The Internet of Things (IoT) is a network that connects any item to the Internet for information exchange and communication to realize intelligent identification, positioning, tracking, monitoring and management. In short, the Internet of Things is the "Internet of Things Connected". As an important part of the perception layer of one of the three hierarchical structures of the Internet of Things, sensors convert physical quantities, chemical quantities, and biomass in the real world into digital signals that can be processed. They are the basis and prerequisite for realizing the Internet of Things. As a supporting technology, MEMS (Micro Electro Mechanical) technology plays a vital role in the development of the Internet of Things.
As the mobile Internet market becomes saturated, the Internet of Things (IoT) has gradually become a new point for global economic growth and technological development. IDC released a report that pointed out that the market value of the global Internet of Things market will increase to $1.7 trillion in 2020. According to IoT data, about 50 billion devices will be connected to the Internet of Things in 2020, 2.5 times the current number. The basic requirement of the Internet of Things is that things are connected, and every object that needs to be identified and managed needs to be equipped with a corresponding sensor. Therefore, the upgrading of sensors has become the key to the rapid development of the Internet of Things. With the advancement of the Internet of Things technology, not only sensors are required to have basic information collection and processing functions, but a high degree of intelligence has also become the basic basis for measuring their performance.
Intelligent sensor (intelligentsensor) is a sensor with information processing function. The smart sensor has a microprocessor, which has the ability to collect, process, and exchange information. It is the product of the integration of the sensor and the microprocessor. Generally, the sensory system of an intelligent robot is composed of multiple sensors. The collected information needs to be processed by a computer, and the use of intelligent sensors can disperse the information, thereby reducing costs. Compared with general sensors, smart sensors have the following three advantages: high-precision information collection can be achieved through software technology, and low cost; it has certain programming automation capabilities; and its functions are diverse.
The main functions of smart sensors are:
(1) With self-calibration, self-calibration and self-calibration functions;
(2) With automatic compensation function;
(3) Able to automatically collect data and preprocess the data;
(4) Capable of automatic inspection, self-selecting range, and self-finding fault;
(5) With data storage, memory and information processing functions;
(6) It has two-way communication, standardized digital output or symbol output function;
(7) It has the functions of judgment and decision processing.
The concept of smart sensors was introduced from abroad, and is usually defined as "sensors with microprocessors and information processing functions." According to the national standard of "Glossary of Sensitive Components and Sensors", the definition of "sensor" here is: a device or device that can sense the prescribed measurement and convert it into a usable output signal according to a certain rule. Usually composed of sensitive components and conversion components.
After entering the 21st century, due to the development of MEMS technology, low energy consumption analog and digital circuit technology, low energy consumption radio frequency (RF) technology, and sensor technology, it is possible to develop small size, low cost and low power consumption micro sensors. This kind of micro sensor is generally equipped with: a sensitive component for sensing physical quantities of the external environment (such as pressure, temperature, humidity, light, sound, magnetism, etc.), a computing module for processing the information collected by the sensitive component, and a communication module The radio transceiver module is a power module that provides energy for various operations of the micro sensor. We call it the "fourth generation smart sensor" or "smart networked sensor".
