A kind of navigation system based on ZigBee technology
Technical field:
The present invention relates to a kind of navigation system, particularly relate to a kind of navigation system based on Zigbee-technology and method.
Background technology:
In recent years, along with expanding economy and social progress, the demand of people to locating information grows with each passing day, especially in the indoor environment of complexity, as places such as office block, Private Lounge, warehouse, hospital, underground parking, libraries, usually need the particular location determining different personnel.Existing indoor positioning technologies has ultrasonic wave location technology, indoor-GPS technology, Wifi location technology and bluetooth location technology.
Ultrasonic wave location technology is issued to from reflector the transit time TOA that ultrasonic receiver experiences calculates distance by measuring ultrasonic wave.Ultrasonic positioning system can be made up of several transponders and a main distance measuring equipment, main distance measuring equipment is placed on testee, the radio signal of same frequency launched by the transponder fixed to position under the effect of command signal, transponder launches ultrasonic signal to main distance measuring equipment after receiving radio signal simultaneously, obtains the distance between main distance measuring equipment and each transponder.When having that more than 3 or 3 transponder does not on the same line give a response simultaneously, the position under the two-dimensional coordinate system at testee place can be determined according to correlation computations.It is higher that ultrasonic wave locates overall positioning precision, and structure is simple, but ultrasonic wave affects very greatly by multipath effect and non-line-of-sight propagation, and need a large amount of bottom hardware facility investments, cost is too high simultaneously.
Indoor-GPS technology, because gps signal is by the impact of various object in indoor environment, signal attenuation is very fast, in order to improve the signal susceptibility of GPS, needing to increase a large amount of auxiliary equipment, thus improve cost and the power consumption of equipment.And the positioning precision of indoor GPS only can reach 5 meters to about 30 meters, can not meet the requirement of indoor positioning preferably.
Wifi location technology is positioned by the decay of Wifi signal and the relation of distance, has wide coverage, and information transfer rate is fast, realizes the advantages such as cost is lower.But because the Wifi signal fluctuation under indoor environment is very large, cause the not high of positioning precision.
Bluetooth technology is a kind of Radio Transmission Technology of short distance low-power consumption, positioned by measure signal intensity, at the bluetooth local area network access point that indoor location is suitable, network configuration is become the basic network connection mode based on multi-user, and ensure that bluetooth local area network access point is main equipment all the time, just can obtain the positional information of user.Bluetooth technology is mainly used in locates among a small circle, such as individual layer hall or warehouse.The maximum advantage of bluetooth indoor wireless location technology is that the little and Signal transmissions of equipment volume is by the impact of sighting distance.Bluetooth location technology deficiency is that the price comparison of bluetooth devices and equipment is expensive, and for the space environment of complexity, the stability of Bluetooth system is slightly poor, large by noise signal interference.
ZigBee technology be a kind of closely, low complex degree, low-power consumption, low rate, low cost bidirectional wireless communication technology.Be mainly used in apart from application that is short, low in energy consumption and that carry out transfer of data between the various electronic equipments that transmission rate is not high and typically have periodic data, intermittent data and low reaction time data to transmit.
Zigbee is a kind of highly reliable wireless data sending network, be one by a wireless data sending network platform that can how to form to 65000 wireless data transmission modules, in whole network range, can intercom mutually between each Zigbee network digital transmission module, the distance between each network node can from the 75m infinite expanding of standard.Each Zigbee " base station " is but less than 1000 yuans.Each Zigbee network node not only itself can as monitored object, and such as its transducer connected directly carries out data acquisition and monitoring, automatically can also pass the data information of coming by other network node of transfer.In addition, each Zigbee network node (FFD) also can in the scope of oneself quorum sensing inhibitor, and multiple isolated child node (RFD) wireless connections not bearing network information transfer task.
Therefore ZigBee technology is applicable to controlled in wireless (as the Industry Control occasion etc.) application to delay requirement harshness.Network capacity is large: the Zigbee network of a hub-and-spoke configuration can hold at most 254 from equipment and a main equipment, can there are maximum 100 ZigBee-networks in a region simultaneously, and network composition flexibly.Reliable: to take collision avoidance strategy, simultaneously for needing the communication service of fixed-bandwidth to reserve dedicated time slot, avoid the competition and conflict that send data.MAC layer have employed the data-transmission mode confirmed completely, the confirmation of the necessary wait-receiving mode side of packet of each transmission.Can retransmit if gone wrong in transmitting procedure.
Summary of the invention:
The object of the invention is to, overcome the shortcoming of prior art, Zigbee-technology and pyroelectricity sensing technology are combined, propose that a kind of cost is low, the navigation system of good positioning effect and method.
To achieve these goals, the present invention is achieved through the following technical solutions: a kind of navigation system based on Zigbee-technology and pyroelectricity sensing technology, and system adopts and comprises sense node, blind node and aggregation node; Sense node is made up of radio-frequency (RF) transceiver and pyroelectric sensor, human body information and radio communication; Described blind node contains radio-frequency (RF) transceiver, by needing the personnel of location to carry, by the information interaction with sense node, realizes location; Described aggregation node, as the coordinator of whole network, is responsible for setting up and managing wireless sensing net.Blind node, aggregation node and multiple sense node form the wireless sense network of self-organizing, and zigbee wireless communication protocol adopts ZigBee2007/PRO agreement.
Based on a localization method for information interaction, adopt and comprise wireless sense network and the Zigbee network that sense node, blind node and aggregation node form self-organizing; Sense node is made up of radio-frequency (RF) transceiver and pyroelectric sensor, human body information and radio communication; Described blind node contains radio-frequency (RF) transceiver, by needing the personnel of location to carry, by the information interaction with sense node, realizes location; Described aggregation node is the coordinator of Zigbee network; Localization method is characterized in that comprising the steps:
After step 1, aggregation node start, select the communication channel preset, set up Zigbee wireless sense network;
Step 2, sense node log in Zigbee radio sensing network, send sense node log messages to aggregation node, and induction log messages comprises No. ID of sense node and the space coordinates of sense node; Aggregation node upgrades sense node information table after receiving induction log messages, and replys login acknowledge message to sense node;
Step 3, blind Node registers Zigbee radio sensing network, send blind Node registers message to aggregation node, and blind Node registers message comprises No. ID of blind node and the initial coordinate of blind node; After aggregation node receives blind Node registers message, reply and log in acknowledge message to blind node;
Step 4, personnel to be positioned carry blind node and move, and when a certain sense node detects human body information, this sense node sends apply for information with the form of broadcast packet, No. ID that inquires blind node; Apply for information comprises No. ID of sense node, the short address of sense node and RSSI value
Step 5, when blind node receives the apply for information of broadcast, according to inquire response strategy, clean culture sends inquire response message to corresponding sense node; Inquire response message comprises No. ID and RSSI value of blind node; The process of inquire response strategy is as follows:
1) if blind node receives the apply for information of a sense node broadcast, then first by the RSSI value in this sense node apply for information and the thresholding R preset
threlatively, if RSSI value is greater than default thresholding R
th, then inquire response message is sent to this sense node;
2) if blind node receives the apply for information of multiple sense node broadcast, then the RSSI value in multiple apply for information is sorted, find that sense node that RSSI value is maximum, then by the RSSI value in this sense node apply for information and the thresholding R preset
threlatively, if RSSI value is greater than default thresholding R
th, send inquire response message to this sense node;
After step 6, sense node receive the response message that blind node sends, send localization message to aggregation node; Comprise in localization message No. ID of blind node, the RSSI value of blind node, No. ID of sense node and sense node space coordinates;
Step 7, aggregation node upgrade the space coordinates of blind node, and send Relocation Commit message to sense node, complete whole position fixing process after receiving the localization message that sense node sends.
Aggregation node is the coordinator of zigbee network, is responsible for building network, only has an aggregation node in system; Sense node is the router of zigbee network; Blind node is the terminal node of zigbee network; Three kinds of nodes form zigbee network jointly.
Beneficial effect of the present invention is: with low cost, algorithm complex is low, node communication expense is little, is easy to carry and disposes flexibly.
Accompanying drawing illustrates:
Fig. 1 is application scenarios schematic diagram of the present invention;
Fig. 2 is the structural representation of sense node of the present invention;
Fig. 3 is the structural representation of blind node of the present invention and aggregation node;
Fig. 4 is the information interaction schematic diagram of localization method of the present invention.
Embodiment:
As shown in Figure 1, the navigation system based on ZigBee technology of the present invention comprises sense node, blind node and aggregation node.Blind node carries by needing the target of locating; Sense node is unified fixed part and is deployed on indoor ceiling, and its space coordinates measures in advance when disposing, and is stored in sense node; Aggregation node is the coordinator of zigbee wireless sense network, is responsible for setting up and managing whole wireless sense network.Sense node is after human body information being detected, and by a series of information interactions with blind node, the changing coordinates of blind node sends to aggregation node the most at last, completes whole position fixing process.
Fig. 2 is the structural representation of sense node, is made up of the radio-frequency module of the microprocessor module of responsible deal with data, wireless data transceiving, the pyroelectric sensor of induction human body information and power module.
Fig. 3 is the structural representation of blind node and aggregation node, is made up of the microprocessor module of responsible deal with data, the radio-frequency module of wireless data transceiving and power module.
Fig. 4 is the information interaction schematic diagram of localization method of the present invention, and concrete realization comprises the following steps:
After step 1, aggregation node start, select the communication channel preset, set up Zigbee wireless sense network.
After step 2, sense node add Zigbee radio sensing network, send sense node log messages to aggregation node, aggregation node upgrades sense node information table after receiving induction log messages, and replys login acknowledge message to sense node.
After step 3, blind node add Zigbee radio sensing network, send blind Node registers message to aggregation node, after aggregation node receives blind Node registers message, reply and log in acknowledge message to blind node.
Step 4, personnel to be positioned carry the blind node signing in wireless sense network and move, and when a certain sense node detects human body information, this sense node sends apply for information with the form of broadcast packet, No. ID that inquires blind node.
Step 5, when blind node receives the apply for information of broadcast, according to inquire response strategy, clean culture sends inquire response message to corresponding sense node.The process of inquire response strategy is as follows:
1) if blind node receives the apply for information of a sense node broadcast, then first by the RSSI value in this sense node apply for information and the thresholding R preset
threlatively, if RSSI value is greater than default thresholding R
th, then inquire response message is sent to this sense node;
2) if blind node receives the apply for information of multiple sense node broadcast, then the RSSI value in multiple apply for information is sorted, find that sense node that RSSI value is maximum, then by the RSSI value in this sense node apply for information and the thresholding R preset
threlatively, if RSSI value is greater than default thresholding R
th, send inquire response message to this sense node;
After step 6, sense node receive the response message that blind node sends, send localization message to aggregation node.
Step 7, aggregation node upgrade the space coordinates of blind node, and send Relocation Commit message to sense node, complete whole position fixing process after receiving the localization message that sense node sends.