The Experts below are selected from a list of 5070 Experts worldwide ranked by ideXlab platform

Songjing Li - One of the best experts on this subject based on the ideXlab platform.

  • Visualization of Flow-Field between the Flapper and Nozzle in a Hydraulic Servo-Valve
    Advanced Materials Research, 2011
    Co-Authors: Jacob M. Mchenya, Sheng Zhuo Zhang, Songjing Li
    Abstract:

    In order to understand the mechanism and get rid of the high-frequency self-excited noise in a hydraulic Servo-Valve, in this paper, the flow field distribution in the pilot stage of a hydraulic flapper-nozzle Servo-Valve is investigated. An assembly is prepared representing the construction and working principle of the flow field inside the pilot stage of a hydraulic flapper-nozzle Servo-Valve. A method of visualization is developed by taking videos for the flow field inside the transparent assembly with a high speed video camera. In this study, at different inlet pressure the high speed video camera was utilized for flow visualization together with computer-assisted image measurement. The shape of the jet flow, the cavitations and vortex flow inside the flow field can be visualized clearly. The proposed method enables to analyze the flow-field in the pilot stage of a hydraulic flapper-nozzle Servo-Valve by giving useful information for better design.

  • Study of self-excited noise and pressure oscillations in a hydraulic jet-pipe Servo-Valve with magnetic fluids
    2010 3rd International Symposium on Systems and Control in Aeronautics and Astronautics, 2010
    Co-Authors: Hao Li, Songjing Li, Jinghui Peng
    Abstract:

    In order to overcome self-excited high frequency oscillations and noise appearing sometimes during the working of hydraulic jet-pipe Servo-Valve, application of magnetic fluid (MF) in hydraulic jet-pipe Servo-Valve is developed in this paper. Large damping can be introduced into the Servo-Valve if magnetic fluid is filled into the working gaps of hydraulic Servo-Valve torque motor. Construction of hydraulic jet-pipe Servo-Valve with magnetic fluid is introduced. The noise signals are tested and recorded when magnetic fluid is applied or not in the Servo-Valve. Experimental results are compared and analyzed using FFT analysis. It is shown that noise of Servo-Valve is depressed when magnetic fluid is applied.

  • influence of magnetic fluids on the dynamic characteristics of a hydraulic Servo Valve torque motor
    Mechanical Systems and Signal Processing, 2008
    Co-Authors: Songjing Li
    Abstract:

    The aim of this paper is to investigate the influence of magnetic fluids on the dynamic characteristics of a hydraulic Servo-Valve torque motor. As a kind of functional materials, magnetic fluids are filled into the working gaps of a hydraulic Servo-Valve torque motor in this paper. Forces on the torque motor due to magnetic fluids are studied. The dynamic mathematical models of the torque motor with magnetic fluids are introduced. After that the dynamic characteristics of the torque motor with magnetic fluids are analyzed and tested. Analysis and experimental results are compared with the results when magnetic fluids are not applied in the motor.

M. Singaperumal - One of the best experts on this subject based on the ideXlab platform.

  • Mathematical modelling and experimental characterization of a high dynamic Servo Valve integrated with piezoelectric actuator
    Proceedings of the Institution of Mechanical Engineers Part I: Journal of Systems and Control Engineering, 2010
    Co-Authors: S. Karunanidhi, M. Singaperumal
    Abstract:

    AbstractA conventional two-stage Servo Valve basically consists of an electrically operated torque motor as the first stage and spool Valve as the second stage. Owing to the limitation in the band width, Servo Valves are not suitable for high-frequency applications. The work presented in this paper deals with the methodology of the mechatronics approach for the design of a piezoelectric actuator with a mechanical amplifier and its integration into a Servo Valve. The analysis and simulation of a multilayer piezoelectric actuator (MLA) a with mechanical amplifier for high-frequency application has been done using icon-based bond graph technique and finite element coupled field analysis for the commercially available piezoelectric actuator. The designed piezoelectric actuator was integrated into an existing flapper-nozzle Servo Valve by replacing the first stage. The dynamics of the Valve integrated into a piezoelectric actuator has been simulated. The required simulation parameters for the actuator have bee...

  • mathematical modelling and experimental characterization of a high dynamic Servo Valve integrated with piezoelectric actuator
    Proceedings of the Institution of Mechanical Engineers Part I: Journal of Systems and Control Engineering, 2010
    Co-Authors: S. Karunanidhi, M. Singaperumal
    Abstract:

    AbstractA conventional two-stage Servo Valve basically consists of an electrically operated torque motor as the first stage and spool Valve as the second stage. Owing to the limitation in the band ...

  • design analysis and simulation of magnetostrictive actuator and its application to high dynamic Servo Valve
    Sensors and Actuators A-physical, 2010
    Co-Authors: S. Karunanidhi, M. Singaperumal
    Abstract:

    Flapper–nozzle type Electro Hydraulic Servo Valve (EHSV) operated by conventional torque motor actuators has been used in wide range of industrial applications. As their bandwidths are limited, they are not suitable for high-speed applications. The work presented in this paper deals with the mechatronic approach for the design of a magnetostrictive actuator with flexure amplifier and a magnetically biased magnetostrictive actuator for application in high frequency flapper–nozzle Servo Valve. A magnetostrictive actuator has been designed, built and integrated into an existing flapper–nozzle Servo Valve by replacing the torque motor. Incorporating the dynamics of the magnetostrictive actuator, the dynamics of the Valve was simulated. Necessary parameters for the actuator have been arrived by finite element model. No load flow characteristics are analyzed and compared with experimental values. Step response has been compared with conventional Valve. The results show that the Valve has satisfactory static and dynamic characteristics for applications in high-speed actuation systems.

Feifei Zhao - One of the best experts on this subject based on the ideXlab platform.

  • Development of low-cost pressure control type quasi-Servo Valve using embedded controller
    Procedia Engineering, 2012
    Co-Authors: Yumi Moriwake, Shujiro Dohta, Tetsuya Akagi, Feifei Zhao
    Abstract:

    Today, the advanced age and less children society is growing up rapidly. The care and welfare equipment to support a nursing care and a self-reliance of the senior and the disabled are actively researched and developed by many researchers. However, the power assisted device required many degrees of freedom. The total weight of the wearable devices using fluid control devices increases so that the number of actuator and control Valves increases according to the degree of freedom. Therefore, in our previous study, we developed a small and light-weight quasi-Servo Valve to reduce the burden of the user. In this paper, we proposed and tested a quasi-Servo Valve by using the small, light-weight and low-cost on/off Valves driven by the pulse width modulation method. The Valve consists of two on/off Valves and a microcomputer. Both Valves are connected in serial. One Valve is used as a switching Valve to exhaust or supply, and another is used as a PWM control Valve that can adjust the Valve opening. And we confirmed that the output flow rate of the tested Valve could be adjusted in analog way. We also proposed the precise analytical model of the tested Valve. By comparing the experimental result with the calculated results using the proposed model and the identified parameters, we confirmed that the model of the Valve was valid. In the next step, a pressure control type quasi-Servo Valve is proposed and tested. The tested Valve consists of the quasi-Servo Valve, a pressure transducer and an inexpensive tiny micro-computer. As a result, by using the tested Valve and P control method with the compensation for the supplied and exhausted flow rates, the pressure control performance of the tested Valve could be improved. © 2012 The Authors.

  • development of low cost pressure control type quasi Servo Valve using embedded controller
    Procedia Engineering, 2012
    Co-Authors: Yumi Moriwake, Shujiro Dohta, Tetsuya Akagi, Feifei Zhao
    Abstract:

    Abstract Today, the advanced age and less children society is growing up rapidly. The care and welfare equipment to support a nursing care and a self-reliance of the senior and the disabled are actively researched and developed by many researchers. However, the power assisted device required many degrees of freedom. The total weight of the wearable devices using fluid control devices increases so that the number of actuator and control Valves increases according to the degree of freedom. Therefore, in our previous study, we developed a small and light-weight quasi-Servo Valve to reduce the burden of the user. In this paper, we proposed and tested a quasi-Servo Valve by using the small, light-weight and low-cost on/off Valves driven by the pulse width modulation method. The Valve consists of two on/off Valves and a microcomputer. Both Valves are connected in serial. One Valve is used as a switching Valve to exhaust or supply, and another is used as a PWM control Valve that can adjust the Valve opening. And we confirmed that the output flow rate of the tested Valve could be adjusted in analog way. We also proposed the precise analytical model of the tested Valve. By comparing the experimental result with the calculated results using the proposed model and the identified parameters, we confirmed that the model of the Valve was valid. In the next step, a pressure control type quasi-Servo Valve is proposed and tested. The tested Valve consists of the quasi-Servo Valve, a pressure transducer and an inexpensive tiny micro-computer. As a result, by using the tested Valve and P control method with the compensation for the supplied and exhausted flow rates, the pressure control performance of the tested Valve could be improved.

  • Development and Analysis of Small-sized Quasi-Servo Valve Using On/Off Valves
    Proceedings of SICE Annual Conference 2010, 2010
    Co-Authors: Tetsuya Akagi, Shujiro Dohta, Feifei Zhao, Keiji Fujita
    Abstract:

    Today, the advanced age and less children society is growing up rapidly. The care and welfare equipments to support a nursing care and a self reliance of the senior and the disabled are actively researched and developed by many researchers. However, the power assisted device required many degrees of freedom. The total weight load of the wearable devices increases so that the number of actuator and control Valves increases according to degrees of freedom. Therefore, we aim to develop a small and light-weight quasi-Servo Valve to decrease the burden of the user. In this paper, we proposed and tested a quasi-Servo Valve by using the small, light-weight and low cost on/off Valves driven by the pulse width modulation method. The Valve consists of two on/off Valves and a microcomputer. Both Valves are connected in serial. One Valve is used as a switching Valve to exhaust or supply, another is used as a PWM control Valve that can adjust output flow rate. And we confirmed that the output flow rate of the tested Valve could be adjusted in analog way. We also proposed the precise analytical model of the tested Valve. By comparing the experimental result with the calculated results using the proposed model and the identified parameters, we could confirm that the model of the Valve is valid. In addition, the optimal PWM period 5 ms of the tested Valve could be obtained by the calculated result in pressure control simulation of the Valve. In addition, the master slave bending control of the pneumatic flexible actuator using the quasi-Servo Valve was also proposed and tested. As a result, by using the tested Valve and PID control method, the control performance of the system could be improved.

S. Karunanidhi - One of the best experts on this subject based on the ideXlab platform.

  • Mathematical modelling and experimental characterization of a high dynamic Servo Valve integrated with piezoelectric actuator
    Proceedings of the Institution of Mechanical Engineers Part I: Journal of Systems and Control Engineering, 2010
    Co-Authors: S. Karunanidhi, M. Singaperumal
    Abstract:

    AbstractA conventional two-stage Servo Valve basically consists of an electrically operated torque motor as the first stage and spool Valve as the second stage. Owing to the limitation in the band width, Servo Valves are not suitable for high-frequency applications. The work presented in this paper deals with the methodology of the mechatronics approach for the design of a piezoelectric actuator with a mechanical amplifier and its integration into a Servo Valve. The analysis and simulation of a multilayer piezoelectric actuator (MLA) a with mechanical amplifier for high-frequency application has been done using icon-based bond graph technique and finite element coupled field analysis for the commercially available piezoelectric actuator. The designed piezoelectric actuator was integrated into an existing flapper-nozzle Servo Valve by replacing the first stage. The dynamics of the Valve integrated into a piezoelectric actuator has been simulated. The required simulation parameters for the actuator have bee...

  • mathematical modelling and experimental characterization of a high dynamic Servo Valve integrated with piezoelectric actuator
    Proceedings of the Institution of Mechanical Engineers Part I: Journal of Systems and Control Engineering, 2010
    Co-Authors: S. Karunanidhi, M. Singaperumal
    Abstract:

    AbstractA conventional two-stage Servo Valve basically consists of an electrically operated torque motor as the first stage and spool Valve as the second stage. Owing to the limitation in the band ...

  • design analysis and simulation of magnetostrictive actuator and its application to high dynamic Servo Valve
    Sensors and Actuators A-physical, 2010
    Co-Authors: S. Karunanidhi, M. Singaperumal
    Abstract:

    Flapper–nozzle type Electro Hydraulic Servo Valve (EHSV) operated by conventional torque motor actuators has been used in wide range of industrial applications. As their bandwidths are limited, they are not suitable for high-speed applications. The work presented in this paper deals with the mechatronic approach for the design of a magnetostrictive actuator with flexure amplifier and a magnetically biased magnetostrictive actuator for application in high frequency flapper–nozzle Servo Valve. A magnetostrictive actuator has been designed, built and integrated into an existing flapper–nozzle Servo Valve by replacing the torque motor. Incorporating the dynamics of the magnetostrictive actuator, the dynamics of the Valve was simulated. Necessary parameters for the actuator have been arrived by finite element model. No load flow characteristics are analyzed and compared with experimental values. Step response has been compared with conventional Valve. The results show that the Valve has satisfactory static and dynamic characteristics for applications in high-speed actuation systems.

Guang Lin Wang - One of the best experts on this subject based on the ideXlab platform.

  • UR - Research on a Precise Grinding Device for Servo Valve Spool
    2018 15th International Conference on Ubiquitous Robots (UR), 2018
    Co-Authors: Guang Lin Wang, Yuxin Zhang
    Abstract:

    The grinding of Valve core and Valve sleeve plays a key part in the manufacturing process of electro-hydraulic Servo Valve, and the grinding precision of the lap matching is directly related to the accuracy of the Servo Valve grinding. The objective of this paper is to develop a set can be used for Servo Valve spool throttle sub-micron precision grinding device which can solve tool setting error, high interference and low efficiency according to theory of acoustic emission and microfeed technology. An overall design scheme of using the acoustic emission technique and the motor driving hand wheel to set tool automatically, and the piezoelectric ceramic for micro feeding is proposed. The test results show that the grinding results are in accordance with the design requirements.

  • Servo Valve Nozzle Fuzzy Clustering Analysis Pairing Algorithm
    Key Engineering Materials, 2015
    Co-Authors: Guang Lin Wang
    Abstract:

    Electro-hydraulic Servo Valve is the key component of an electro-hydraulic Servo control system, and double nozzle flapper Valve is the main type of electro-hydraulic Servo Valve. Nozzles are the important part of a double nozzle flapper Valve, the pairing quality is directly related to the performance of the Servo Valve .Servo Valve is of symmetrical structure, and the use of nozzles is also in pairs. The process of nozzles matched in pairs is called pairing process. Because the orifice diameter of the nozzle is only about 0.2 to 0.3 mm, it is difficult to pair with the method of direct measurements. Besides, as a kind of hydraulic components, nozzles are usually paired by flow rate measured under differential pressure. Two nozzles will be matched to a pair if their pressure-flow rate characteristic curve is within the allowed tolerance. To ensure the success rate of pairing, it usually needs a large number of machined nozzles to be sifted. According to the principle of clustering analysis, we propose a new paring algorithm which can match nozzles efficiently and automatically.

  • Development and Experimental Study of Magnetic Property for Servo Valve Torque Motor
    Key Engineering Materials, 2014
    Co-Authors: Cheng Cheng Li, Dong Xiang Shao, Guang Lin Wang
    Abstract:

    Torque motor is an electrical-mechanical converter of Servo Valve, is bridge which connects the electrical devices and hydraulic devices, is one of key components of Servo Valve. The permanent magnet torque motor is studied in this paper. As key parameters of design of Servo Valve, the magnetic property of torque motor determines magnitude of the electromagnetic torque. At present, many manufactures of Servo Valve pays more attention on the test of integral Servo Valve. The design of torque motor also bases on experience, lacking of specialized tool for torque motor test. This paper described the principle of magnetic property of the test, developed a test system for magnetic characteristics, and established the relationship between the electromagnetic torque and current control current, and the relationship between output angular displacement and control current.