Class Of Adaptive Control Systems Research Articles

Structure of the information management system of cereal crops cultivation

The problems of constructing and implementing the structure of the information management system (IMS) for the cultivation of grain crops based on the optimization of the choice of agricultural technologies in view of the methods of the management theory, system and compartmental approaches are considered. The objects of management are soil, a cultivated crop and ecology of the agricultural landscape area used. It is concluded that the IMS belongs to the class of adaptive control systems with prediction by a multidimensional dynamic stochastic object. A new quality of the management system, which significantly determines its structure, is shown, namely the presence of a control loop for maintaining soil fertility and ecology in crop rotation and a control loop for the agrocenosis of the crop. A hierarchical block diagram of the object management system with forecasting is proposed, which implements functional transformations of the information flow in the IMS. As a criterion for choosing an alternative agricultural technology, environmental and economic efficiency was used, modified in view of the management goals and the composition of the machine and tractor fleet. The analytical description of the processes of the agrobiosystem at the modern level is based on the compartmental approach with the description of phenomena in the form of differential equations. The content of the compartment describes the process of energy and mass transfer in the system: soil – vegetation cover – ground layer of the air based on functional (theoretical) dynamic simulation. Based on the results of the information review, the possibility of implementation of such a management system has not been currently identified. The use of empirical simulation models in the IMS is unacceptable, since a change in a crop or natural-climatic zone will require the development of a new empirical model. The systems for simulating biophysical processes WOFOST, DSSAT, DSSAT Cropping System (CSM), APSIM and AGROTOOL, using methods of functional dynamic simulation within the framework of the compartmental approach, have been analyzed. The developed IMS structure using the AGROTOOL crop productivity model is implemented on condition that new modules of compartments are created.

On the application of neural network technologies for control problems in cognitive transportation systems

In the work, the functions of cognition are brought in line with the aspects of the functioning of cognitive transport systems and technologies. We consider the mathematical apparatus of cognitive technologies – neural network control systems, based on trained multi-layer neural networks of direct action in the class of adaptive control systems for dynamic objects. The possibility and variants of their inclusion in the control system of the transport system are clarified. On the basis of the considered approach, a country road recognition system based on a convolutional neural network has been developed, which will automatically segment rural roads using satellite images and build a road network diagram to analyze the spatial development of transport networks and to control unmanned vehicles. The development of a neural network based on U-net was carried out in Python 3x. The training set consists of 880 images prepared by hand mark up. The accuracy of the developed model when testing on prepared samples was 64%. According to the results of the study, conclusions were drawn and prospects for further functional development of the developed tools were determined.

The synthesis of control system to synchronize ship generator assemblies

This paper considers the construction of principles and the synthesis of a system of effective control over the processes of synchronization of generator sets (GSs) that form a part of the distributed MP-control systems for complex ship technical systems and complexes (STS and C). The tasks of synchronization have been set, the process and database models have been built, the system configurations have been defined. Based on the use of resultant functions, we have determined stages in solving the tasks of control over the frequency adjustment synchronization in a hierarchical sequence. The performance analysis of the STS and C control elements has been carried out; the use of the integrated optimization criteria and dual management principles has been proposed. Practical techniques to manage the GS synchronization have been given. We have solved the problem of high-speed control over the frequency of synchronized objects based on the principles of adjustment. That has made it possible to determine in advance the moments of GS enabling under the deterministic and stochastic statement of the synchronization task. The results of the experimental study into the GS synchronization processes are given; the effectiveness of the proposed GS control has been proven. The principles underlying the construction of procedures to control the GS composition when using the methods of "rigid" and "flexible" thresholds have made it possible to define the optimization criteria and implement a control law that satisfied the condition for an extremum, which is an indicator of the feasibility of the set goal and takes into consideration the limitations of control influences. We managed to design a system in the class of adaptive control systems by the appropriate decomposition of the system's elements by splitting a synchronization task into the task on performance and the task on control under the required conditions. The given examples of the processes where the synchronization failed while using standard synchronizer control algorithms, as well as processes of successful GS synchronization when applying the proposed synchronizer dual control algorithms, have confirmed the reliability of the main scientific results reported here.

Transient Performance Improvement in Reduced-Order Model Reference Adaptive Control Systems

The objective of model reference adaptive control systems is to drive the trajectories of an uncertain dynamical system to the trajectories of a given reference model capturing a desired closed-loop system performance. To this end, most adaptive control signals take the form ua(t) = −ŴT(t)σ(x(t)), where x(t) ∈ ℝn denotes the state vector of an uncertain dynamical system, σ:ℝn → ℝs denotes a known basis function, and Ŵ(t) ∈ ℝs×m denotes an estimation of the unknown weight matrix W ∈ ℝs×m satisfying sm update laws (here m denotes the number of control inputs). In this paper, we focus on a class of reduced-order, computationally less expensive, model reference adaptive control systems that are only predicated on a scalar update law. Specifically, our contribution is to utilize a command governor architecture in order to improve transient performance of this class of adaptive control systems. We prove the stability of the overall closed-loop system using Lyapunov stability theory and we also present an illustrative numerical example for demonstrating the efficacy of the proposed architecture.

On the asymptotic property analysis for a class of adaptive control systems with σ‐modification

SUMMARYWith the effect of σ‐modification in adaptive control systems, robustness is achieved at the potential expense of destroying some of the convergence properties. This paper proposes a qualitative analysis method for the situations where the σ‐modification may lead to perfect tracking and also, given the prior knowledge of system parameters, may allow proper modification of the adaptive algorithm. The applicability of the proposed analysis method is illustrated by two examples, where the system control gains that lead to global asymptotic convergence are given explicitly. Further, simulations are performed to verify the qualitative analysis results. Copyright © 2012 John Wiley & Sons, Ltd.

最適性に基づく適応制御系の再設計

A class of adaptive control systems which are not only asymptotically stable but also optimal or sub-optimal to some meaningful cost functionals, are derived. By relating Lyapunov functions with solutions of Hamilton-Jacobi (-Isaacs) equations, three types of adaptive optimal control problems are solved (Type 1/spl sim/3), and the adaptive /spl Hscr//sup 2/ (Type 2) and /spl Hscr//sup /spl infin// (Type 1 and 3) optimal (sub-optimal) control systems are constructed for generalized adaptive control problems.

Robust stabilization for a class of adaptive control systems with delayed state perturbations

Abstract The problem of robust stabilization for a class of adaptive control systems with delayed state perturbations is considered. An algorithm for direct adaptive control is proposed. Based on Lyapunov theory and Lyapunov-Krasovskii functional, it is shown that the closed-loop dynamical system resulting from the proposed adaptive control schemes is globally stable in the sense of uniform ultimate boundedness. Finally, a numerical example is given to demonstrate the validity of the results.

Stability of Control Systems with Local Adaptive Feedback Loops

This paper discusses stability of a class of adaptive control systems. The system considered consists of an adaptive block and non-adaptive blocks. The adaptive block is constructed by the conventional model reference adaptive control (MRAC) approach. Assuming the general properties of MRAC, sufficient conditions for the whole system to be stable are obtained.