摘要:

AbstractThis paper presents a new, optimal digital redesign technique for finding an optimal cascaded digital controller from the given continuous‐time counterpart by minimizing a quadratic performance index. The control gains can be obtained by solving a set of Lyapunov equations. The developed optimal cascaded digital controller enables the state and/or outputs of the digitally controlled closed‐loop sampled‐data system to optimally match those of the original continuous‐time closed‐loop system at any instant between sampling periods. The developed control law can be implemented using inexpensive and reliable digital electronics with a relatively long sampli

ISSN:0143-2087    

DOI:10.1002/oca.4660120402

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1991

数据来源: WILEY

摘要:

AbstractPhotocells contain a silicon‐based solar energy absorbing material. An optimal design of the interface between this material and the exterior medium is desired. The problem is modelled by the Helmholtz equation. The interface is assumed to be periodic and thus only one period is considered. It is shown that the problem has a solution if the interface is not allowed to oscillate too much. An approximation of the solution is computed with the finite element method coupled with an integral Fourier method for the radiation condition. The numerical simulations show fairly large improvements in the efficiency of the photocel

ISSN:0143-2087    

DOI:10.1002/oca.4660120403

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1991

数据来源: WILEY

摘要:

AbstractUniform cubic B‐splines are applied to solve the optimal trajectory planning problem for robotic manipulators. It is first shown that the trajectory planning problem can be formulated as an optimal control problem with state and control constraints. The resulting optimal control problem is then solved numericall

ISSN:0143-2087    

DOI:10.1002/oca.4660120404

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1991

数据来源: WILEY

摘要:

AbstractA forgetful student wishes to accomplish a high knowledge level (ambitious) with a small effort (lazy). Two learning patterns are addressed. First, at low or intermediate knowledge level, the student improves faster as more knowledge is absorbed. Secondly, at high knowledge level, the more the student learns, the harder it is for an equal amount of improvement to be made. The study problem is cast into an optimal control setting. Study strategies are explored. One interesting finding in the second case is that the student may need to reduce the work intensity as the examination is approaching.

ISSN:0143-2087    

DOI:10.1002/oca.4660120405

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1991

数据来源: WILEY

摘要:

AbstractA direct analytical solution of angular velocities is given for regulating the angular momentum of a spacecraft using reaction jets only. The solution, which appears to be new, may be written down in terms of characteristic values and characteristic vectors. These values and vectors satisfy an algebraic non‐linear equatio

ISSN:0143-2087    

DOI:10.1002/oca.4660120406

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1991

数据来源: WILEY

摘要:

AbstractOptimal control of kinematically redundant manipulators involves the use of extra degrees of freedom to improve their performance by energy minimization, singularity avoidance, obstacle avoidance, higher dexterity, etc. In this paper we deal with the obstacle avoidance problem by using modern control theory and choosing an integral‐type performance index which results in a global optimization scheme. Obstacles are expressed as Cartesian space constraints. The state constraint function and control effort are minimized globally as a performance index. The control effort which maximizes the Hamiltonian and minimizes the performance index is used to find the self‐motion of the manipulator. A simulation for a three‐degrees‐of‐freedom redundant planar robot is presented to demonstrate the effectiveness of t

ISSN:0143-2087    

DOI:10.1002/oca.4660120407

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1991

数据来源: WILEY

ISSN:0143-2087    

DOI:10.1002/oca.4660120401

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1991

数据来源: WILEY