The composition, function, characteristics, development trend and application of intelligent sensors are analyzed in detail.

Recently, the Ministry of Industry and Information Technology officially issued the "three-year action guide for smart sensor industry (2017-2019)" (referred to as the "guide"). In order to implement the strategy of Made-in-China 2025, the Ministry of Industry and Information Technology launched the compilation of the guide in April 2016 and issued it formally on November 20, 2017. The overall goal of the Guide is to achieve a significant breakthrough in the sensor industry by 2019, with the smart sensor industry reaching 26 billion yuan in scale. Five enterprises with more than 1 billion yuan in main business and 20 enterprises with more than 100 million yuan in main business. The production capacity of micro-electro-mechanical system (MEMS) process line has increased steadily.

What is a smart sensor?

As a tool for human to obtain information, sensors are an important part of modern information technology. Traditionally, the output of sensors is mostly analog signals, which do not have the function of signal processing and networking, and need to be connected to a specific measuring instrument to complete the signal processing and transmission functions. Intelligent sensors can process raw data internally, exchange data with the outside world through standard interfaces, and change the work of sensors through software control according to actual needs, so as to realize intellectualization and networking. Because of the use of standard bus interface, intelligent sensor has good openness and expansibility, which brings great development space to the expansion of the system.

The composition, function, characteristics, development trend and application of intelligent sensors are analyzed in detail.

The concept of smart sensors was first proposed by NASA in the process of developing spacecraft, and was formed in 1979. Spacecraft requires a large number of sensors to continuously send data such as temperature, position, speed and attitude to the ground or spacecraft processors. Even using a large computer, it is difficult to process such huge data at the same time. Moreover, the spaceship limits the volume and weight of the computer, so we hope that the sensor itself has the function of information processing. Therefore, when the sensor is combined with the microprocessor, an intelligent sensor appears.

Intelligent sensor is a new type of sensor which can sense and detect some information of the object under test, can learn, reason, judge and process signals, and has communication and management functions. Intelligent sensors have the abilities of automatic zero calibration, calibration, compensation and data acquisition. Its ability determines that the intelligent sensor also has high accuracy and resolution, high stability and reliability, and good adaptability. Compared with traditional sensors, it also has a very high performance-price ratio.

The early intelligent sensor is that the output signal of the sensor is processed and transformed, and then sent by the interface to the microprocessor for calculation and processing. In the 1980s, the smart sensor mainly took the microprocessor as the core, and integrated the sensor signal adjustment circuit, the microcomputer memory and the interface circuit into a chip, which made the sensor have certain artificial intelligence. Intelligent measurement technology has been further improved in the 1990s. The sensor has realized miniaturization, integration of structure, array and digital mode. It is easy to use and operate. It also has self-diagnosis function, memory and information processing function, data storage function, multi-parameter measurement function, network communication function, logical thinking and judgment function.

Generally speaking, intelligent sensors can be divided into three types: sensors with judgment ability, sensors with learning ability and sensors with creativity.

Structure Composition of Intelligent Sensor

The composition, function, characteristics, development trend and application of intelligent sensors are analyzed in detail.

Intelligent sensor system is mainly composed of sensors, microprocessors and related circuits, as shown in the figure. The sensor converts the measured physical and chemical quantities into corresponding electrical signals and sends them to the signal modulation circuit. After filtering, amplification and A/D conversion, the sensor is sent to the microprocessor. The microprocessor calculates, stores and analyses the received signal. On the one hand, it adjusts the sensor and signal conditioning circuit through the feedback loop to realize the regulation and control of the measurement process. On the other hand, it transmits the results of the processing to the output interface. After the processing of the interface circuit, the digital measurement results are customized according to the output format and interface. Microprocessor is the core of intelligent sensor. Because microprocessor gives full play to the functions of various software, it makes sensor intelligent and greatly improves the performance of sensor.

The composition, function, characteristics, development trend and application of intelligent sensors are analyzed in detail.

Characteristics of Intelligent Sensors

High accuracy

Intelligent sensors can automatically correct system errors such as overall system calibration, non-linearity and so on by automatic zero-correction and real-time comparison with standard reference standards. Large amounts of data are collected in real-time for analysis and processing to eliminate the impact of accidental errors and ensure the high accuracy of intelligent sensors.

High reliability and stability

Intelligent sensors can automatically compensate for the drift of system characteristics caused by the change of working conditions and environmental parameters, such as the drift of zero and sensitivity caused by fluctuation of ambient temperature and supply voltage of the system; after the change of measured parameters, they can automatically change the range, carry out real-time system self-examination, analysis and judgment of the rationality of the collected data, and automatically respond to abnormal situations. Emergency treatment.

High SNR and High Resolution

Because the intelligent sensor has the functions of data storage, memory and information processing, the noise in the input data can be removed and useful data can be extracted automatically by digital filtering and other correlation analysis processing. The influence of cross sensitivity in multi-parameter state can be eliminated by data fusion and neural network technology.

Strong Adaptability

intelligent sensor

Please read the Chinese version for details.