Wireless sensors have a wide range of applications; almost every electronic device in our daily lives contains a wireless sensor. Therefore, wireless sensors are not unfamiliar to most people. To further enhance everyone's understanding of wireless sensors, this article will introduce wireless sensors and their different types.
The components of a wireless sensor are encapsulated in a housing. During operation, it is powered by a battery or vibration generator, forming nodes in a wireless sensor network. These randomly distributed micro-nodes, integrating sensors, data processing units, and communication modules, form a self-organizing network. A sensor network system typically includes sensor nodes, aggregation nodes, and management nodes.
Sensor network systems typically include sensor nodes, aggregation nodes, and management nodes.
A large number of sensor nodes are randomly deployed within or near the monitoring area, forming a network through self-organization. Data monitored by each sensor node is transmitted hop-by-hop along other sensor nodes. During transmission, the monitoring data may be processed by multiple nodes, routed to a convergence node after multiple hops, and finally reaches the management node via the Internet or satellite. Users configure and manage the sensor network, issue monitoring tasks, and collect monitoring data through the management node.
A Wireless Sensor Network (WSN) is a multi-hop, self-organizing network system composed of a large number of inexpensive, miniature sensor nodes deployed within a monitoring area. It communicates wirelessly to collaboratively sense, collect, and process information about objects within the network's coverage area and transmit it to observers. Sensors, the sensed objects, and observers constitute the three essential elements of a wireless sensor network.
The rapid development of Micro-Electro-Mechanical Systems (MEMS), Systems-on-Chip (SoC), wireless communication, and low-power embedded technologies has given rise to Wireless Sensor Networks (WSNs), which have brought about a revolution in information perception due to their low power consumption, low cost, distributed nature, and self-organizing characteristics. A WSN is a multi-hop, self-organizing network composed of a large number of inexpensive miniature sensor nodes deployed within a monitoring area, formed through wireless communication.
Many believe this technology is comparable in importance to the Internet: just as the Internet enabled computers to access digital information regardless of its location, sensor networks will expand people's ability to interact remotely with the real world. It's even been called a completely new type of computer system because of its departure from the ubiquitous nature of past hardware and its collective analytical capabilities. However, in many ways, today's wireless sensor networks are like the Internet in the 1970s, when it connected fewer than 200 universities and military labs, and researchers were still experimenting with various communication protocols and addressing schemes. Now, most sensor networks connect fewer than 100 nodes; more nodes and communication lines would make them too complex and difficult to function properly. Another reason is that individual sensor nodes are still relatively expensive, and battery life, even at its best, only lasts a few months. However, these problems are not insurmountable. Some wireless sensor network products are already on the market, and new products with compelling features will emerge within the next few years.
Wireless sensor networks (WSNs) utilize a wide variety of sensors to detect diverse phenomena in the surrounding environment, including earthquakes, electromagnetic fields, temperature, humidity, noise, light intensity, pressure, soil composition, and the size, speed, and direction of moving objects. MEMS-based micro-sensing and wireless networking technologies offer WSNs a broad range of applications. These potential application areas can be categorized as follows: military, aerospace, counter-terrorism, explosion protection, disaster relief, environmental, medical, healthcare, home, industrial, and commercial.
Types of wireless sensors
Wireless sensors consist of modules encapsulated in a housing. During operation, they are powered by a battery or vibration generator, forming wireless sensor network nodes, and are widely used in various fields. What types of wireless sensors are there? Below is a detailed introduction.
Vibration sensor
Each node's maximum sampling rate can be set to 4kHz, and each channel is equipped with an anti-aliasing low-pass filter. Collected data can be wirelessly transmitted to a computer in real time or stored in the node's built-in 2MB data storage, ensuring data accuracy. The effective outdoor communication distance is up to 300m, and the node consumes only 30mA of power, allowing for continuous measurement for 18 hours using a built-in rechargeable battery. If a node with a USB interface is selected, you can both charge the node via USB and quickly download data from the storage to your computer.
strain sensor
The node boasts a compact structure and small size, comprising a power module, a data acquisition and processing module, and a wireless transceiver module, all encapsulated in a PPS plastic housing. Each channel of the node has an independent high-precision 120-1000Ω bridge resistor and amplification and conditioning circuitry, allowing for convenient automatic software switching between 1/4-bridge, half-bridge, and full-bridge measurement modes. It is compatible with various types of bridge sensors, such as strain, load, torque, displacement, acceleration, pressure, and temperature sensors. The node supports both 2-wire and 3-wire input methods, with automatic bridge balancing, and data can be stored in the node's built-in 2MB data memory. The effective outdoor communication distance reaches 300 meters. Continuous measurements can be performed for over ten hours.
Torque sensor
The node features a compact structure and small size, encapsulated in a resin housing. Each channel of the node incorporates a high-precision 120-1000Ω bridge resistor and amplification and conditioning circuitry. Automatic bridge balancing is implemented. The node achieves an over-the-air transmission rate of up to 250K BPS, an effective real-time data transmission rate of 4K SPS, and an effective indoor communication distance of up to 100 meters. The node incorporates dedicated power management hardware and software, consuming only 25mA under continuous real-time transmission conditions. Using a standard 9V battery, it can perform continuous measurements for dozens of hours. For long-term monitoring applications, transmitting torque values at 5-minute intervals eliminates the need for battery replacements for several years, significantly improving the system's maintenance-free operation.
