Types Of Control Structures Research Articles

Control of new energy‐intensified triple column extractive distillation using feed split technique

AbstractBACKGROUNDHere, we investigated the control performance of extractive distillation intensified with ‘feed split’ (FS) technique – a process intensification technique that has not been widely applied to extractive distillation. Today, only a handful of studies have been reported on this topic, with only one focusing on the control performance and reporting the significant trade‐off between the steady‐state and dynamic performances. Nonetheless, the previous control study was based on the complex double column FS configuration. Recently, a new triple column FS configuration was reported (Sep. Purif. Technol. 2022 (297) 121467), but its control performance was not investigated. Hypothetically, the triple column FS configuration is less complex and does not involve any column integration and thus, may demonstrate a better dynamic performance. This study analyzed the control performances of the triple column FS configuration and the conventional configuration for the binary azeotropic separation of tetrahydrofuran and ethanol.RESULTSTwo types of control structures were examined for both configurations, i.e., the basic temperature control structure and the different feed forward temperature control schemes. The best control structure from each configuration is compared and findings showed that the conventional configuration provides better controllability performance.CONCLUSIONOur results suggested that the conventional configuration can bring the product qualities closer to their setpoint, while providing a lower transient deviation. © 2023 Society of Chemical Industry (SCI).

Design and Simulation of CNC Milling Machine on Matlab

The development and revision of milling machines and components are continuous. With the help of computer technology, we can simulate some activities in a manufacturing system. The main purpose of a simulation is to understand and imitate the behavior of a particular manufacturing system on a computer, before hardware creation, thereby reducing the amount of testing and experimentation in the field. By using a virtual system, less material is wasted and the constraints on the actual operation of the machine in the field can be minimized. In the field of milling machinery, various modeling and simulation methods have been introduced so far. Today, the manufacture of a machine tool can no longer use the time-consuming and costly manufacturing and testing of physical prototypes to detect weak points and then optimize the design. In contrast, the current machine tool design process uses "virtual prototyping" technology to reduce the cost and time of hardware testing and iterative improvements to physical prototypes. The model of a milling machine can be simulated in Matlab simulations through analytical methods using various compositions. The presented virtual modeling methods and milling machine tool simulations make it possible to design, perform complex analyses, test, optimize, and use various types of control structures. in the computer simulation.
 Keywords: Milling Machine, CNC Miling Machine, Matlab

Event-triggered flocking control of multi-agent systems in presence of cyber attacks

We propose an event-triggered control system for multi-agent systems with the double-integrator network to achieve resilient flocking behavior in the presence of cyberattacks. The method can manage connectivity and increase the robustness of the topology graph via a three-state hybrid control. Each state of hybrid control has a distinct triggering condition. The developed event-triggered update rules can mitigate the influence of the noncooperative agents using the weighted mean subsequence reduced algorithm and reduce unnecessary communication among them. As a result, the performance of the system can effectively improve. Convergence of the velocity and orientation of the agents is guaranteed by using this type of control structure and resilient consensus protocol. We assume that the bound on the number of noncooperative agents in the neighbor sets of cooperative agents is known. The proposed scheme with the event-triggering rules can avoid Zeno behaviors inherently. Finally, a simulation example is worked out to demonstrate the effectiveness of the proposed approach.

Realizing brachistochronic planar motion of a variable mass nonholonomic mechanical system by an ideal holonomic constraint with restricted reaction

The paper considers realization of the brachistochronic motion of a nonholonomic mechanical system, composed of variable mass particles, by means of an ideal holonomic constraint with restricted reaction. It is assumed that the system performs planar motion in an arbitrary field of forces and that it has two degrees of freedom. In addition, the laws of the time-rate of mass variation of the particles, as well as relative velocities of the expelled and gained particles, respectively, are known. Restricted reaction of the holonomic constraint is taken for the scalar control. Applying Pontryagin?s maximum principle and singular optimal control theory, the problem of brachistochronic motion is solved as a two-point boundary value problem (TPBVP). Since the reaction of the constraint is restricted, different types of control structures are examined, from singular to totally nonsingular. The considerations are illustrated via an example.

Detection of Control Structures in Spoken Utterances

State-of-the-art intelligent assistant systems such as Siri and Cortana do not consider control structures in the user input. They reliably react to ordinary commands. However, their architectures are not designed to cope with queries that require complex control flow structuring. We propose a system to overcome these limitations. Our approach models if-then-else, loop, and concurrency constructs in spoken utterances explicitly. The model bridges the gap between linguistic and programmatic semantics.To demonstrate our concept, we apply a rule-based approach. We have implemented three prototypes that use keyphrases to discover potential control structures depending on the type of control structure. However, the full structures are determined differently. For conditionals we use chunk and part-of-speech (POS) tags provided by natural language processing tools; for loops and concurrency we make use of an action extraction approach based on semantic role labeling (SRL). Additionally, we use coreference information to determine the extent of the respective structure.The explicit modeling of conditionals, loops, and concurrent sections allows us to evaluate the accuracy of our approaches independently from each other and from other language understanding tasks. We have conducted two user studies in the domain of humanoid robotics. The first focused on conditionals. Our prototype achieves F1scores from 0.783 (automatic speech recognition) to 0.898 (manual transcripts) on unrestricted utterances. In the second, the prototypes for loop and concurrency detection also proved useful. F1scores range from 0.588 (automatic speech recognition) to 0.814 (manual transcripts) for loops and from 0.622 (automatic speech recognition) to 0.842 (manual transcripts) for concurrent sections respectively.

CONTROL AND GRID SYNCHRONIZATION OF TWO LEVEL VOLTAGE SOURCE INVERTER UNDER TEMPORARY VOLTAGE UNBALANCE

This paper presents the operation of grid tied, two level voltage source inverter (VSI) during network voltage unbalance. The control system was implemented in synchronous rotating reference frame dq0 (SRF). Two types of control structures were investigated herein. First utilizes the Double Decoupled SRF Phase-locked loop (DDSRF-PLL) synchronisation with positive and negative sequence currents control. Second one is simplified system that does not provide symmetrical components decomposition and decoupling for synchronisation. Simulation results exhibited a superior performance of the DDSRF-PLL control system under grid voltage unbalance.

Smart Investment for Redundancies Selection Integrated to Reconfigurable Fault-Tolerant Control Design

This paper presents a methodology for the optimal hardware redundancies selection in the context of reconfigurable fault-tolerant control design. Assuming that a nominal controller of reduced dimension has been successfully designed, the objective is to accommodate a presumed set of failures, including partial, total, and simultaneous actuator faults, preserving the system stability and maintaining an acceptable dynamic performance. The methodology is based on a multiobjective optimization framework to obtain a suitable trade-off between conflicting design objectives such as controllability and performance. The selection of additional hardware devices (not included in the nominal controller) is penalized to determine the minimum number of redundancies that should be installed. In addition, the redundancies selection is performed without explicitly considering the type of control structure. The effectiveness of the proposed approach is tested using the well-known Tennessee Eastman benchmark.

Design of Neural Network Control System for Controlling Trajectory of Autonomous Underwater Vehicles

A neural network based robust control system design for the trajectory of Autonomous Underwater Vehicles (AUVs) is presented in this paper. Two types of control structure were used to control prescribed trajectories of an AUV. The vehicle was tested with random disturbances while taxiing under water. The results of the simulation showed that the proposed neural network based robust control system has superior performance in adapting to large random disturbances such as underwater flow. It is proved that this kind of neural predictor could be used in real-time AUV applications.

A tool for the collection of industrial software metrics data

A tool has been designed under Windows 3.1, which converts a 'C' software to its abridged version that lists program characteristics of interest to the metric researchers. These characteristics may be operators, operands lists, their frequency of occurrences, number of terminators, different types of control structures, internal and external variables, etc. This information may be useful for the researchers but prevents the reconstruction of the original source code.

Control Structures for a Sidestream Distillation Column Separating a Ternary Mixture

The distillation under study is that of an impurity which accumulates on intermediate trays due to the thermodynamics of the ternary system. Often a binary azeotrope between the impurity and one of the main products forces the sidestram to contain a significant amount of the main products. The resulting control problem is to minimize the sidestream flow (i.e. maximize main product recovery) while maintaining the two high quality end products. This control problem may be viewed as a three point control problem. This paper investigates first sensor selection with the goal of identifying the column states using relatively few sensors. Next actuators are selected with the goal of obtaining a control problem of low sensitivity. A simple strategy for controlling the location of the maximum concentration of the accumulating impurity is discribed and lowest control sensitivity is obtained for a (L,V)-type of control structure.

The evolution of control architectures for automated manufacturing systems

While there have been several control architectures proposed, a framework that identifies the relationships between such architectures has been missing. The purpose of this paper is to trace the evolution of control structures for automated manufacturing systems (AMS), identify the relationships between the architectures, and identify key design decisions that are affected by each type of control structure. AMS control architectures are defined, as are their importance as a critical design decision for automated manufacturing systems. The demands that automated manufacturing make upon a control architecture are discussed. Subsequently the four basic control architectures representing an evolution of design are presented. The characteristics, advantages, and disadvantages of each of the basic forms are reviewed. Examples are presented to highlight these attributes. The paper concludes with projections on possible future directions of control architectures.

The design tree: a visual approach to top-down design and data flow

Top-down design, an accepted technique for program development in most teaching environments, is an integral part of the introductory computing courses taught at Carnegie Mellon University. Although this planning technique works well for experts, it's application among less experienced users is limited: many novices abandon this technique as soon as implementation begins, focusing their attention instead on low-level details. This paper proposes a solution to this problem: the Design Tree, a simple graphic tool used to represent the top-down decomposition of a problem. This tool can be used by instructors, as well as students, independent of the software used to build their programs. The Design Tree not only facilitates top-down decomposition of problems, but also help students decide what type of control structures and data flow to use in implementation.

Types of control structure in expert systems

Types of control structure in expert systems

Types of control structure in expert systems

The concept of an expert system covers an increasingly large group of software packages which often have more dissimilarities than points in common. We shall not attempt to give a precise definition of an expert system here, because this might impose too restrictive a framework on the rest of our discussion. We shall simply state that, as is generally recognized, an expert system is a piece of software intended to resolve a certain category of problems, that it uses for this purpose a large quantity of knowledge specific to the field in question, and that in each expert system there is a very distinct separation between this knowledge and the procedures which make use of it.

Types of Control Structure in Expert Systems

The concept of an expert system covers an increasingly large group of software packages which often have more dissimilarities than points in common. We shall not attempt to give a precise definition of an expert system here, because this might impose too restrictive a framework on the rest of our discussion. We shall simply state that, as is generally recognized, an expert system is a piece of software intended to resolve a certain category of problems, that it uses for this purpose a large quantity of knowledge specific to the field in question, and that in each expert system there is a very distinct separation between this knowledge and the procedures which make use of it.

Market versus Mandator. Control Structure and Strategies for Change in School Organizations1

Abstract Berg, G. 1984. Market versus Mandator. Control Structure and Strategies for Change in School Organizations. Scandinavian Journal of Educational Research 28, 49‐70. An organization's activities are a function of the external control originating in its environment and the internal control regulating the interaction of its various component parts. In other words, an organization is shaped by its external and internal control structures. The nature of this control varies from one organization to another, the character of the control structure being dependent on the tasks or functions the organization is there to perform. It is argued that the type of control structure existing determines (a) what theoretical model has the greatest explanatory value in an analysis of phenomena occurring in a specific organization, and (b) what strategy for change corresponds to the control structure in question. 1 This article was originally presented at two conferences: Conference on the relationship between educatio...

Inferring control structures from the behaviour of a production system

A control structure for production systems derived from the control structure of a programmed grammar is introduced. This type of control structure is proved to be more general and flexible than the classical control structure based on the concept of a Markov Normal algorithm. A method is discussed for inferring a control structure consistent with the observations of the behaviour of a production system whose rules are known. Finally, some criteria are given for choosing a suitable control structure from the set of control structures actually inferred.

Experimental Investigations of Computer Program Debugging and Modification

Although greater emphasis is placed on the task of computer program composition, debugging and modification often consume more time and expense in production environments. Debugging is the task of locating syntactic and semantic errors in programs and correcting these errors. Modification is the change of a working program to perform alternate tasks. The factors and techniques which facilitate debugging and modification are poorly understood, but are subject to experimental investigation. Controlled experiments can be performed by presenting two groups of subjects with two forms of a program or different programming aids and requiring the same task. For example, in one study we presented an 81 line FORTRAN program containing three bugs to distinct groups of subjects. One of the groups received a detailed flowchart, but our results indicated that this aid did not facilitate the debugging procedure. Similar negative results were obtained for a modification task. In other experiments, comments and meaningful variable names were useful in debugging and modularity facilitated modification. Other potentially influential factors, which are subject to experimental study, include indentation rules, type of control structures, data structure complexity and program design. These and other human factor experiments in programming have led to a cognitive model of programmer behavior which distinguishes between the hierarchically structured, meaningfully acquired semantic knowledge and the rotely memorized syntactic knowledge. Errors can be classed into syntactic mistakes which are relatively easy to locate and correct and two forms of semantic mistakes. Semantic errors occur while constructing an internal semantic structure to a representation in the syntax of a programming language. Modification is interpreted as the acquisition of an internal semantic structure by studying a program, followed by modification of this structure and revision of the code.

Nested Interpreters and System Structure

The paper treats the problem of nests of interpreters i.e. multiple levels of interpretation of programs. The goal of the paper is to expose a control structure which models the important characteristics of such nests. Using a comparison with the Burroughs B6700 philosophy, a more general system model is introduced. There are two major results - a new type of control structure, and the conclusion that generalized nests perforce require retained environments.