This research is about the combined use of pressure cable sensors and CCD systems in the needs of burglary, surveillance, monitoring and so on. For its characteristics, it can be used in prisons, labor camps, drug rehabilitation centers, for monitoring. Can also be used in museums, homes, etc., to play the role of anti-theft. In these applications, the requirements of the sensor's covert and timely understanding of the situation, so the pressure cable sensor and CCD combined with the use of this sensor is not easy to be found, and CCD together, can play a better role in anti-theft, monitoring.
With the development of science and technology, people for the public **** business or private demand for anti-theft surveillance products more and more demanding, people require high efficiency, high performance (for example, can be adapted to both high temperature and low temperature and other special environments), low-cost, easy to operate, etc., the subject is to adapt to the needs of this society and the emergence of this topic.
Research (social survey) situation:
Sensor technology is one of the important technologies of modern measurement and automation systems, from the development of the universe to the bottom of the sea to explore the mysteries of the sea, from the process control of the production to the life of modern civilization, almost every technology can not be separated from the sensor, therefore, many countries attach great importance to the development of sensor technology. Such as Japan's sensor technology as one of the six core technologies (computers, communications, lasers, semiconductors, superconductors and sensors).
In all types of sensors in the pressure sensor has a small size, light weight, high sensitivity, stable and reliable, low cost, easy to integrate the advantages, can be widely used for pressure, height, acceleration, liquid flow, flow rate, level, pressure measurement and control. In addition to this, it is also widely used in water conservancy, geology, meteorology, chemical industry, medical and health care. As the technology is a combination of plane technology and three-dimensional processing, and easy to integrate, so can be made into a sphygmomanometer, anemometer, water velocity meter, pressure gauge, electronic scale and automatic alarm devices. Pressure sensors have become the most mature technology in all types of sensors, the most stable performance, the most cost-effective class of sensors.
CCDs are widely used in digital photography, astronomy, especially optical telemetry, optical and spectral telescopes, and high-speed photography, such as Lucky imaging. CCDs are widely used in video cameras, digital cameras, and scanners, except that video cameras use dot-matrix CCDs, which are used to capture flat images in both x and y directions, while scanners use linear CCDs, which have only x and y directions. is a linear CCD, it only x a direction, y direction scanning by the scanner's mechanical device to complete.
There are two kinds of CCD process, one is the TTL process, one is the CMOS process, now the market said the TTL and CMOS are in fact CCD, only the processing process is different, the former is a milliampere power consumption, while the latter is a microampere power consumption. TTL process CCD image quality is better than the CMOS process CCD. CCD widely used in industry, civilian products. CCDs are widely used in industry and civil products.
Proposed research methodology: (specifically write the research methodology and implementation of this topic)
(1) according to the characteristics of the pressure cable sensor, the design of the detection of the front-end circuit, the circuit to meet the characteristics of high and low temperature resistance, such as the emergence of the transboundary situation, the pressure cable sensor detects the situation after the alarm, and at the same time the CCD monitors the scene, will be the sensor alarm signal and the CCD monitoring signal sent to the same gateway node. The sensor alarm signal and CCD monitoring signal will be sent to the same gateway node, and then the gateway node will send the signal to the host computer through wireless.
Which streamlined 51 kernel as the gateway node microprocessor.
The overall structure diagram is as follows:
(2) The front-end circuit mainly includes pressure module, CCD module. Among them, the pressure module includes a pressure sensor unit and a signal amplification unit, where the pressure sensor module is used to sense the external pressure and convert the pressure into a differential voltage value, and the signal amplification unit is mainly used to amplify the input voltage signal and convert it into a single voltage signal from the differential signal.
Research plan: (fill in the research content of the topic and time nodes)
(Phase schedule:
March 15, 2012 Graduation design theme, students hand in the graduation design theme report, the defense
May 9, 2012; the College of the graduation design of the midterm inspection, hand in the translation
May 30, 2012 ; hand in the graduation design thesis, the college centralized review
June 11-15, 2012 student graduation defense)
Literature review (not less than 1000 words of the body + 15 references, which should include English references)
1. Widely used in electronic computers, robotics, automatic control technology and other technologies. Practical applications are very wide, as large as CNC machine tools , automobiles as small as household appliances have sensors. Sensor installation, connection and other factors can affect the sensor measurement results. Only through practice, hands-on use of sensors, you can know how the sensor should be connected to other circuits, how to work properly. We usually use the pressure sensor is mainly the use of piezoelectric effect manufactured, such sensors are also known as piezoelectric sensors
Piezoelectric sensors in the main piezoelectric materials used in the quartz, potassium sodium tartrate and dihydrogenamine phosphate. Quartz (silicon dioxide) is a natural crystal in which the piezoelectric effect is found. Within a certain temperature range, the piezoelectric properties are always present, but after the temperature exceeds this range, the piezoelectric properties disappear completely (this high temperature is the so-called "Curie point").
The piezoelectric effect is the main operating principle of piezoelectric sensors, which cannot be used for static measurements because the charge after an external force is preserved only if the loop has an infinite input impedance. This is not the case in practice, so this determines that piezoelectric sensors can only measure dynamic stresses.
Piezoelectric sensors are mainly used in the measurement of acceleration, pressure and force. Piezoelectric acceleration sensor is a commonly used accelerometer. It has excellent features such as simple structure, small size, light weight and long service life. Piezoelectric acceleration sensors have been widely used in vibration and shock measurements in airplanes, automobiles, ships, bridges and buildings, especially in aviation and astronautics where they have a special place. Piezoelectric sensors can also be used to measure combustion pressure measurements and vacuum measurements inside engines. It can also be used in the military industry, for example, it is used to measure the instantaneous change in the chamber pressure of the gun bullet in the chamber and the muzzle of the shock wave pressure. It can be used to measure both large and tiny pressures.
2. CCD image sensor, also known as charge-coupled device image sensor. Can be converted into electrical signals from the image data from optical signals, is an indispensable into the image of the world's imaging components.CCD image sensor and the traditional camera tube comparison, with a small size, light weight, electricity, low price, long life, strong shock resistance and not affected by the magnetic field and other advantages.
For more monitoring camera system, I hope all the video input signal is vertically synchronized, so that the camera output in the change, will not cause screen distortion, but due to the multi-camera system, the camera power supply may be taken from the three-phase power supply in different phases, or even the whole system is not synchronized with the AC power supply, at this time, measures can be taken are: are using the same external synchronization signal generator Generated by the synchronization signal into the camera's external synchronization input to adjust the synchronization, so as to obtain the appropriate vertical synchronization, phase adjustment range of 0 ~ 360 degrees.
The core of the CCD sensor is a photodiode, which produces an output current after receiving light, the intensity of which corresponds to the light intensity.
CCD photodiode in addition to including the photodiode, in its periphery also includes a storage unit for the control of adjacent charge, but the photodiode occupies the vast majority of the area, that is to say, CCD photodiode in the effective light-sensitive elements in the larger area, under the same conditions can receive stronger light signals, corresponding to the output current is also strong, the performance of the output results of the captured image content
Working Principle: After receiving light, the light-sensitive element produces a corresponding current, the size of the current corresponds to the intensity of the light, so the light-sensitive element output electrical signals are analog. In the CCD, each photoreceptor does not do further processing, but the electrical signal is directly output to the next photoreceptor storage unit, combined with the analog signal generated by the element in the output to the third photoreceptor, and so on, to know that the combination of the last photoreceptor signals eventually form a unified output. As the light-sensitive element generated by the electrical signal is very weak, can not be directly analog-to-digital conversion work, so these output data must be done to unify the amplification process, this task by the sensor amplifier is specifically responsible for the amplifier processing, after the amplifier, the electrical signal strength of each image point have been the same magnitude of the increase, but due to the CCD itself can not carry out the AD conversion, and therefore also need a special analog-to-digital conversion chip Processing, and ultimately to, the form of binary digital image matrix output to the specialized DSP processing chip.
3. Computer, microcontroller experimental development system to complete the program editing, compiling, downloading programs and other tasks.
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