The Experts below are selected from a list of 156 Experts worldwide ranked by ideXlab platform

Hironori A. Fujii - One of the best experts on this subject based on the ideXlab platform.

  • Optimization of generalized potential in Mission Function control - Analytical and experimental results
    Journal of Guidance Control and Dynamics, 1996
    Co-Authors: Hironori A. Fujii, Masaki Takinami, Khoichi Matsuda
    Abstract:

    The Mission Function control utilizes the second law of Lyapunov and employs a Mission Function that is a Lyapunov Function, including a hypothetical potential Function, generalized potential. The Mission Function is characterized for its ability to include any Functional form of positive-definite generalized potential to complete the control objective. The Functional form of the generalized potential is optimized in the sense of minimizing a performance index, and a robust optimal nonlinear and distributed control algorithm for the slew maneuver of flexible structures is presented. The employment of the optimal nonlinear generalized potential naturally achieves improvement of control performance, and it avoids the excessive excitation of the vibration of flexible structures for large attitude angle reorientation in the case of a quadratic generalized potential. The usefulness of the present optimized generalized potential for Mission Function control is verified both by a numerical simulation and by a hardware experiment.

  • Deployment/retrieval control of a tethered subsatellite under effect of tether elasticity
    Journal of Guidance Control and Dynamics, 1996
    Co-Authors: Kentaroh Kokubun, Hironori A. Fujii
    Abstract:

    The deployment/retrieval control of a tethered subsatellite connected through an elastic tether to a main body is studied. The dynamical model of the tether is a continuum, and the effect of tether elasticity is taken into account. Large deflection theory is adopted to formulate the strain of tether. The motion is described by nonlinear, partial differential, and time-varying equations and is treated directly without using any approximation of the modal analysis. The Mission-Function control algorithm is applied to the deployment/retrieval control of the subsatellite connected through the elastic tether. Results of numerical simulation show that the present control law works quite well for deployment/retrieval control of the subsatellite, and that the elastic vibrations of the tether are suppressed satisfactorily.

  • Mission Function control of tethered subsatellite deployment retrieval in plane and out of plane motion
    Journal of Guidance Control and Dynamics, 1991
    Co-Authors: Hironori A. Fujii, Kenji Uchiyama, Kentaroh Kokubun
    Abstract:

    ANY tethered subsatellite systems are proposed for various future applications including the Shuttle-based "skyhook" concept.1'3 Dynamics of deployment/re trieval of such systems is time varying and nonlinear, and its control is rather complicated. Many studies are reported in the area of control and dynamics of a tethered subsatellite.1 A control algorithm called the Mission- Function control is applied successfully to control deployment and retrieval of a tethered subsatellite.2 The dynamics treated in Ref. 2 are restricted to a case where the tether is assumed to swing only in the orbital plane. This Note extends the numerical analysis in Ref. 2. Both inplane and out-of-plane motions are taken into account for a dynamical model. Results of the numerical analysis show an excellent controlled behavior of the Mission-Function control algorithm, even for the present dynamical model.

  • Mission Function control for a slew maneuver experiment
    Journal of Guidance Control and Dynamics, 1991
    Co-Authors: Hironori A. Fujii, Toshiyuki Ohtsuka, Satoshi Udou
    Abstract:

    A control algorithm named Mission Function control is experimentally demonstrated and verified on a slew maneuver of a flexible space structure model. The Mission Function control algorithm employs a Lyapunov-type Function that consists of generalized energy Functions. The model consists of a rigid body having a cantilevered flexible appendage; it is controlled to slew in a horizontal plane by a torque motor. Analytical study indicates that vibrational motion of the flexible appendage can be sensed by strain gauges as a bending moment and shear force at the root of the appendage. Results of the experiment show that a simple implementation of the algorithm leads to excellent controlled behavior of the slew maneuver as well as excellent control robustness.

  • Mission Function Control of Tethered Subsatellite Deployment/Retrieval: In-Plane and Out-of-Plane Motion
    Journal of Guidance Control and Dynamics, 1991
    Co-Authors: Hironori A. Fujii, Kenji Uchiyama, Kentaroh Kokubun
    Abstract:

    ANY tethered subsatellite systems are proposed for various future applications including the Shuttle-based "skyhook" concept.1'3 Dynamics of deployment/re trieval of such systems is time varying and nonlinear, and its control is rather complicated. Many studies are reported in the area of control and dynamics of a tethered subsatellite.1 A control algorithm called the Mission- Function control is applied successfully to control deployment and retrieval of a tethered subsatellite.2 The dynamics treated in Ref. 2 are restricted to a case where the tether is assumed to swing only in the orbital plane. This Note extends the numerical analysis in Ref. 2. Both inplane and out-of-plane motions are taken into account for a dynamical model. Results of the numerical analysis show an excellent controlled behavior of the Mission-Function control algorithm, even for the present dynamical model.

Kentaroh Kokubun - One of the best experts on this subject based on the ideXlab platform.

  • Deployment/retrieval control of a tethered subsatellite under effect of tether elasticity
    Journal of Guidance Control and Dynamics, 1996
    Co-Authors: Kentaroh Kokubun, Hironori A. Fujii
    Abstract:

    The deployment/retrieval control of a tethered subsatellite connected through an elastic tether to a main body is studied. The dynamical model of the tether is a continuum, and the effect of tether elasticity is taken into account. Large deflection theory is adopted to formulate the strain of tether. The motion is described by nonlinear, partial differential, and time-varying equations and is treated directly without using any approximation of the modal analysis. The Mission-Function control algorithm is applied to the deployment/retrieval control of the subsatellite connected through the elastic tether. Results of numerical simulation show that the present control law works quite well for deployment/retrieval control of the subsatellite, and that the elastic vibrations of the tether are suppressed satisfactorily.

  • Mission Function control of tethered subsatellite deployment retrieval in plane and out of plane motion
    Journal of Guidance Control and Dynamics, 1991
    Co-Authors: Hironori A. Fujii, Kenji Uchiyama, Kentaroh Kokubun
    Abstract:

    ANY tethered subsatellite systems are proposed for various future applications including the Shuttle-based "skyhook" concept.1'3 Dynamics of deployment/re trieval of such systems is time varying and nonlinear, and its control is rather complicated. Many studies are reported in the area of control and dynamics of a tethered subsatellite.1 A control algorithm called the Mission- Function control is applied successfully to control deployment and retrieval of a tethered subsatellite.2 The dynamics treated in Ref. 2 are restricted to a case where the tether is assumed to swing only in the orbital plane. This Note extends the numerical analysis in Ref. 2. Both inplane and out-of-plane motions are taken into account for a dynamical model. Results of the numerical analysis show an excellent controlled behavior of the Mission-Function control algorithm, even for the present dynamical model.

  • Mission Function Control of Tethered Subsatellite Deployment/Retrieval: In-Plane and Out-of-Plane Motion
    Journal of Guidance Control and Dynamics, 1991
    Co-Authors: Hironori A. Fujii, Kenji Uchiyama, Kentaroh Kokubun
    Abstract:

    ANY tethered subsatellite systems are proposed for various future applications including the Shuttle-based "skyhook" concept.1'3 Dynamics of deployment/re trieval of such systems is time varying and nonlinear, and its control is rather complicated. Many studies are reported in the area of control and dynamics of a tethered subsatellite.1 A control algorithm called the Mission- Function control is applied successfully to control deployment and retrieval of a tethered subsatellite.2 The dynamics treated in Ref. 2 are restricted to a case where the tether is assumed to swing only in the orbital plane. This Note extends the numerical analysis in Ref. 2. Both inplane and out-of-plane motions are taken into account for a dynamical model. Results of the numerical analysis show an excellent controlled behavior of the Mission-Function control algorithm, even for the present dynamical model.

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

  • Mission Function control of tethered satellite climber system
    Acta Astronautica, 2015
    Co-Authors: Hirohisa Kojima, Kosei Fukatsu, Pavel M Trivailo
    Abstract:

    Because the tether of a tethered satellite system (TSS) can be extremely long, it would be difficult to inspect the damage to the tether. The ultimate configuration of a TSS could be a space elevator (SE). The tether needs to carry a crawler or climber to inspect damage to the tether or transport travelers on the SE. Coriolis force due to the climber motion causes librational motion of the tether. The numerical simulations have shown that the original Mission-Function (MF) control is not applicable to a TSS with a climber because it was intended for subsatellite deployment and retrieval control using a tether, not for a climber on the tether. This paper proposes a new MF control to suppress the librational motion of a tether with a climber. The proposed MF control is a modified version of the original MF control. The active force to drive the climber is determined from the MF. A simplified dynamic model of a TSS with a single climber is used to evaluate the derived controller. The effectiveness of the proposed method is verified through numerical simulations.

  • Mission-Function control of tethered satellite/climber system
    Acta Astronautica, 2015
    Co-Authors: Hirohisa Kojima, Kosei Fukatsu, Pavel M Trivailo
    Abstract:

    Because the tether of a tethered satellite system (TSS) can be extremely long, it would be difficult to inspect the damage to the tether. The ultimate configuration of a TSS could be a space elevator (SE). The tether needs to carry a crawler or climber to inspect damage to the tether or transport travelers on the SE. Coriolis force due to the climber motion causes librational motion of the tether. The numerical simulations have shown that the original Mission-Function (MF) control is not applicable to a TSS with a climber because it was intended for subsatellite deployment and retrieval control using a tether, not for a climber on the tether. This paper proposes a new MF control to suppress the librational motion of a tether with a climber. The proposed MF control is a modified version of the original MF control. The active force to drive the climber is determined from the MF. A simplified dynamic model of a TSS with a single climber is used to evaluate the derived controller. The effectiveness of the proposed method is verified through numerical simulations.

Hirohisa Kojima - One of the best experts on this subject based on the ideXlab platform.

  • Mission Function control of tethered satellite climber system
    Acta Astronautica, 2015
    Co-Authors: Hirohisa Kojima, Kosei Fukatsu, Pavel M Trivailo
    Abstract:

    Because the tether of a tethered satellite system (TSS) can be extremely long, it would be difficult to inspect the damage to the tether. The ultimate configuration of a TSS could be a space elevator (SE). The tether needs to carry a crawler or climber to inspect damage to the tether or transport travelers on the SE. Coriolis force due to the climber motion causes librational motion of the tether. The numerical simulations have shown that the original Mission-Function (MF) control is not applicable to a TSS with a climber because it was intended for subsatellite deployment and retrieval control using a tether, not for a climber on the tether. This paper proposes a new MF control to suppress the librational motion of a tether with a climber. The proposed MF control is a modified version of the original MF control. The active force to drive the climber is determined from the MF. A simplified dynamic model of a TSS with a single climber is used to evaluate the derived controller. The effectiveness of the proposed method is verified through numerical simulations.

  • Mission-Function control of tethered satellite/climber system
    Acta Astronautica, 2015
    Co-Authors: Hirohisa Kojima, Kosei Fukatsu, Pavel M Trivailo
    Abstract:

    Because the tether of a tethered satellite system (TSS) can be extremely long, it would be difficult to inspect the damage to the tether. The ultimate configuration of a TSS could be a space elevator (SE). The tether needs to carry a crawler or climber to inspect damage to the tether or transport travelers on the SE. Coriolis force due to the climber motion causes librational motion of the tether. The numerical simulations have shown that the original Mission-Function (MF) control is not applicable to a TSS with a climber because it was intended for subsatellite deployment and retrieval control using a tether, not for a climber on the tether. This paper proposes a new MF control to suppress the librational motion of a tether with a climber. The proposed MF control is a modified version of the original MF control. The active force to drive the climber is determined from the MF. A simplified dynamic model of a TSS with a single climber is used to evaluate the derived controller. The effectiveness of the proposed method is verified through numerical simulations.

Jixiang Fan - One of the best experts on this subject based on the ideXlab platform.

  • Slewing maneuver and vibration control of tethered space solar power satellite
    2011 Second International Conference on Mechanic Automation and Control Engineering, 2011
    Co-Authors: Di Zhou, Jixiang Fan
    Abstract:

    Control approach is presented for vibration suppression of tethered space solar power satellite (SSPS) during slewing maneuver by combining attitude control and active vibration control based on tether tension. The mathematical description for the slewing motion of tethered SSPS is proposed. Mission Function (MF) Control Algorithm is applied in the design of a PD controller, which is able not only to stabilize the satellite attitude but also suppress vibration of the flexible solar panel. An additional active flexible control system, acting on the flexible parts can be desired for the further micro-vibration suppression, is designed by employing the MF control algorithm and the nonlinearity of the flexible tether is taken into account in the controller design. In the design process, the stability of the vibration control system is proved. Simulation results demonstrate the proposed approach can significantly reduce the vibration of the flexible solar panel during and after the maneuver operation.