第1页 / 共8页
第2页 / 共8页
第3页 / 共8页
第4页 / 共8页
第5页 / 共8页
第6页 / 共8页
第7页 / 共8页
第8页 / 共8页
关于温湿度检测的外文翻译.doc
滨 州 学 院
毕业设计（论文）开题报告
题
目 基于单片机的粮库温湿度智能检测系统的研究
系 （ 院 ） 物理与电子科学系 年 级
2009 级
专
业 电子信息科学与技术 班 级
1 班
学 生 姓 名
董乃旭
学 号 2009010551
指 导 教 师
李 洁
职 称
讲师
滨州学院教务处
二〇一三年三月
An Automatic Measuring System Based on Atmospherical
Measurement Used for Temperature Relay
For temperature relay, it is very important to measure its temperatures for action
and reversion. In this paper, anautomatic measuring system based on atmospherical
measurement is discussed, which is very simple andprecise in practical application. In
atmospherical measurement, it is crucial to design a favorable temperaturefield. The
resistance stove is designed for simulating temperature field. The even temperature is
improved bylong-time warm-up and placing orifice-board in testing room. According
to the enactment controlling temperature curve, the algorithm of fuzzy control is used
to control the temperature in temperature field. The regulating voltage mode of
double-direction Bi-directional thyristors is used for controlling temperature. The
system consists of the console and the resistance stove ， and the console includes
software platform and hardware platform. In this system, The method of grouping the
resistance wire of resistance stove according to the power is put forward, and the
performance of resistance stove is improved based on this method. The measuring
precision is improved by using the minimum two-multiplication to calibrate the error.
At present, the system has been practically applied in manufacture, which has gained
obvious economy benefit and will be widely applied in the future.
1. Introduction
The temperature relay is one of common relays, which takes action when the
outside temperature arrives at the given temperature. The temperature relay performs
lots of functions, such as temperature control, fire alarm, automatic ignition, wiring
heat-protection, so it is widely used in scientific research, industry and defense
industry etc. For temperature relay, it is very important to measure its temperatures
for action and reversion. But in the current manufacture, the manual measuring
methods, such as spot-check method, mercuric thermometer method etc, dominate the
measuring methods. However there are some inescapable short comings in these
methods, such as low efficiency, large labor intensity and bad precision etc. Thus
measurement has become the bottleneck of the quality of temperature relay. With the
perpetual progress in the technology, the need for product quality gets more and more
strict and the degree in manufacture automatization gets more and more deep. For
temperature relay, today the manual measuring methods have become unfitted for the
need for manufacture and will be necessarily replaced by the automatic measuring
methods. In this paper, an automatic measuring system based on atmospherical
measurement is discussed, which is very simple and precise in practical application.
2. Measuring principie
Two kinds of metals whose inflated coefficient make a great deal of difference
are hard composed together, and then the dishing twin-sheet metal comes into
being.When the temperature relay arrives at a certain given value, one upward curving
force will come into being in twin-sheet metal as a result of big expanding for nether
metal and small expanding for upper metal. When the twin-sheet metal bends at a
certain extent, it will drive the electric contact and switch on or switch off the circuit.
When the temperature relay reduces at a certain given value, the twin-sheet metal
gradually involutes. When the twin-sheet metal resumes at a certain extent, it will 3rd
International Symposium on Instrumentation Science and Technology Aug. 18~22,
2004, Xi’an. China drive the electric contact in inverse direction and switch on or
switch off the circuit. The working principle of dishing twin-sheet metal is described
as Fig1:1-the initiatory state(room temperature), 2-the state after heated or cooled,
3-displacement.
The temperature relay takes action due to the rising of ambience temperature or
the heating of passing current.The resistance of relay is very small. So compared with
the temperature rising caused by ambience temperature, the temperature rising caused
by current heating also is very small and can be ignored. Thus measuring
temperatures for action and reversion is implemented by controlling the environment
temperature. There are three methods for measuring temperatures for action and
reversion, which are
and
testing-block measurement in GJB1517-92.
atmospherical measurement
liquid measurement,
[1] Liquid Measurement
In the constant temperature trough whose temperature can be intercalated, the
medium that is water or oil is equably churned up. The measuring method is that the
product is placed in the constant temperature trough heated or cooled. Because the
liquid is equably churned up,
the even temperature, good and the temperature
precision is fairly high in which the temperature error is
the temperature fluctuating
degree is ±0.3℃. Thus the heating coherence of the products that are placed in
different position in the constant temperature trough is very good, the measuring
precision is very high and the parameter-repeating quality is all right. But this method
is just applied in sealed temperature relay and the oil can stain the product. So few
manufacturer adopts the method. Only the disputed appears and precise measurement
is needed, the method is adopted.
[2] Atmospherical Measurement
The electrical oven whose temperature can be intercalated equably churns up the
atmosphere. The measuring method is that the product is placed in the electrical oven
heated or cooled. In the temperature field, the even temperature that is ±2℃and the
temperature precision in which the temperature error is ±2℃ and the temperature
fluctuating degree is ±1.5℃are both not good. The heating coherence of the products
that are placed in different position in the electrical oven, the measuring precision and
the parameter-repeating quality apparently are not as much as liquid measurement.
But the method is widely adopted because of simpleness,few pollution and batch.
[3] Testing-block Measurement
A coppery block with a thermometer whose diameter isφ60~φ90mm and whose
thickness is 20~30mm and a set of heating or cooling device make up of the
measuring system.The measuring method is that in the room temperature the product
is tightly placed on the surface of testing-block that is placed on the heating or cooling
device whose temperature can be adjusted, and the temperature characteristic of the
product is determined by measuring the temperature of the testing-block. Adjusting
temperature of the testing-block is very hard because of measured in the room
temperature, thus only a few product can be measured each time and the method
unfits
for volume-produce. But because of its simpleness, it fits for a small quantity of
produce.
Generally speaking, if the product is sealed and isn’t stained by oil, liquid
measurement is adopted; if the product is placed in the heating or sealed body,
atmospherical measurement is adopted; if the product is placed on the surface of the
controlled object in room temperature, testing-block measurement is adopted. In this
system, atmospherical measurement is adopted.
In atmospherical measurement, the electrical oven is used for simulating the
temperature around the temperature relay. So for accomplishing
environmental
measurement and enhancing precision, it is crucial to design a favorable temperature
field. In this system, the resistance stove is designed for simulating temperature field.
The performance of the temperature field is greatly improved by the even temperature
and by the algorithm for controlling temperature.
Because the temperature field takes atmosphere as the diathermanous medium,
heat convection has a great effect on the distribution of the temperature field. In
course of measuring, the fan is used for strengthening heat convection. But because of heat
radiation in the testing room and obstruction from the diathermanous board onthe clamp
that doesn’t make heated atmosphere swimmingly cycle,
the temperature field
degressively distributes by height in the vertical, and the temperature grads field
comes into being. Thus the temperature asymmetry is inevitable. In this system, two
methods are used for improving the even temperature. One is that by long-time
warm-up atmosphere in testing room is adequately heated and the temperature grads
is reduced.The other is that the orifice-board for making airflow equably flow is
placed in testing room,
thereby the temperature stability in the section of the
measuring point is effectively ensured.
In the light of academic analysis and repeating experimentation, the perfect
controlling temperature curve of the temperature field is described as Fig 2:TB-the
demarcated temperature for action , the parameter which express the decentralization
of the temperature for action. Firstly the temperature high-rate rises. When the
temperature arrives at the range of the temperature for action, the temperature rises by
the slower rate K2 and the temperature for action is measured. When the temperature
arrives at the upper limit of the temperature for action, the temperature falls by the
slower rate K3 and the temperature is measured. For the resistance stove, lag, inertia
and nonlinear are bad and the parameter changes with time. Thus according to the
enactment controlling temperature curve, the algorithm of fuzzy control is used to
control the temperature in temperature field. So the model of the controlled object can
be avoided identifying and Robust is excellent. The regulating voltage mode of
double-direction Bi-directional thyristors is used for controlling temperature. Firstly
the value and error of the temperature are fuzzied, and then the fuzzy rule from
repeating experimentation does fuzzy illation, then through the barycenter method
fuzzy estimate calculates the accurate value, at last after D/A transform the accurate
value controls the Bi-directional thyristors by regulating voltage, so temperature
rising
Or falling of the resistance stove can be controlled.
3. Automatic measuring system
Automatically controlled by the computer, the temperature of the resistance
stove reposefully rises from the lower limit of the temperature for action. When the
relay takes action, the temperature for action is displayed and the arraignment appears,
then the computer automatically controls the temperature reposefully falling. When
the relay reverts, the temperature for reversion is also displayed and the arraignment
appears, thereby an integrated measuring process ends.
Based on Windows2000 operating system, the software developed by Microsoft
Visual Basic 6.0 makes up of measuring module, user interface and database of
measuring result. As control core of the measuring system, the measuring module
automatically controls temperature rising or falling of the resistance stove, real-time
acquires the temperature signal and the switch signal of the temperature relay,
measures and records temperatures for action and reversion, alarms beyond the
temperature range etc. The user interface consists of command button and menu,
real-time temperature curve and the windows that real-time display measuring state
and real-time modify parameters, which offers the user a friendly man-machine
interface. forms for the future analysis and estimate. Thus the database of measuring
result is created, which effectively performs the functions of data backup and printing
recordation. Furthermore, some accessorial programs are designed, such as hardware
exception handles, real-time modify parameters program, upgrade program etc, which
effectively enhance reliability and maintainability of the system.
In this system, two methods are adopted aiming at some technical difficulty in
measuring process, which obviously enhance the holistic quality.
[1] The method of grouping the resistance wire of resistance stove according to
the power
The three-phase SSR electric power regulator indirectly regulates heating power
through regulating switching on and off time of the resistance wire, thereby controls
temperature rising or falling of the resistance stove. But the regulative extent of
high-power stove wire is so wide that it is very difficult to accurately control the rate
of rising or falling. For enhancing regulative sensitivity, lower-power stove wire
should be adopted. However because the system comes down to more than twenty
products and the measuring upper limit arrives at 600, the low-power stove wire
cannot heat
the method
ofgrouping the resistance wire of resistance stove according to the power is put
forward, which is that the low-power stove wire is applied in low temperature and the
high-power stove wire is applied in high temperature. It is practically proved that the
method effectively solves above problem and improves the quality of resistance stove.
to such a high temperature. Facing to this problem,
[2] The holistic minimum two-multiplication to calibrate the error
In this system, the holistic minimum two-multiplication to calibrate the error is
adopted. Firstly the current temperature at measuring point is mensurated by the
high-precision temperature sensor, at the same time the current value output to
computer is gained, and then a set of such data is mensurated in the temperature
range.coefficients of the minimum two-multiplication multinomial are gained. At last
when the coefficients are input nto program,
the fitting of temperature cure is
accomplished and the holistic system error is calibrated.
4. Conclusion
The automatic measuring system used for temperature relay has been checked
and accepted. The critical result is shown as follows. Thus it can be seen that the
system has gained obvious economy benefit and will be widely applied in the future.
References
[1] HU Hong-bin. Measuring for temperature characteristic of temperature relay.
Electro Mechanical element, 2003,(9):46-48
[2] SUN Kai. Controlling temperature system of resistance stove. Sensor Technology,
2003,22(2): 50-52
[3] ZHONG Guo-min, WANG Gai-ming. A system used for controlling temperature.
Automatization transaction, 1993,19(2):223-226
[4] CHEN Hua, FU Li-hua.Application of controlling temperature using fuzzy control
theory.
Journal of Liaoning university, 1995,22(1):34-38
[5] LI Xian-ming.Research for automatic measuring system of temperature relay.
Electron and
Automatization, 1997(3):24-27
相关推荐
2023年江西萍乡中考道德与法治真题及答案.doc
2012年重庆南川中考生物真题及答案.doc
2013年江西师范大学地理学综合及文艺理论基础考研真题.doc
2020年四川甘孜小升初语文真题及答案I卷.doc
2020年注册岩土工程师专业基础考试真题及答案.doc
2023-2024学年福建省厦门市九年级上学期数学月考试题及答案.doc
2021-2022学年辽宁省沈阳市大东区九年级上学期语文期末试题及答案.doc
2022-2023学年北京东城区初三第一学期物理期末试卷及答案.doc
2018上半年江西教师资格初中地理学科知识与教学能力真题及答案.doc
2012年河北国家公务员申论考试真题及答案-省级.doc
2020-2021学年江苏省扬州市江都区邵樊片九年级上学期数学第一次质量检测试题及答案.doc
2022下半年黑龙江教师资格证中学综合素质真题及答案.doc
