scholarly journals Integrated Communication and Control Systems: Part II—Design Considerations

1988 ◽  
Vol 110 (4) ◽  
pp. 374-381 ◽  
Author(s):  
Asok Ray ◽  
Yoram Halevi
Keyword(s):  
Control Systems ◽  
Dynamic Performance ◽  
Sufficient Conditions ◽  
System Stability ◽  
Time Varying ◽  
Control Loops ◽  
Analysis And Design ◽  
Integrated Communication ◽  
And Control ◽  
Analytical Approaches

Asynchronous time-division multiplexed networks, used in Integrated Communication and Control Systems (ICCS), introduce time-varying and possibly stochastic delays in the feedback control loops. The objective of this on-going research is to develop a comprehensive methodology for the analysis and design of the above class of delayed control systems. In the first part [1] of this two-part paper, we developed a discrete-time, finite-dimensional, time-varying model of the delayed control system; necessary and sufficient conditions for system stability have been established for periodically varying delays. This second part elucidates the significance of the above model relative to the system dynamic performance as well as addresses major criteria for and outlines alternative analytical approaches to ICCS design. Pertinent concepts are illustrated by simulation.

Integrated Communication and Control Systems: Part I—Analysis

1988 ◽  
Vol 110 (4) ◽  
pp. 367-373 ◽  
Author(s):  
Yoram Halevi ◽  
Asok Ray
Keyword(s):  
Control System ◽  
Control Systems ◽  
Dynamic Performance ◽  
Digital Data ◽  
Time Varying ◽  
Data Traffic ◽  
Time Model ◽  
Loop Control ◽  
Integrated Communication ◽  
And Control

Computer networking is a reliable and efficient means for communications between disparate and distributed components in complex dynamical processes like advanced aircraft, spacecraft, and autonomous manufacturing plants. The role of Integrated Communication and Control Systems (ICCS) is to coordinate and perform interrelated functions, ranging from real-time multi-loop control to information display and routine maintenance support. In ICCS, a feedback control loop is closed via the common communication channel which multiplexes digital data from the sensor to the controller and from the controller to the actuator along with the data traffic from other loops and management functions. Due to the asynchronous time-division multiplexing of the network protocol, time-varying and possibly stochastic delays are introduced in the control system, which degrade the system dynamic performance and are a source of potential instability. The paper is divided into two parts. In the first part, the delayed control system is represented by a finite-dimensional, time-varying, discrete-time model which is less complex than the existing continuous-time models for time-varying delays; this approach allows for simpler schemes for analysis and simulation of ICCS. The second part of the paper addresses ICCS design considerations and presents simulation results for certain operational scenarios of ICCS.

Integrated Communication and Control Systems: Part III—Nonidentical Sensor and Controller Sampling

1990 ◽  
Vol 112 (3) ◽  
pp. 357-364 ◽  
Author(s):  
Luen-Woei Liou ◽  
A. Ray
Keyword(s):  
Control System ◽  
Control Systems ◽  
Dynamic Performance ◽  
Time Dependent ◽  
Dimensional Model ◽  
Analysis And Design ◽  
Finite Dimensional ◽  
Alternative Approaches ◽  
Integrated Communication ◽  
And Control

Networking in Integrated Communication and Control Systems (ICCS) introduces randomly varying delays which degrade the system dynamic performance and are a source of potential instability. In Part I [1] of this sequence of papers we developed a discrete-time, finite-dimensional model of the delayed control system for analysis and design of ICCS where the sensor and controller have identical sampling rates. In Part II [2] we proposed two alternative approaches for ICCS design, namely, identical and nonidentical sampling rates for sensor and controller. This Part III presents extended modeling of ICCS for nonidentical sensor and controller sampling rates. This model is also suitable for analyzing tracking problems, i.e., control systems with time-dependent reference inputs.

A Stochastic Regulator for Integrated Communication and Control Systems: Part I—Formulation of Control Law

1991 ◽  
Vol 113 (4) ◽  
pp. 604-611 ◽  
Author(s):  
Luen-Woei Liou ◽  
Asok Ray
Keyword(s):  
Performance Evaluation ◽  
Control Systems ◽  
Dynamic Performance ◽  
State Feedback Control ◽  
Control Law ◽  
Spatially Distributed ◽  
Integrated Communication ◽  
Finite Time Horizon ◽  
And Performance ◽  
And Control

Integrated Communication and Control Systems (ICCS), recently introduced and analyzed in a series of papers [1–7], are applicable to complex dynamical processes like advanced aircraft, spacecraft, automotive, and manufacturing processes. Time-division-multiplexed computer networks are employed in ICCS for exchange of information between spatially distributed plant components as well as for coordination of the diverse control and decision-making functions. Unfortunately, an ICCS network introduces randomly varying, distributed delays within the feedback loops in addition to the digital sampling and data processing delays. These network-induced delays degrade the system dynamic performance, and are a source of potential instability. This two-part paper presents the synthesis and performance evaluation of a stochastic optimal control law for ICCS. In this paper, which is the first of two parts, a state feedback control law for ICCS has been formulated by using the dynamic programming and optimality principle on a finite-time horizon. The control law is derived on the basis of a stochastic model of the plant which is augmented in state space to take into account the effects of randomly varying delays in the feedback loop. The second part [8] presents numerical analysis of the control law and its performance evaluation by simulation of the flight dynamic model of an advanced aircraft.

Analysis and Design of Associative Memories Based on Recurrent Neural Networks with Linear Saturation Activation Functions and Time-Varying Delays

2007 ◽  
Vol 19 (8) ◽  
pp. 2149-2182 ◽  
Author(s):  
Zhigang Zeng ◽  
Jun Wang
Keyword(s):  
Neural Networks ◽  
Recurrent Neural Networks ◽  
Sufficient Conditions ◽  
Time Varying ◽  
Activation Functions ◽  
Analysis And Design ◽  
Design Procedures ◽  
The Neural Network ◽  
Saturation Region ◽  
The Neural Networks

In this letter, some sufficient conditions are obtained to guarantee recurrent neural networks with linear saturation activation functions, and time-varying delays have multiequilibria located in the saturation region and the boundaries of the saturation region. These results on pattern characterization are used to analyze and design autoassociative memories, which are directly based on the parameters of the neural networks. Moreover, a formula for the numbers of spurious equilibria is also derived. Four design procedures for recurrent neural networks with linear saturation activation functions and time-varying delays are developed based on stability results. Two of these procedures allow the neural network to be capable of learning and forgetting. Finally, simulation results demonstrate the validity and characteristics of the proposed approach.

Performance Analysis of Integrated Communication and Control System Networks

1990 ◽  
Vol 112 (3) ◽  
pp. 365-371 ◽  
Author(s):  
Y. Halevi ◽  
A. Ray
Keyword(s):  
Control System ◽  
Statistical Analysis ◽  
Performance Analysis ◽  
Control Systems ◽  
Manufacturing Plants ◽  
Asynchronous Time Division Multiplexing ◽  
Processing Plants ◽  
Integrated Communication ◽  
Time Division ◽  
And Control

This paper presents statistical analysis of delays in Integrated Communication and Control System (ICCS) networks [1–4] that are based on asynchronous time-division multiplexing. The models are obtained in closed form for analyzing control systems with randomly varying delays. The results of this research are applicable to ICCS design for complex dynamical processes like advanced aircraft and spacecraft, autonomous manufacturing plants, and chemical and processing plants.

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