On-line Automatic Control Research Articles

Sensory Prediction of Limb Movement Is Critical for Automatic Online Control.

Fast, online control of movement is an essential component of human motor skills, as it allows automatic correction of inaccurate planning. The present study explores the role of two types of concurrent signals in error correction: predicted visual reafferences coming from an internal representation of the hand, and actual visual feedback from the hand. While the role of sensory feedback in these corrections is well-established, much less is known about sensory prediction. The relative contributions of these two types of signals remain a subject of debate, as they are naturally interconnected. We address the issue in a study that compares online correction of an artificially induced, undetected planning error. Two conditions are tested, which only differ with respect to the accuracy of predicted visual reafferences. In the first, “Prism” experiment, a planning error is introduced by prisms that laterally displace the seen hand prior to hand movement onset. The prism-induced conflict between visual and proprioceptive inputs of the hand also generates an erroneous prediction of visual reafferences of the moving hand. In the second, “Jump” experiment, a planning error is introduced by a jump in the target position, during the orienting saccade, prior to hand movement onset. In the latter condition, predicted reafferences of the hand remained intact. In both experiments, after hand movement onset, the hand was either visible or hidden, which enabled us to manipulate the presence (or absence) of visual feedback during movement execution. The Prism experiment highlighted late and reduced correction of the planning error, even when natural visual feedback of the moving hand was available. In the Jump experiment, early and automatic corrections of the planning error were observed, even in the absence of visual feedback from the moving hand. Therefore, when predicted reafferences were accurate (the Jump experiment), visual feedback was processed rapidly and automatically. When they were erroneous (the Prism experiment), the same visual feedback was less efficient, and required voluntary, and late, control. Our study clearly demonstrates that in natural environments, reliable prediction is critical in the preprocessing of visual feedback, for fast and accurate movement.

Microwave method of nondestructive control of thermal characteristics of building material

A contactless microwave method and corresponding information-measuring system (IMS) for determination of thermal and physical characteristics thermal and physical characteristics (TPH) of building materials and products are considered. The method provides microwave heating of the samples by exposing the surface of the sample to electromagnetic field of the microwave range through a circular area, as well as temperature control of the environment and in the center of the circle. A microprocessor-based IMS system developed for practical implementation of the proposed method provides determination of the thermal and physical characteristics of the objects under study with high accuracy. A possibility of on-line automatic control of all operations of the thermophysical experiment, as well as the control of heat losses to the environment from the surface of the circular spot subjected?? to microwave heating and the timely correction of those losses to improve the accuracy of the final results is a distinctive feature of the system. Analysis of the calculated and experimental data showed that the elimination of the impact of the contact thermal resistance arising between the surfaces of the sample and the heating element on the determination of the desired thermal characteristics increases the accuracy of the method by 6— 8 %. The developed method allows more accurate determination of the thermal characteristics compared to other known techniques and can be used in practice of general thermal measurements and thermal engineering for construction.

Two Paradigms on Study Slab Continuous Casting Process with Mold Electromagnetic Stirring

Electromagnetic stirring (EMS) is an efficient technology to control the flow structure in slab continuous casting mold. But there is still an important opened problem to be answered firstly, that is, what kind of flow structure is our goal by using electromagnetic stirring in order to get good casting products, and how to optimize the flow fields in slab continuous casting mold with EMS? Two kinds of research paradigms are proposed in this study. One is based on causal relationship between the flow field and its effects on the mold flux entrapment and solidification process. Two parameters, named Mold Flux Entrapment Index and Velocity Uniform Index were proposed in order to evaluate the flow field in the mold. Based on these two indexes, optimization stirring parameters were proposed under different casting situation. The other research paradigm is machine learning big data model based on correlation analysis of nearly all the input parameters of casting machine and slab quality as an output parameter. Data acquisition from the continuous casting machine, data mining by machine learning algorithms and online automatic control parameters output are three main aspects in the second research frame.

Cerebellar contribution to spatial realignment: A tDCS study during multiple-step prism adaptation

Several processes are devoted to error reduction in response to a visual displacement, such as the one induced by wedge prisms. Strategic calibration and spatial realignment contribute to the iteratively process that allows a progressive adjustment of motor commands to reduce the magnitude of errors. Isolating the specific contributions to motor behaviour coming from these distinct processes is not possible using traditional single-step Prism Adaptation (PA), where participants are directly exposed to full prismatic shift. Here, we selectively investigated the effect of realignment on motor behaviour by means of a PA paradigm (the multiple-step PA) that allows to elude the development of strategic calibration. We tested for a specific cerebellar contribution to realignment by means of transcranial Direct Current Stimulation (tDCS) in healthy subjects. Confirming and expanding previous imaging and stimulation results, our study causally demonstrates cerebellar involvement in spatial realignment. Additionally, our results point to a possible contribution of the cerebellum in automatic online control. The role of a cortico-cerebellar network accounting for this results and possible clinical applications are proposed and discussed.

Use of artificial intelligence in the production of high quality minced meat

A design for an automatic line for minced meat production according to new production technology based on an innovative meat milling method is proposed. This method allows the necessary degree of raw material comminution at the stage of raw material preparation to be obtained, which leads to production intensification due to the traditional meat mass comminution equipment being unnecessary. To ensure consistent quality of the product obtained, the use of on-line automatic control of the technological process for minced meat production is envisaged. This system has been developed using artificial intelligence methods and technologies. The system is trainable during the operation process, adapts to changes in processed raw material characteristics and to external impacts that affect the system operation, and manufactures meat shavings with minimal dispersion of the typical particle size. The control system includes equipment for express analysis of the chemical composition of the minced meat and its temperature after comminution. In this case, the minced meat production process can be controlled strictly as a function of time, which excludes subjective factors for assessing the degree of finished product readiness. This will allow finished meat products with consistent, targeted high quality to be produced.

Automatic online control of motor adjustments in reaching and grasping

Following the princeps investigations of Marc Jeannerod on action–perception, specifically, goal-directed movement, this review article addresses visual and non-visual processes involved in guiding the hand in reaching or grasping tasks. The contributions of different sources of correction of ongoing movements are considered; these include visual feedback of the hand, as well as the often-neglected but important spatial updating and sharpening of goal localization following gaze-saccade orientation. The existence of an automatic online process guiding limb trajectory toward its goal is highlighted by a series of princeps experiments of goal-directed pointing movements. We then review psychophysical, electrophysiological, neuroimaging and clinical studies that have explored the properties of these automatic corrective mechanisms and their neural bases, and established their generality. Finally, the functional significance of automatic corrective mechanisms–referred to as motor flexibility–and their potential use in rehabilitation are discussed.

Image Analysis Technique as a Tool for Extracting Features from the Copper Surface Froth in the Flotation Process

The froth can be adopted as an indicator of the performance of flotation processes. The study of froth image structure would enable us to establish a number of parameters from which could convey the froth characteristics. To monitor the operating performance of the floatation cell by machine vision system, it is crucial to identify and extract those features that are descriptive of the surface froth. Consequently, it can provide interdependency between the froth characteristics with the operating conditions on one hand (e.g., aeration rate, froth depth, chemical compound and pH variation) and the cell parameters performance on the other hand, as well (e.g., copper grade, recovery and solid contents). The aim of the present study is to examine the copper froth characteristics, by adopting an image analysis technique and hence evaluating froth features such as the average bubble size, bubbles distribution, bubble shape features, bubble elongation factor, image average color and the color distribution. Owing to the intricacy aspect of the froth structure and in order to match properly between the real froth and the segmentation images, this algorithm adopts features similar to proper filters in the pre-processing stage, edge detection functions, threshold functions and different mathematical morphology models. The findings of this work reveal that the size and shape of the froth bubbles plays an important role in classifying the froth. Hence, it is possible to incorporate such features for either evaluating the flotation cell performance or adopting it for the automatic on-line control of the flotation process. The findings of this research could also be implemented towards the training of the operators.

Movement duration does not affect automatic online control

Pisella et al. (2000) have shown that fast aiming movements are automatically modified on-line in response to a change in target position. Specifically, when a movement is less than 300ms in duration the reach is completed to a target’s new location even when one never intended to respond to the target jump. In contrast, when movements are slower, the reach is completed according to instructions. At present, it is unclear if it is possible for one’s intentions to guide the initial stages of these slow movements. To determine if the intentional control mechanism can guide the initial stages of a slow aiming movement, participants aimed to targets that could jump at movement onset, with a slow and very slow movement time goal. In particular, participants were to point towards (“pro-point”) or away from (“anti-point”) the target jump, with a movement time goal of 500 or 1200ms. Results showed that in the anti-point condition, movement trajectories first deviated in the same direction as the target jump, followed by a response in the intended (opposite) direction. This suggests that while movement outcome is controlled by the intentional system, even in these slow aiming movements the automatic system is engaged at movement onset.

Automatic scada systems for reliable monitoring and control of kayseri wastewater treatment plant

An automatic control and estimation strategy for wastewater treatment plants, particularly for Kayseri WWTP, will be introduced in this study. The main idea in this study is to develop and evaluate a control mechanism which can be applied practically to improve and protect the performance of the mentioned treatment plant. It has also been discussed for a proper solution for the reliability of the Kayseri WWTP. At this point, on-line automatic control systems seems as an effective method for this aim Parameters that will be measured are as follows: flow rate, chemical oxygen demand (COD), conductivity, pH, suspended solids (SS) and toxicity. A damage will prevent the plant from operating for days or weeks. With such a system, shock loadings coming to WWTP will be monitored by the automatic control system Highly polluted wastewater or shock loadings will be collected in a storage tank and then fed to the treatment plant at an optimal time.

Reducing istanbul sewer networks operational problems: Requirements on automatic control systems

In this study, quantity of wastewater and rainfall, and the number of sewer failures were observed between years 1996 and 2001 to determine the reasons of Istanbul sewer networks operating problems. The cost of reparations due to failures was calculated according to Istanbul Water and Sewerage Administration (ISKI) unit prices. The total cost of the reparations show us how expensive can be operating sewer networks. Hence, sewer networks must be controlled by online automatic control systems to eliminate the number of failures and operational cost. Sewer networks must also be checked by circuit closed television (CCTV) to reduce construction failures. Flow rate, gases (CH4, H2S), oxygen (O2), pumping signals could be measured by the on-line automatic control system on the trunk manhole to reduce failures and operational cost. The on-line automatic control systems have many advantages to be used as control technique for sewer networks. These advantages were evaluated briefly.

A significant step forward : the full metallurgical control of the mechanical properties of hot-rolled strip with VAI-Q Strip

VAI-Q Strip is a quality control system, based on physical-metallurgical models, for hot-rolled strip. This joint development of VOEST-ALPINE Industrieanlagenbau and VOEST-ALPINE Stahl Linz allows the automatic on-line control of the mechanical properties using very accurate prediction methods. Since the beginning of 2000, an extended version of the system is in operation at VOEST-ALPINE Stahl Linz and very good quality results, as well as cost savings, have been achieved.

Aspects of quality management: Accuracy in dosing antineoplastic drugs

Introduction. When preparing parenteral antineo plastic preparations, different production techniques are used in hospital pharmacies or oncologic wards. National and International regulations and quality standards define the requirements for drug produc tion, independent of the methods that are used. Materials and Methods. In the present study we compared the precision of a weight-controlled dosing system supported by production and docu mentation software to a conventional volume-con trolled dosing method. The weight-controlled method, where one technician produces the applica tions software-leaded with a connected electronic balance, includes an automatic online control and documentation of each procedure step. The pharma cists role in the production process is reduced to the endcontroller before distributing the drugs. The vol ume-controlled method, mostly used in Germany, is based on dose analogous volume calculation as mea sured by syringes. Lack of automatic control and documentation requires the pharmacist as a control ler at every step of production. To determine the difference in dosing accuracy of both methods, we measured and calculated the deviations of the real from the target doses/masses for both methods. Results. With our weight-controlled method, every single dosage and the cumulative dose for one drug of one patients therapy lay within a 5% deviation limit of the required dose. Without validation of syringe volume and consideration of galenic factors, our volume-controlled method does not consistently meet the deviation limit of 10% required in the pharmacopoeia. Conclusion. The weight-controlled method is superior in dosing accuracy to the conventional method, because syringe-volume deviations, densities of drug solutions, overfillings and other factors are not considered in the volume-controlled method. Only with great expense in manual documentation, the volume-controlled method correspond to the guidelines in Chapters 1, 4, and 5 of the "Guidelines for Good Manufacturing Practice of the European Communities," where requirements on quality assur ance systems, documentation and production are described.

On-line automatic control system for monitoring an anaerobic fluidized-bed reactor: response to organic overload

The aim of this study was to develop an automatic system based on selected parameters collected from the biological process to control a fluidized-bed reactor. In the first part of this study, identification of parameters sensitive to overloads was carried out with vinasses as wastewater. From these results, three parameters, considered as the most realistic for the monitoring of the reactor, were selected: pH in the liquid phase, the biogas production and its concentration of dihydrogen. These were used to develop an algorithm based on expert system principle. This automatic control system calculated the flow rate of the feeding pump in order to adjust continuously the load applied to the reactor. The system was used to monitor and control several kinds of overload in an anaerobic fluidized bed reactor, of laboratory and pilot scales. The strategy used was able to operate automatically the digesters.

Intelligent Control of Contamination Level in Hydraulic Control Systems

The paper describes a strategy lor on-line automatic control of the contamination level of the working fluid in the hydraulic control and the lubrication systems of modem heavy machinery. The strategy integrates condition monitoring of the fluid, intelligent interpretation and use of the results and the way they are changing, and selective action to correct deficiencies. Because of the ubiquitous and heuristic nature of fluid contamination, a knowledge-based approach involving fuzzy logic is taken for the analysis and decision-making component of the strategy. The work is well advanced, though not complete.

Target Optimization Control—Automatic On-Line Control of a Process to Maximize Profits

Abstract This paper characterizes and investigates a Target Optimization Control which responds to variations in process standard deviation. Procedures for estimating the process standard deviation are discussed, and optimal controls are derived for each of three representative profit functions.