CN105654766A - Underground parking car finding system based on ZigBee fingerprint positioning technology and control method thereof - Google Patents

Abstract

A large-scale underground parking lot car-finding system based on ZigBee fingerprint positioning technology, which helps car owners park and leave. After returning to the parking lot for a long time, they can quickly find their own parking spaces, improve the efficiency of the parking lot, and save time and energy for car owners. ;? The present invention can help car owners find their own parking spaces as soon as possible, saves the time and energy of car owners, and improves the efficiency of the parking lot; improves the automation of car search, and automatically realizes on-site registration (binding), positioning and parking. Leave the logout (unbind) process. Minimize the manual operation process of the car owner in the process of finding the car; considering the situation of multiple people parking at the same time and multiple people looking for the car at the same time, while the ultrasonic ranging sensor accurately detects the parking space, the ZigBee wireless network node locates the handheld parking lot card, and bind the two to avoid confusion in the binding of parking spaces and parking cards when multiple people park at the same time.

Description

A car-finding system and control method in an underground parking lot based on ZigBee fingerprint positioning technology

technical field

The invention relates to a guidance system and a control method for using a ZigBee wireless sensor network and a fingerprint positioning system to help users accurately find a car after parking in an underground large parking lot when returning.

Background technique

In recent years, with the rapid development of social economy, the number of cars has doubled. In the process of using cars, people not only have the inconvenience of driving and parking, but also have difficulties in finding cars. After a long time, I can't remember exactly where my car is parked, and it takes time and effort to find my parking space in the parking lot.

In the large underground parking lot, the difficulty of finding a car is particularly obvious. The area of the existing large underground parking lot is getting larger and larger, and because the parking lot is underground, the building structure is relatively similar, and there are not many available reference points for memory parking spaces. Finally, after staying in the shopping mall or office on the ground for a long time, you may forget where your original parking space is.

Contents of the invention

The technical problem to be solved by the present invention is to design and develop a large-scale underground parking lot car-finding system based on ZigBee fingerprint positioning technology to help car owners park and leave. After returning to the parking lot for a long time, they can quickly find their own parking spaces and improve the parking space It improves the efficiency of the field and saves the time and energy of the car owner.

In order to solve the problems of the technologies described above, the present invention adopts the following solutions:

A large-scale underground parking lot car-finding system based on ZigBee fingerprint positioning technology, characterized in that it includes a wireless sensor network platform, a hand-held parking card, a liquid crystal display, and a background service center;

1) The wireless sensor network platform is composed of ZigBee sensor nodes arranged on the top of the parking lot or between floors and ultrasonic ranging nodes installed on each parking space. The wireless sensor network platform is constructed between the nodes through network protocols and communication protocols. The wireless sensor network transmits the wireless signal strength indication signal RSSI on the hand-held parking card to the background service center, and the background service center calculates the actual position of the owner and the hand-held parking card;

2) Hand-held parking card: The hand-held parking card is actually a ZigBee sensor node. When the user is at a certain location, the parking card measures the wireless signal strength RSSI value of the ZigBee sensor node arranged above the parking lot, and passes these RSSI values through the parking lot. The ZigBee sensor node above the field sends back to the background service center, and then the background service center obtains the location of the parking card and the owner itself according to the fingerprint positioning algorithm;

3) The background service center is integrated with the computer, programming board and the root node of the ZigBee sensor network, and receives the parking space information detected by other nodes through the CTP protocol, and then sends it to the computer through the serial port to form the overall parking space information map of the parking lot. The root node of the ZigBee sensor network Connected to the computer through the programming board, the backstage service center is responsible for collecting the parking lot situation in real time and displaying it on the LCD screen. The backstage service center also chooses a path to guide the car owner to his own parking space according to the current location of the car owner.

4) Liquid crystal display screen: installed at the key intersection of the parking lot, it communicates data with the background server through a wired method, receives the direction guidance data from the background service center, and instructs the car owner to the parking space.

Further, a ZigBee sensor node and an ultrasonic ranging sensor are arranged above each parking space, and the ZigBee sensor node is integrated with the ultrasonic ranging sensor through an interface, and the ultrasonic sensor signal is transmitted back to the background service center through the ZigBee wireless network.

A control method for a car-finding system in a large underground parking lot based on ZigBee fingerprint positioning technology, which is characterized in that the ZigBee fingerprint algorithm is used for positioning, a large number of ZigBee sensor nodes above the parking lot form anchor nodes, and the parking card in the owner's hand is a node to be positioned According to the fingerprint positioning algorithm, the location of the parking card and the owner is obtained.

Furthermore, when the car owner is parking, the parking space is automatically registered, and the hand-held parking card is bound to the parking space. When the car owner leaves the parking space, the system automatically cancels the user, and the hand-held parking card is unbound from the parking space.

Further, when the car owner parks, the ultrasonic ranging sensor detects the parking signal of the parking space, and sends it back to the background through the wireless sensor network to obtain the parking space number; and the ZigBee node uses the fingerprint positioning method to calculate the position of the hand-held card in the background; Bind with the hand-held parking card number.

Furthermore, when the car owner is looking for a car, the wireless network detects that a new parking card appears at the entrance of the parking lot, and starts to locate the parking card, and in the background, according to the current location of the parking card and the parking space, calculate the guiding path and display it in the parking lot on the display screen at key junctions.

The advantages and effects of the present invention are: 1) the present invention can help car owners find their own parking spaces as soon as possible, save the time and energy of car owners, and also improve the use efficiency of the parking lot; 2) the present invention improves the efficiency of finding cars The degree of automation, automatically realize the process of registration (binding), positioning and leaving logout (unbinding). The manual operation process of the car owner's car search process is reduced to the greatest extent; 3) The present invention considers the situation when many people park at the same time and many people search for cars at the same time. While the ultrasonic ranging sensor accurately detects the parking space, the ZigBee wireless network The node locates the hand-held parking card and binds the two to avoid the confusion of the binding between the parking space and the parking card when multiple people park at the same time.

Description of drawings

Fig. 1 is the overall structure of the car-finding system of the present invention;

Fig. 2 is the network structure of the car-finding system in the parking lot;

Fig. 3 is a schematic diagram of two stages of fingerprint positioning;

Fig. 4 is the binding process of the hand-held parking card and the parking space;

Figure 5 is the unbinding process of holding the parking card in the parking space.

detailed description

Figure 1 is the overall structure diagram of the car-finding system in the parking lot. It mainly includes four parts: wireless sensor network platform, hand-held parking card, LCD display, and background service center.

The wireless sensor network platform is composed of ZigBee sensor nodes arranged on the top of the parking lot or between floors and ultrasonic ranging nodes installed on each parking space. The ZigBee sensor nodes run the TinyOS operating system inside, and the nodes communicate with each other through network protocols and communication protocols. Build a wireless sensor network platform. The wireless sensor network will transmit the wireless signal strength indicator signal RSSI on the hand-held parking card to the background service center, and the background service center will calculate the actual location of the owner and the hand-held parking card.

A ZigBee sensor node and an ultrasonic ranging sensor are arranged above each parking space, and the ZigBee sensor node is integrated with the ultrasonic ranging module through a 51-pin interface, and the ultrasonic sensor signal is transmitted back to the background service center through the ZigBee wireless network.

When the owner parks, the ultrasonic sensor detects the parking signal of the parking space, and sends it back to the background through the wireless sensor network to obtain the parking space number; and the ZigBee sensor node uses the fingerprint positioning method to calculate the position of the hand-held card in the background; ID binding.

When the car owner is looking for a car, the wireless network detects that a new parking card appears at the entrance of the parking lot, and starts to locate the parking card, and in the background, according to the current location of the parking card and the parking space, calculate the guiding path and display it at the key intersection of the parking lot on the display.

The parking lot service system provides users with navigation services when they pick up their cars. The navigation services are mainly composed of electronic display screens at important intersections in the parking lot.

The wireless sensor network platform uses sensors (ultrasonic ranging sensors are used here) to sense whether the parking space is occupied or vacant, integrates ultrasonic ranging modules and wireless sensor nodes, and deploys them at the top of the parking space to judge the vacancy status of the parking space through distance measurement. And use the wireless sensor network platform to send the location occupancy situation to the parking space distribution system in the background server. The wireless sensor network platform also interacts with the hand-held parking card, uses RSSI fingerprint positioning technology to determine the user's location in the parking lot, and guides the user to walk to their parking space correctly.

Hand-held parking card: The hand-held parking card is actually a ZigBee network node. When the user is at a certain location, the hand-held parking card measures the wireless signal strength RSSI value of the ZigBee sensor node arranged above the parking lot, and passes these RSSI values through the parking lot. The ZigBee sensor node above sends back to the background service center, and then the background service center obtains the location of the parking card and the owner itself according to the fingerprint positioning algorithm.

When the hand-held parking card enters the parking lot, the user takes it at the entrance and carries it with him. When the user returns to pick up the car, he interacts with the surrounding wireless sensor nodes and uses the fingerprint positioning algorithm to locate the hand-held parking card.

The background service center receives the parking space occupancy information sent by the sensor nodes in real time, stores the data in the database and updates it in real time after analyzing the data; The user finds his own parking space. The background service center is integrated with the computer, programming board and ZigBee sensor node. As the root node of the wireless sensor network, the ZigBee sensor node receives the parking space information detected by other nodes through the CTP protocol, and then sends it to the computer through the serial port to form the overall parking space information map of the parking lot. . The ZigBee sensor node is connected with the computer through the programming board. The background service center is responsible for collecting the parking spaces in the parking lot in real time and displaying them on the LCD screen. The background service center also selects a path to guide the car owner to his own parking space according to the current location of the car owner.

LCD screen: Installed at the key intersection of the parking lot, it communicates data with the background service center through wired methods, receives the direction guidance data from the background service center, and instructs the car owner to the parking space.

Fig. 2 is the network structure adopted by the car-finding system in the present invention, which is mainly divided into three parts: the wireless sensor network platform adopts an open-source TinyOS operating system, and adopts a data aggregation protocol CTP (CollectionTreeProtocol) between wireless sensor nodes to carry out routing and forwarding; The CTP protocol is a TinyOS-based data aggregation protocol applied to wireless sensor networks. The car-finding system communicates point-to-point with the hand-held parking card; the electronic display screen of the parking service system and the background are connected by wires.

Fig. 3 is a flow chart of the ZigBee fingerprint positioning technology in the present invention, which can generally be divided into two stages: the first stage is the off-line training stage. First, it is necessary to uniformly select a reference point in the target positioning area, and collect the wireless signal strength RSSI sample vectors from each access point at the reference point position. The location coordinates of each reference point and the corresponding set of wireless signal strength RSSI sample vectors constitute a location fingerprint. Then, store all the fingerprint information in the database, which constitutes RadioMap. The second stage is the online positioning stage. First, measure the wireless signal strength RSSI vector samples in real time through the user terminal. Then, match the real-time RSSI vector sample with the location fingerprint in RadioMap, or directly input the constructed positioning function to obtain the positioning result. ZigBee fingerprint algorithm is used for positioning. A large number of ZigBee sensor nodes above the parking lot constitute the anchor node. The parking card in the owner's hand is the node to be located. According to the fingerprint positioning algorithm, the location of the parking card and the owner is obtained.

Figure 4 shows the binding process between the parking card and the parking space held by the owner when parking (automatically registering the parking space). The specific matching and binding steps are as follows:

a) When the car owner is parking, the ultrasonic ranging sensor node located above the parking space detects that there is a vehicle parked, and sends a positioning request message to the surrounding handheld parking cards (vehicles parked at the same time in the parking lot); at the same time, the parking space The upper ultrasonic ranging sensor node sends the status change information of the parking space to the background service center.

b) After the handheld parking card receives the positioning request message, record the triggered anchor node ID. And send a positioning request message to the surrounding anchor nodes.

c) After receiving the positioning request message of the parking card, the surrounding anchor nodes calculate the signal reception strength RSSI of the parking card, and then send <anchor node ID, RSSI> to the parking card.

d) After receiving the RSSI information sent back by the anchor node with the hand-held parking card, use the received group value information to form fingerprint information, and arrange it in descending order, set the threshold d or the time exceeds t, and keep the RSSI greater than d as fingerprints, park The card sends the fingerprint information of each anchor point to the corresponding anchor node in turn.

e) The anchor node receives the fingerprint information of the hand-held parking card, sends it back to the background, performs model matching in the background, and calculates the distance r from the anchor node whose code number is ID, that is, <anchor node ID, r>. According to the obtained <anchor node ID, r>, the parking card location calculation is performed by the centroid method or the k-nearest neighbor method.

f) Find the parking space closest to the positioning result, which is one of the parking spaces that trigger the above binding process, and bind the parking space number with the parking card number.

g) The background sends a binding message to the nearest parking card, and finally the parking card records the ID of the bound parking space, and sets the binding flag to 1.

Figure 5 shows the process of unbinding the parking card with the parking space (automatically canceling the user) when the owner leaves the parking space after picking up the car. The specific matching and binding steps are as follows:

a) After the vehicle leaves the parking space, it triggers the state of the ultrasonic sensor node above the parking space, and it sends an unbinding request message to the surrounding hand-held parking cards. At the same time, the ultrasonic sensor node sends the status change information of the parking space to the background service center; deletes the corresponding navigation information in the background service center.

b) After the hand-held parking card receives the message, the hand-held parking card whose binding flag is 1 parses the message type, and judges whether the anchor node ID triggered in the message is the bound parking space ID, and if so, sets the binding flag If it is 0, the sending binding is unaffected; if the anchor node ID does not match the parking space ID, just discard the received message. If the binding flag bit is already 0, the message is also discarded.

c) The ultrasonic sensor node receives the confirmation information and completes the unbinding process. Otherwise, timeout and resend.

Claims (6)

1. the large-scale underground parking lot vehicle-searching system based on ZigBee fingerprint location technology, it is characterised in that it comprises a wireless sensor network platform, hand-held parking card, liquid crystal display, background service center;

1) by being arranged in, the ZigBee sensor node on top, parking lot or between layer forms wireless sensor network platform with the ultrasonic ranging node being arranged on each parking stall; radio sensing network platform is built by procotol and communication protocol between node; radio sensing network passes the wireless signal strength indicator signal RSSI on hand-held parking card back background service center, calculates the physical location of car owner and hand-held parking card by background service center;

2) hand-held parking card: hand-held parking card is in fact also a ZigBee sensor node; when user is when a certain position; parking card measures the wireless signal strength RSSI value of the ZigBee sensor node arranged above parking lot; and pass the ZigBee sensor node of these RSSI value above parking lot back background service center, then obtain parking card and the position at car owner self place by background service center according to fingerprinting localization algorithm;

3) background service center is integrated by computer, programming plate and ZigBee sensor network root node, the parking space information of other nodal test is received by CTP agreement, it is sent to computer again by serial ports, form the overall parking space information figure in parking lot, ZigBee sensor network root node is connected with computer by programming plate, background service center is responsible for the parking stall situation in real-time collecting parking lot, and it is displayed on liquid-crystal display screen, the position that background service center is also current according to car owner, selecting paths guides car owner to oneself parking stall;

4) liquid crystal display: the crucial crossing being arranged on parking lot, carries out data interaction by wired mode and background server, and the direction receiving background service center guides data, and car owner is to parking stall in instruction.

2. a kind of large-scale underground parking lot vehicle-searching system based on ZigBee fingerprint location technology as claimed in claim 1, it is characterized in that arranging above each parking stall a ZigBee sensor node and ultrasonic distance-measuring sensor, and being undertaken integrated by ZigBee sensor node by interface and ultrasonic distance-measuring sensor, ultrasonic transducer signal transfers back to background service center by ZigBee wireless network.

3. a kind of large-scale underground parking lot vehicle-searching system control method based on ZigBee fingerprint location technology as claimed in claim 1, it is characterized in that utilizing ZigBee fingerprint algorithm to position, a large amount of ZigBee sensor node above parking lot forms anchor node, parking card in car owner's hand is node to be positioned, obtains parking card and the position at car owner place according to fingerprinting localization algorithm.

4. a kind of large-scale underground parking lot vehicle-searching system control method based on ZigBee fingerprint location technology as claimed in claim 3, it is characterized in that car owner is when parking, automatically parking stall is registered, hand-held parking card and parking stall binding, when car owner leaves parking stall, the automatic logging off users of system, the releasing binding of hand-held parking card and parking stall.

5. a kind of large-scale underground parking lot vehicle-searching system control method based on ZigBee fingerprint location technology as claimed in claim 3, when it is characterized in that car owner parks, ultrasonic distance-measuring sensor detects parking stall stop sign, passes backstage back by radio sensing network, obtains parking stall number; And ZigBee node utilizes fingerprint location method in the hand-held card position of hind computation; On backstage by parking stall number and the numbering binding of hand-held parking card.

6. a kind of large-scale underground parking lot vehicle-searching system control method based on ZigBee fingerprint location technology as claimed in claim 3, when it is characterized in that car owner seeks car, wireless network detects that new parking card appears at Entrance, start to locate this parking card, and on backstage, according to parking card present position, parking stall, calculate path of navigation, it is displayed on the display screen of parking lot key crossing.