scholarly journals COMPARISON OF METHODS FOR CONTROLLED THERMAL DEFORMATIONS IN MACHINE TOOLS

2021 ◽  
Vol 2021 (3) ◽  
pp. 4597-4604
Author(s):  
A.P. Kuznetsov ◽  
◽  
H. J. Koriath ◽  
Keyword(s):  
Metal Cutting ◽  
Functional Relationship ◽  
Control Method ◽  
Control Device ◽  
Temperature Measurements ◽  
Measured Temperature ◽  
Machine Accuracy ◽  
Thermal Deformations ◽  
Temperature Errors ◽  
Tool Types

Progress in improving the accuracy of metal-cutting machines is inextricably linked and driven by deeper knowledge gained through the study of thermal processes and effects occurring in machines, which can be used to manage them. This led to the dominance of temperature errors in the balance of machine accuracy, the share of which changed from 20-30% to 70% during the period from 1950 to 2020, which is determined by the absolute value of the achievable machine accuracy. Types and forms of compensation methods were formed (1990-2020), which were based on the use of linear and nonlinear regression or correlation methods. Performing experiments can establish the functional relationship between the measured temperature in the machine nodes and the amount of displacement. With good repeatability and stable reproducibility of the result, an equation expresses this functional relationship. Applying this equation to a program, a control device compensates the thermal deformations. However, in all cases, it is necessary to determine the number and location of temperature measurements on the machine, determining the compensation accuracy. The proposed sensorless model is based on a thermal behavior model and does not require temperature measurements. A method is presented and justified for estimating the number of temperature measurement locations based on thermophysical analysis by applying the finite element method in comparison with the analytical method in order to achieve the required compensation accuracy. For several machine tool types, a comparison is given regarding the control method of the TCP spindle displacement without sensors and with temperature sensors. The limits of their rational use are presented.

Active Noise Control Using Phase-Compensated, Damped Resonant Filters

2005 ◽  
Vol 128 (2) ◽  
pp. 148-155 ◽  
Author(s):  
Jesse B. Bisnette ◽  
Adam K. Smith ◽  
Jeffrey S. Vipperman ◽  
Daniel D. Budny
Keyword(s):  
Noise Control ◽  
Control Method ◽  
Active Noise Control ◽  
Control Device ◽  
Modal Control ◽  
Pass Filter ◽  
Acoustic Transducers ◽  
Active Noise ◽  
The Impact ◽  
Resonant Filters

An active noise control device called active noise absorber or ANA, which is based upon damped, resonant filters is developed and demonstrated. It is similar to structural positive position feedback (PPF) control, with two exceptions: (1) Acoustic transducers (microphone and speaker) cannot be truly collocated, and (2) the acoustic actuator (loudspeaker) has significant dynamics. The speaker dynamics can affect performance and stability and must be compensated. While acoustic modal control approaches are typically not sought, there are a number of applications where controlling a few room modes is adequate. A model of a duct with speakers at each end is developed and used to demonstrate the control method, including the impact of the speaker dynamics. An all-pass filter is used to provide phase compensation and improve controller performance and permits the control of nonminimum phase plants. A companion experimental study validated the simulation results and demonstrated nearly 8 dB of control in the first duct mode. A multi-modal control example was also demonstrated producing an average of 3 dB of control in the first four duct modes.

The Application of S7-200 PLC Reactive Compensation Device in Small Substation

2012 ◽  
Vol 479-481 ◽  
pp. 1476-1480
Author(s):  
Qing He Chu ◽  
Wen Si Cao ◽  
Zhen Nie
Keyword(s):  
Reactive Power ◽  
Control Method ◽  
High Reliability ◽  
Reactive Power Compensation ◽  
Control Device ◽  
Reactive Compensation ◽  
Reconstruction Project ◽  
Compensation Device ◽  
And Control

In the present rural power grid reconstruction project ,according to the problems of capacitor reactive power compensation in rural small substation. Take a small substation for instance, according to its operation and control method, set the criterion of the capacitor bank switching. A new high reliability, flexible reactive power compensation control device based on s7-200 PLC is designed. It plays an important role in improving the power supply , guaranteeing the quality of voltage, reducing the loss of rural power gid.

Comparison of Ventilated and Unventilated Air Temperature Measurements in Inland Dronning Maud Land on the East Antarctic Plateau

2021 ◽  
Vol 38 (12) ◽  
pp. 2061-2070
Keyword(s):  
Austral Summer ◽  
Radiative Heating ◽  
Temperature Measurements ◽  
Shortwave Radiation ◽  
Relay Station ◽  
Antarctic Plateau ◽  
Temperature Bias ◽  
Dronning Maud Land ◽  
Weak Winds ◽  
Temperature Errors

Abstract Surface temperature measurements with naturally ventilated (NV) sensors over the Antarctic Plateau are largely subject to systematic errors caused by solar radiative heating. Here we examined the radiative heating error in Dronning Maud Land on the East Antarctic Plateau using both the newly installed automatic weather stations (AWSs) at NDF and Relay Station and the existing AWSs at Relay Station and Dome Fuji. Two types of NV shields were used in these AWSs: a multiplate radiation shield and a simple cylinder-shaped shield. In austral summer, the temperature bias between the force-ventilated (FV) sensor and the NV sensor never reached zero because of continuous sunlight. The hourly mean temperature errors reached up to 8°C at noon on a sunny day with weak wind conditions. The errors increased linearly with increasing reflected shortwave radiation and decreased nonlinearly with increasing wind speed. These features were observed in both the multiplate and the cylinder-shaped shields. The magnitude of the errors of the multiplate shield was much larger than that of the cylinder-shaped shield. To quantify the radiative errors, we applied an existing correction model based on the regression approach and successfully reduced the errors by more than 70% after the correction. This indicates that we can use the corrected temperature data instead of quality controlled data, which removed warm bias during weak winds in inland Dronning Maud Land.

Research on Human-Computer Interaction Control Method in the Background of Internet of Things

2021 ◽  
Author(s):  
Yingying Hu ◽  
Zhongyang Li
Keyword(s):  
Internet Of Things ◽  
Control Method ◽  
Computer Control ◽  
Control Device ◽  
Smart Devices ◽  
The Internet ◽  
Interactive Control ◽  
Interaction Control ◽  
Different Types ◽  
The Internet Of Things

Against the background of the growing development of the Internet of Things, this article conducts research on more efficient methods for controlling the interconnection of all things, and proposes that smart devices use the same operating platform, and the human-computer interface presents universal modular controls for manipulation, it can satisfy the requirement that one device controls several different types of controlled device simultaneously. At the same time, the interactive method uses the controlled device to actively submit control content to the control device, and discusses the human-computer interactive control method applicable to the Internet of Everything, and strives to achieve a convenient and easy-to-use human-computer control experience.

scholarly journals Thermal Conductivity of High Performance Concrete in Wide Temperature and Moisture Ranges

10.14311/174 ◽  
2001 ◽  
Vol 41 (1) ◽  
Author(s):  
J. Toman ◽  
R. Černý
Keyword(s):  
Thermal Conductivity ◽  
High Performance ◽  
Room Temperature ◽  
High Performance Concrete ◽  
Measuring Method ◽  
Point Of View ◽  
Temperature Measurements ◽  
Temperature Fields ◽  
Measured Temperature ◽  
Hot Wire

The thermal conductivity of two types of high performance concrete was measured in the temperature range from 100 °C to 800 °C and in the moisture range from dry material to saturation water content. A transient measuring method based on analysis of the measured temperature fields was chosen for the high temperature measurements, and a commercial hot wire device was employed in room temperature measurements of the effect of moisture on thermal conductivity. The measured results reveal that both temperature and moisture exhibit significant effects on the values of thermal conductivity, and these effects are quite comparable from the point of view of the magnitude of the observed variations.

Modeling Reservoir Temperature Transients and Reservoir-Parameter Estimation Constrained to the Model

2010 ◽  
Vol 13 (06) ◽  
pp. 873-883 ◽  
Author(s):  
Obinna O. Duru ◽  
Roland N. Horne
Keyword(s):  
Flow Rate ◽  
Oil And Gas ◽  
Mechanistic Model ◽  
Operator Splitting ◽  
Temperature Data ◽  
Temperature Measurements ◽  
Solution Technique ◽  
Measured Temperature ◽  
Reservoir Temperature ◽  
Temperature Transient

Summary Permanent downhole gauges (PDGs) provide a continuous source of downhole pressure, temperature, and sometimes flow-rate data. Until recently, the measured temperature data have been largely ignored, although a close observation of the temperature measurements reveals a response to changes in flow rate and pressure. This suggests that the temperature measurements may be a useful source of reservoir information. In this study, reservoir temperature-transient models were developed for single- and multiphase-fluid flows, as functions of formation parameters, fluid properties, and changes in flow rate and pressure. The pressure fields in oil- and gas-bearing formations are usually transient, and this gives rise to pressure/temperature effects appearing as temperature change. The magnitudes of these effects depend on the properties of the formation, flow geometry, time, and other factors and result in a reservoir temperature distribution that is changing in both space and time. In this study, these thermometric effects were modeled as convective, conductive, and transient phenomena with consideration for time and space dependencies. This mechanistic model included the Joule-Thomson effects resulting from fluid compressibility and viscous dissipation in the reservoir during fluid flow. Because of the nature of the models, the semianalytical solution technique known as operator splitting was used to solve them, and the solutions were compared to synthetic and real temperature data. In addition, by matching the models to different temperature-transient histories obtained from PDGs, reservoir parameters such as average porosity, near-well permeabilities, saturation, and some thermal properties of the fluid and formation could be estimated. A key target of this work was to show that temperature measurements, often ignored, can be used to estimate reservoir parameters, as a complement to other more-conventional techniques.

scholarly journals Cooperative Control Method of Active and Semiactive Control: New Framework for Vibration Control

2014 ◽  
Vol 2014 ◽  
pp. 1-11 ◽  
Author(s):  
Kazuhiko Hiramoto
Keyword(s):  
Vibration Control ◽  
Active Control ◽  
Cooperative Control ◽  
Control Method ◽  
Design Method ◽  
Control Object ◽  
Control Device ◽  
Semiactive Control ◽  
Control Input ◽  
Control Approach

A new control design framework for vibration control, the cooperative control of active and semiactive control, is proposed in the paper. In the cooperative control, a structural system having both of an actuator and a semiactive control device, for example, MR damper and so forth, is defined as the control object. In the proposed control approach, the higher control performance is aimed by the cooperative control between the active control with the actuator and the semiactive control with the semiactive control device. A design method to determine the active control input and the command signal to drive the semiactive control device based on the one-step prediction of the control output is proposed. A simulation example of a control system design for a benchmark building is presented to show the effectiveness of the proposed control framework.

Temperature control and calibration in quench furnaces and some new temperature measurements in the system CaO–MgO–Al2O3–SiO2

1969 ◽  
Vol 37 (285) ◽  
pp. 1-15 ◽  
Author(s):  
G. M. Biggar ◽  
M. J. O'Hara
Keyword(s):  
Temperature Control ◽  
Temperature Measurements ◽  
Temperature Errors ◽  
Invariant Equilibria

SummaryTechniques associated with temperature control and measurement in quench furnaces are described and a study made of calibration problems. Systematic temperature errors as great as 30°C in published results from separate laboratories are explicable. A comprehensive redetermination of temperatures of invariant equilibria in systems containing CaO, MgO, Al2O3, SiO2, Na2O, Fe-O2, has been initiated and the results to date are presented, including approximate determinations of three invariant equilibria in the system CaO-MgO-Al2O3-SiO2 involving liquid, monticellite, spinel, and two of merwinite, periclase, and forsterite, which are important in the melting of magnesia refractories, and precise determinations of the three newly recognized invariant equilibria involving liquid, spinel, diopside, and two of forsterite, melilite, and anorthite.

Depth Control of Underwater Robot with Metal Bellows Mechanism for Buoyancy Control Device Utilizing Phase Transition

2013 ◽  
Vol 25 (5) ◽  
pp. 795-803
Author(s):  
Koji Shibuya ◽  
◽  
Yukihiro Kishimoto ◽  
Sho Yoshii
Keyword(s):  
Phase Transition ◽  
Control Method ◽  
Control Device ◽  
Underwater Robot ◽  
Maximum Output ◽  
Depth Control ◽  
Metal Bellows ◽  
Control Devices ◽  
Target Depth ◽  
Buoyancy Control

The ultimate goal of this study is to develop a buoyancy control device that utilizes volume change due to phase transition of material between solid and liquid states. This paper describes the depth control method for an underwater robot fitted with the metal bellows buoyancy control devices that we have developed in this study. Four metal bellows buoyancy control devices are installed on an underwater robot. We first measured underwater robot buoyancy change and found that it agreed roughly with theoretical values. We then checked whether the robot could change buoyancy successively so that the robot rises or sinks as commanded. We then conducted a series of experiments on robot depth control in which if the robot depth is more than a certain distance different from the target depth, control devices are either heated or cooled at maximum output. If such a difference is within the threshold, proportional control is applied to develop output in proportion to the distance to the target depth. Experimental results showed that the underwater robot followed varied target depth with a steady-state deviation of a few cmor so, except in some cases of failure.

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