Control Software Package Research Articles

Model-based control - a hydroinformatics approach to real-time control of urban drainage systems

This paper describes a new approach to real time control of urban drainage systems: model-based control. A hydrodynamic numerical model is included in the control loop to provide information about the expected situation. The introduction of the numerical model not only changes the level of information available, but also the way in which it is applied. It allows for a more dynamic control where more control strategies can be analysed. It also promotes global control, in which the situation of the entire urban drainage system is taken into account. A software package for model-based control, MOUSE ONLINE, is described.

MVS Integrity: The Intruder's Point of View

Although IBM offers three operating systems for use on its mainframe, Multiple Virtual Storage (MVS) is considered the workhorse. MVS is used by the majority of large corporate data centers to support batch and online production applications, and it generally supports the most stringent security requirements. Indeed, IBM has issued a statement claiming that there are no known integrity exposures in MVS. MVS has become more powerful and efficient with each new release; however, it offers only limited native features for both sign-on security (verifying the identity of potential users) and resource protection (restricting access to data and other system resources to particular users). Most MVS installations have purchased access control software to provide this additional level of security. Currently, three access control software packages dominate this market: IBM's RACF, and Computer Associates' two products, CA-ACF2 and CA-TOP SECRET.

The Weak Link in Distributed Data Base Security

The architecture of data bases has changed significantly in recent years in response to changes in the needs of users and in the underlying technologies. Changes in microprocessor design have made powerful personal workstations commodity items; network and multimedia capabilities have become commonplace. The development of innovative distributed data bases is one of the major consequences of changes in these enabling technologies. The period of 1980 to 1988 was the era of the centralized data base. Data base administrators extolled the virtues of centralizing data and of removing physical and logical redundancies. Large integrated IMS, IDMS, and other data bases were developed at great effort and expense. Software vendors, in turn, developed new tools and techniques for securing these centralized data bases. For example, extensions to such major access control software packages as RACF and CA-ACF2 were introduced. The era of the distributed data base, which began in 1988 and continues to the present, has necessitated the development of new control tools and techniques.

Computer simulation of the Sherritt nickel-copper matte acid leach process

The Sherritt acid leach process has been used in several locations for the recovery of nickel and copper from high-grade mattes, in order to produce a concentrated platinum group metals residue. Process steps include matte grinding, atmospheric leaching, pressure leaching, residue filtration, selenium removal, copper electrowinning, and nickel sulphate crystallization. Since 1987, computer simulation of the acid leach process has been utilized for process design, operability and control studies, control system testing, and personnel training. Material balances and dynamic simulations were generated on an IBM compatible personal computer, using flowsheet simulation software capable of communicating with other computers. A PC-based process control software package was also used to develop an operator console for the simulator, as a tool for personnel training. This paper presents an overview of the development and application of computer simulation for this process.

An Integrated System for Supervisory Process Control using ADA

The paper presents an integrated software package for supervisory process control using ADA language. This system performs process control using classical and heuristic controllers, supervision in order to detect abnormal situations and on-line monitoring. Using ADA language, the definition of the different processes (control, supervision and monitoring) can be easily implemented using the concurrent programming techniques inherent to the language. Specifically, a rule-based system which compensates for dead-zone phenomena in a position control servomechanism is developed. The supervisor module is designed to detect and avoid undesirable on-linear control phenomena such as steady state errors, limit cycling or excursions into unwanted zones. It constitutes an intelligent compensator for system input nonlinearities which may be generalized to other non-linearity types.

Automated Serials Control for Special Libraries

Abstract This paper describes briefly the features which are common to the Serials Control software packages which are available in Australia at present. It also describes some of the less common features which are available in some packages.

Programmable logic controllers find a home in wastewater treatment

Efforts to computerize wastewater treatment plants have had mixed results. A wastewater treatment plant presents significant obstacles to computer automation. One of the most challenging problems is coping with the aggressive environment of the plant. Industrially hardened programmable logic controllers (PLCs) have found a home in the wastewater treatment field. These small, reliable, and rugged computers are gaining acceptance in this conservative industry. Standard process control and data acquisition software packages are available from most PLC manufacturers for use on a supervisory personal computer workstation networked to their PLCs. In addition, similar third-party generic software packages, which support the PLCs of multiple manufacturers, can be procured. These packages provide functions such as interactive graphics, database, trending, historic storage, and report generation. Networks containing personal computers and PLCs offer an attractive alternative to the conventional large distributed computer system (DCS). A compomplex PLC network can equal a DCS in capability, while a simple PLC network can offer fast, reliable control of a single process. In each case, PLCs offer the advantage of a rugged input/output (I/O) system designed for the factory floor. Process control applications with fail-safe provisions are suitable to PLCs and can be demonstrated throughout the plant. Although they are industrially hardened, caution must be exercised in the application of PLCs. The corrosive nature of the atmosphere at a wastewater treatment plant still presents challenges. However, properly installed, PLCs maintain their reputation for reliability.

The control system for the TISOL facility at TRIUMF

We describe the control system of the on-line isotope separator test facility TISOL at TRIUMF. The system uses OPTOMUX hardware for interfacing to devices and an IBM PC as control computer, which also provides the user interface. A short description of the TICS control software package is also given.

The new secondary channel control system at TRIUMF

The control of the secondary channels at TRIUMF has been decentralized. Each channel is now controlled through a single CAMAC crate from an IBM PC in the experimental counting room. Intelligent motor controllers were developed to replace the ageing slit control system. Advanced features of the control software package TICS, such as computer optimization of channel parameters and high-voltage conditioning of the de separators, are described.

Expert Control System for Rougher Flotation of Phosphate

The parameters of a detailed phenomenological flotation model for the rougher flotation bank have been evaluated performing large steady state sampling in the plant. The dynamic model has been used in simulation of the operation of a rougher flotation bank, as a step in development of expert control of a larger flotation system. The simulator has been interfaced with the ONSPEC control software package run in the IBM DOS environment, the software for flotation circuit simulation and expert control system design is described. The control strategy tested by simulation aims to maximize the recovery, while the concentrate grade is maintained above a given minimum level. The determination of the manipulated variables hierarchy of the bank is described and the simulated results of expert control are presented.

Advanced Portable Control Station

A new data acquisition and control software package for IIP 9000/300 series UNIX workstations is presented. Four simultaneously running tasks take care of data acquisition, control, on-line graphics, and online parameter changes. The portable control station is meant for demanding on-site measurement and control tasks. Most of commercial digital automation systems are too inflexible for advanced control implementations. Commercial software for microcomputers is also quite limited, emphasizing more signal analysis than control.The paper also reviews single-input single-output (SISO) and multivariable (MIMO) control algorithms implemented in the software. Both fixed parameter (SISO PID, MIMO PID) and self-tuning algorithms (SISO STC, MIMO PI) are available. Experiments with a MIMO self-tuning Pl-controller were performed at a laboratory-scaled head box of paper machine at Tampere University of Technology. Tests on a DC-servo motor were also carried out, using a SISO-PID controller and a STC.

Practical Issues in the Implementation of Adaptive Controllers

Adaptive controllers have been extensively studied and developed mainly from the theoretical point of view, Some Commercially adaptive controllers exhibite simp1e performances and are suitable for special purpose applications, such as PID initial Payameters setting or autotuning.In a software package for process digital control, the control algorithm itself is a reduced part of the written code, most of it being devoted to communications, alarms treatment and information handling. So, if time constraints are not very severed, the adaptive control algorithm can be enlarged with supervision features, allowing a correct and safe operation. In the paper, experimental results from the use of a package for the mill control in a cement factory are reported. The available options include PID control and indirect adaptive control with RLS parameters estmation and a variety of control approaches, such as pole placement, minimum variance and finite setting time.The adaptive control may be also supervised, and the most significative parameters of the adaption scheme are remarked.Discussion of these results point out the appropriatness of the different control algorithms according to the dynamics of the process model.

A Simulation Study of Expert Control System for A Phosphate Flotation Process

The parameters of a detailed phenomenological flotation model have been evaluated by steady state testing. The dynamic model has been used in simulation of the operation of a rougher flotation cell, as a step in development of expert control of a larger flotation system. The simulator has been interfaced with the ONSPEC control software package run in the IBM DOS environment. The control strategy aims to maximization of the recovery, while the concentrate grade is maintained above a given minimum level. The hierarchy of manipulated variables of the cell is described and the simulated results of expert control are presented.

Use of State Observers for Control and Profile Estimation of a Large Scale Nitric ACID Absorption Column

For nitric acid plants, UHDE has developed a software package for optimization and control during operation. The individual program modules comprehend tasks for optimal continous control, medium term production scheduling and online process monitoring for predictive maintenance.Within this system a state observer is used for the estimation of the acid composition profile in the absorption column. A second observer is part of the control system for the acid concentration in the product flow. The profile estimator is based on a detailed nonlinear high order thermodynamic model of the absorption process. For control, a very simple model based on a global balance equation of the plant and lumped dynamics proved to be sufficient. Model parameters are estimated in addition to the state variables by both observers to ensure steady state accuracy and convergence.

Species preservation in an optimal harvest model with random prices

In this paper, we consider an optimal harvest model in which the objective is to maximize the expected return. The unit price of biomass is assumed constant until a random time when the price increases by a given amount. Furthermore, due to obvious environmental protection requirements, it is assumed that the fishery population is bounded from below for all time so as to reduce the danger of species extinction. Clearly, this problem is an optimal control problem in which a random parameter is involved. However, due to its special structure, it is shown that the problem is convertible into a deterministic optimal control problem and hence is solvable by an existing optimal control software package, MISER. The practical implication of several computed results obtained by this approach is discussed. They are also compared with other related results in the literature.

Example applications of the partial state model reference adaptive design technique

AbstractThis paper presents an implementation methodology for adaptive control schemes. The latter have been developed bearing in mind the available theoretical results as well as the practical requirements. This leads to an adaptive control software package which can run on several digital computers, including the IBM‐PC and compatibles. Simulation results involving two adaptive control benchmarks are presented.

AutoTool I: A Human Focus on the Development of Software for Tool Control

A software package for wet process tool control (AutoTool) developed to provide the capability for flexible, user-oriented manufacturing tool control, is described. The conception and communication of the system design, from user to engineer to programmer, is detailed. The program structure of AutoTool is described with respect to functionality. Special emphasis is given to the user interface.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

A Simulation Study of Expert Control System for Flotation

Computer aided control system design (CACSD) has become very common during the last ten yea*rs. Even the use of these software packages for the design of the control strategies which use the conventional Single Input Single Output (SISO) controllers has shown to be a powerful tool for a control engineer. In the current paper a simulation study of control strategies for the flotation process is presented. The derivation of a dynamic model to simulate the flotation process is described. The interfacing of this simulator with the ONSPEC control software package is discussed. Differences between the classical PID-control strategies and the expert strategy designed using this software for the flotation process are discussed.

AutoTool I: a human focus on the development of software for tool control

A software package for wet process tool control (AutoTool) developed to provide the capability for flexible, user-oriented manufacturing tool control, is described. The conception and communication of the system design, from user to engineer to programmer, is detailed. The program structure of AutoTool is described with respect to functionality. Special emphasis is given to the user interface.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

Hardware and software for reconstruction of electron density vs height distribution

A description of the hardware and software comprising ionosonde “Basis”, IVK-2 and a software package for ionosonde control, data entry and the processing of ionograms is given. This software permits an N(h) profile to be produced in 5 minutes. The program that reconstructs the electron density height distribution is based on the ITERAN program developed by Gulyaeva. The modified program allows operation on a CM-4 computer and is able to calculate the electron density in the interlayer region.