Control System In Order Research Articles

Roadstone aggregate: An intelligent route to computer integrated manufacturing

Cone crushers are used in the production of aggregate for use in roadmaking and other industries. The U.K. aggregate industry produces around 240 Mtonnes/year involving an energy consumption of some 4.8 TWh/year from the National Grid. This is estimated at an annual figure of around 3% of all electricity generated in the U.K. A programme of work has been carried out concerning the CIM of aggregate. This paper describes the automation of the crusher adopting a mechatronic approach utilizing distributed control and incorporating heuristic knowledge of rock mechanics. Rigorous specifications exist for finished aggregate. Classification of the produced aggregates is of paramount importance for feedback to the crusher control system in order to adjust continuously the operational parameters. A product sampling system digitizes the particle geometry, processing algorithms extract dimensional data and image features while a neural network classifier assigns a qualitative shape descriptor to each particle. The new measurement and control system, incorporating several novel sensors, has proved highly effective in trials, validating the approach for a single crusher. The concept may now be extended to provide a CIM environment for a whole quarry circuit consisting of primary jaw crushers and cone crushers used for the secondary and subsequent stages.

An Overall Machine Monitoring and Maintenance Management System

For years, machine diagnosis systems give an important contribution to the rationalization of the maintenance department. In the article at hand a system is introduced which meets the special demands of transport vehicles in coal mining. Its basic functionality, however, can be adapted to other industrial applications. The diagnosis system goes together with a Maintenance Planning and Control System in order to get a data management which is free of contradictions and redundancies.

Mining robotics: Application of computer vision to the automation of a roadheader

Automation of mining operations involves the use of sensing, remote monitoring and control systems in order to confront a variety of situations and environmental conditions. The need of profitability of a mine sometimes requires that selective cutting be performed in order to separate rich ore from waste at the cutting stage. Basically, the problems to be solved are those of modelling an uncontrolled, changing mine environment and programming the machine to cut a pattern accordingly. We present in this paper how image segmentation and classification, 3-D scene perception and path planning can cooperate to solve such a complex problem as selective cutting.

Establishing Human Factors Criteria for Space Control Systems

This paper describes the development of a human factors methodology and its application to the operational test and evaluation of space control systems. The method uses a correlational approach to link human factors measures to the mission effectiveness of space control systems. Experiment 1 describes an initial wide-spectrum attempt to identify human factors predictors of system performance. Based on the results of Experiment 1. the human factors measures and analysis method were refined and applied in the test of an operational satellite control system in Experiment 2. Experiment 3 applied the same methodology to a different satellite control system in order to determine the generalizability of the approach. The methodology worked with more than one system and was robust with respect to changes in personnel and location. The methodology was sensitive to changes in software, hardware, and procedures, and it yielded data that correctly reflected those changes.

Simulation and Optimisation of a Manufacturing Control System Using Real Operating Data

This paper describes the computer simulation of the requirements planning and capacity planning functions of a real and live manufacturing control system in order to optimise the operating parameters. The manufacturing control system simulation study examines the relationship between the master production schedule, batching rule, and capacity requirements. The results show the need to optimise system parameters to obtain maximum benefits from a manufacturing control system, and the need for continuous appraisal. The importance of using real operating data from a manufacturing control system for simulation studies in order to optimise the system performance is also demonstrated.

Time optimal control for induction motor servo system

A time-optimal position control scheme based on Pontryagin's minimum principle is proposed for a current-source-inverter (CSI) fed induction motor system. The induction motor with field-oriented control is modeled with a fast time-optimal position control system of second order which has two modes of operation: the first bang-bang mode operates until the position is close to target, followed by second DC braking mode which gives asymptotic stability. In order to realize this aim, the time-optimal controller is added instead of the speed controller to the conventional field oriented control loop of the CSI-fed induction motor. The validity of the time-optimal control solution has been verified by an experimental test. Experimental results are in close agreement with a digital simulation.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

Adaptive Predictive Control of a Boiling Water Reactor

This paper reports on an adaptive predictive control system (APCS) is applied to the design of the recirculation and feedwater control systems of a boiling water reactor. The APCS uses the dead zone method to modify the adaptive law; thus, it is stable in the presence of unmodeled dynamics and bounded disturbances. Two single-input/single-output control systems are used instead of a multi-input/multi-output control system in order to simplify parameter adaptation. The interactions among the subsystems are treated as unmeasured disturbances. A simulation using the reactor model shows that the dome pressure versus recirculation pump speed subsystem is a non-minimum-phase system. To handle this system, the weighting polynomials for the system input and output are incorporated to form an augmented minimum-phase system and then the augmented system is controlled. The proposed algorithm is stable, does not require persistent excitation of the reference input, and performs well, which makes it practical for implementation.

Development of simultaneous optimum design of structural and control system of flexible structures.

This paper presents a new approach to the simultaneous optimum design of a structural and control system in order to realize an increasing number of elements. For simplicity, we take up a flexible beam as a dynamic model which based on the Euler-Bernoulli theory. The lateral vibration of beam is controlled under given disturbance. For simplicity, the transformation ratio of cross-sectional area is taken as a structural design variable. In this way, the number of the structural design variable is only one in spite of the increasing number of elements. However, the shape of the structure is limited. The location of the sensor and actuator is taken as a control design variable. These two design variables are optimized to minimize a performance function composed of kinetic and control energy. In the numerical examples, it is shown that the simultaneous optimum design of the structural and control system is useful.

A new open GKS-based supervision system in use at GANIL

Since the beginning of 1989, a new supervision system has been added to the GANIL control system in order to get a better view of data handled by programmable controllers. This supervisory system has been designed around software named IMAGIN, provided by the French company Sferca IMAGIN runs on VAX/VMS workstations and its graphic capabilities are based on the GKS IIc standard. It consists of software modules, including a graphic editor and a “configurer” used to create dynamic objects associated with external variables. The real-time display achieved by an “animator” process is synchronized with user software programs by means of mailboxes. This gives the whole system the capability of meeting any specific requirement. Moreover, this supervisory system is capable of controlling the programmable controllers as well as any processor which can be reached from the workstations. This paper describes the main features of IMAGIN software and then emphasizes some implementations which have been carried out at GANIL, to supervise either the programmable controllers or the existing control system.

OT&amp;E Service Report Classification

Many problems encountered during operational test and evaluation of Air Force systems are described in service reports, an important element in the communication of test findings to the system acquisition community. Since many service reports cite deficiencies in the man-machine interface, service report data are an important source of human factors information. However, they are not readily integrated with other test data because of their qualitative character. This paper describes attempts to classify service reports from two complex command, control and communications type systems in order to make the data more usable. Classification schemes emphasizing (1) likely engineering solutions to the problems and (2) human activities affected by the problems were applied. Classification results were consistent with known characteristics of the system, and revealed interesting trends in the data. Some support was obtained for both the reliability and validity of the classification schemes as well. Implications of the results for service report analysis are discussed.

Introducing Nurses to Computers in a Multi-hospital Environment

Implementing an Order Control System provides for automated communication of patient orders and charges.

A set covering approach to metallurgical grade assignment

Early in 1986 Bethlehem Steel Corporation installed two continuous slab caster machines to modernize the steelmaking facilities at two of its major plants. The installation of this equipment, at a total cost of about half a billion dollars, required accompanying production planning and control systems (PPC) in order to function efficiently. The PPC module responsible for assigning metallurgical grades to customer orders uses a minimum cardinality set covering approach which not only minimizes the number of metallurgical grades required to satisfy a given collection of customer orders, but also is able to ‘show preference’ to priority orders. The algorithm, Optsol is used in a two-pass mode to quickly generate very good solutions to these large scale (up to 1000 zero-one variables and 2500 constraints) problems. When compared to the traditional method of grade assignment, this approach has the potential to significantly improve caster productivity and to reduce semi-finished inventory.

Feedback stabilization of single-input nonlinear systems

Nonlinear geometric techniques (partial feedback linearization) and center manifold theory allow to reduce the design of a feedback stabilizing control for single-input nonlinear systems into a lower dimensional stabilization problem. The reduced order control system is explicitly constructed.

Electrodeposited Metallic Superlattices

ABSTRACTElectrochemical deposition of artificial compositionally modulated superlattices is described. It is shown that the quality of these alloys is comparable or superior to materials produced by vapor deposition or sputtering. The ambient temperature process described by Yahalom has been modified to include a feedback and control system in order to compensate for natural convective disturbances in the electrolyte. Data is presented for copper-nickel samples of varying wavelengths down to 2 nm which suggests that magnetic properties of thin nickel layers are comparable with bulk nickel. Alloys of other types whose properties can be tailored on a near atomic scale will also be discussed along with potential applications.

Chapter 31 Noradrenergic and cholinergic mechanisms responsible for the gain regulation of vestibulospinal reflexes

Experiments performed in precollicular decerebrate cats have shown that dorsal pontine structures, including the LC and the related dorsal pRF, play an important role not only in the control of posture but also in the gain regulation of the VS reflexes. The LC neurons, which are not only noradrenergic but also NE-sensitive due to the existence of self-inhibitory synapses acting on a2-adrenoceptors, send inhibitory afferents to the dorsal pRF; on the other hand, these pontine reticular neurons, which are presumably cholinergic as well as cholinoceptive due to the existence of self-excitatory synapses, project excitatory afferents to the medullary inhibitory RS system. The increased discharge of these pontine reticular neurons and the related inhibitory RS neurons following local injection of cholinergic agonists into the dorsal pRF decreased the postural tonus in the ipsilateral limbs but greatly enhanced the amplitude of the EMG modulation and thus the response gain of ipsilateral limb extensors to labyrinth stimulation. This finding did not depend on the decreased postural activity, since it was still observed when the EMG activity was reflexly maintained by an increased static stretch of the muscle. Similar results were also obtained when the discharge of the pontine reticular neurons and the related inhibitory RS neurons was raised after local injection of an a2-adrenergic agonist into the LC, leading to functional inactivation of the noradrenergic LC neurons. On the other hand, an increased postural activity in the ipsilateral limbs as well as a reduced gain of the corresponding VS reflexes were obtained when the discharge of the pontine reticular neurons and the related inhibitory RS neurons was reduced, as shown after local injection of cholinergic agonists into the LC leading to activation of the noradrenergic neurons. There was also evidence that cholinergic excitatory afferents to the LC originated from the ipsilateral dorsal pRF. The effects described above were dose-dependent as well as site-specific, as shown by histological controls. In conclusion, the pontine structures described above operate as a variable-gain regulator acting at the motoneuronal level during the VS reflexes. Since the same structures are also responsible for the spontaneous fluctuations in posture related to the sleep waking cycle, they may well intervene as a control system in order to adapt to the animal state the response gain of limb extensors following labyrinth stimulation.

An Adaptively Controlled Electrohydraulic Servo-Mechanism: Part 1: Adaptive Controller Design

A systematic model reference adaptive control design scheme is presented. The control scheme is developed and analysed within the framework of a sampled data system with a parameter adaptive algorithm designed on the basis of hyper stability theory. A number of supervisory functions are used to supplement the basic adaptive control system in order to enhance robust controller action.

Compensation of a Second-Order Control System with a Variable Nonlinear Characteristic using a Microprocessor

Several cases of a compensation technique for a second order control system are described based on the idea of displacement of the equivalent Nyquist critical point during the system operation. The displacement of the Nyquist point is achieved by changing the characteristic of a nonlinear network constructed by means of a microprocessor. The time instants when the change occurs are properly selected so that the time response characteristics are improved.

Effective Management of Engineering Design

The effectiveness of project management has a significant impact on the success and profitability of the results achieved. Sophisticated project management computer systems with enormous appetites for manhours are often used instead of effective management of the essential components of the project. Excellent project managers recognize that they will have unparalleled opportunities during the next several decades as the market increasingly recognizes the positive impact which they can have on results. These project managers will motivate, plan, schedule and control team members, their productivities and the project with simple, rather than complex systems. They will organize their teams and ensure that the team's interfaces with clients and customers are carefully managed. They will combine their ability to manage people with effective planning, practical control and meaningful reward systems in order to deliver results on budget and on schedule. Experience and effectiveness, increasing productivity, prof...

Fault-Tolerant and Fail-Safe Microcomputer Systems for Modern Automatic Process Control by Redundancy

Fault-tolerant automation subsystems have to be added to a modern distributed process control system in order to fulfill the most stringent requirements in view of reliability and safety of process control. The paper describes design features and experience with both new 1-out-of-2 hot standby system and 2-out-of-3 system, each one operating in a fully synchronized mode. The subsystems have the same scope of functions as a basic non-redundant system and are suitable for non-stop process control. Operator communication, observation and configuration can be carried out either from a central control room via a bus system and special operating subsystems, or from a direct coupled local operating station.

Metabolic profiles of rats of different ages

Urine samples from 6- to 31-month-old male Fischer F344 rats were analyzed using a high performance liquid chromatograph and a unique computer-based data analysis and quality control system in order to discover substances that could be used as markers in the aging process. Metabolic profiles of the organic acids from these urines yielded 42 peaks whose areas could be measured reliably. Of the 42 peaks, 10 were found by analysis of variance to vary significantly (p < 0.05) with age. Rats from the four ages could also be distinguished using a multivariate statistic (discriminant analysis).