CN110824426B - Optical indoor positioning method and positioning device - Google Patents
Optical indoor positioning method and positioning device Download PDFInfo
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- CN110824426B CN110824426B CN201911103971.8A CN201911103971A CN110824426B CN 110824426 B CN110824426 B CN 110824426B CN 201911103971 A CN201911103971 A CN 201911103971A CN 110824426 B CN110824426 B CN 110824426B
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
- G01S5/00—Position-fixing by co-ordinating two or more direction or position line determinations; Position-fixing by co-ordinating two or more distance determinations
- G01S5/16—Position-fixing by co-ordinating two or more direction or position line determinations; Position-fixing by co-ordinating two or more distance determinations using electromagnetic waves other than radio waves
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02D—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN INFORMATION AND COMMUNICATION TECHNOLOGIES [ICT], I.E. INFORMATION AND COMMUNICATION TECHNOLOGIES AIMING AT THE REDUCTION OF THEIR OWN ENERGY USE
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- Y02D30/70—Reducing energy consumption in communication networks in wireless communication networks
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Abstract
The invention discloses an optical indoor positioning method, which comprises the following steps: the light source emits a variable frequency modulation light signal, the receiver receives the signal, the signal is coupled and squared through the multiplier or the frequency multiplier, the filtered electric signal is collected by the data collector, fourier transformation is carried out in a digital domain to obtain frequency domain information of the electric signal, the frequency of a target item is obtained, and then the distance between the receiver and the light source is obtained. The invention provides a novel optical indoor positioning technology, which combines the propagation characteristics of analysis light with a signal processing technology, innovates the problem of processing optical signals, and can realize high-precision, rapid and accurate indoor positioning by using simple equipment comprising a light source and a receiver. In this item, by setting an appropriate light source modulation frequency, a signal received by a receiver is subjected to signal processing, and the absolute position of a target is determined.
Description
Technical Field
The invention belongs to the technical field of optics and signal processing, and particularly relates to an optical indoor positioning method and a positioning device for realizing accurate positioning of a receiver space position by utilizing a light source array with specially modulated light intensity.
Background
In increasingly complex urban environments, there is an increasing demand for location information, and location technology is therefore of particular importance. The personnel are precisely positioned under special environments, and information exchange is carried out, so that the working efficiency can be greatly improved, and the loss is reduced. Especially in environments such as disaster sites and the like, high-risk building rescue tasks and the like.
Outdoor positioning technology based on global satellite navigation systems is now quite mature. The IEEE reports that Broadcom semiconductors claim that they can already use the GPS signal system to provide navigation services to mobile devices with an accuracy of up to 30 cm. In dense communities, interiors of buildings, airport halls, exhibition halls, warehouses, supermarkets, libraries, underground parking lots, mines, etc., it is often necessary to determine location information of facilities, mobile terminals or their holders, and articles indoors. However, satellite positioning systems cannot function effectively due to limitations in terms of positioning time, positioning accuracy, and complex environments. In an environment where satellite positioning cannot be used, such as indoors, people use an indoor positioning technology as an auxiliary method for realizing positioning, so that the problems that satellite signals are weak and cannot penetrate a building when reaching the ground are solved. Based on the above situation, indoor positioning technology is receiving more and more attention.
The indoor environment is more complex than the outdoor environment. The layout, internal structure, building materials, finishing materials, decorative articles, etc. of the building can have an effect on the effective indoor positioning. At present, several indoor positioning technologies are proposed to meet the requirements and applications in different occasions. Common indoor positioning technologies include ultrasonic positioning technology, infrared positioning technology, wireless local area network (WIFI) positioning technology, bluetooth positioning technology, and the like. The ultrasonic positioning technology is used for ranging according to the time difference between the echo wave and the emission wave, has high positioning precision, but needs to arrange a large number of measuring devices in space, and has high positioning cost; the infrared light-based positioning technology realizes positioning by detecting azimuth angle and pitch angle, and the positioning technology has short propagation distance and rapidly reduces positioning accuracy along with the increase of distance; the emerging WIFI positioning technology with the development of the Internet is used for positioning by measuring the distance from a user to a wireless hotspot, is easy to be interfered by other signals, and has higher energy consumption; the Bluetooth positioning technology is used for positioning by measuring the intensity of a received signal, is only suitable for positioning in a short distance and a small range, and has poor stability. In addition, there is a research report of indoor positioning technology based on visible light, and the technology has the advantages of economy, high positioning precision and the like, but the system related to the technology reported at present is complex, and the development prospect is limited.
Disclosure of Invention
A first object of the present invention is to provide a method of optical indoor positioning.
A second object of the present invention is to provide a positioning device used in the optical indoor positioning method.
In order to achieve the above purpose, the technical scheme adopted by the invention is as follows:
the first aspect of the present invention provides an optical indoor positioning method, comprising the steps of:
the light source emits a variable frequency modulation light signal, the receiver receives the signal, the signal is coupled and squared through the multiplier or the frequency multiplier, the filtered electric signal is collected by the data collector, fourier transformation is carried out in a digital domain to obtain frequency domain information of the electric signal, the frequency of a target item is obtained, and then the distance between the receiver and the light source is obtained.
The light source comprises two or more light sources, the intensity of light emitted by each light source is a sinusoidal signal, and the frequency of the sinusoidal signal changes linearly with time.
Taking the simplest two light source points as an example, the indoor positioning method provided by the invention is realized in the situation shown in fig. 1. Modulating the light source signals to enable the light signals emitted by the two light sources to meet the following conditions:
S 1 ＝A 1 cos{2π[ω+γ(t-t 1 )]t}
S 2 ＝A 2 cos{2π[ω+Δω+γ(t-t 2 )]t}
wherein A is 1 、A 2 Respectively are light sources S 1 、S 2 Amplitude, t 1 、t 2 Respectively light signals from the light source S 1 、S 2 The time taken for transmission to the receiver, γ, is the optical signal modulation rate.
The signals between the light sources are synchronous, the intensity change rate is the same, but the initial frequency between different light sources is slightly different; under the control of the synchronous signal, the frequency of the intensity change of the light source is changed according to the rule of triangular wave or sawtooth wave: 1) When the light source changes according to the triangle wave rule, each light source tunes the speed gamma from the respective initial frequency according to the same frequency, and reaches the respective final frequency after the time period T; then the frequency of each light source reaches the initial frequency after the time period T at the tuning rate-gamma from the final frequency; then remodulating from the starting frequency, and the process is repeated; 2) When the intensity of the light source changes according to the sawtooth wave law, under the control of a synchronous signal, each light source tunes the rate gamma from the respective initial frequency according to the same frequency, and reaches the respective final frequency after the time period T; the frequency of each light source is tuned from the initial frequency again, and the process is repeated, namely the frequency of the intensity modulation of each light source changes according to the sawtooth wave rule.
The photoelectric detector of the receiver detects the light signals emitted by the two light sources at the same time and respectively inputs the light signals to the two input ends of the multiplier, or the two light signals are mixed together and then input to the frequency multiplier; the output signal of the multiplier or the frequency multiplier is filtered by a low-pass filter to obtain the difference frequency information of two paths of light intensity, and the difference frequency signal is analyzed to obtain the frequency information of the difference frequency signal, so that the position information of the receiver relative to the light source is calculated.
The electric signal obtained after the signal received by the receiver is coupled and squared satisfies the following conditions:
A 1 A 2 cos{2π[Δω+γ(t 1 -t 2 )]t } the default frequencies are all positive for the singleness of the spatial location solution, which needs to be satisfied
Wherein Δt is max At t 1 -t 2 The maximum possible, i.e. the time required for the light signal from one light source to another, i.e.>
Where d is the distance between the two sources, and c is the speed of light as shown in FIG. 1. The frequency sweep rate available on the whole satisfies +.>
The filter is obtained by filtering out signals with frequency higher than 2DeltaomegaTarget item containing target location information: s is S n (t)＝A 1 A 2 cos{2π[Δω+γ(t 1 -t 2 )]t}。
Acquisition of S with data acquisition device n (t) obtaining a discrete signal: s is S n (nT)＝A 1 A 2 cos{2π[Δω+γ(t 1 -t 2 )]nT, wherein T is the sampling period of the data acquisition card, and S can be obtained through data analysis n The frequency f of (t), the target term frequency satisfies:
Δω±Δ Δ ω+γ(t 1 -t 2 )＝f±df
thereby obtaining the distance d of the receiver from the first light source 1 The method comprises the following steps:
wherein Deltad, delta Δ ω, Δγ is the uncertainty of the measuring instrument.
According to different environments and conditions, the precision of the measuring instrument can be increased by changing the variation range and the modulation rate of the frequency of the light source, and the stroboscopic frequency of the light source is maximized so as to meet the required measuring range and precision requirements.
The second aspect of the present invention provides a positioning device used in the optical indoor positioning method, which is composed of two or more light sources, a receiver, a multiplier or a frequency multiplier, a filter, a data collector, and a computer, wherein the light sources are used for sending variable frequency modulated light signals, the receiver is used for receiving the variable frequency modulated light signals sent by the light sources, the multiplier or the frequency multiplier is used for processing the variable frequency modulated light signals sent by the light sources and received by the receiver to obtain sinusoidal signals, the filter is used for filtering signals with the frequency higher than 2Δω, the data collector is used for collecting the sinusoidal signals output by the filter, and the computer is used for outputting the obtained position information of the receiver relative to the light sources.
The invention is realized based on the following principle: based on the light propagation characteristics, a signal processing technology is adopted, and the optical signal is converted into an electrical signal to obtain time information related to the distance, thereby obtaining position information. In order to realize indoor positioning, a special modulated light source is adopted, and the frequencies of the two light sources are changed linearly. The useful electrical signal is obtained by coupling, squaring and filtering the signal received by the receiver. After the electric signal is converted into a digital signal through the data collector, the digital signal is processed by a computer, the electric signal is changed into a frequency domain from a time domain, and a frequency spectrum is analyzed to obtain a target item frequency. By combining the characteristics of the optical signals, the time difference between the optical signals of the two light sources and the receiver can be calculated, and then the position information can be obtained. When the selected instrument has different precision and the stroboscopic frequency of the used light source is different, the measuring range and precision of the design device can be changed, so that the device can be effectively utilized in different environments and under different situations.
By adopting the technical scheme, the invention has the following advantages and beneficial effects:
the invention provides a novel optical indoor positioning technology, which combines the propagation characteristics of analysis light with a signal processing technology, innovates the problem of processing optical signals, and can realize high-precision, rapid and accurate indoor positioning by using simple equipment comprising a light source and a receiver. In this item, by setting an appropriate light source modulation frequency, a signal received by a receiver is subjected to signal processing, and the absolute position of a target is determined.
The indoor optical positioning method comprises the steps that a system comprises a light source array and a receiver, the light source array emits light signals with the intensity modulated according to a specific rule, the light signals detected by the receiver are processed through a frequency doubling and filtering circuit and then output sinusoidal signals, the frequency of the signals is related to the position of the receiver relative to the light source, and the position information of the receiver is obtained through detecting the frequency of the sinusoidal signals.
According to the optical indoor positioning method, the light source emits the optical signal with the special modulation frequency, and after the receiver detects the optical signal of the light source, the relative position of the receiver and the light source is mapped to the frequency of the output signal linearly through the signal processing circuits such as frequency multiplication, filtering, analog-to-digital conversion and the like, so that the accurate detection of the position is realized. The method only uses unidirectional information transfer from the light source to the receiver, has simple and convenient equipment, is beneficial to installation, and has great application potential in the fields of disaster sites, gao Weilou U rescue, positioning in a pit, positioning in a tunnel and the like.
The optical indoor positioning method combines the light propagation characteristics and the signal processing technology, the light source array comprises two or more light sources, the intensity of light emitted by each light source is a sine signal, and the frequency of the sine signal changes linearly with time. The optical signals are converted into electric signals, the electric signals are converted into digital signals through the data acquisition device, then the digital signals are processed through the computer, frequency information is obtained through Fourier transformation, time information is obtained through calculation, and then the position information of the receiver is obtained.
According to the optical indoor positioning method, on one hand, the optical characteristics and the signal processing are combined, so that simplification and convenience of the device and the principle are realized; on the other hand, the invention has higher adjustability, and can be applied to different occasions and under different conditions by changing the strobe frequency of the light source and the precision of the measuring instrument so as to change the measuring range and the precision. In yet another aspect, the present invention is applicable to both fixed point indoor positioning and indoor positioning of moving objects. The principle and the device of the invention are simple and convenient, have the advantages of wide application range, high measurement precision and the like, and have great application potential in indoor positioning technology.
Drawings
FIG. 1 is a schematic diagram showing an implementation of the indoor optical positioning method of the present invention.
Fig. 2 is a simplified schematic diagram of a positioning device used in the optical indoor positioning method of the present invention. Wherein 1 is a light source, 2 is a receiver, 3 is a multiplier, 7 is a frequency multiplier, 4 is a filter, 5 is a data collector, and 6 is a computer.
Fig. 3 is a schematic diagram of the relationship between the light intensity of the modulated light signal and time, and a schematic diagram of the time domain (left) and the frequency domain (right) of the light intensity of the light source.
Fig. 4 is a schematic diagram of frequency versus time of an optical signal, on: saw tooth wave; the following steps: triangular wave.
Detailed Description
In order to more clearly illustrate the present invention, the present invention will be further described with reference to preferred embodiments. It is to be understood by persons skilled in the art that the following detailed description is illustrative and not restrictive, and that this invention is not limited to the details given herein.
Example 1
The invention is realized based on the following principle:
based on the light propagation characteristics, a signal processing technology is adopted, and the optical signal is converted into an electrical signal to obtain time information related to the distance, thereby obtaining position information. In order to realize indoor positioning, a special modulated light source is adopted, and the frequencies of the two light sources are changed linearly. The useful electrical signal is obtained by coupling, squaring and filtering the signal received by the receiver. After the electric signal is converted into a digital signal through the data collector, the digital signal is processed by a computer, the electric signal is changed into a frequency domain from a time domain, and a frequency spectrum is analyzed to obtain a target item frequency. By combining the characteristics of the optical signals, the time difference between the optical signals of the two light sources and the receiver can be calculated, and then the position information can be obtained. When the selected instrument has different precision and the stroboscopic frequency of the used light source is different, the measuring range and precision of the design device can be changed, so that the device can be effectively utilized in different environments and under different situations.
Taking the simplest two light source points as an example, the indoor positioning method provided by the invention is realized in the situation shown in fig. 1. FIG. 1 is a schematic diagram showing an implementation of the indoor optical positioning method of the present invention. Modulating the light source signals to enable the light signals emitted by the two light sources to meet the following conditions:
S 1 ＝A 1 cos{2π[ω+γ(t-t 1 )]t}
S 2 ＝A 2 cos{2π[ω+Δω+γ(t-t 2 )]t}
wherein A is 1 、A 2 Respectively are light sources S 1 、S 2 Amplitude, t 1 、t 2 Respectively light signals from the light source S 1 、S 2 Transmitting to receivingThe time it takes.
The electric signal obtained after the signal received by the receiver is coupled and squared satisfies the following conditions:
A 1 A 2 cos{2π[Δω+γ(t 1 -t 2 )]t } the default frequencies are all positive for the singleness of the spatial location solution, which needs to be satisfied
Wherein Δt is max At t 1 -t 2 The maximum possible, i.e. the time required for the light signal from one light source to another, i.e.>
Where d is the distance between the two sources, and c is the speed of light as shown in FIG. 1. The frequency sweep rate available on the whole satisfies +.>
The target item containing the target position information is obtained by using a low-pass filter (filtering out the signal with the frequency higher than 2Δω): s is S n (t)＝A 1 A 2 cos{2π[Δω+γ(t 1 -t 2 )]t}
Obtaining discrete signals by using a data acquisition card: s is S n (nT)＝A 1 A 2 cos{2π[Δω+γ(t 1 -t 2 )]nT, where T is the sampling period of the data acquisition card. S can be obtained through data analysis n Frequency f of (t).
As can be seen from fig. 2 and 3, fig. 2 is a simplified schematic diagram of a positioning device used in the optical indoor positioning method according to the present invention, one positioning device used in the optical indoor positioning method is composed of two or more light sources 1, a receiver 2, a multiplier 3 or a frequency multiplier 7, a filter 4, a data collector 5, and a computer 6, wherein the light sources 1 are used for emitting variable-frequency modulated light signals, the receiver 2 is used for receiving the variable-frequency modulated light signals emitted by the light sources 1, the multiplier 3 or the frequency multiplier 7 is used for processing the variable-frequency modulated light signals emitted by the light sources 1 received by the receiver 2 to obtain sinusoidal signals, the filter 4 is used for filtering signals with a frequency higher than 2Δω, the data collector 5 is used for collecting the sinusoidal signals output by the filter 4, and the computer 6 is used for outputting the obtained position information of the receiver 2 relative to the light sources 1. Fig. 3 is a schematic diagram of the relationship between the light intensity of the modulated light signal and time, and a schematic diagram of the time domain (left) and the frequency domain (right) of the light intensity of the light source. The intensity of the light emitted by each light source is a sinusoidal signal, and the frequency of the sinusoidal signal varies linearly with time over a period T.
In fig. 4, fig. 4 is a schematic diagram of frequency versus time of an optical signal, and the following is shown: saw tooth wave; the following steps: triangular wave. The target term frequency satisfies:
Δω±Δ Δ ω+γ(t 1 -t 2 )＝f±df
the distance from the receiver to the emission source S1 is thus obtained as:
an optical indoor positioning method comprises the following steps:
the light source emits variable frequency modulation light signals, the receiver receives the signals, the signals are coupled and squared through the multiplier or the frequency multiplier, the filtered electric signals are collected by the data collector and then are subjected to Fourier transformation in the digital domain, frequency domain information of the electric signals is obtained, the frequency of a target item is obtained, and then the distance between the receiver and the light source is obtained.
The light source comprises two or more light sources, the intensity of light emitted by each light source is a sinusoidal signal, and the frequency of the sinusoidal signal changes linearly with time.
Taking the simplest two light source points as an example, the indoor positioning method provided by the invention is realized in the situation shown in fig. 1. Modulating the light source signals to enable the light signals emitted by the two light sources to meet the following conditions:
S 1 ＝A 1 cos{2π[ω+γ(t-t 1 )]t}
S 2 ＝A 2 cos{2π[ω+Δω+γ(t-t 2 )]t}
wherein A is 1 、A 2 Respectively are light sources S 1 、S 2 Amplitude, t 1 、t 2 Respectively light signals from the light source S 1 、S 2 The time taken for transmission to the receiver, γ, is the optical signal modulation rate.
The signals between the light sources are synchronous, the intensity change rate is the same, but the initial frequency between different light sources is slightly different; under the control of the synchronizing signal, each light source tunes the rate gamma from the respective initial frequency according to the same frequency, and reaches the respective final frequency after the time period T; the frequency of each light source is tuned from the initial frequency again, and the process is repeated, namely the frequency of the intensity modulation of each light source changes according to the sawtooth wave rule.
The photoelectric detector of the receiver detects the light signals emitted by the two light sources at the same time, the light signals are mixed together and then input into the frequency multiplier, the output signal of the frequency multiplier is subjected to low-pass filtering processing to obtain difference frequency information of two paths of light intensity, the difference frequency signal is analyzed to obtain frequency information of the difference frequency signal, and then the position information of the receiver relative to the light sources is calculated.
The electric signal obtained after the signal received by the receiver is coupled and squared satisfies the following conditions:
A 1 A 2 cos{2π[Δω+γ(t 1 -t 2 )]t } the default frequencies are all positive for the singleness of the spatial location solution, which needs to be satisfied
Wherein Δt is max At t 1 -t 2 The maximum possible, i.e. the time required for the light signal from one light source to another, i.e.>
Where d is the distance between the two sources, and c is the speed of light as shown in FIG. 1. The frequency sweep rate available on the whole satisfies +.>
The filter filters out signals with frequency higher than 2Δω to obtain target items containing target position information: s is S n (t)＝A 1 A 2 cos{2π[Δω+γ(t 1 -t 2 )]t}。
Acquisition of S with data acquisition device n (t) obtaining a discrete signal: s is S n (nT)＝A 1 A 2 cos{2π[Δω+γ(t 1 -t 2 )]nT, wherein T is the sampling period of the data acquisition card, and S can be obtained through data analysis n The frequency f of (t), the target term frequency satisfies:
Δω±Δ Δ ω+γ(t 1 -t 2 )＝f±df
thereby obtaining the distance d of the receiver from the first light source 1 The method comprises the following steps:
wherein Deltad, delta Δ ω, Δγ is the uncertainty of the measuring instrument.
According to different environments and conditions, the precision of the measuring instrument can be increased by changing the variation range and the modulation rate of the frequency of the light source, and the stroboscopic frequency of the light source is maximized so as to meet the required measuring range and precision requirements.
The invention provides a novel optical indoor positioning technology, which combines the propagation characteristics of analysis light with a signal processing technology, innovates the problem of processing optical signals, and can realize high-precision, rapid and accurate indoor positioning by using simple equipment comprising a light source and a receiver. In this item, by setting an appropriate light source modulation frequency, a signal received by a receiver is subjected to signal processing, and the absolute position of a target is determined.
The indoor optical positioning method comprises the steps that a system comprises a light source array and a receiver, the light source array emits light signals with the intensity modulated according to a specific rule, the light signals detected by the receiver are processed through a frequency doubling and filtering circuit and then output sinusoidal signals, the frequency of the signals is related to the position of the receiver relative to the light source, and the position information of the receiver is obtained through detecting the frequency of the sinusoidal signals.
According to the optical indoor positioning method, the light source emits the optical signal with the special modulation frequency, and after the receiver detects the optical signal of the light source, the relative position of the receiver and the light source is mapped to the frequency of the output signal linearly through the signal processing circuits such as frequency multiplication, filtering, analog-to-digital conversion and the like, so that the accurate detection of the position is realized. The method only uses unidirectional information transfer from the light source to the receiver, has simple and convenient equipment, is beneficial to installation, and has great application potential in the fields of disaster sites, gao Weilou U rescue, positioning in a pit, positioning in a tunnel and the like.
The optical indoor positioning method combines the light propagation characteristics and the signal processing technology, the light source array comprises two or more light sources, the intensity of light emitted by each light source is a sine signal, and the frequency of the sine signal changes linearly with time. The optical signal is converted into an electrical signal, frequency information is obtained by fourier transform, time information is obtained by calculation, and position information of the receiver is obtained.
According to the optical indoor positioning method, on one hand, the optical characteristics and the signal processing are combined, so that simplification and convenience of the device and the principle are realized; on the other hand, the invention has higher adjustability, and can be applied to different occasions and under different conditions by changing the strobe frequency of the light source and the precision of the measuring instrument so as to change the measuring range and the precision. In yet another aspect, the present invention is applicable to both fixed point indoor positioning and indoor positioning of moving objects. The principle and the device of the invention are simple and convenient, have the advantages of wide application range, high measurement precision and the like, and have great application potential in indoor positioning technology.
The foregoing description is only illustrative of the preferred embodiment of the present invention, and is not to be construed as limiting the invention, but is to be construed as limiting the invention to any and all simple modifications, equivalent variations and adaptations of the embodiments described above, which are within the scope of the invention, may be made by those skilled in the art without departing from the scope of the invention.
Claims (10)
1. An optical indoor positioning method is characterized by comprising the following steps:
the light source emits a variable frequency modulation light signal, the receiver receives the signal, the signal is coupled and squared through the multiplier or the frequency multiplier, the filtered electric signal is collected by the data collector and then is subjected to Fourier transform in a digital domain to obtain frequency domain information of the electric signal, the frequency of a target item is obtained, and then the distance between the receiver and the light source is obtained;
the light source comprises two or more light sources, the intensity of light emitted by each light source is a sinusoidal signal, and the frequency of the sinusoidal signal changes linearly with time.
2. The method of claim 1, wherein the light source signals are modulated such that the light signals from the two light sources satisfy:
S 1 ＝A 1 cos{2π[ω+γ(t-t 1 )]t}
S 2 ＝A 2 cos{2π[ω+Δω+γ(t-t 2 )]t}
wherein A is 1 、A 2 Respectively are light sources S 1 、S 2 Amplitude, t 1 、t 2 Respectively light signals from the light source S 1 、S 2 The time taken for transmission to the receiver, γ, is the optical signal modulation rate.
3. The method of claim 1 or 2, wherein the signals between the light sources are synchronized with the same rate of intensity change but with a smaller difference in initial frequency between the different light sources; under the control of the synchronizing signal, each light source tunes the rate gamma from the respective initial frequency according to the same frequency, and reaches the respective final frequency after the time period T; then the frequency of each light source reaches the initial frequency after the time period T at the tuning rate-gamma from the final frequency; the process is repeated from the beginning to the beginning, i.e. the frequency of the intensity modulation of each light source is changed according to the triangle wave rule.
4. The method of claim 1 or 2, wherein the signals between the light sources are synchronized with the same rate of intensity change but with a smaller difference in initial frequency between the different light sources; under the control of the synchronizing signal, each light source tunes the rate gamma from the respective initial frequency according to the same frequency, and reaches the respective final frequency after the time period T; the frequency of each light source is tuned from the initial frequency again, and the process is repeated, namely the frequency of the intensity modulation of each light source changes according to the sawtooth wave rule.
5. The method for positioning an optical room according to claim 1 or 2, wherein the photodetector of the receiver detects the light signals emitted by the two light sources at the same time, the light signals are respectively input to two input ends of the multiplier, the output signals of the multiplier are filtered by the low-pass filter to obtain the difference frequency information of the two light intensities, the difference frequency signal is analyzed to obtain the frequency information, and the position information of the receiver relative to the light sources is calculated.
6. The method according to claim 1 or 2, wherein the photoelectric detector of the receiver detects the light signals emitted by the two light sources simultaneously, the light signals are mixed together and then input to the frequency multiplier, the output signal of the frequency multiplier is subjected to low-pass filtering processing to obtain difference frequency information of the two light intensities, the difference frequency signal is analyzed to obtain frequency information of the difference frequency signal, and then the position information of the receiver relative to the light sources is calculated.
7. The method according to claim 2, wherein the signal received by the receiver is coupled and squared to obtain an electrical signal satisfying:
A 1 A 2 cos{2π[Δω+γ(t 1 -t 2 )]t } the default frequencies are all positive for the singleness of the spatial location solution, which needs to be satisfied
Wherein Δt is max At t 1 -t 2 The maximum possible, i.e. the time required for the light signal from one light source to another, i.e.>
Wherein d is the distance between the two emission sources, and c is the speed of light; sweep Rate satisfies->
8. The method of claim 2, wherein the filter filters out signals with a frequency higher than 2Δω to obtain a target item containing target position information: s is S n (t)＝A 1 A 2 cos{2π[Δω+γ(t 1 -t 2 )]t}。
9. The method of claim 2, wherein the S is collected by a data collector n (t) obtaining a discrete signal: s is S n (nT)＝A 1 A 2 cos{2π[Δω+γ(t 1 -t 2 )]nT, wherein T is the sampling period of the data acquisition card, and S can be obtained through data analysis n The frequency f of (t), the target term frequency satisfies:
Δω±Δ Δ ω+γ(t 1 -t 2 )＝f±df
thereby obtaining the distance d of the receiver from the first light source 1 The method comprises the following steps:
wherein Deltad, delta Δ ω, Δγ is the uncertainty of the measuring instrument.
10. A positioning device used in the optical indoor positioning method as claimed in claim 2, characterized in that it is composed of two or more light sources, a receiver, a multiplier or frequency multiplier, a filter, a data collector, and a computer, wherein the light sources are used for emitting frequency-conversion modulated light signals, the receiver is used for receiving the frequency-conversion modulated light signals emitted by the light sources, the multiplier or frequency multiplier is used for processing the frequency-conversion modulated light signals emitted by the light sources and received by the receiver to obtain sinusoidal signals, the filter is used for filtering signals with frequency higher than 2Δω, the data collector is used for collecting the sinusoidal signals output by the filter, and the computer is used for outputting the obtained position information of the receiver relative to the light sources.
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| DE19549303A1 (en) * | 1995-06-19 | 1997-01-02 | Wissenschaftlich Tech Optikzen | Analyser for short and ultra-short light pulses |
| CN105676206A (en) * | 2016-01-14 | 2016-06-15 | 中国人民解放军空军工程大学 | Linear frequency-modulated signal microwave photon frequency multiplication method and device |
| CN106663912A (en) * | 2014-06-05 | 2017-05-10 | 瑞尼斯豪公司 | Laser device |
| CN108828615A (en) * | 2018-06-11 | 2018-11-16 | 深圳市镭神智能系统有限公司 | Light emitting unit, optical signal detecting module, optical system and laser radar system |
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| DE19549303A1 (en) * | 1995-06-19 | 1997-01-02 | Wissenschaftlich Tech Optikzen | Analyser for short and ultra-short light pulses |
| CN106663912A (en) * | 2014-06-05 | 2017-05-10 | 瑞尼斯豪公司 | Laser device |
| CN105676206A (en) * | 2016-01-14 | 2016-06-15 | 中国人民解放军空军工程大学 | Linear frequency-modulated signal microwave photon frequency multiplication method and device |
| CN108828615A (en) * | 2018-06-11 | 2018-11-16 | 深圳市镭神智能系统有限公司 | Light emitting unit, optical signal detecting module, optical system and laser radar system |
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