In this paper , the unilaterally constrained motions of a large class of rigid bodiessystems are studied both locally and globally. The main conclusion is that locally,such a system bahaves like a particle in a R...In this paper , the unilaterally constrained motions of a large class of rigid bodiessystems are studied both locally and globally. The main conclusion is that locally,such a system bahaves like a particle in a Riemannian manifold with boundary;globally.under the assumption of energy conservation, the system behaves like a billiards system over a Riemannina manifold with boundary展开更多
In this paper, a novel adaptive fuzzy control scheme is presented. The controller is constructed by using a table lookup scheme and self tuning techniques, which includes the identification block, the fuzzification,...In this paper, a novel adaptive fuzzy control scheme is presented. The controller is constructed by using a table lookup scheme and self tuning techniques, which includes the identification block, the fuzzification, the updating rule base, the defuzzification, and the crisp controller (sub controller), etc. The adaptive fuzzy controller is designed in detail by means of a triangular membership function and the center of gravity method. The control scheme addressed here is implemented to control the motion of the end effector of a two link constrained flexible manipulator. Computer simulation results show that the novel adaptive fuzzy control scheme works quite well.展开更多
A rigid flexible coupling physical model which can represent a flexible spacecraft is investigated in this paper. By applying the mechanics theory in a non-inertial coordinate system,the rigid flexible coupling dynami...A rigid flexible coupling physical model which can represent a flexible spacecraft is investigated in this paper. By applying the mechanics theory in a non-inertial coordinate system,the rigid flexible coupling dynamic model with dynamic stiffening is established via the subsystemmodeling framework. It is clearly elucidated for the first time that,dynamic stiffening is produced by the coupling effect of the centrifugal inertial load distributed on the beamand the transverse vibration deformation of the beam. The modeling approach in this paper successfully avoids problems which are caused by other popular modeling methods nowadays： the derivation process is too complex by using only one dynamic principle; a clearly theoretical explanation for dynamic stiffening can＇t be provided. First,the continuous dynamic models of the flexible beamand the central rigid body are established via structural dynamics and angular momentumtheory respectively. Then,based on the conclusions of orthogonalization about the normal constrained modes,the finite dimensional dynamic model suitable for controller design is obtained. The numerical simulation validations showthat： dynamic stiffening is successfully incorporated into the dynamic characteristics of the first-order model established in this paper,which can indicate the dynamic responses of the rigid flexible coupling system with large overall motion accurately,and has a clear modeling mechanism,concise expressions and a good convergence.展开更多
In this paper, a novel adaptive fuzzy control scheme is presented . The controller is constructed by using a table lookup scheme and self tuning techniques, which includes the identification block, the fuzzification...In this paper, a novel adaptive fuzzy control scheme is presented . The controller is constructed by using a table lookup scheme and self tuning techniques, which includes the identification block, the fuzzification, the updating rule base, the defuzzification, and the crisp controller (sub controller), etc. The adaptive fuzzy controller is designed in detail by means of triangular membership function and the center of gravity method. The control scheme addressed here is implemented to control the motion of the end effector of a two link constrained flexible manipulator. Computer simulation results show that the novel adaptive fuzzy control scheme works quite well.展开更多
As a nonrelativistic particle constrained to remain on an(N−1)-dimensional((N≥2))hypersurface embedded in an N-dimensional Euclidean space,two different components pi and pj(i,j=1,2,3,...N)of the Cartesian momentum o...As a nonrelativistic particle constrained to remain on an(N−1)-dimensional((N≥2))hypersurface embedded in an N-dimensional Euclidean space,two different components pi and pj(i,j=1,2,3,...N)of the Cartesian momentum of the particle are not mutually commutative,and explicitly commutation relations[p^(^)_(i),p^(^)_(j)](≠0) depend on products of positions and momenta in uncontrollable ways.The generalized Dupin indicatrix of the hypersurface,a local analysis technique,is utilized to explore the dependence of the noncommutativity on the curvatures around a local point of the hypersurface.The first finding is that the noncommutativity can be grouped into two categories;one is the product of a sectional curvature and the angular momentum,and another is the product of a principal curvature and the momentum.The second finding is that,for a small circle lying a tangential plane covering the local point,the noncommutativity leads to a rotation operator and the amount of the rotation is an angle anholonomy;and along each of the normal sectional curves centering the given point the noncommutativity leads to a translation plus an additional rotation and the amount of the rotation is one half of the tangential angle change of the arc.展开更多
文摘In this paper , the unilaterally constrained motions of a large class of rigid bodiessystems are studied both locally and globally. The main conclusion is that locally,such a system bahaves like a particle in a Riemannian manifold with boundary;globally.under the assumption of energy conservation, the system behaves like a billiards system over a Riemannina manifold with boundary
文摘In this paper, a novel adaptive fuzzy control scheme is presented. The controller is constructed by using a table lookup scheme and self tuning techniques, which includes the identification block, the fuzzification, the updating rule base, the defuzzification, and the crisp controller (sub controller), etc. The adaptive fuzzy controller is designed in detail by means of a triangular membership function and the center of gravity method. The control scheme addressed here is implemented to control the motion of the end effector of a two link constrained flexible manipulator. Computer simulation results show that the novel adaptive fuzzy control scheme works quite well.
文摘A rigid flexible coupling physical model which can represent a flexible spacecraft is investigated in this paper. By applying the mechanics theory in a non-inertial coordinate system,the rigid flexible coupling dynamic model with dynamic stiffening is established via the subsystemmodeling framework. It is clearly elucidated for the first time that,dynamic stiffening is produced by the coupling effect of the centrifugal inertial load distributed on the beamand the transverse vibration deformation of the beam. The modeling approach in this paper successfully avoids problems which are caused by other popular modeling methods nowadays： the derivation process is too complex by using only one dynamic principle; a clearly theoretical explanation for dynamic stiffening can＇t be provided. First,the continuous dynamic models of the flexible beamand the central rigid body are established via structural dynamics and angular momentumtheory respectively. Then,based on the conclusions of orthogonalization about the normal constrained modes,the finite dimensional dynamic model suitable for controller design is obtained. The numerical simulation validations showthat： dynamic stiffening is successfully incorporated into the dynamic characteristics of the first-order model established in this paper,which can indicate the dynamic responses of the rigid flexible coupling system with large overall motion accurately,and has a clear modeling mechanism,concise expressions and a good convergence.
文摘In this paper, a novel adaptive fuzzy control scheme is presented . The controller is constructed by using a table lookup scheme and self tuning techniques, which includes the identification block, the fuzzification, the updating rule base, the defuzzification, and the crisp controller (sub controller), etc. The adaptive fuzzy controller is designed in detail by means of triangular membership function and the center of gravity method. The control scheme addressed here is implemented to control the motion of the end effector of a two link constrained flexible manipulator. Computer simulation results show that the novel adaptive fuzzy control scheme works quite well.
基金This work is financially supported by National Natural Science Foundation of China under Grant No.11675051.
文摘As a nonrelativistic particle constrained to remain on an(N−1)-dimensional((N≥2))hypersurface embedded in an N-dimensional Euclidean space,two different components pi and pj(i,j=1,2,3,...N)of the Cartesian momentum of the particle are not mutually commutative,and explicitly commutation relations[p^(^)_(i),p^(^)_(j)](≠0) depend on products of positions and momenta in uncontrollable ways.The generalized Dupin indicatrix of the hypersurface,a local analysis technique,is utilized to explore the dependence of the noncommutativity on the curvatures around a local point of the hypersurface.The first finding is that the noncommutativity can be grouped into two categories;one is the product of a sectional curvature and the angular momentum,and another is the product of a principal curvature and the momentum.The second finding is that,for a small circle lying a tangential plane covering the local point,the noncommutativity leads to a rotation operator and the amount of the rotation is an angle anholonomy;and along each of the normal sectional curves centering the given point the noncommutativity leads to a translation plus an additional rotation and the amount of the rotation is one half of the tangential angle change of the arc.
