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This paper applies the minimum data/maximum entropy modelling approach to the mean-square optimal control of flexible mechanical systems having a priori uncertainties in the structural elastic operator. With appropriate choice of the state variables, these uncertainties may be modelled as random skew-hermitian perturbations of the system dynamics map. After formulating the maximum entropy stochastic...
A scalar discrete-time state estimation and stochastic optimal control problem is considered which differs from the standard linear-quadratic-Gaussian case only by the presence in the dynamics of a quadratic term in the state and noise variables with a small coefficient. With respect to this coefficient, precise results are given concerning the asymptotic convergence in probability of a certain approximation...
One obstacle to effective control integration, particularly in aircraft systems, is the premature partitioning of the total system into semiautonomous subsystems. This partitioning results from functional divisions that are based on older technology. A requirements definition process is proposed that allows the requirements to be specified independently of an assumed design mechanization. The designer...
Proportional+Integral+Double Integral form of adaptive laws for Model. Reference Adaptive Control, are suggested, Stability of the system is proved using Liapunov theory. The LECE analysis and the root locus plot of a typical example are provided for comparison. Digital computer simulation results showing satisfactory working of the laws, are presented.
Vehicle operating policies are developed and a longitudinal controller is designed to satisfy the stringent performance criteria of an Automated Guideway Transit (AGT) System operating under model-reference control. The complete control system is comprised of two parts, a model generator and a vehicle controller. The generation of a model velocity, based on ideal vehicle kinematics which include jerk...
The recent interest in integrated control for aircraft electronic systems has been paralleled with increased interest in standardization by the military. Computer architecture, high order programming languages and data transfer via multiplexing have all been defined in standards. What is the effect of standardization on the application of integrated control technology? Will it help or hinder design...
Traffic signal control in urban areas has a major impact on the performance of the transportation network. Existing computer-based traffic control systems are mostly of the First Generation type, i.e., they implement control strategies that were calculated off-line based on historical traffic flow information. The purpose of the study described in this paper was to develop and test demand-responsive...
Future control systems for the traffic in city streets are expected to be less binding on the driver than those used at present. It is accordingly of interest to inquire into how such systems might operate. The paper describes a formulation of the control problem under such conditions and outlines a method for its solution. The method has two desirable features, namely that of being "dynamic"...
A closed-loop form of observer is presented for multivariable control of processes exhibiting time delay or "dead time" characteristics. With this method under ideal conditions (i.e., a perfect fit of the model to the process), the separation of the system poles does not include any deadtime effects. Thus, higher controller gains could normally be used under these conditions. Here, response...
The design of integrated control systems currently being planned for incorporation into future fighter aircraft includes additional areas of concern for the control system engineer. Specialized design techniques are required for such integrated control systems whether they provide straightforward coupled outer-loop to inner-loop control modes or are implemented as multi-input, multi-output configurations...
An adaptive control system is proposed for the control of CSTR process. The system is designed to be adapted to the parameter changes due to the variation of the operation conditions and also to the unmeasurable concentration changes at the inlet. The parameter adaptation is made by sensitivities at the steady state. Through the experiments conducted on a partially simulated stirred tank reactor,...
We address discrete linear stochastic proposes in which the control variable takes unknown jumps at unknown times and remains constant between jumps. We present a three-stage Friedland-like filtering technique for obtaining the optimum estimates of the state and the control. A search procedure is presented which greatly reduces the number of times that the log likelihood ratio needs to be evaluated...
This paper deals with the estimation of the unmeasurable states of a linear, time-invariant dynamic system by first identifying the initial state of the system. This new approach makes use of the state transition concept to predict the future behavior of the system. A state estimator which operates in series with the initial state identifier is developed. Satisfactory state estimates have been obtained...
The Air Force, in conjunction with the Navy, NASA, and industry, has been conducting R&D on integrated control systems for the past twenty years. Flight evaluation programs have included: maneuver load control, body bending mode stabilization, active flutter supression, terrain following, integrated flight/fire control (IFFC), advanced fighter technology integration (AFTI), and integrated flight...
This paper considers the problem of mean-square optimal control for a linear system with stochastic parameters and limited prior information. For specific application to flexible mechanical systems, consideration is limited to the class of multiplicative parameter perturbations of skew-hermitian type. To avoid ad hoc assumptions regarding a priori statistics, a prior probability assignment is induced...
On making use of an invariant imbedding, an initial-value solution of the recursive Hopf type integral equations with semi-degenerate asymmetric kernels is presented for the linear least-squares filtering problems with time-variant properties. Furthermore, it is shown that the real-time solution of the optimal estimate is reduced to a Cauchy system for an integral of the stochastic processes weighted...
A class of general structured discrete-time deterministic observers is developed. The one-step predicting or Luenberger observers and the current-update observers may be obtained from this class of general structured observers. Interesting relationships and important properties among various full-order observers are established. Optimal discrete-time observer gains are then derived, and it is shown...
In this paper, a direct approach is proposed for obtaining the steady-state Kalman filter gain matrix for linear discrete time systems with the coloured observation noise. The proposed approach does not require priori knowledge of the noise covariance matrices, and does not employ the suboptimal Kalman filter. The two new algorithms for estimating gain matrix K are obtained, and the estimate of gain...
Mode cancellation in multivariable stochastic systems may be caused by certain relationships between the input, the output and the internal structure of the system. Clearly, mode cancellation implies that the system's order cannot be identified from the output. Necessary and sufficient conditions for mode retention are derived and their implications on the order identification problem are considered.
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