The Experts below are selected from a list of 3039 Experts worldwide ranked by ideXlab platform

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

  • identification of Pneumatic Cylinder friction parameters using genetic algorithms
    IEEE-ASME Transactions on Mechatronics, 2004
    Co-Authors: Jihong Wang, J D Wang, N Daw
    Abstract:

    A method for identifying friction parameters of Pneumatic actuator systems is developed in this paper, based on genetic algorithms (GA). The statistical expectation of mean-squared errors is traditionally used to form evaluation functions in general optimization problems using GA. However, it has been found that, sometimes, this type of evaluation function does not lead the algorithms to have a satisfactory convergence, that is, the algorithm takes a long period of time or fails to reach the values of parameters to be identified. Different evaluation functions are, therefore, studied in the paper and two types of evaluation functions are found to have the expected rate of convergence and the precision. The algorithm is initially developed and tested using the benchmark data generated by simulations before it is applied for parameter identification using the data obtained from the real system measurement. The results obtained in the paper can provide the manufacturers with the observation to the characteristics inside the Pneumatic Cylinders.

  • modelling study analysis and robust servo control of Pneumatic Cylinder actuator systems
    IEE Proceedings - Control Theory and Applications, 2001
    Co-Authors: Jihong Wang, D J D Wang, Philip Moore, Junsheng Pu
    Abstract:

    A modelling study on Pneumatic Cylinder actuator systems is carried out based on the standard orifice theory. The Pneumatic Cylinder actuators are modelled as a cascade connection of two nonlinear subsystems affine in the control input. The model validation has been conducted by comparing open-loop system dynamic responses obtained through simulation and experiments. Finally, a class of robust servo control strategy is proposed, which guarantees the profile following precision. An example is included to demonstrate the servo control design procedure.

  • a practical control strategy for servo Pneumatic actuator systems
    Control Engineering Practice, 1999
    Co-Authors: Jihong Wang, Junsheng Pu, Philip Moore
    Abstract:

    Abstract A practical control strategy with a simple controller structure is proposed for servo-Pneumatic Cylinder actuator systems. Theoretical analysis reveals that the acceleration of the piston indirectly represents the Cylinder chamber pressure difference so it is possible to employ acceleration feedback instead of pressure feedback in the construction of servo-Pneumatic actuator control systems. The main features of the control strategy developed in the paper are (1) using acceleration feedback to improve the stability of the system; and (2) introducing time-delay minimisation and optimised null offset compensation to address the problem of time delay and dead zone, which are mainly caused by the compressibility of air and friction. The experimental studies have been conducted using an asymmetric Pneumatic Cylinder system and the results show that the system performance has been much improved when compared with a conventional PID controller.

Philip Moore - One of the best experts on this subject based on the ideXlab platform.

  • modelling study analysis and robust servo control of Pneumatic Cylinder actuator systems
    IEE Proceedings - Control Theory and Applications, 2001
    Co-Authors: Jihong Wang, D J D Wang, Philip Moore, Junsheng Pu
    Abstract:

    A modelling study on Pneumatic Cylinder actuator systems is carried out based on the standard orifice theory. The Pneumatic Cylinder actuators are modelled as a cascade connection of two nonlinear subsystems affine in the control input. The model validation has been conducted by comparing open-loop system dynamic responses obtained through simulation and experiments. Finally, a class of robust servo control strategy is proposed, which guarantees the profile following precision. An example is included to demonstrate the servo control design procedure.

  • a practical control strategy for servo Pneumatic actuator systems
    Control Engineering Practice, 1999
    Co-Authors: Jihong Wang, Junsheng Pu, Philip Moore
    Abstract:

    Abstract A practical control strategy with a simple controller structure is proposed for servo-Pneumatic Cylinder actuator systems. Theoretical analysis reveals that the acceleration of the piston indirectly represents the Cylinder chamber pressure difference so it is possible to employ acceleration feedback instead of pressure feedback in the construction of servo-Pneumatic actuator control systems. The main features of the control strategy developed in the paper are (1) using acceleration feedback to improve the stability of the system; and (2) introducing time-delay minimisation and optimised null offset compensation to address the problem of time delay and dead zone, which are mainly caused by the compressibility of air and friction. The experimental studies have been conducted using an asymmetric Pneumatic Cylinder system and the results show that the system performance has been much improved when compared with a conventional PID controller.

Atila Yilmaz - One of the best experts on this subject based on the ideXlab platform.

  • Application of wireless, embedded microcontroller circuit for a semi-active above-knee prosthesis with Pneumatic Cylinder
    2015 23nd Signal Processing and Communications Applications Conference (SIU), 2015
    Co-Authors: Mevlüt Said Saraçoğlu, Tuna Orhanlı, Doğukan Şahin, Atila Yilmaz
    Abstract:

    This study presents the embedded microcontoller of data acquisition unit, performance analysis, and wireless data transfer capability of the semi active above knee joint with Pneumatic Cylinder developed in Hacettepe University Biomedical Research Laboratory. For this purpose an embedded microcontroller based data acquisition card has been designed and programmed in order to have an adaptive capability for coping with different phases of the gait. This prosthesis also responses the instantaneous gait velocity alterations and it adjusts the damping variable of the Pneumatic Cylinder via a stepper motor. System detects the related gait phases and gait velocities from the signal of inertial measurement unit (IMU). Printed board tests and gait performance evaluation tests are conducted with associated Bluetooth wireless transfer unit. It has been shown that the kinematic variables have been measured and analyzed successfully by this embedded wireless system.

  • Application and comparison of finite state control of above-knee prosthesis with Pneumatic Cylinder at different phases
    2015 23nd Signal Processing and Communications Applications Conference (SIU), 2015
    Co-Authors: Tuna Orhanlı, Atila Yilmaz
    Abstract:

    In this study, performance test results of “various phases state control” of the semi active knee joint with Pneumatic damper have been presented in a comparative manner. Performance tests have been conducted with natural human gait and prosthetic gait via image based motion measurement system and sensor based motion measurement system. Subjects are realized gait onto treadmill with different gait velocities as 1 km/h, 2 km/h and 3 km/h. The phase control of the prosthetic gait is performed under two phase, three phase and five phase scenarios. Under the facts drawn by these performance tests, the optimum control strategy related to phases of gait can be determined in a qualitative fashion and the response of the developed prosthesis under different gait velocities can be measured successfully. Mean absolute knee angle error results from natural gait and prosthetic gait are considered as performance criteria, derived from image based motion measurement system. It is concluded that the response time of the stepper motor causes a major limitation onto proper control over the Pneumatic Cylinder based prosthesis and associated conclusions are shared.

  • SIU - Application of wireless, embedded microcontroller circuit for a semi-active above-knee prosthesis with Pneumatic Cylinder
    2015 23nd Signal Processing and Communications Applications Conference (SIU), 2015
    Co-Authors: Mevlüt Said Saraçoğlu, Tuna Orhanlı, Doğukan Şahin, Atila Yilmaz
    Abstract:

    This study presents the embedded microcontoller of data acquisition unit, performance analysis, and wireless data transfer capability of the semi active above knee joint with Pneumatic Cylinder developed in Hacettepe University Biomedical Research Laboratory. For this purpose an embedded microcontroller based data acquisition card has been designed and programmed in order to have an adaptive capability for coping with different phases of the gait. This prosthesis also responses the instantaneous gait velocity alterations and it adjusts the damping variable of the Pneumatic Cylinder via a stepper motor. System detects the related gait phases and gait velocities from the signal of inertial measurement unit (IMU). Printed board tests and gait performance evaluation tests are conducted with associated Bluetooth wireless transfer unit. It has been shown that the kinematic variables have been measured and analyzed successfully by this embedded wireless system.

  • SIU - Application and comparison of finite state control of above-knee prosthesis with Pneumatic Cylinder at different phases
    2015 23nd Signal Processing and Communications Applications Conference (SIU), 2015
    Co-Authors: Tuna Orhanlı, Atila Yilmaz
    Abstract:

    In this study, performance test results of “various phases state control” of the semi active knee joint with Pneumatic damper have been presented in a comparative manner. Performance tests have been conducted with natural human gait and prosthetic gait via image based motion measurement system and sensor based motion measurement system. Subjects are realized gait onto treadmill with different gait velocities as 1 km/h, 2 km/h and 3 km/h. The phase control of the prosthetic gait is performed under two phase, three phase and five phase scenarios. Under the facts drawn by these performance tests, the optimum control strategy related to phases of gait can be determined in a qualitative fashion and the response of the developed prosthesis under different gait velocities can be measured successfully. Mean absolute knee angle error results from natural gait and prosthetic gait are considered as performance criteria, derived from image based motion measurement system. It is concluded that the response time of the stepper motor causes a major limitation onto proper control over the Pneumatic Cylinder based prosthesis and associated conclusions are shared.

Junsheng Pu - One of the best experts on this subject based on the ideXlab platform.

  • modelling study analysis and robust servo control of Pneumatic Cylinder actuator systems
    IEE Proceedings - Control Theory and Applications, 2001
    Co-Authors: Jihong Wang, D J D Wang, Philip Moore, Junsheng Pu
    Abstract:

    A modelling study on Pneumatic Cylinder actuator systems is carried out based on the standard orifice theory. The Pneumatic Cylinder actuators are modelled as a cascade connection of two nonlinear subsystems affine in the control input. The model validation has been conducted by comparing open-loop system dynamic responses obtained through simulation and experiments. Finally, a class of robust servo control strategy is proposed, which guarantees the profile following precision. An example is included to demonstrate the servo control design procedure.

  • a practical control strategy for servo Pneumatic actuator systems
    Control Engineering Practice, 1999
    Co-Authors: Jihong Wang, Junsheng Pu, Philip Moore
    Abstract:

    Abstract A practical control strategy with a simple controller structure is proposed for servo-Pneumatic Cylinder actuator systems. Theoretical analysis reveals that the acceleration of the piston indirectly represents the Cylinder chamber pressure difference so it is possible to employ acceleration feedback instead of pressure feedback in the construction of servo-Pneumatic actuator control systems. The main features of the control strategy developed in the paper are (1) using acceleration feedback to improve the stability of the system; and (2) introducing time-delay minimisation and optimised null offset compensation to address the problem of time delay and dead zone, which are mainly caused by the compressibility of air and friction. The experimental studies have been conducted using an asymmetric Pneumatic Cylinder system and the results show that the system performance has been much improved when compared with a conventional PID controller.

Jan Vyhnanek - One of the best experts on this subject based on the ideXlab platform.

  • transformer position sensor for a Pneumatic Cylinder
    Sensors and Actuators A-physical, 2019
    Co-Authors: Pavel Ripka, Andrey Chirtsov, Mehran Mirzaei, Jan Vyhnanek
    Abstract:

    Abstract A novel transformer-based sensor for a Pneumatic Cylinder enables measurements of the piston position to be made through a thick conductive Cylinder. Unlike existing industrial solutions, which are mainly based on a moving magnet, our sensors do not require modifications to the parts inside the Cylinder. Finite element analysis results are compared with measurements at various piston positions and excitation frequencies. Using a suitable model for the magnetic properties of the iron piston bar, we achieved good agreement between the model and reality. When the sensor is operated at 100 Hz, the sensitivity is 200 mV/FS and the raw linearity error is 1.6% of the full 400 mm stroke.

  • Inductance position sensor for Pneumatic Cylinder
    AIP Advances, 2018
    Co-Authors: Pavel Ripka, Andrey Chirtsov, Mehran Mirzaei, Jan Vyhnanek
    Abstract:

    © 2017 Author(s). The position of the piston in Pneumatic Cylinder with aluminum wall can be measured by external inductance sensor without modifications of the aluminum piston and massive iron piston rod. For frequencies below 20 Hz the inductance is increasing with inserting rod due to the rod permeability. This mode has disadvantage of slow response to piston movement and also high temperature sensitivity. At the frequency of 45 Hz the inductance is position independent, as the permeability effect is compensated by the eddy current effect. At higher frequencies eddy current effects in the rod prevail, the inductance is decreasing with inserting rod. In this mode the sensitivity is smaller but the sensor response is fast and temperature stability is better. We show that FEM simulation of this sensor using measured material properties gives accurate results, which is important for the sensor optimization such as designing the winding geometry for the best linearity.