CN104567875A - Indoor hybrid positioning system and method based on inertial positioning and VLC for mobile phone - Google Patents

Abstract

The invention provides an indoor hybrid positioning system and method based on mobile phone inertial positioning and VLC technology. The downlink includes a visible light downlink transmission module and an inertial and VLC hybrid positioning module. The visible light downlink transmission module includes: downlink transmission processor and visible light LED; the inertial and VLC hybrid positioning module includes: VLC positioning receiver, communication interface and built-in Gyroscope, acceleration sensor, APP module. The uplink includes a positioning data sending module and a positioning data receiving module. The positioning data sending module includes: a Bluetooth module of a smart phone; the positioning data receiving module includes: a terminal Bluetooth receiving module. The present invention makes full use of the hardware equipment integrated in the current smart phone, simplifies the positioning device, is simple to operate, and is convenient for daily carrying. At the same time, it uses the target position to realize the push of position-related information. It has wide application and strong practicability. It will be used in future supermarkets, It can be effectively applied in public places such as libraries.

Description

Indoor hybrid positioning system and method based on mobile phone inertial positioning and VLC

technical field

The invention relates to an indoor hybrid positioning system and method based on mobile phone inertial positioning and VLC, and belongs to the technical field of visible light communication.

Background technique

The indoor positioning solution based on visible light communication (Visible Light Communication, VLC) technology uses white light emitted by white semiconductor light-emitting diodes (Light Emitting Diode, LED) as the carrier of positioning signals, so there is no electromagnetic radiation and is not limited by the application environment; and The transmission channel of VLC generally adopts the direct channel, and the multipath interference is relatively small, so the positioning scheme can achieve relatively high accuracy; in addition, the indoor positioning system based on VLC technology is compatible with the future VLC communication technology, so it does not need expensive hardware Equipment investment, the cost is relatively low. Existing patent application number: CN201410084621 patent application: "An indoor positioning method based on visible light tags" provides a device and method for precise positioning based on light intensity, but these methods also have certain defects. Where the direct light of the LED cannot reach or where it is blocked, the positioning accuracy of this positioning method will drop sharply or even fail.

The principle of the inertial positioning system is to use the gyroscope and the acceleration sensor to measure the direction and distance of the object's movement, and obtain the position coordinates after the movement from the initial position of the object. The positioning algorithm is simple and easy to implement, and it is not affected by whether there is light in the surrounding environment, but the disadvantage is that there are cumulative errors, and it is not suitable for long-term use. Therefore, introducing the inertial positioning technology into the VLC indoor positioning system can complement the VLC indoor positioning technology and further improve the positioning accuracy of the indoor positioning system.

Existing patent application number: CN201410067768 patent: "Indoor hybrid positioning system and method based on inertial positioning and VLC technology", the downlink transceiver module requires the use of related FPGA, and the uplink transceiver module also requires the use of related FPGA and infrared LED emission sensing device , the whole system device is complicated, additional configuration of related equipment is required, and it is not easy to carry.

In the 21st century, smart phones are gradually used in people's daily life. The gyroscope and accelerometer integrated in the mobile phone provide the possibility for inertial positioning, and the Bluetooth function in the mobile phone also provides the possibility for information uploading. Therefore, we only need to connect the external VLC positioning module to the mobile phone through the communication serial port, and we can realize the mixed positioning of VLC technology and mobile phone inertial positioning, and at the same time realize the upload of information through the mobile phone Bluetooth. The device is simple to implement and portable, and can greatly meet people's indoor positioning needs.

Contents of the invention

The purpose of the present invention is to propose an indoor hybrid positioning system and method based on mobile phone inertial positioning and VLC in order to solve the problem that the existing indoor hybrid positioning system device is complex and not easy to carry.

An indoor hybrid positioning system based on mobile phone inertial positioning and VLC, including a visible light downlink transmission module, an inertial and VLC hybrid positioning module, a positioning data transmission module and a positioning data receiving module.

The connection relationship of the above components is as follows: the visible light downlink sending module sends modulation and coding signals through visible light, the VLC positioning receiver in the inertial and VLC hybrid positioning module receives and demodulates the visible light signal and judges the positioning information, the inertial and VLC hybrid positioning module and The positioning data sending module is connected through a mobile phone, and data is transmitted between the positioning data sending module and the positioning data receiving module through Bluetooth signals.

The downlink is composed of the visible light downlink sending module and the inertial and VLC hybrid positioning module, and the uplink is composed of the positioning data sending module and the positioning data receiving module.

The visible light downlink sending module includes: a downlink sending processor and a visible light LED; the signal output end of the downlink sending processor is connected to the drive input end of the visible light LED, wherein the downlink sending processor is composed of a single-chip microcomputer or FPGA and its driving circuit, and the single-chip microcomputer Or the FPGA generates a signal frame sent by the visible light LED, which contains the position information of the visible light LED in the room; the signal frame is amplified by the drive circuit, and the amplified modulation signal is loaded on the driving current of the visible light LED; the visible light The LED emits the modulated signal in the form of visible light.

The inertial and VLC mixed positioning module includes: a VLC positioning receiver, a communication interface and a built-in gyroscope, an acceleration sensor, and an APP module in the mobile phone. The VLC positioning receiver includes a photodetector and a VLC positioning data acquisition and processing unit. The photodetector converts the optical signal into an electrical signal, and the VLC positioning data acquisition and processing unit converts the electrical signal into analog-to-digital conversion, and calculates the received photoelectric conversion Signal strength; the communication interface adopts serial port or bluetooth to complete the communication between the VLC positioning receiver and the built-in modules of the mobile phone; the gyroscope is used to measure the direction; the acceleration sensor is used to measure the moving distance of the mobile phone; the APP module receives the communication The photoelectric conversion signal strength of the VLC positioning receiver transmitted from the interface is used for threshold judgment. If the signal strength is higher than the threshold, the APP module selects the location information based on VLC technology through the intensity relationship of different LEDs and the RSS positioning method. That is, when it is lower than the threshold, it is considered that the optical signal is blocked, and the APP module selects the position information based on inertial positioning. The connection relationship of the above modules is: the VLC positioning receiver outputs the signal strength after photoelectric conversion, the communication interface transmits the signal strength information to the mobile APP module, the mobile APP module obtains the signal strength through the communication interface, and outputs the light positioning information according to the threshold judgment Or inertial positioning information.

The positioning data sending module uses the bluetooth module in the mobile phone to send out the positioning data.

The positioning data receiving module uses the terminal Bluetooth to receive positioning data.

An indoor hybrid positioning method based on mobile phone inertial positioning and VLC, the specific steps are:

Step 1, the visible light downlink transmitting module sends positioning code information;

The positioning coding information is based on a plurality of LED coding information (the number of LEDs is not less than 3). Each LED corresponds to a unique ID code. The positioning coding information is based on time division multiplexing (TDM), and has a common frame header. When the detector receives the coding information of multiple LEDs at the same time, it can recognize different ID codes;

Step 2, the inertial and VLC hybrid positioning module obtains the current coded signal strength of different LEDs through the VLC positioning receiver;

Step 3, the inertial and VLC hybrid positioning module sends the coded signal strength information obtained in step 2 to the mobile phone through the communication interface through the VLC positioning receiver;

Step 4, the mobile phone obtains inertial positioning information through the gyroscope and accelerometer;

The method of obtaining inertial positioning is: first set the initial position of the mobile phone before it moves as the coordinate origin, use the mobile phone containing the accelerometer to perform inertial navigation, and the mobile phone uses the basic acceleration formula to solve the acceleration information to obtain the relative to the initial position. Positioning is carried out through the relative relationship between the displacement and the initial position.

Step 5. The APP module compares the intensity of the encoded signal obtained from the communication interface with the threshold. When the intensity of the encoded signal is greater than the threshold, it calculates the relative intensity relationship of multiple LEDs, and obtains the attenuation distance of light transmission according to the intensity relationship, and locates the VLC. The location of the photodetector in the receiver is based on the relative positional relationship (RSS positioning) of multiple LED light sources. When the coded signal strength is lower than the threshold, the inertial positioning value in step 4 is used as the positioning value.

Step 6, the mobile phone uploads the final positioning data to the positioning data receiving module through the Bluetooth protocol of the positioning data sending module.

Beneficial effect

Compared with the prior art, the present invention has the following significant advantages:

The present invention makes full use of the hardware equipment integrated in the current smart phone, simplifies the positioning device, is simple to operate, and is convenient for daily carrying; uses the target position to realize the push of position-related information, has wide application and strong practicability, and will be used in future supermarkets, books, etc. It can be effectively applied in public places such as museums.

Description of drawings

Fig. 1 is the structural block diagram of the indoor hybrid positioning device provided by the present invention;

2 is a schematic diagram of a prototype experiment system of an indoor visible light positioning system based on LED lighting in a specific embodiment;

Fig. 3 is a schematic block diagram of a prototype experiment of an indoor visible light positioning system based on LED lighting in a specific embodiment;

Explanation of symbols: 1-first LED light, 2-second LED light, 3-third LED light, 4-single LED light schematic diagram, 5-optical signal, 6-customer.

Detailed ways

The present invention will be described in detail below in conjunction with specific embodiments. The following examples illustrate the present invention in detail, but the specific implementation forms of the present invention are not limited thereto. The description of this implementation is only used to help understand the method of the present invention and its core idea; at the same time, for those of ordinary skill in the art, according to the idea of the present invention, there will be changes in the specific implementation and scope of application. The content of the description should not be construed as limiting the present invention. Various obvious changes made to it without departing from the spirit of the method described in the present invention and the scope of the claims are within the protection scope of the present invention.

As shown in FIG. 1 , the hybrid positioning device of the present invention includes a visible light downlink transmitting module; an inertial and VLC hybrid positioning module; a positioning data sending module; and a positioning data receiving module. The prototype experiment system of the indoor visible light positioning system based on LED lighting in this embodiment is shown in FIG. 2 , and its corresponding system principle block diagram is shown in FIG. 3 .

Embodiment 1: The visible light downlink transmission module includes: a downlink transmission processor and a visible light LED;

Seeing the light downlink sending module generates a positioning coding signal by FPGA (EP2C8Q208C8), and the driving circuit amplifies the signal and loads it on the corresponding LED light. The visible light LED emits the modulated signal in the form of visible light.

The inertial and VLC hybrid positioning module includes: VLC positioning receiver, communication interface and built-in gyroscope, acceleration sensor and APP module in the mobile phone;

The light intensity in the positioning receiver is converted into an electrical signal by the photodetector PDA10A. After the signal is processed by FPGA, the modulation signal intensity of different LEDs can be extracted. The communication interface uses the chip FT311D to realize serial communication.

The mobile phone used is Samsung I9508, and the serial port communication configuration parameters are set to 9600 baud rate, 8 data bits, 0 parity bit, and 1 stop bit. Through the above configuration, the communication between FPGA and mobile phone is realized.

The received signal strength is transmitted to the mobile phone through the serial port. The APP module in the mobile phone judges the magnitude of the light intensity. When the magnitude of the light intensity is less than the threshold, it is considered that the light positioning is invalid. If the magnitude of the light intensity is greater than the threshold, the positioning value can be obtained by the method of receiving signal strength.

The positioning data sending module is the bluetooth module of the smart phone; the bluetooth module sends out the positioning data.

The positioning data receiving module is a terminal Bluetooth receiving module; the terminal Bluetooth receiving module receives positioning data.

Example 2:

Using the same visible light downlink transmitting module as in Embodiment 1; positioning data sending module; positioning data receiving module; in the communication interface of the inertial and VLC hybrid positioning module, the Bluetooth module ATK-HC05-V1 is used.

Disconnect KEY (or connect GND), the Bluetooth module can send and receive data normally at this time, otherwise it cannot send and receive data normally. Install on the mobile phone: Bluetooth serial port assistant V1.97apk in the module supporting information. After installing the software, open the software, enter the search Bluetooth device interface, click the device to enter the selection operation mode, enter the password, and complete the pairing. The Bluetooth module should be connected successfully. Data can be exchanged. The light intensity signal can be transmitted to the mobile phone through the Bluetooth module.

The working steps of the above-mentioned indoor hybrid positioning device are as follows:

Step 1, the visible light downlink transmitting module sends positioning code information;

The positioning coding information is based on 3 LED coding information. Each LED corresponds to a unique ID code. The positioning coding information is based on time division multiplexing (TDM), and has a common frame header. When the detector receives the coding information of 3 LEDs at the same time, it can recognize different ID codes;

Step 2, the inertial and VLC hybrid positioning module obtains the current coded signal strength of different LEDs through the VLC positioning receiver;

Step 3, the inertial and VLC hybrid positioning module sends the coded signal strength information obtained in step 2 to the mobile phone through the communication interface through the VLC positioning receiver;

Step 4, the mobile phone obtains inertial positioning information through the gyroscope and accelerometer;

The method of obtaining inertial positioning is: first set the initial position of the mobile phone before it moves as the coordinate origin, use the mobile phone containing the accelerometer to perform inertial navigation, and the mobile phone uses the basic acceleration formula to solve the acceleration information to obtain the relative to the initial position. Positioning is carried out through the relative relationship between the displacement and the initial position.

Step 5. The APP module compares the intensity of the encoded signal obtained from the communication interface with the threshold. When the intensity of the encoded signal is greater than the threshold, it calculates the relative intensity relationship of multiple LEDs, and obtains the attenuation distance of light transmission according to the intensity relationship, and locates the VLC. The location of the photodetector in the receiver is based on the relative positional relationship (RSS positioning) of multiple LED light sources. When the coded signal strength is lower than the threshold, the inertial positioning value is used as the positioning value.

Step 6, the mobile phone uploads the final positioning data to the positioning data receiving module through the Bluetooth protocol of the positioning data sending module.

Specific embodiments of the present invention have been described above. It should be understood that the present invention is not limited to the specific embodiments described above, and those skilled in the art may make various changes or modifications within the scope of the claims, which do not affect the essence of the present invention.

Claims (8)

1., based on an indoor hybrid location system for mobile phone inertial positioning and VLC technology, it is characterized in that: comprise the descending sending module of visible ray, inertia and VLC mixed positioning module, locator data sending module and locator data receiver module; By the descending sending module of visible ray and inertia and VLC mixed positioning module composition downlink, form up-link by locator data sending module and locator data receiver module;

The descending sending module of described visible ray comprises: descending sending processor and visible LED; The signal output part of descending sending processor is connected with the driving input end of visible LED, and wherein, descending sending processor produces the signal frame that visible LED sends, and this signal frame contains the positional information of visible LED in indoor; This signal frame carries out Current amplifier by driving circuit, and the modulation signal after amplifying is loaded on the drive current of visible LED; Signal after modulation is launched with visible ray form by visible LED;

Described inertia and VLC mixed positioning module comprise: VLC location receivers, gyroscope, acceleration transducer, APP module built-in in communication interface and mobile phone; Described VLC location receivers contains photodetector, VLC position data collecting processing unit, photodetector converts electric signal to light signal, VLC position data collecting processing unit carries out analog to digital conversion electric signal, and calculates the photoelectric conversion signal intensity received; Described communication interface completes the communication of each intermodule of VLC location receivers and embedded in mobile phone; Described gyroscope is used for direction of measurement; Acceleration transducer is for measuring mobile phone displacement; APP module receives the photoelectric conversion signal intensity of the VLC location receivers that communications interface transmission is come, carry out threshold value judgement, if signal intensity is higher than threshold value, by strength relationship and the RSS localization method of different LED, APP model choice is based on VLC technology gained positional information, illumination more weak namely lower than threshold value time, think that light signal is blocked, APP model choice is based on inertial positioning gained positional information; The annexation of above-mentioned module is: the signal intensity after the conversion of VLC location receivers output photoelectric, communication interface is transferred to signal strength information in mobile phone A PP module, mobile phone A PP module obtains signal intensity by communication interface, and exports light-seeking information or inertial positioning information according to threshold value judgement;

Locator data sending module refers to the bluetooth module of smart mobile phone, by bluetooth module, locator data is sent;

Locator data receiver module refers to terminal Bluetooth receiver module; Described terminal Bluetooth receiver module receives locator data.

2., based on the indoor hybrid location system based on mobile phone inertial positioning and VLC technology according to claim 1, it is characterized in that: described descending sending processor is FPGA and driving circuit thereof.

3., based on the indoor hybrid location system based on mobile phone inertial positioning and VLC technology according to claim 1, it is characterized in that: the descending sending processor of the descending sending module of described visible ray is single-chip microcomputer and driving circuit thereof.

4. based on the indoor hybrid location system based on mobile phone inertial positioning and VLC technology according to claim 1, it is characterized in that: in described inertia and VLC mixed positioning module, communication interface is serial ports.

5. based on the indoor hybrid location system based on mobile phone inertial positioning and VLC technology according to claim 1, it is characterized in that: in described inertia and VLC mixed positioning module, communication interface is bluetooth.

6., based on an indoor hybrid locating method of mobile phone inertial positioning and VLC, it is characterized in that: concrete steps are:

Step 1, visible ray downlink module sends location coding information;

Step 2, inertia and VLC mixed positioning module obtain the coded signal intensity of current different LED by VLC location receivers;

Step 3, inertia and VLC mixed positioning module are sent to the coded signal strength information that step 2 obtains in mobile phone by communication interface by VLC location receivers;

Step 4, mobile phone obtains inertial positioning information by gyroscope and accelerometer;

Step 5, APP module compares the coded signal intensity obtained from communication interface and threshold value, when coded signal intensity is greater than threshold value, calculate multiple LED relative intensity relation, obtain the attenuation distance of optical transport according to strength relationship, orient the relative position relation based on multiple LED light source at the photodetector place in VLC location receivers; When coded signal intensity is lower than threshold value, using the inertial positioning numerical value of step 4 as locator value;

Step 6, mobile phone is uploaded to locator data receiver module final locator data by the Bluetooth protocol of locator data sending module.

7. based on a kind of indoor hybrid locating method based on mobile phone inertial positioning and VLC according to claim 6, it is characterized in that: location coding information described in step 1 is for based on multiple LED coded message; The ID coding that each LED is corresponding unique; Location coding information, based on time division multiplex, has common frame head, when detector receives the coded message of multiple LED simultaneously, can identify different ID codes.

8. based on a kind of indoor hybrid locating method based on mobile phone inertial positioning and VLC according to claim 6, it is characterized in that: obtaining inertial positioning method described in step 4 is: the initial position first set before mobile phone does not move is true origin, the mobile phone comprising accelerometer is utilized to carry out inertial navigation, mobile phone utilizes basic Acceleration Formula to resolve acceleration information, draw the displacement relative to initial position, and then positioned by the relativeness of displacement and initial position.