Plane positioning system based on triangular synchronous light source

Abstract

The invention discloses a plane positioning system based on a triangular synchronous light source, which is characterized in that an edge computing device on a to-be-positioned moving object uses an optical signal receiver (such as a silicon photocell) to receive light source signals deployed in an isosceles right triangle shape on a parallel plane, computes a phase difference, computes an optical path difference through triangulation, and determines the position of the to-be-positioned moving object according to the phase difference. And solving to obtain a possible coordinate point list, and screening out the obtained coordinates of the to-be-positioned object according to the received relative light intensity, so as to be applied to scenes such as vehicle and personnel positioning through street lamps in places such as parks, hospitals, prisons and the like.

Description

Technical Field

[0001] The present invention is applied to the technical field of positioning of moving objects in a plane, and in particular to a plane positioning system based on a triangular synchronous light source. Background Art

[0002] In addition to the characteristics of energy conservation, environmental protection, long service life, and small volume, the fourth-generation visible light source device (for example: LED) can also achieve communication through high-frequency modulation. Due to its flexible deployment method and wide coverage, the distance from the detection point to the visible light source device can be accurately obtained by means of visible light communication, and positioning and navigation can be realized.

[0003] Visible light source positioning usually adopts measurement schemes based on received signal strength, received signal angle, and received signal arrival time. In the measurement scheme based on received signal strength, the received optical power is usually affected by the brightness of the light source, and factors such as light scattering and reflection, light signal transmission and reception angles, and background light interference will directly affect its ranging and positioning accuracy; in the measurement scheme based on received signal angle, there is usually a lack of accurate and operable light incident angle measurement methods; in the measurement scheme based on received signal arrival time, it is difficult to accurately achieve signal synchronization and time measurement. Therefore, there are certain problems in the direct use of these measurement schemes. Summary of the Invention

[0004] The purpose of the present invention is to provide a plane moving object positioning system through three-point synchronous light sources of an isosceles right triangle in view of the deficiencies of the prior art.

[0005] Technical Solution:

[0006] A plane positioning system based on a triangular synchronous light source deploys a light source controller module and light source points L0, L1, and L2 on the light source plane, and the light source points are deployed in an isosceles right triangle; an edge computing device that can receive light sources L0, L1, and L2 is deployed on the object to be positioned on the positioning plane.

[0007] The distance between the light source plane and the positioning plane is fixed. Assuming that the light source plane is the reference plane z = 0 and the positioning plane is z = h. The fixed light source point coordinates on the light source plane are L0(0, 0, 0), L1(1, 0, 0), and L2(0, 1, 0), and the optical paths of the visible light emitted from the light source points to the object to be positioned are d 0 、d 1 and d 2 , then the coordinates (x, y, z) of the object to be positioned satisfy:

[0008]

[0009] where Δ 1 =|d 0 -d1 |, Δ 2 = |d 0 -d 2 |, Δ 1 <1, Δ 2 <1.

[0010] The visible light signals transmitted by the light source points L0, L1, and L2 are where P is the optical signal intensity gain emitted from the light source point, ω is the modulation emission frequency, θ is the initial phase angle, is an arbitrary transmission time.

[0011] The visible light signals received by the calculation device from L0, L1, and L2 on the upper edge of the object to be located in the positioning plane are respectively where t0, t1, and t2 are the reception delays respectively.

[0012] After phase shift processing, we can respectively obtain Further obtain P through the trigonometric formula 0 P 1 sin(ω(t 1 -t 0 ))), P 0 P 2 sin(ω(t 2 -t 0 ))). Finally, through the arcsine function calculation and the speed of light c, the optical path difference Δ can be obtained 1 = c|t 1 -t 0 |, Δ 2 = c|t 2 -t 0 |.

[0013] Several coordinate values {(x i , y i , h)|i = 1,..., k} can be calculated from Equation (1). According to the principle of light intensity attenuation: the attenuation of light intensity is inversely proportional to the square of the optical path. Therefore, further screening can be carried out through the magnitude relationship of the received visible light intensity, so as to obtain a definite coordinate value solution. For example: if P 0 ≥ P 1 ≥ P 2 , then there must be (x 2 + y 2 ) ≤ ((x - 1) 2 + y 2 ) ≤ (x 2 + (y - 1) 2 ).

[0014] Advantages of the present invention

[0015] The hardware of the present invention is simple. It only requires the deployment of three fixed visible light power supplies with modulation modules and edge computing devices that follow the objects to be located and moved. All calculations and processing can be completed at the receiving end, or can be summarized and remotely sent to a centralized server for unified processing. Synchronization and control are simple, and the cost has certain advantages. This method can be extended to the positioning of multiple moving objects; on the other hand, its application scenarios are extensive, such as vehicle and personnel positioning through street lights in outdoor venues such as parks, hospitals, and prisons. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a schematic structural diagram of the system of the present invention

[0017] Figure 2 It is a block diagram of the light source controller of the present invention

[0018] Figure 3 It is a block diagram of the edge computing device of the present invention

[0019] Figure 4 It is a working flow chart of the computing module in the edge computing device of the present invention

[0020] Figure 5 It is a schematic diagram of the same-frequency decomposition and calculation of the optical signal of the present invention DETAILED DESCRIPTION OF THE EMBODIMENTS

[0021] The present invention will be further described below in conjunction with embodiments, but the protection scope of the present invention is not limited thereto:

[0022] As Figure 1 shown, a planar positioning system based on a triangular synchronous light source deploys a light source controller module and light source points L0, L1, and L2 on the light source plane, and the light source points are deployed in an isosceles right triangle; an edge computing device that can receive light sources L0, L1, and L2 is deployed on the object to be located on the positioning plane.

[0023] The distance between the light source plane and the positioning plane is fixed. Assuming the light source plane is the reference plane z = 0 and the positioning plane is z = h. The fixed light source point coordinates on the light source plane are L0(0,0,0), L1(1,0,0), and L2(0,1,0), and the optical paths from the light source points to the object to be located are d0, d1, and d2 respectively.

[0024] As Figure 2As shown in the figure, the light source controller on the light source plane is composed of a power supply module, a modulation module, and an amplifier connected in sequence. The amplifier is connected to light source points L0, L1, and L2, and the lengths of the physical connection lines are the same, ensuring that the characteristics of the visible light signals emitted from L0, L1, and L2 are the same. The modulation module periodically modulates the transmitted micro-signal according to the set frequency and initial phase angle parameters; the amplifier performs a constant light intensity gain on the modulated micro-signal from the modulation module to drive the light source to emit visible light signals; the hard wiring connecting the amplifier and the light source should have the same length, thereby ensuring that the signal characteristics emitted by the light source are the same, that is: the same frequency, the same phase angle, and the same light intensity; the power supply module provides the power supply for the light source controller. The logic of each module is simple and will not be elaborated specifically.

[0025] As Figure 3 shown, the edge computing device on the positioning plane is composed of a power supply module, a computing module, a phase shift module, a comparison module, an amplifier, and a silicon photocell connected in sequence. The silicon photocell receives the visible light signal and transfers it to the amplifier; the amplifier linearly amplifies the signal intensity; the comparison module calculates the light intensity amplitude, phase angle calculation, and frequency comparison for the amplified signal; the phase shift module performs a phase shift operation according to the amplified signal and the frequency; the computing module calculates according to the aforementioned trigonometric formulas, arcsine function calculations, optical path difference calculations, solving joint quadratic binary equations, and screening coordinates, thereby obtaining the coordinates of the moving object; the power supply module provides the power supply for the edge computing device. The processing logic flowchart of the computing module is as Figure 4 shown, and the logic of other modules is simple and will not be elaborated specifically.

[0026] The following actual cases give specific descriptions:

[0027] Suppose the distance of the light source plane is 15 meters, and the distances between the light source points in the light source plane are 20 meters, that is, the light source point coordinates are (0, 0, 0), (20, 0, 0), and (0, 20, 0), and the coordinates of the object to be measured are (X, Y, Z). Through per-unit value conversion Figure 1 of each data in it, L0(0, 0, 0), L1(1, 0, 0), L2(0, 1, 0), h = 0.75, and the target coordinates (x, y, z), where x = 0.05X, y = 0.05Y, z = 0.05Z = h.

[0028] A visible light signal with a modulation frequency of 40 MHz is obtained at the receiving point. Through the same-frequency separation technology of photosensitive devices, three visible light signals can be obtained, as Figure 5 shown.

[0029] The visible light intensities P0, P1, and P2 are 26, 42, and 46 respectively. The reference calculation point signals 17.08293874, 8.777213639, and 25.86015237 are selected. Through phase shift, the data 38.3689098, 45.1548507, and 109.5237605 are obtained. Through the trigonometric formula, Δ 1 = 3.067814837, Δ 2 = 6.185461077. After per-unit value conversion, Δ 1 = 0.153390742, Δ 2 = 0.309273054. Then, the coordinate points can be transformed and the simultaneous equations (1) can be written as:

[0030]

[0031] By solving this system of equations, the set of coordinate points (0.312659841, 0.806178615, 0.75),

[0032] (0.35754405, 0.188669047, 0.75), (0.641188338, 0.143785238, 0.75), and (0.693717814, 0.866477143, 0.75) can be obtained.

[0033] According to the light intensity logical relationship P0 < P1 < P2, only the relative optical path 1.232027045 > 0.844591417 > 0.499072759 calculated from the coordinate points of the 4th group satisfies the inverse proportional relationship with the light intensity. Therefore, the coordinate (x, y, z) of this group is the correct value (0.693717814, 0.866477143, 0.75). Finally, for the 4th group of coordinate points (x, y, z), the coordinate values are restored, and the coordinates (X, Y, Z) of the target object are obtained as (13.87435628, 17.32954286, 15).

[0034] The specific embodiments described in this article are only illustrative of the spirit of the present invention. Those skilled in the art of the present invention can make various modifications or supplements to the described specific embodiments or use similar methods to replace them, but will not deviate from the spirit of the present invention or exceed the scope defined by the appended claims.

Claims

1. A plane positioning system based on triangular synchronous light source, characterized in that The horizontal plane where the object to be positioned is located is recorded as the positioning plane, and the light source plane is set to be parallel to the positioning plane; light source points L0, L1 and L2 are deployed on the light source plane; the light source points are deployed in an isosceles right triangle, and the coordinates are recorded as L0 (0, 0, 0), L1 (1, 0, 0) and L2 (0, 1, 0) respectively; Then the coordinates (x, y, z) of the object to be located satisfy equation group (1): Wherein, h represents the distance from the positioning plane to the light source plane; the values ​​of Δ1 and Δ2 are obtained by deploying edge computing devices that can receive light sources L0, L1, and L2 on the object to be positioned on the positioning plane; Solve the equation group (1) to obtain multiple sets of coordinate solutions of the objects to be located {(x i ,y i ,h)|i=1,...,k}, and obtain the final coordinates (x, y, z) of the object to be located according to the light intensity logic screening.

2. The planar positioning system according to claim 1, characterized in that The values ​​of Δ1 and Δ2 are obtained specifically by the following steps: S1, the optical signals received by the edge computing device from each light source are: Among them, P0, P1, and P2 represent the light signal intensity gain of each light source point, ω is the modulation transmission frequency, is any sending time, t0, t1, t2 represent the receiving delay of each light source point, and θ is the initial phase angle; S2, after phase shift processing, is obtained: S3, according to the trigonometric formula: P0P1 sin(ω(t1-t0)), P0P2sin(ω(t2-t0)) S4, obtained by the inverse sine function: t1-t0 and t2-t0 S5, then: Δ1=c|t1-t0|, Δ2=c|t2-t0|, c is the speed of light.

3. The planar positioning system according to claim 1, characterized in that The light intensity logic is specifically: the attenuation of light intensity is inversely proportional to the square of the optical path.

4. The planar positioning system according to claim 3, characterized in that The square of the optical path of the light source point L0 is: 2 +y 2 ; The square of the optical path of the light source point L1 is: (x-1) 2 +y 2 ; The square of the optical path of the light source point L2 is: x 2 +(y-1) 2 .

5. The planar positioning system according to claim 1, characterized in that The distances of each light source point are converted into L0 (0,0,0), L1 (1,0,0) and L2 (0,1,0) through per-unit values, and then the equation group is calculated; after the coordinates of the object to be located are determined, the coordinate values ​​are restored.

6. The planar positioning system according to claim 1, characterized in that Each light source point is controlled by a light source controller module.

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