1、1现代检测技术概述（Overview of modern detection technology）This article is contributed by ZHOU_451Ppt documents may experience poor browsing on the WAP side. It is recommended that you first select TXT, or download the source file to the local view.Modern detection technologyIntelligent electronic police mon
2、itoring systemNumberTechnical indexImage resolution 700x560 true color 16Mbit CCD lens minimum illumination 560 line 12 48mm 3 / recording mode per vehicle per vehicle image storage capacity 14000 Zhang Zhang power 250W power supply voltage 220VAC 50Hz models all category 5 km / hour 10-200 kilomete
3、rs per hour km speed detectionDetection technology overviewFirst, the basic concept of detection1 、 detection and measurement: detection is more extensive measurement, detection and measurement:To determine the measurement attribute and the value of the object quantity for the purpose of the operati
4、on of all measurement: detection: detection technology: measuring signal detection (very important) signal detection (very important) detection process: information extraction, signal storage and transmission, display recording, analysis and processing: information extraction and detection process s
5、ignal conversion, storage and transmission, display and record detection technology: detection method, detection structure, signal processing integrated detection techniques: structure detection method, detection,2, classification of detection* according to the measured value of the physical propert
6、y classification: electric and nonelectric physical properties according to measured value classification: power, physical attribute classification according to the detection principle of classification * (physical, chemical and biological): according to the detection principle of classification (ph
7、ysical, chemical and biological): electromagnetic method and optical method microwave method and ultrasonic method, radiation method, electromagnetic method, optical method, microwave method and ultrasonic method, radiation method, electrochemical analysis, chromatographic analysis, chemical analysi
8、s, chromatographic analysis, mass spectrometry analysis * detection method of classification: active and passive, direct and indirect detection methods according to the classification, and non contact type contact type: active and passive, direct and indirect, contact and non-contact, dynamic and st
9、atic3 units of measurementMeasurement: Measurement: measuredBase measure, unit multiple (result), multiple (result)The international system of units (SI) International System of units (SI) basic unit: SI basic unit: seven units of physical quantity independent of length (m) quality time current ther
10、modynamic temperature amount of substance quantity kg) mol) CD) (kg) (s) (A) (K) (mol) (CD) communication the physical distance is the original unit kg standard physical units kg of standard prototype unit distance meters of light in a vacuum 1s time 1/299792485 light in vacuum 1s time 1/299792485 1
11、s propagation distance time: SI combination unit: the basic unit derived energy (energy (J) = force * distance = mass * the acceleration distance (J = kg * kg (m/s2) M = M2 kg/s2 kg/s): length, length and quality of energy (ears): focal length, quality, time) scientist (Scientists) much / little Muc
12、h prefix: mm, prefix nm (much / much smaller prefixes: mm, m, nm (10-9m); kHz, MHz (Hz), GHz (Hz), GHz kHz, MHz (106Hz), GHz (109Hz)Two, the function and significance of detection technology1, product inspection and quality control of the important means of passive testing, active detection (online
13、detection), active detection (online detection) quality control areas2 、 widely used in the monitoring of large-scale equipment safety and economic operation, dynamic monitoring of fault monitoring system to ensure the safety of equipment and personnel, improve the economic benefits, the state of qu
14、antity tends to automatic control3, the indispensable part of the automation system management production process: logistics, production process: “logistics“, “information flow“, “information flow“ control, detection, access to information, analysis and judgmentAutomation: information acquisition, i
15、nformation transfer, information processing, information transmission, information automation: information acquisition, information transfer, information processing, development and perfection of information transmission, 4, detection technology to promote the level of progress of detection methods
16、of modern science and technology decision science research the depth and breadth of theoretical research results cannot do without detection means necessaryThree, detection system compositioninformation acquisitionTransformationDisplay and processingAnalysis and processing section (analysis and proc
17、essing section, communication interface and bus), communication interface and bus)(signal detection section) signal conversion section (signal detection section) (signal conversion part)1, signal detection section,The sensor device (Sensor) sensor detection function (signal) extraction (measured), t
18、ransmission (signal transformation part) signal extraction (measured), transmission (signal), transmission part) features: features: 1) the output voltage, current, frequency) output for voltage and current, two A: Two: digital, digital and analog volume 2) electrical output is generally weak): elec
19、trical output is generally weak: voltage millivolt, microvolt level, current; Ma nanoamp grade millivolt, microvolt level, Ma; 3) output signal and noise mixed with sensor the internal noise) the signal-to-noise ratio of the sensor is small, the signal-to-noise ratio of the sensor output signal, the
20、 weak signal submerged in noise 4) characteristics of the output of the sensor is linear or nonlinear) 5) outside Changes in environment will affect the output characteristics of the sensor) selection: measurement accuracy, measurement range, measurement accuracy, selection: measuring range, the obj
21、ect to be measured by the environmental condition and the most diverse and form detection system of the sensor and the detection system of the volume and cost limitations in the detection system the most diverse and form and the measured part of resistors and capacitors, resistors, capacitors and in
22、ductors associated most closely2, signal conversion part,The detection signal conditioning circuit output impedance is high output impedance is high; impedance transformation; weak output signals; signal amplification of weak output signals; signal submerged in noise; noise suppression signal submer
23、ged in noise; voltage / current (voltage and current output current needs; (V/A) converted to current output current;) (analog digital analog / digital (A/D) conversion to digital signal output digital) objective: 1) to the output of sensor is transform into easy to handle or the amount of amplifica
24、tion) 2) to eliminate or suppress unwanted signals in the sensor output) 3) improve the measurement and analysis accuracy, improve the measurement) 4) which simplify the subsequent system) signal suitable for analysis and processing.3, analysis and processing,Continuously inject new content into the
25、 research center of the detection system, strong problem analysis ability, strong computer system problem analysis ability, complex system real-time control, automation, automation and intelligence4 、 communication interface and bus part,Function: the management of data between different systems and
26、 functions: transmission management data between different systems, state and control and information exchange between the system and the host computer / system information exchange interface system and host computer system to exchange information with the general standard interface of different sys
27、tems especially products from different manufacturers to USB, IEEE-488, RS-232 (Internet), serial, parallel and parallel), (serial), (hardware) hardware) bus: common channel signal line transmitting digital signal collection of RS-232C, VXI, Centronics (parallel), (parallel) (specification, structur
28、e, structure specification)Four 、 detection methodSelect the properties, the measured properties, characteristics and classification of the measuring tasks measured: Classification: (1) according to the measurement procedures: direct measurement, indirect measurement according to the measurement pro
29、cedures: direct measurement, (2) according to the measured values obtained: offset measurement, zero position measurement, according to the measured value the way to obtain: offset measurement, zero position measurement, differential measurement (3) according to the sensor and the object to be teste
30、d whether direct contact: contact measurement, according to the sensor and the object to be tested whether direct contact: contact measurement and non-contact measurement (4) according to the characteristics of the object changes: the static and dynamic measurement according to the characteristics o
31、f the measurement object changes: static measurement,1 direct measurement and indirect measurement,A simple comparison with similar reference to get the measurement (direct measurement and similar benchmarks were simple compared to get the measurement (direct measurement instrument for measuring cal
32、ibration of the device to be measured): direct measurement): scale object size, object size balance weight,Indirect measurements are difficult to measure or difficult to carry out. Direct measurement of load resistance, power = voltage * current (relation) direct measurement) target variable indepen
33、dent variable (direct measurement)The measured Y and the variables of other variables functions or variables) were measured to determine the direct and the other variables of X function (or n variables with other variables direct function between the ground measurements, obtained Y measurements, obt
34、ained by calculating function through the function calculation2 、 offset method and zero position method,1) the offset method obtains the energy required for the signal conversion from the measurements): the spring balance 2) the zero position method does not obtain energy from the signal source) ex
35、amples: the balance scales the object, the high-precision measurement, the measurement error3, differential measurement,Structure: two sensors, symmetrical structure: two sensor symmetrical structure and function measurement of anti symmetric role in two sensor function: eliminate the influence of i
36、nterference measurement principle, measurement principle of linear linearization, improve the sensitivity (detection structure) common detection structure)Two4. Contact measurement, non-contact measurement, contact measurement,Non contact measurement: non-contact measurement: to avoid impact on the
37、object being measuredBeing measured does not vary with timeBeing measured over time5 、 static measurement, dynamic measurement, static measurement,To determine the instantaneous value to be measured, it is necessary to determine the instantaneous value to be measured and the law of its change with t
38、ime5-1 follow up tracking measurement,The high precision electronic balance, high precision electronic scale, servo accelerometer, servo accelerometer and high precision pressure sensor are based on the zero position measurement5-2, active exploration and information feedback detection,One of the si
39、gns of intelligent detectionThe sensor information processing results of the detected objectSome characteristics of the signal simulation of nonlinear mapping by learning optimal solution continuously adjust the connection strength adjustment of position and attitude of the test results has the adju
40、stment object of the deterministic location ability of neural network adaptive ability to change the sensitivity of the sensor temperature sensor self-learning,Five, the development trend of detection technologyDetection technology, important means, scientific researchRelated disciplines: Physics, c
41、hemistry, mathematics, biology, and related disciplines: Physics, chemistry, mathematics, biology, materials science, etc., to promote experimental research and developmentNew detection theory, new detection theory, methods and technical means1 、 sensor level improvement,1) the new principle, new ma
42、terials and new technology) new principle, new materials and new function of sensor optical fiber sensor, liquid crystal sensor, pressure sensor (optical fiber sensor, liquid crystal sensor, pressure sensor (with organic polymer materials as the sensitive element) sensitive element) 2) new areas, ne
43、w areas, new sensor) demandMicrobial sensors, chemical sensors, biomimetic sensors (instead of visual, olfactory, chemical sensors, microbial sensors, biomimetic sensors (instead of vision, smell, taste and hearing) and the detection of ultra high temperature and ultra high pressure, smell and heari
44、ng) and a new sensor for the detection of ultra high temperature and ultra high pressure and ultra low temperature and high vacuum extreme parameters3) sensor development towards high precision miniaturization and integration direction) integration: the integration of microelectronic technology: a n
45、umber of the same type of sensor integrated in a chip or array of features: plane / space measurement features: point measurement plane measurements of space charge coupled devices (for example: charge coupled device (CCD) photosensitive element array multi function digital camera) sensing the diffe
46、rent functions of the integrated sensor features: features: multiple parameters were a sensor can simultaneously measure different types: multifunctional sensor integration of various components in the measurement of blood II: the sensor and subsequent processing circuit integrated integration: feat
47、ures: reduce interference, improve the sensitivity, easy to use; features: reduce interference, improve the sensitivity, easy to use; can realize real-time data processing and sensor ( The data processing circuit (data processing) sensor and data processing circuit): Micro micro / nanotechnology, na
48、notechnology and miniaturization: micron nanotechnology and the MEMS technology of small, small volume and weight slightly2, the detection system is developed from analog to digital to intelligent, and the detection system is analog,Multiple, complex object or system to the computer as the center, d
49、etection of multiple detection system of complex object or system parameters; data storage, transmission, processing and analysis of complex processing; detection; data storage, transmission, processing or processing complex analysis; fault diagnosisbridgeNonlinear error of 1. leg bridge and its actual output voltage compensationR, U, I, R, 1, U0 = Ui = 1 + R, 2 R, 4 R + 2, R 4 R?The relative nonlinear error of the bridge isU0 1? R 11? R 1? R? 8 = ? 1 = 1 + 1 =? = epsilon 1 = K? 1? 2 R 2 R 2 U0? 2 R?OneOne of the 2. Wheatstone bridge nonlinear error compensation method and compe
