Distributed measurement wireless sensor network

Abstract

The invention discloses a distributed measurement wireless sensor network which comprises a center node and child nodes, and the child nodes are divided into child nodes I and child nodes II. The central node is used for synchronizing a system clock, collecting the sensor wireless signals uploaded by the child nodes, summarizing and packaging the sensor wireless signals, uploading the sensor wireless signals to the upper computer, and receiving upper computer configuration signals to configure the wireless sensor network; the child node I is used for collecting temperature signals, at most 18 thermocouple temperature signals can be collected at the same time, sensor data are packaged and uploaded to the center node, and the thermocouple type can be freely topologies according to the use requirement of a user. The child node II is used for collecting vibration sensor signals, packaging sensor data and uploading the sensor data to the center node, and at most three paths of vibration signals can be collected at the same time. According to the invention, reliable and safe acquisition of distributed multi-measuring-point sensing signals in a compact space can be realized.

Description

Technical Field

[0001] This invention relates to a distributed measurement wireless sensor network, applicable to scenarios involving a large number of distributed measurements within a compact space. Background Technology

[0002] In special application scenarios such as aviation, aerospace, and trains, sensing systems are characterized by numerous parameters and complex types, which puts forward new requirements for sensor size and weight.

[0003] Wireless sensing technology is increasingly widely used in related fields due to its characteristics such as being cable-free, flexible in deployment, and easy to use. The application scenarios in these scenarios are characterized by the need to deploy a large number of sensing points in a localized area, requiring a single wireless acquisition node to integrate and collect multiple signals to achieve distributed measurement; at the same time, because the measured objects are valuable products, high security requirements are placed on the wireless acquisition node itself.

[0004] Currently, civilian wireless sensing technologies such as Zigbee and LoRa suffer from several reliability issues: 1. Frequent network topology changes lead to unstable communication connections; 2. Node energy limitations may cause them to enter low-power modes, affecting communication quality. Security issues include: 1. The communication frequency bands are public and susceptible to interference; 2. The communication protocols are publicly available and can be decoded by third parties; 3. The authentication mechanisms are inadequate and can be accessed by third parties. Therefore, existing wireless sensing technologies fail to meet the requirements for both communication reliability and security. Summary of the Invention

[0005] In view of this, the present invention provides a distributed measurement wireless sensor network that enables reliable and secure acquisition of distributed multi-point sensor signals within a compact space.

[0006] A distributed measurement wireless sensor network includes a central node and sub-nodes, wherein the sub-nodes are divided into two types: sub-node I and sub-node II. The central node is used to synchronize the system clock, collect the sensor wireless signals uploaded by the child nodes, summarize and package them and upload them to the host computer, and receive the configuration signals from the host computer to configure the wireless sensor network. The sub-node I is used to collect temperature signals. It can collect up to 18 thermocouple temperature signals at the same time, package the sensor data and upload it to the central node. The thermocouple type can be freely topologically customized according to user needs. The sub-node II is used to collect vibration sensor signals, package the sensor data and upload it to the central node. It can collect up to 3 vibration signals at the same time.

[0007] Furthermore, the sub-node includes a housing, a base plate, a top cover plate, an antenna, a printed circuit board, a battery, a battery retaining ring, and a connector; The housing is open at both the top and bottom. An independent battery compartment is located inside the housing. The open end of the battery compartment is located at the bottom of the housing. The top cover and bottom plate are respectively installed at the top and bottom of the housing to completely enclose it. The antenna is fixed inside the top cover. The printed circuit board is fixedly connected to the upper end face of the housing. The space between the printed circuit board and the top cover is the antenna compartment. The battery is installed inside the battery compartment through a battery clamping ring. The cavity between the battery compartment, the printed circuit board and the housing forms a wiring compartment. The side wall opening of the housing communicates with the wiring compartment. The connector is installed at the opening of the side wall of the housing.

[0008] Furthermore, the shells of both the central node and the sub-nodes are integrally machined from aluminum alloy material.

[0009] Furthermore, the printed circuit board has reserved mounting pads for shielding in the radio frequency operating area and the shielding is soldered to ensure that the product has good electromagnetic compatibility.

[0010] Furthermore, the top cover plates of the central node and the child nodes are made of polytetrafluoroethylene material, and the antenna is pasted inside the top cover plate during installation.

[0011] Furthermore, the antenna is a rectangular microstrip antenna with hemispherical transmission. The antenna backplane is treated with large-area copper plating, the operating frequency band is 915MHz, and the radio frequency signal transmission direction is perpendicular to the backplane direction and transmitted to the outer hemispherical direction, so as not to cause radio frequency interference to the printed circuit board.

[0012] Furthermore, the battery retaining ring is made of polytetrafluoroethylene, which serves both as battery insulation and mechanical fixing function.

[0013] Beneficial effects: 1. The distributed measurement wireless sensor network of the present invention includes a central node and sub-nodes. The sub-nodes are divided into two types: sub-node I and sub-node II. Sub-node I can collect 18 thermocouple temperature signals, and sub-node II can collect three vibration signals. At the same time, the system has the ability to expand to multiple nodes and is suitable for distributed measurement scenarios with multiple sensor nodes in a compact space.

[0014] 2. The battery compartment and wiring compartment of this invention are mechanically isolated, so that problems such as battery leakage will not spread outward, ensuring operational safety; the wiring compartment is used for wiring between connector leads and printed circuit boards, and is mechanically isolated from the antenna compartment and battery compartment; the antenna compartment is used to install the antenna, and there is no metal obstruction on the top and sides of the antenna, ensuring a good wireless signal transmission path and improving communication reliability.

[0015] 3. This invention adopts a built-in antenna design, which is friendly to installation and use in the compact space of aerospace models and improves space utilization.

[0016] 4. The internal space of the sub-node of the present invention is designed with independent isolation of multiple compartments, which not only ensures the safety of the battery isolation, but also solves the reliability problem of the antenna being omnidirectional and unobstructed. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the structure of a child node in this invention; Figure 2 This is a schematic diagram of the shell structure; Figure 3 This is a schematic diagram of the battery clamping ring structure; Figure 4 Software flowchart for the central node of a wireless sensor network; Figure 5 A flowchart illustrating the workflow of a sub-node in a wireless sensor network; Figure 6 This is a flowchart of the hierarchical hibernation mode operation.

[0018] Among them, 1-shell, 2-base plate, 3-top cover plate, 4-antenna, 5-printed board, 6-battery, 7-battery retaining ring, 8-connector. Detailed Implementation

[0019] The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0020] This invention provides a distributed measurement wireless sensor network, including a central node and sub-nodes, wherein the sub-nodes are divided into two types: sub-node I and sub-node II. The central node is used to synchronize the system clock, collect the sensor wireless signals uploaded by the child nodes, summarize and package them and upload them to the host computer, and receive the configuration signals from the host computer to configure the wireless sensor network. Sub-node I is used to collect temperature signals. It can collect up to 18 thermocouple temperature signals at the same time, package the sensor data and upload it to the central node. The thermocouple type can be freely topologically customized according to user needs. Sub-node II is used to collect vibration sensor signals, package the sensor data and upload it to the central node. It can collect up to 3 vibration signals at the same time.

[0021] The composition and structure of the central node and child nodes are similar. The following explanation uses the child node as an example to illustrate its structure, as shown in the attached diagram. Figure 1As shown, the sub-node includes a housing 1, a bottom plate 2, a top cover plate 3, an antenna 4, a printed circuit board 5, a battery 6, a battery retaining ring 7, and connectors 8. The housing 1 is open at both the top and bottom ends, and the housing 1 has an independent battery compartment inside. The open end of the battery compartment is located at the bottom end of the housing 1. The top cover plate 3 and the bottom plate 2 are respectively installed at the top and bottom ends of the housing 1 to completely close it. The antenna 4 is glued and fixed inside the top cover plate. The printed circuit board 5 is fixedly connected to the upper end face of the housing 1. The space between the printed circuit board 5 and the top cover plate 3 is the antenna compartment. Two batteries 6 are installed inside the battery compartment through the battery retaining ring 7. The cavity between the battery compartment, the printed circuit board 5, and the housing 1 forms a wiring compartment. The side wall opening of the housing 1 is connected to the wiring compartment. Two connectors 8 are installed at the opening of the side wall of the housing 1.

[0022] Both the top cover plate 3 of the central node and the sub-nodes are made of polytetrafluoroethylene (PTFE). The antenna 4 is pasted inside the top cover plate during installation. PTFE has good signal transmission in the antenna's operating frequency band and will not affect the wireless signal transmission. At the same time, PTFE has good machinability and high temperature resistance, which can meet the requirements of the operating environment. The top cover plates of sub-nodes 1 and 2 are the same size and are interchangeable. Antenna 4 is a rectangular microstrip antenna that emits in a hemispherical direction. The antenna backplane is covered with a large area of ​​copper. The operating frequency band is 915MHz. The radio frequency signal is emitted in the outer hemispherical direction perpendicular to the backplane, so as not to cause radio frequency interference to the printed circuit board. The printed circuit board 5 has reserved pads for mounting shielding covers in the radio frequency operating area, which can be used to solder shielding covers to ensure that the product has good electromagnetic compatibility. Sub-node 1 and sub-node 2 each have two built-in 3677 button batteries, which balances the working energy capacity requirements and the small size requirements. At the same time, the dual-battery design ensures that the node power supply has redundancy and improves reliability. Sub-node 1 and sub-node 2 each have two built-in battery retaining rings 7, which are used to fix the battery. The structural diagram is shown below. Figure 3 As shown, one battery retaining ring 7 is fixed on the housing 1, and the other battery retaining ring 7 is fixed on the base plate 2. The material is made of polytetrafluoroethylene, which has both battery insulation function and mechanical fixing function. The base plate 2 is made of aluminum alloy and has a pre-drilled hole for fixing the battery pressure ring 7.

[0023] Functions and workflows of each individual node Central node: The basic software framework of the central node is shown below. Figure 4 .

[0024] The central node transmits control commands (wake-up, data reading, sleep, etc.) to each wireless sensor network sub-node wirelessly. The central node enables wireless matching and networking communication between the central node and the sub-nodes based on the written wireless sensor network sub-node device ID information; The central node periodically uploads and sends the aggregated measurement data from the sub-nodes via the Ethernet interface. At the same time, it sends the data acquisition command for the next cycle to each sub-node to carry out the data acquisition for the next cycle.

[0025] As the core unit of the entire sensor network, the central node is designed as a redundant unit to ensure reliable operation. This means that the central node has two independent power supply circuits, radio frequency processor circuits, and independent network port modules. Each of these modules can independently complete the networking control and data reception and forwarding functions of the wireless sensor network.

[0026] To avoid the wireless modules within the central node from simultaneously vying for control of the wireless network, the central node employs a dual-redundancy decision-making method based on the synchronization of two internal modules and wireless scanning to allocate network control rights. This ensures effective control of the entire wireless sensor network while avoiding the uncertainty caused by control competition.

[0027] Child nodes: The basic software framework for child nodes is shown below. Figure 5 .

[0028] Among them, wireless sensor network sub-node 1 can connect to thermocouple sensor network to complete temperature parameter acquisition and transformation, and wireless sensor network sub-node 2 can connect to vibration sensor to complete vibration parameter acquisition and transformation. Wireless sensor network sub-nodes can receive command signals from the wireless sensor network central node and respond according to their own operating mode.

[0029] The wireless sensor network sub-nodes are powered by their own batteries and have two modes: sleep and operation. In operation mode, they acquire sensor data in real time and wirelessly transmit data according to the data acquisition instructions from the central node. The transmitted data includes sensor acquisition results and sub-node status information (wireless reception strength, transmission power, battery voltage, etc.). They can also receive and respond to sleep commands from the wireless sensor network central node, switching from operation mode to sleep mode. In sleep mode, the nodes operate with extremely low power consumption and can remain dormant for over two years. The nodes can receive and respond to wake-up commands from the wireless sensor network central node, switching from sleep mode back to operation mode. The hibernation mode is set to hierarchical hibernation mode. Figure 6The software flowchart illustrates the tiered sleep mode. When a node transitions from real-time operation mode to sleep mode, the tiered sleep mode is executed. This ensures that the synchronization signal is rescanned within a short period after entering sleep mode, minimizing data loss in real-time mode due to accidental sleep interruptions. To conserve power, the tiered sleep mode is not executed when entering sleep mode from other modes, ensuring minimal power consumption during sleep mode.

[0030] In summary, the above are merely preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A distributed measurement wireless sensor network, characterized in that, It includes a central node and child nodes, and the child nodes are divided into two types: child node I and child node II; The central node is used to synchronize the system clock, collect the sensor wireless signals uploaded by the child nodes, summarize and package them and upload them to the host computer, and receive the configuration signals from the host computer to configure the wireless sensor network. The sub-node I is used to collect temperature signals. It can collect up to 18 thermocouple temperature signals at the same time, package the sensor data and upload it to the central node. The thermocouple type can be freely topologically customized according to user needs. The sub-node II is used to collect vibration sensor signals, package the sensor data and upload it to the central node. It can collect up to 3 vibration signals at the same time.

2. The distributed measurement wireless sensor network as described in claim 1, characterized in that, The sub-node includes a housing, a base plate, a top cover plate, an antenna, a printed circuit board, a battery, a battery retaining ring, and connectors; The housing is open at both the top and bottom. An independent battery compartment is located inside the housing. The open end of the battery compartment is located at the bottom of the housing. The top cover and bottom plate are respectively installed at the top and bottom of the housing to completely enclose it. The antenna is fixed inside the top cover. The printed circuit board is fixedly connected to the upper end face of the housing. The space between the printed circuit board and the top cover is the antenna compartment. The battery is installed inside the battery compartment through a battery clamping ring. The cavity between the battery compartment, the printed circuit board and the housing forms a wiring compartment. The side wall opening of the housing communicates with the wiring compartment. The connector is installed at the opening of the side wall of the housing.

3. The distributed measurement wireless sensor network as described in claim 2, characterized in that, The shells of both the central node and the sub-nodes are integrally machined from aluminum alloy.

4. A distributed measurement wireless sensor network as described in claim 3, characterized in that, The printed circuit board has pre-reserved mounting pads for the shielding cover in the radio frequency operating area, and the shielding cover is welded on to ensure that the product has good electromagnetic compatibility.

5. A distributed measurement wireless sensor network as described in claim 4, characterized in that, The top cover plates of the central node and sub-nodes are made of polytetrafluoroethylene (PTFE) material, and the antenna is attached to the inside of the top cover plate during installation.

6. A distributed measurement wireless sensor network as described in claim 5, characterized in that, The antenna is a rectangular microstrip antenna that emits in a hemispherical direction. The antenna backplane is coated with copper over a large area. The operating frequency band is 915MHz. The radio frequency signal is emitted in a direction perpendicular to the backplane and outwards in a hemispherical direction, so as not to cause radio frequency interference to the printed circuit board.

7. A distributed measurement wireless sensor network as described in claim 5 or 6, characterized in that, The battery retaining ring is made of polytetrafluoroethylene and has both battery insulation and mechanical fixing functions.

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