Language：Japanese   Publisher：The Institute of Electronics, Information and Communication Engineers  

CiNii Books

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Language：Japanese   Publisher：The Japan Society of Mechanical Engineers  

This paper proposes a relative position and attitude control method by using only magnetic force with multi-dipole for formation-flying spacecrafts. The control method can be widely applied to re-configurable space structures that architect large structure or reconstruct themselves by assembling basic structural units. One remarkable benefit of the method is that it does not require reaction wheels for relative attitude controls and then fuels for unloading. This paper focuses on current control of dipoles which produce strong nonlinear magnetic forces and suggests a way of linearization by using a corresponding linear reference system. A feasibility of this method and controllability of the strong nonlinear system is discussed, and then the series of position and attitude control simulation are shown, and the future works are suggested in the paper.

DOI： 10.1299/kikaic.79.1540

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Language：Japanese   Publisher：The Japan Society of Mechanical Engineers  

CiNii Books

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Language：English   Publisher：The Japan Society of Mechanical Engineers  

This paper proposes a relative position and attitude control method by using only magnetic force with multi-dipole for formation-flying spacecrafts. The control method can be widely applied to re-configurable space structures that architect large structure or reconstruct themselves by assembling basic structural units. One remarkable benefit of the method is that it does not require reaction wheels for relative attitude controls and then doesn't require any fuel for unloading. This paper focuses on current control of dipoles which produce strong nonlinear magnetic forces and suggests a way of linearization by using a corresponding linear reference system. A feasibility of this method and controllability of the strong nonlinear system is discussed, and then the series of position and attitude control simulation are shown, and the future works are suggested in the paper.

DOI： 10.1299/spacee.6.44

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Language：Japanese   Publisher：The Japan Society of Mechanical Engineers  

One of the most important issues in space structure designs is to reduce total weight of the structure. Structural size of a solar cell paddle for spacecraft becomes large corresponding to increasing electric power requirements for future advanced missions. Lightweight structures can be adopted for many space applications considering growing requirements of future missions. In the design of solar array paddles deployable structure has a large percentage of the total weight. In the deployment mechanism, using components with low rigidity and lightweight may reduce the total weight. Then we should consider influence of the deployment mechanism on structural characteristics. We performed structural analysis and experiment to clarify the dependence of the dimension and the configuration of deployment mechanism. As a result, we found that the influence on the vibration characteristics of the deployment mechanism like a hinge disposed between the panels against large structure is small and in particular the influence of the bending stiffness in the vertical direction of the panel surface is large. We found that it becomes possible to lightweight by obtaining optimum design parameters such as the Young's modulus and the cross-sectional area of deployment mechanism corresponding to the scale of structure.

CiNii Books

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Language：Japanese  

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Language：Japanese   Publisher：The Japan Society of Mechanical Engineers  

This research proposes a relative position and attitude control method using magnetic force with dipole magnets for formation-flighting spacecrafts without reaction wheels. This technology can be widely applied to re-configurable space structures that architect or/ re-structure themselves by assembling basic structural units. One remarkable benefit is that this control method can extend mission term in comparison to conventional control methods with magnetic force because spacecrafts never require any types of fuel for position controls or unloadings. This paper focuses on current control of dipoles which produce strong nonlinear magnetic forces and suggested a way of linearization of a nonlinear system for control. Also feasibility of this method and controllability are investigated, then the series of attitude control simulation are shown, and the next step for developing this technology will be discussed in the following chapter.

CiNii Books

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Language：Japanese   Publisher：The Japan Society of Mechanical Engineers  

CiNii Books

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Language：Japanese  

CiNii Books

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Language：Japanese  

A buckling analysis method based on Co-rotational formulated FEM for flexible multi body beam structures is proposed. This method makes it possible to analyze light weight deployable beam structures that may be subjected to buckling load. This paper especially focuses on a method of buckling mode identification and buckling mode injection while a structure undergoes mechanical motion. In this method, a buckling mode is estimated even though a bifurcation point is not accurately obtained. The validity of this method is confirmed in a numerical examination.

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Language：Japanese   Publisher：The Japan Society of Mechanical Engineers  

A formula of multibody finite element analysis based on the corotational formulated finite element method and the direct coordinate partitioning for deployable truss structures is proposed. A beam element used in linear finite element analyses is a basic element in the formula. A corotational frame is defined by node coordinate systems attached to a beam element. A tangent stiffness matrix contains a virtual rotation displacement of the corotational frame. By the appropriate transformation of this virtual displacement, a simple geometric stiffness for the formula is obtained. The formula makes it possible to analyze the deploying motions of large deformed deployable truss structures, to be applicable to general finite elements, and to increase convergence speed of the Newton method in a solution algorithm. This improvement is achieved by neglecting virtual work done by rigid body motion in the process of employing the geometric stiffness to the conventional formula. A validity of this formula is confirmed through results of a numerical deployment analysis of a deployable beam structure.

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Language：Japanese   Publisher：The Institute of Electronics, Information and Communication Engineers  

A study of Ka-band multi-beam antenna is described. To meet the high gain requirements, polarization discrimination panel is used to keep proper feed arrangement. Nine interleaved beams are used for Japan main islands and Okinawa to avoid interference, and the RF sensor closed loop are used to minimize pointing loss.

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Language：Japanese   Publisher：The Institute of Electronics, Information and Communication Engineers  

A study of Ka-band multi-beam antenna is described. To meet the high gain requirements, polarization discrimination panel is used to keep proper feed arrangement. Nine interleaved beams are used for Japan main islands and Okinawa to avoid interference, and the RF sensor closed loop are used to minimize pointing loss.

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An optimization method for structure and control system of smart structure systems through the use of a feedback linearization technique is proposed. The system addressed here is the smart structure system that can change its system parameters such as inertia, viscosity, and stiffness, and can control itself by changing these parameters. The system is nonlinear, and behaves as a structure and a control system. The proposed method employs the feedback linearization technique to the optimization procedure, and then both a performance evaluation method and a BMI optimization method for linear systems can apply to the system. A numerical example is carried out to evaluate the proposed method.

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Language：Japanese  

A formula of multibody finite element analysis based on the corotational formulated finite element method and the direct coordinate partitioning for deployable truss structures is proposed. A beam element used in linear finite element analyses is a basic element in the formula. A corotational frame is defined by node coordinate systems attached to a beam element. A tangent stiffness matrix contains a virtual rotation displacement of the corotational frame. By the appropriate transformation of this virtual displacement, a simple geometric stiffness for the formula is obtained. The formula makes it possible to analyze the deploying motions of large deformed deployable truss structures, to be applicable to general finite elements, and to increase convergence speed of the Newton method in a solution algorithm. This improvement is achieved by neglecting virtual work done by rigid body motion in the process of employing the geometric stiffness to the conventional formula. A validity of this formula is confirmed through results of a numerical deployment analysis of a deployable beam structure.

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Language：Japanese   Publisher：The Japan Society of Mechanical Engineers  

The buckling analysis method based on Corotational formulated FEM for complex flexible multibody beam structures is proposed. This method makes it possible to analyze light weight deployable beam structures that may be subjected to buckling taking into account the geometric nonlinearity stemming from large rotations. The mechanical motion, elastic deformation and buckling can be handled by the consolidated mathematical treatment and computational algorithm presented in this paper. This paper especially focuses on a buckling mode injection method while a concerned structure undergoes mechanical motion. A buckling mode is estimated even though a bifurcation point is not accurately obtained. The validity of this method is confirmed in a numerical examination.

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Language：Japanese   Publisher：The Japan Society of Mechanical Engineers  

We've been investigating large deployable antennas that sizes have 10 to 20 m. As its mechanical scale is getting large, shape measurement and prediction by ground test become difficult. Then the shape analysis is important. The electrical surfaces of these antennas are composed of metallic mesh and cable network. The mesh component has membrane characteristics. In this study, we describe some analysis results of membrane and cable structures for deployable antennas.

CiNii Books

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Language：Japanese  

The buckling analysis method based on Corotational formulated FEM for complex flexible multibody beam structures is proposed. This method makes it possible to analyze light weight deployable beam structures that may be subjected to buckling taking into account the geometric nonlinearity stemming from large rotations. The mechanical motion, elastic deformation and buckling can be handled by the consolidated mathematical treatment and computational algorithm presented in this paper. This paper especially focuses on a buckling mode injection method while a concerned structure undergoes mechanical motion. A buckling mode is estimated even though a bifurcation point is not accurately obtained. The validity of this method is confirmed in a numerical examination.

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Language：English   Publisher：THE JAPAN SOCIETY FOR AERONAUTICAL AND SPACE SCIENCES  

A formula of variable inertia systems, which contain controllable inertia, is introduced, and a feedback linearization technique for the variable inertia systems is proposed. This linearization technique allows us to control the variable inertia systems through linear control methods without linear control inputs. The formula of variable inertia systems consists of two subsystems related to rotation and variable inertia. The rotational subsystem contains an ordinary differential equation, and the subsystem of variable inertia is independent from the alternative subsystem. Because of these system properties, the proposed technique is composed of a noninteracting condition to linear control inputs for the rotational subsystem, and a servo controller for the subsystem of variable inertia to satisfy the noninteracting condition. The resulting closed-loop system becomes linear. To validate the feedback linearization technique, a vibration suppression controller for a 2-DOF variable inertia system without dampers is derived, and numerical simulations of the controlled system are carried out. The simulation results confirm that the system is sufficiently controlled through the feedback linearization technique without linear control inputs.

DOI： 10.2322/tjsass.45.1

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Other Link： https://jlc.jst.go.jp/DN/JALC/00156870052?from=CiNii

Language：Japanese   Publisher：The Japan Society of Mechanical Engineers  

Future space missions will require increasingly large and flexible space structure systems. Because their system properties are difficult to be precisely identified, to control the systems with the stability and control performance guaranteed, we have to consider the system uncertainties which could be caused by identification errors or uncontrolled modes. A model expression, an identification method, and a control method proposed in this paper can explicitly deal with the uncertainties by applying the fuzzy theory. This control method for the systems ensures their stability with prescribed admissibility and reliability. The validity of the identification method and the control method are confirmed by a numerical example with a conventional control method.

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Language：Japanese   Publisher：Information Processing Society of Japan (IPSJ)  

Variable inertia systems, which include variable moment of inertia and can be controlled by changing the moment of inertia, are formulated and their noninteracting controllers are derived for the systems to suppress disturbances. The formula of variable inertia systems consists of two subsystems related to rotation and variable inertia. The rotational subsystem contains an ordinary differential equation and the subsystem of the variable inertia is independent. Because of these system properties, it is proposed that the noninteracting controllers are employed for the systems, and derived from a noninteracting condition for the rotational subsystems to known disturbances, a disturbance estimator, and a servo controller for the subsystem associated with the variable inertia. Then the resulting closed loop system is noninteractive to disturbances. For a demonstration and a confirmation of the control effectiveness, a detailed application of the procedure of the noninteracting controller design and results of numerical simulations for an example are illustrated.

CiNii Books

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Language：Japanese   Publisher：The Japan Society of Mechanical Engineers  

This paper proposes a method for solving BMI problems in simultaneous design of structure and control systems. This method transfers simultaneous design problems with H_∞, H_2, and pole placement constraints described by BMIs into dual-LMI problems by Schur complement, and locally solves the problems through the cone complementary linearization algorithm. A simple numerical example indicates that the method comparatively quickly finds a structured controller which contains structural parameters.

CiNii Books

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Language：Japanese   Publisher：Information Processing Society of Japan (IPSJ)  

Variable inertia systems, whose inertia is variable and can be used to control the sustems, are formulated and their noninteracting controllers are derived. Because the systems contain variable inertia term, it is proposed that the noninteracting controllers are employed for the systems, and derived from a noninteracting condition to known disturbances, a disturbance estimator, and a servo controller to satisfy the condition. Then the resulting closed loop system is noninteractive to disturbances. For a confirmation of the control effectiveness, results of numerical simulations for an example with the noninteracting controller are illustrated.

CiNii Books

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Language：Japanese   Publisher：The Japan Society of Mechanical Engineers  

In this paper, a simultaneous design method for systems with variable inertial term is proposed. Because conventional control methods can hardly deal with the system due to the variable inertial term, a noninteracting control is applied to linearize the system. In addition, to insure the reliability of the imperfectly linearized system, evaluation methods in H_2 and H_∝ are determined. Through the linearization method and the evaluation methods, conventional linear control methods can be applied to the system. The property of this structure system concerns the control performance so that the simultaneous design method of structure and control is employed to design the controlled system. This design method is applied to an example of a system with variable inertial term, and it is confirmed that the method can design the controller and improve the control performance.

CiNii Books

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Applicant：日本電信電話株式会社

Application no：特願2003-318844  Date applied：2003.9

Announcement no：特開2005-086698  Date announced：2005.3

J-GLOBAL

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Applicant：日本電信電話株式会社

Application no：特願2003-318844  Date applied：2003.9

Announcement no：特開2005-086698  Date announced：2005.3

Patent/Registration no：特許第3891972号  Date issued：2006.12

J-GLOBAL

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Applicant：日本電信電話株式会社

Application no：特願2003-318845  Date applied：2003.9

Announcement no：特開2005-086699  Date announced：2005.3

Patent/Registration no：特許第3889384号  Date issued：2006.12

J-GLOBAL

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Applicant：日本電信電話株式会社

Application no：特願2003-318862  Date applied：2003.9

Announcement no：特開2006-080578  Date announced：2006.3

J-GLOBAL

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Applicant：日本電信電話株式会社

Application no：特願2003-318847  Date applied：2003.9

Announcement no：特開2006-080577  Date announced：2006.3

J-GLOBAL

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Applicant：日本電信電話株式会社

Application no：特願2003-318846  Date applied：2003.9

Announcement no：特開2005-082092  Date announced：2005.3

J-GLOBAL

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Applicant：日本電信電話株式会社

Application no：特願2003-318845  Date applied：2003.9

Announcement no：特開2005-086699  Date announced：2005.3

J-GLOBAL

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Applicant：日本電信電話株式会社

Application no：特願2002-211347  Date applied：2002.7

Announcement no：特開2004-054605  Date announced：2004.2

J-GLOBAL

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