Communications in Process Control (Part 1)

1982 ◽  
Vol 15 (11) ◽  
pp. 427-432
Author(s):  
P. R. Matthews

The last decade has seen many new measurement and control techniques developed. This has been principally due to the development of low cost electronic circuits and, more recently, the microprocessor. As a result of this rapid development the instrument and process control engineer is faced with the arduous task of interfacing new and old equipment with differing transmission and communication requirements. The situation is further complicated by the numerous transmission and communication techniques that are available and the usual dogma of finding differing communication interfaces at either end of the connecting cable. This paper provides an insight to the array of transmission and communication techniques currently in use and looks at new techniques which are being developed. The application of the transmission and communication techniques to process control systems is a subject which is now under careful scrutiny as the establishment of an effective transmission and communication configuration can result in an appreciable cost advantage and increased transmission efficiency. A number of these configurations (networks) are discussed.

1983 ◽  
Vol 105 (1) ◽  
pp. 27-30 ◽  
Author(s):  
A. H. Waldie ◽  
S. E. Hughs ◽  
M. N. Gillum

Cotton fiber moisture content is one of the most important factors that affects the operation of the cotton ginning process. A system has been developed that measures cotton’s dielectric constant and density with sufficient accuracy to indicate moisture content of the fiber during processing. An electronic capacitor and a pneumatic density sensor supply measurements to a microprocessor which combines them into a predicted moisture content. Tests showed that these predicted readings are more precise than conventional oven-moisture determinations and that they can be used for process control in the ranges from 6.5- to 12-percent moisture content.


1983 ◽  
Vol 27 (7) ◽  
pp. 589-591
Author(s):  
Carole A. Bohn

The new technologies proposed and/or retrofitted into Navy crewstations have demonstrated increasing sophistication and flexibility. Additionally, the crewstation technologies have shown very rapid development cycles. The current approach of reliance solely on flight testing has proven inadequate because of the multitude of equipment operating modes, lack of experimental control of situational variables, possible location/placement of components, variety of operational environments, dynamic crew tasking, and control/display technology unique characteristics. Test methods and relevent criteria are lacking. A quick fix is the use of low fidelity mockups for rapid testing and methods development. Such an approach can be both effective with respect to test dollars and responsive to the dynamics of the control/display development cycle. The present paper discusses the use of the low fidelity simulation in two specific developments. The first example presents the design of formats for a universal control/display layout to be used as a replacement for conventional pushbutton technology. The second example presents testing designed to determine the amount and type of control/display required for a crewstation functional upgrade. Both examples are from the test and evaluation work being performed on Navy patrol aircraft. Finally, a laboratory will be described which is being developed to permit this approach to testing.


2010 ◽  
Vol 174 ◽  
pp. 211-214 ◽  
Author(s):  
Zhen Liu ◽  
Jian Hong ◽  
Sheng Hui Li

with the rapid development of digital printing, the method and standard of quality detection for digital printing become focus of research. The main work and innovations in this paper include: ①Computer image analysis method was applied to ink-jet printing quality detection for the first time; ②Compared with traditional printing quality test, ink dot, line, color patch and MTF (Modulation Transfer Function) were selected as measurement and control elements. And the test proofs for detecting printing quality were designed; ③The detection algorithm and the overall detection process were put forward in this paper. The result of the experiment demonstrates: the detection method based on capturing measurement and control elements by CCD can accurately accomplish the objective quality evaluation for ink-jet printing. Detection method of print was improved to extend the scope of detection by this research, which could be generalized as a standard method for the detection of ink-jet printing quality.


2020 ◽  
Vol 245 ◽  
pp. 07029
Author(s):  
Benjamin LaRoque

Project 8 is applying a novel spectroscopy technique to make a precision measurement of the tritium beta-decay spectrum, resulting in either a measurement of or further constraint on the effective mass of the electron antineutrino. ADMX is operating an axion haloscope to scan the mass-coupling parameter space in search of dark matter axions. Both collaborations are executing medium-scale experiments, where stable operations last for three to nine months and the same system is used for development and testing between periods of operation. It is also increasingly common to use low-cost computing elements, such as the Raspberry Pi, to integrate computing and control with custom instrumentation and hardware. This leads to situations where it is necessary to support software deployment to heterogeneous architectures on rapid development cycles while maintaining high availability. Here we present the use of docker containers to standardize packaging and execution of control software for both experiments and the use of kubernetes for management and monitoring of container deployment in an active research and development environment. We also discuss the advantages over more traditional approaches employed by experiments at this scale, such as detached user execution or custom control shell scripts.


HortScience ◽  
1997 ◽  
Vol 32 (1) ◽  
pp. 64-67 ◽  
Author(s):  
S. Poni ◽  
E. Magnanini ◽  
B. Rebucci

The reported system interfaces a commercially available portable infrared gas analyzer with a measurement and control module for continuous and automated measurements of whole-canopy gas exchange. Readings were taken for several days, under mostly sunny or partly cloudy conditions, on two potted vines (total leaf area per vine of ≈1.3 m2) enclosed in inflated polyethylene chambers. The air flow rate through the chambers was provided by a centrifugal blower and set at 5 L·s-1 by a butterfly valve. It prevented ΔCO2 from dropping below –40 mL·L-1. Switching of the two CO2 analysis channels to the infrared gas analyzer (operated in a differential mode) was achieved by solenoid valves, whereas wet and dry-bulb temperatures at chambers' inlet and outlet were measured by low-cost, custom-made thermocouple psychrometers. Whole-vine assimilation rate (WVA) and whole-vine transpiration rate were calculated from the inlet—outlet differences in CO2 and absolute humidity. When compared to assimilation measured on single leaves (SLA) under saturating light at equivalent times, the WVA reduction (area basis) was ≈50%, suggesting that whole-canopy photosynthetic efficiency based on SLA readings can be greatly overestimated.


2021 ◽  
Vol 261 ◽  
pp. 01013
Author(s):  
Changbao Guo

With the rapid development of modern society, the measurement and control requirements of key variables of air conditioning test technology are also increasing. When the parameters of HVAC system are measured and controlled, there are a large number of sensors and instruments used. When sensor failure or measurement error distortion occurs, the air conditioning system cannot operate normally and automatically. At the same time, some variables in the test parameters cannot be directly collected by the sensor. In order to solve these problems, researchers have focused on soft measurement technology in recent years, which provides a good breakthrough for the measurement and control of air conditioning system test parameters. This paper expounds the application of soft measurement technology in HVAC system.


2019 ◽  
Vol 105 ◽  
pp. 01006 ◽  
Author(s):  
Olga Puhova ◽  
Vladimir Lebedev

The article presents the findings of the research in the field of automatic control of peat mass quality in hollow peat pot production. The strength of the finished product determines its integrity and crumblability which affect the loss during drying and transportation. Therefore, knowing the strength characteristics we can use them for quality control. Besides, not strength but heterogeneity in the distribution of pores, moisture, and density is responsible for crumbling. Automatic regulation of effective peat mass water content is one of the main stages determining the quality. At this stage automatic control of the flow, dispersion and water content of peat mass entering the pulper tank as well as measurement and control of the amount of additional elements introduced, such as mineral components, wood pulp, and water to form the required consistency, are provided for. The models of automatic process control are built and analyzed with the methods of differential equation theory, numerical integration, and stability theory. The model is implemented with the custom-made proprietary software. The model adequacy is determined empirically by comparing the data obtained on the model with the actual technological process.


2014 ◽  
Vol 556-562 ◽  
pp. 2492-2495
Author(s):  
Ming Yu Tong ◽  
Di Jian Xu ◽  
Jin Liang Shi

with the rapid development of science and technology, in all fields of temperature control system of the precision, stability and other requirements of increasingly high, the control system is the myriads of changes. Computer measurement and control technology, the traditional electronic measuring changed dramatically in the principle, function, accuracy and automation degree, degree of automation of the scientific experiment and application engineering to improve. Temperature control key lies in the two aspects of temperature measurement and control. Temperature measurement is based on temperature control, this technology is quite mature. But because of the increasingly complex control object, control in the temperature still exist many problems. This thesis presents the design of industrial temperature resistance furnace computer using PID algorithm, Smith predictive control algorithm, darin algorithm, three algorithms are studied based on the control system, and the control algorithm was simulated using the MATLAB simulation software, and the advanced control algorithm is studied [1-3].


Sign in / Sign up

Export Citation Format

Share Document