfer and the sensor function, which can obtain the angular velocity variation when its attitude changes. First, the present paper analyzes the principle of the pump and the flow characteristics in the tube. The calculation formula for the pump flow is also obtained. Second, the relationship between pump attitude and flow is identified, which theoretically verifies the Gyroscopic Effect of the pump. Finally, a pump is fabricated for experimental testing of the relationship between pump attitude and flow. Experimental results show that when Archimedes spiral θ = 4 π is selected for the tube design, the pump is most efficient, and the pressure differential between pump inlet and outlet is 29 mm H2O, which achieves a one-way mean flow. On the other hand, when the rotation speed of the plate is 70 r/min, the pressure differential is 9 mm H2O, which is 1.5 times that of 0 rpm rotation speed. The spiral tube valveless piezoelectric pump can turn the element attitude into a form of pressure output, which is important for the multi-function integration of the valveless piezoelectric pump and for the development of civil gyroscope in the future.
Yan Jiang - One of the best experts on this subject based on the ideXlab platform.
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Simulation Analysis and Experimental Verification of Spiral-tube-type Valveless Piezoelectric Pump with Gyroscopic Effect
Chinese Journal of Mechanical Engineering, 2014Co-Authors: Xuefei Leng, Zhang Jianhui, Yan Jiang, Shouyin Wang, Chunsheng ZhaoAbstract:The current research of the valveless piezoelectric pump focuses on increasing the flow rate and pressure differential. Compared with the valve piezoelectric pump, the valveless one has excellent performances in simple structure, low cost, and easy miniaturization. So, their important development trend is the mitigation of their weakness, and the multi-function integration. The flow in a spiral tube element is sensitive to the element attitude caused by the Coriolis force, and that a valveless piezoelectric pump is designed by applying this phenomenon. The pump has Gyroscopic Effect, and has both the actuator function of fluid transfer and the sensor function, which can obtain the angular velocity when its attitude changes. First, the present paper analyzes the flow characteristics in the tube, obtains the calculation formula for the pump flow, and identifies the relationship between pump attitude and flow, which clarifies the impact of flow and driving voltage, frequency, spiral line type and element attitude, and verifies the Gyroscopic Effect of the pump. Then, the finite element simulation is used to verify the theory. Finally, a pump is fabricated for experimental testing of the relationship between pump attitude and pressure differential. Experimental results show that when Archimedes spiral θ=4π is selected for the tube design, and the rotation speed of the plate is 70 r/min, the pressure differential is 88.2 Pa, which is 1.5 times that of 0 r/min rotation speed. The spiral-tube-type valveless piezoelectric pump proposed can turn the element attitude into a form of pressure output, which is important for the multi-function integration of the valveless piezoelectric pump and for the development of civil gyroscope in the future.
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Theory and experimental verification of spiral flow tube-type valveless piezoelectric pump with Gyroscopic Effect
Sensors and Actuators A: Physical, 2013Co-Authors: Xuefei Leng, Jianhui Zhang, Yan Jiang, Jin-yuan Zhang, Xue-cheng Sun, Xiao-guang LinAbstract:Abstract Valveless piezoelectric pump has low-cost and easy miniaturization characteristics, and its important development trend is multi-function integration. The current paper reports a new phenomenon that the flow in a spiral tube element is sensitive to the element attitude caused by the Coriolis force, and that a valveless piezoelectric pump is designed by applying this phenomenon. The valveless piezoelectric pump has both the actuator function of fluid transfer and the sensor function, which can obtain the angular velocity variation when its attitude changes. First, the present paper analyzes the principle of the pump and the flow characteristics in the tube. The calculation formula for the pump flow is also obtained. Second, the relationship between pump attitude and flow is identified, which theoretically verifies the Gyroscopic Effect of the pump. Finally, a pump is fabricated for experimental testing of the relationship between pump attitude and flow. Experimental results show that when Archimedes spiral θ = 4 π is selected for the tube design, the pump is most efficient, and the pressure differential between pump inlet and outlet is 29 mm H2O, which achieves a one-way mean flow. On the other hand, when the rotation speed of the plate is 70 r/min, the pressure differential is 9 mm H2O, which is 1.5 times that of 0 rpm rotation speed. The spiral tube valveless piezoelectric pump can turn the element attitude into a form of pressure output, which is important for the multi-function integration of the valveless piezoelectric pump and for the development of civil gyroscope in the future.