CN201174774Y - An Indoor Positioning System Based on 433MHz Wireless Transmission Network - Google Patents

Abstract

The utility model discloses an indoor positioning system based on a 433MHz wireless transmission network. The positioning system is composed of a server and a wireless network; the wireless network is composed of 2 to 4 readers, multiple reference nodes and tracking target nodes; the readers are respectively connected to the server through a computer communication interface or a wireless LAN communication interface; multiple reference nodes Distributed in a network, the horizontal and vertical distances between any two adjacent reference nodes are 1 to 4 meters, and the tracking target node is located in the grid composed of reference nodes; the distance between the reader and the farthest reference node is 800 meters Within meters; each reader is connected to multiple reference nodes and tracking target nodes through wireless signals, and there is no signal connection between the reference nodes and tracking target nodes. The utility model has the characteristics of low cost, long communication distance and precise positioning.

Description

An Indoor Positioning System Based on 433MHz Wireless Transmission Network

technical field

The utility model relates to a wireless positioning system, in particular to an indoor positioning system based on a 433MHz wireless transmission network.

Background technique

In recent years, as people's demand for positioning information continues to increase, positioning systems have been more and more widely used. GPS is a mature outdoor positioning technology, but since satellite signals are difficult to enter indoors, another technology is needed to realize the indoor positioning function. Current indoor positioning systems include systems based on infrared, ultrasonic, wireless local area network and radio frequency identification technologies, while systems using UHF radio frequency identification technology include 315MHz, 433MHz, 860-960MHz and other frequency bands. At present, the existing indoor positioning systems have various deficiencies, such as the problem of line-of-sight (infrared rays), small range, high cost, complex implementation methods, low accuracy, and low cost performance.

Contents of the invention

The purpose of the utility model is to overcome the shortcomings of the prior art, combining the radio frequency identification indoor positioning technology and the characteristics of the 433MHz wireless transmission network, to provide an effective system to reduce the overall cost, increase signal coverage, improve positioning accuracy An indoor positioning system based on a 433MHz wireless transmission network for tracking and positioning objects such as objects or objects.

The utility model is achieved through the following technical solutions:

An indoor positioning system based on a 433MHz wireless transmission network, which is composed of a server and a wireless network; the wireless network is composed of 2 to 4 readers, multiple reference nodes and tracking target nodes; the readers communicate through computer communication interfaces or wireless LANs The interface is connected to the server; multiple reference nodes are distributed in a network, and the horizontal and vertical distances between any two adjacent reference nodes are 1 to 4 meters. The tracking target node is located in the grid composed of reference nodes; the reader distance The distance of the farthest reference node is within 800 meters; each reader is connected with multiple reference nodes and tracking target nodes through wireless signals, and there is no signal connection between the reference nodes and tracking target nodes.

In order to further realize the purpose of the utility model, the wireless communication module is a CC1020 type wireless communication module with a relatively long transmission distance of 433 MHz frequency band.

Described central processing unit is PIC16F876 type central processing unit.

The power supply module is a 2.4-3.6V DC power supply or a 3V battery.

Described communication interface is computer communication interface or wireless local area network communication interface; Computer communication interface comprises MAXIM MAX3232RS-232 serial port communication module or Realtek RTL8139 local area network communication module; Described wireless local area network communication interface is Intel PRO2100 802.11b wireless local area network communication module.

In the indoor positioning system based on the 433MHz wireless transmission network of the present invention, the readers, reference nodes, and tracking target nodes of the wireless network part all adopt wireless communication modules with a longer transmission distance of 433MHz frequency band.

In the indoor positioning system based on the 433MHz wireless transmission network of the utility model, the reader, the reference node and the tracking target node in the wireless network use the method of time division multiple access to avoid the collision phenomenon when communicating.

The utility model has the following advantages and beneficial effects:

(1) The wireless network part uses a mature 433MHz wireless communication module, so the overall cost of the indoor positioning system can be effectively reduced.

(2) The 433MHz wireless communication module has a long communication distance, and can achieve the purpose of large-scale indoor positioning or precise indoor positioning by adjusting different transceiver powers.

(3) The use of reference nodes, on the one hand, can improve the positioning accuracy, and on the other hand, it can overcome the deterioration of the positioning effect caused by indoor environmental changes such as the flow of people in the room and changes in the placement of items.

Description of drawings

Figure 1 is a system hardware connection diagram.

Fig. 2 is a structural block diagram of a reference node and a tracking target node.

Figure 3 is a structural block diagram of the reader.

Figure 4 is a flow chart of the system work.

Detailed ways

The utility model will be described in further detail below in conjunction with the accompanying drawings, but the embodiments of the utility model are not limited thereto.

As shown in Figure 1, the indoor positioning system based on the 433MHz wireless transmission network is composed of a server 1 and a wireless network; the wireless network is composed of multiple readers 2, multiple reference nodes 3 and tracking target nodes 4; two readers 2 They are respectively connected to the server 1 through a computer communication interface or a wireless local area network communication interface. In theory, the greater the number of readers, the higher the positioning accuracy, but this will increase the overall cost of the system and the amount of calculation of the system, so it is more appropriate to use 2 to 4 readers, and 2 are used in Figure 1 Reader. A plurality of reference nodes 3 are distributed in a network, and the horizontal and vertical distances between any two reference nodes are 1 to 4 meters. The tracking target node 4 is located in the grid formed by the reference nodes 3; the reader 2 is the farthest The distance of the reference node 3 is within 800 meters.

As shown in Figure 2, both the reference node 3 and the tracking target node 4 include a wireless communication module 21, a central processing unit 22, and a power supply module 23, and the power supply module 21 is electrically connected to the wireless communication module 21 and the central processing unit 22 respectively, and the wireless communication module 21 is connected with central processing unit 22 signal.

As shown in FIG. 3 , the reader 2 includes a wireless communication module 21 , a central processing unit 22 , a power supply module 23 and a communication interface 24 . The power supply module 21 is electrically connected with the wireless communication module 21 , the central processing unit 22 and the communication interface 24 respectively. Signal connection among the communication module 21 , the central processing unit 22 and the communication interface 24 . The communication interface 24 is an ordinary computer communication interface or a wireless local area network communication interface.

The readers, reference nodes, and tracking target nodes of the wireless network all use wireless transceiver modules in the 433MHz frequency band with a long transmission distance, and use time-division multiple access methods to avoid collisions when communicating. The maximum communication distance of each node in the wireless network depends on the communication distance of the selected wireless communication module 21, and the communication distance of the 433MHz wireless communication module 21 is generally 0-800 meters under ideal conditions (the specific performance of different modules is slightly different) . When used in an indoor positioning system, the reference nodes 3 can be placed according to the actual accuracy requirements. The typical application is to place the reference nodes 3 at intervals of 1-2 meters. The smaller the interval, the higher the positioning accuracy. The general accuracy requirements , the reference nodes 3 can be placed at intervals of 1 to 4 meters. In terms of hardware configuration, the reference node 3 and the tracking target node 4 are the same, but since the reference node 3 is generally placed in a hidden place such as under the floor or above the ceiling, while the tracking target node 4 is worn on a person or an object, Therefore, there will be differences in specific circuit and shape designs to adapt to different usage methods.

In terms of hardware composition, each part has optional components. Server 1 can select personal computer or computer server; Wireless communication module 21 can select CC1020 of Chipcon Company; Central processing unit 22 can select PIC16F876 of Microchip Company, and power supply module 23 can use the DC power supply of 2.4-3.6V to supply power or use the battery of 3V For power supply, the reader 2 and the reference node 3 are recommended to use a DC power supply, and the tracking target node 4 can only be powered by a battery because it will be worn on the target; the communication interface 24 can be a computer communication interface or a wireless LAN communication interface; the computer communication interface It can be MAXIM MAX3232RS-232 serial communication module or Realtek RTL8139 LAN communication module; the wireless LAN communication interface can be Intel PRO2100 802.11b wireless LAN communication module.

The indoor positioning system based on the 433MHz wireless transmission network of the utility model can be used for tracking and positioning of personnel and objects in exhibition venues, meeting rooms, hospitals and other occasions. The target to be tracked and positioned carries a tracking target node, through which the tracking target node communicates with the reference node to the reader, and the server calculates the position of the target in real time to realize the functions of positioning and tracking.

In Figure 1, the reference nodes are regularly placed indoors, and the reference nodes can be powered by a DC power supply, or can be directly powered by a battery. Place the reader in the corner of the room, and the reader is powered by a DC power supply. The reader is connected with the server through a computer communication interface or a wireless local area network communication interface. The target being tracked and positioned carries a tracking target node with it. Each reader, reference node, and tracking target node has a unique number. In the wireless network, the information of each node is collected by the reader, and then the specific location of each tracking target node in the room is calculated by the server.

The wireless network in the system of the utility model uses a 433MHz wireless frequency band, and the reader adopts the method of time division multiple access for the communication of the reference node and the tracking target node, thereby avoiding communication collisions between various wireless communication modules, improving positioning intensive reading, and simultaneously Reduce radio pollution and reduce power consumption in wireless network environments. In addition, the wireless communication system based on the 433MHz frequency band is relatively mature, and the cost is relatively low, thereby reducing the difficulty of building the system.

The indoor positioning method based on the 433MHz wireless transmission network of the present utility model, as shown in Figure 4, comprises the following steps:

a. When the target needs to be positioned, the server sends a positioning command to the reader through the computer communication interface or the wireless LAN communication interface;

b. After receiving the positioning command from the server, the reader uses the method of time division multiple access to sequentially send request commands to each reference node and tracking target node. Specifically, the reader first sends a request command to one of the nodes in a certain order, and then sends request commands to other nodes in turn after receiving the response command returned by the node;

c. After receiving the request command, the reference node and the tracking target node immediately send a response command to the reader, and the response command includes the number of the node and other relevant information;

d. After receiving the response commands from all reference nodes and tracking target nodes, the reader sorts out the data including response commands and node signal field strength and sends them to the server;

e. After receiving the data from the reader, the server calculates the exact location of the tracking target node according to the LANDMARC algorithm.

The indoor positioning system and positioning method based on the 433MHz wireless transmission network of the utility model all use mature 433MHz wireless transceiver modules in the wireless network part, which can effectively reduce the overall cost of the indoor positioning system. By adjusting different transceiver powers, the purpose of wide-range indoor positioning or precise indoor positioning can be achieved. The use of reference nodes can improve positioning and intensive reading, and can overcome the deterioration of positioning effects caused by indoor environment changes such as the flow of people in the room and changes in the placement of items, thereby improving the performance and intensive reading of indoor positioning.

Claims (5)

1. An indoor positioning system based on a 433MHz wireless transmission network, characterized in that: the positioning system is composed of a server and a wireless network; the wireless network is composed of 2 to 4 readers, multiple reference nodes and tracking target nodes; the reader Connect to the server through computer communication interface or wireless local area network communication interface; multiple reference nodes are distributed in a network shape, the horizontal and vertical distances between any two adjacent reference nodes are 1 to 4 meters, and the tracking target node is located at the reference node In the grid formed; the distance between the reader and the farthest reference node is within 800 meters; each reader is connected with multiple reference nodes and tracking target nodes through wireless signals, and the distance between the reference node and the tracking target node Signal connections are not made. Both the reference node and the tracking target node include a wireless communication module, a central processing unit, and a power supply module, the power supply module is electrically connected to the wireless communication module and the central processing unit, and the wireless communication module is connected to the central processing unit in a signal manner. The reader includes a wireless communication module, a central processing unit, a power supply module, a computer communication interface or a wireless local area network communication interface; the power supply module is electrically connected to the wireless communication module, the central processing unit, and the computer communication interface or the wireless local area network communication interface; Signal connection between modules, CPU and communication interface. 2. The indoor positioning system based on a 433MHz wireless transmission network according to claim 1, wherein the wireless communication module is a CC1020 wireless communication module with a relatively long transmission distance in the 433MHz frequency band. 3. The indoor positioning system based on a 433MHz wireless transmission network according to claim 1, wherein the central processing unit is a PIC16F876 central processing unit. 4. The indoor positioning system based on a 433MHz wireless transmission network according to claim 1, wherein the power supply module is a 2.4-3.6V DC power supply or a 3V battery. 5. The indoor positioning system based on a 433MHz wireless transmission network according to claim 1, wherein said communication interface is a computer communication interface or a wireless local area network communication interface; the computer communication interface includes a MAXIM MAX3232 RS-232 serial communication module Or Realtek RTL8139 LAN communication module; the wireless LAN communication interface is Intel PRO2100 802.11b wireless LAN communication module.

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