CN104914407B - A kind of indoor positioning device and localization method - Google Patents

Abstract

The present invention is applicable to the technical field of positioning, and provides an indoor positioning device, which includes a base, a light source, a rotating part, a rotating housing and a controller; the rotating housing is divided into a plurality of coding circles, and each coding circle is divided into a plurality of coding bits, The angle of the coded bits in the latitude direction is 360/N degrees, and the coded bits are arranged in different ways in different coded circles; several coded bits in the coded circle are in the light-transmitting state, there are no more than two consecutive non-transparent coded bits, and several The coding bits arranged in a specific way form the start bit and the end bit; each coding circle includes a special coding bit; the base is also equipped with an optical coupler, and the side of the rotating part facing the base is equipped with a light shield, and the rotating part Every time the light blocking sheet is driven through the slot, the light source undergoes a frequency jump. The invention achieves positioning through a special rotating shell and a jumping light source, combined with the sensing light signal at the receiving end, has a simple structure and a novel, accurate, stable and low-cost positioning method, and is suitable for indoor high-precision positioning.

Description

An indoor positioning device and positioning method

technical field

The invention belongs to the technical field of positioning, and in particular relates to an indoor positioning device and a positioning method.

Background technique

With the advancement of science and technology and the development of social economy, people's demand for indoor positioning services is increasing day by day. In some public places, such as shopping malls, airports, exhibition halls, office buildings, warehouses, underground parking lots, etc., accurate indoor positioning information can be convenient for users. Shopping, traveling, finding indoor targets, etc.; able to efficiently manage available space and inventory materials; able to navigate police, firefighters, soldiers, and medical staff to complete specific indoor tasks. Smart spaces and ubiquitous computing are inseparable from location-based services, so indoor positioning has broad application prospects. Although GPS can meet the needs of many applications in outdoor positioning, it is difficult to use GPS in indoor environments because the signals are blocked by building walls and indoor objects, etc., in indoor environments. position.

Research on indoor positioning technology at home and abroad is relatively rich. According to positioning principles, there are proximity detection, fingerprint matching, and multilateral/angle methods. The proximity detection method takes the detected position of the signal source as the positioning position, and the accuracy is low. The fingerprint matching method can obtain better positioning accuracy by using the signal feature matching in the indoor environment, but the positioning results are easily affected by indoor multipath effects and environmental changes. The positioning results are unstable and the accuracy is not high, and a fingerprint database needs to be established. cumbersome. The multilateral/angle method needs to accurately measure the distance/angle and other information from the positioning point to the reference point through algorithms such as TOA, TDOA, and AOA, and then use trilateration to locate the target. If the position information of the reference node is accurate and the measurement distance is accurate, the position of the target node can be accurately measured, but in actual measurement, there will be errors in these data values, which will affect the positioning results. If full indoor coverage is required, a large number of reference points need to be arranged, and the cost is high.

The patent with the application number CN201110054768.3 proposes a weighted trilateration positioning method based on RSSI. The limitation is that this method cannot accurately measure the distance between nodes, resulting in large positioning errors.

The patent application number CN201210290193.X proposes a WLAN indoor positioning method based on matrix correlation. The limitation is that collecting indoor environmental feature fingerprints requires a lot of manpower and material resources, and due to the complex indoor environment and obvious multipath effects, wireless signals are easily affected. The positioning accuracy is not high.

Contents of the invention

The object of the present invention is to provide an indoor positioning device, which aims to simplify the structure of the positioning device, and has high positioning accuracy, good stability and low cost.

The present invention is achieved in this way. An indoor positioning device is characterized in that it includes a base, a light source arranged on the base, a rotating member, a rotating housing arranged on the rotating member, and a controller;

The rotating shell is a hemispherical shell or a shell circumscribed on a hemispherical surface formed by splicing a plurality of facets or annular surfaces; the luminous point of the light source is located at the center of the hemispherical surface;

The rotating housing is divided into a plurality of coded circles parallel to the latitude, and the angle α of each coded circle relative to the light source in the longitude direction is known; each coded circle is divided into a plurality of coded bits, and the coded bits are relative to the The angle β of the central point of the coding circle is 360/N degrees, wherein N is the number of coding bits in one coding circle, and the coding bits of different coding circles are arranged in different ways;

In each coding circle, several coding bits are in the light-transmitting state, and there are no consecutive two or more non-light-transmitting coding bits, and a number of coding bits arranged in a specific way constitute the start bit of the coding circle and end bit;

Each coding circle includes a special coding bit having a shape different from other coding bits, and the width of the special coding bit has a preset variation law in the longitude direction;

The base is also provided with an optical coupler with a slot, and the side of the rotating member facing the base is provided with a light-blocking sheet, and the rotating member drives the light-blocking sheet to pass through the slot once, so that The controller controls the light source to undergo a frequency jump;

The indoor positioning device also includes a receiving end, which is used to sense the optical signal at the point to be located and detect the frequency jump point, and perform positioning according to the optical signal and the frequency jump point.

Another object of the present invention is to provide an indoor positioning method based on the above-mentioned indoor positioning device, including the following steps:

Driving the rotating housing to rotate, so that the projection aperture of the rotating housing projected from the light source to the horizontal plane where the point to be positioned is located also rotates accordingly;

The light signal is sensed by the receiving end at the point to be positioned, and the projection aperture where it is located is determined according to the light signal, and then the angle between the line between the inner edge of the projection aperture and the light source and the rotation axis of the rotating housing is determined θ ^r =r*α, wherein, r is the number of projection apertures inside the projection aperture where the point to be located is located;

Determine the angle Δθ ^r between the point to be positioned and the inner edge of the projection aperture relative to the light source according to the width of the special code bit sensed by the receiving end, and then determine the angle between the line between the point to be positioned and the light source and the rotation axis θ=θr + ^{Δθr ;}

When the light blocking sheet passes through the card slot, the direction indicated by the projection of the end of the start bit and the end bit on the horizontal plane is the initial direction, and the frequency jump point and the start point of the light source are detected by the receiving end. The end of the bit and the end bit, determine the angle ω ^r between the front edge of the coding bit projection where the point to be positioned is located and the initial direction;

Determine the angle Δω ^r between the point to be positioned and the front edge of the projection of the code bit where it is located relative to the center of the projection aperture when the frequency jump occurs according to the continuously collected light-transmitting coded bit data after the frequency jump point is detected by the receiving end, and then determine the distance between the point to be positioned and the front edge of the projection aperture. The angle ω=ω ^r +Δω ^r between said initial directions;

The position of the point to be located is determined according to the angle θ and the angle ω.

The positioning device provided by the embodiment of the present invention is provided with a rotating housing with a special structure, and the frequency jump rule of the light source is designed, and a signal receiving end senses the optical signal, according to the setting of the encoding ring, encoding bits and special encoding bits of the rotating housing , combined with the collected optical signal, the coordinates of a certain point in the indoor space can be calculated by the above method. The structure of the device is simple and the positioning method is novel, accurate and stable. Point, not easily affected by the external environment, high precision and good stability, low cost, suitable for indoor high-precision positioning.

Description of drawings

FIG. 1 is a structural diagram of an indoor positioning device provided by an embodiment of the present invention;

Fig. 2 is a three-dimensional structural schematic diagram of a rotating housing of an indoor positioning device provided by an embodiment of the present invention;

Fig. 3 is a schematic top view of the rotating housing of the indoor positioning device provided by the embodiment of the present invention;

Fig. 4 is a schematic diagram of the working state of the indoor positioning device provided by the embodiment of the present invention;

Fig. 5 is a schematic projection of the rotating housing of the indoor positioning device provided by the embodiment of the present invention;

Fig. 6 is a schematic diagram of positioning in a preset coordinate system;

Fig. 7 is a schematic structural diagram of a receiving end of an indoor positioning device provided by an embodiment of the present invention.

detailed description

In order to make the object, technical solution and advantages of the present invention clearer, the present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described here are only used to explain the present invention, not to limit the present invention.

The specific realization of the present invention is described in detail below in conjunction with specific embodiment:

Please refer to Figures 1 to 3, the embodiment of the present invention provides an indoor positioning device, including a base 1, a light source 2 mounted on the base 1, a rotating part 3, a rotating housing 4 mounted on the rotating part 3, and a controllable A controller 5 for frequency hopping of the light source 2 . Wherein, the rotating member 3 can be driven to rotate by a driving motor 6 , and the driving motor 6 can also be built in the base 1 . Specifically, the rotating member 3 may include a ring, on which the rotating housing 4 is fixed, and can rotate synchronously with the ring. The rotating shell 4 is a hemispherical shell or a shell circumscribed on a hemispherical surface formed by splicing a plurality of small planes or annular surfaces. In short, the rotating shell 4 is hemispherical or has a hemispherical shape. The base surface has a circular or regular polygonal cross-section (the cross-section perpendicular to the rotation axis), and the light emitting point of the light source 2 is located at the center of the hemisphere. The rotating housing 4 is divided into a plurality of coded circles 41 parallel to the latitude. The angle α of each coded circle 41 relative to the light source 2 in the longitude direction is known, and preferably the angle α of each coded circle 41 is equal. In addition, each coding circle 41 is also divided into a plurality of coding bits 411, and the coding bits 411 are arranged sequentially along the latitude direction, and the angle β of each coding bit 411 relative to the center point of the coding circle 41 in the latitude direction is all equal, which is 360° /N degrees, where N is the number of coded bits 411 in one code circle 41 . In order to distinguish different coded circles 41 during positioning, it is necessary to arrange the coded bits 411 of different coded circles 41 in different ways, that is, each coded circle 41 has its particularity. Further, in each coding circle 41, several coding bits 411 are in the light-transmitting state, and other coding bits 411 are in the non-light-transmitting state, and there are no consecutive two or more non-light-transmitting coding bits 411, several The coding bits 411 arranged in a specific way form the start bit and the end bit of the coding circle 41, because the rotating housing 4 performs a circular rotation, so the start bit and the end bit are the same. For ease of description, they are all referred to as end bits hereinafter. In this embodiment, a plurality of (3, 4, 5, etc.) light-transmitting code bits can be set in each code circle 41 as the end bit S, as shown in Figure 5, and the end bits of different code circles 41 The number of encoded bits 411 contained is the same and the position is the same, and the top and bottom are aligned. In this embodiment, the light-transmitting coding bit can be marked as "1", and the non-light-transmitting coding bit can be marked as "0". Each coding circle 41 can be expressed as a sequence of "1" and "0" arranged according to a certain rule. For example, if the above-mentioned end bit is 5 consecutive light-transmitting coding bits, it is "11111". Of course, the finer the division of the coding circle 41 and coding bits, the higher the positioning accuracy.

In addition, each coding circle 41 includes a special coding bit 412 different in shape from other coding bits, and the width of the special coding bit 412 has a preset variation law in the longitude direction, for example, the farther away from the apex of the rotating shell 4, the wider the width. The bigger, the whole is triangular or trapezoidal, then the width at a certain position is related to the distance from the position to the inner edge of the coding circle 41, and the distance between the inner edge a of the coding circle 41 and the point to be positioned relative to the center of the sphere can be determined according to the width data. Zhang Jiao. In this embodiment, the special coded bits 412 may be in a shape in which the edges on both sides are not parallel to or coincident with the meridian, and the overall shape is triangular or trapezoidal, and the special coded bits 412 of different coded circles 41 are at the same longitude. Wherein, "inner edge a" refers to the edge close to the center of the coding circle, and "outer edge b" refers to the edge away from the center of the coding circle.

The base 1 is provided with an optical coupler 11 with a card slot, and the side of the rotating member 3 facing the base 1 is provided with a light-blocking sheet 31. When the rotating member 3 rotates, the light-blocking sheet 31 is driven to pass through the card slot once, and the controller 5 Control the light source 2 to undergo a frequency jump, and the receiving end 7 at the point to be positioned can sense the frequency jump, and the system performs positioning according to the optical signal sensed by the receiving end 7, the frequency jump point, the start bit and the end bit information , the specific positioning process will be described later.

With further reference to Figures 4-6, the positioning principle of the device is as follows: the rotating housing 4 can be projected in space by the light source 2, and a projection aperture 8 is formed in any horizontal plane where the point to be positioned is located. When the rotating housing 4 rotates, the projected The aperture 8 also rotates at the same time. When the projection aperture 8 where the receiving end 7 is located rotates, the receiving end 7 can detect the change of light intensity, and the signal corresponds to the corresponding coding ring 41, so that it can be determined which projection aperture 8 the receiving end 7 is located in. , and then the angle θ between the connecting line between the point to be positioned and the light source 2 and the central axis can be determined. This included angle θ is not sufficient for positioning. Also determine the angle ω of the point to be located relative to the initial orientation. When defining the light blocking sheet 31 to pass through the optical coupler 11, the direction indicated by the projection of the end of the end bit on the horizontal plane where the point to be located is the initial direction D, after determining the angle ω of the receiving end 7 relative to the initial direction, Combined with the known coordinates of the light source 2, the coordinates of the point to be positioned can be determined.

Further, the light source 2 is set to work at the first frequency and the second frequency. During the measurement, when the light barrier 31 just passes through the middle of the optical coupler 11 slot, the state of the optical coupler 11 will change and trigger External interrupt, when controller 5 detects this interrupt signal, reset the flickering frequency of light source 2 according to the following rules:

If the current flicker frequency of the light source 2 is the first frequency, then the flicker frequency of the light source 2 is set to the second frequency;

If the current flickering frequency of the light source 2 is the second frequency, then the rotating housing 4 is further rotated by an angle occupied by the code bit 411, and then the flickering frequency of the light source 2 is set to the first frequency.

This design is because there is a non-transparent coding bit in the rotating housing 4. When the receiving end 7 is in the projection of the non-transparent coding bit, the frequency jump occurs, and the receiving end 7 cannot sense it. However, the above two jumping modes are set and There are no more than two consecutive non-transparent coded bits, which can ensure that the receiving end 7 can definitely detect frequency hopping. And through the identification of the first frequency and the second frequency, it can be judged whether the jump point is at the initial position or one coding bit after the initial position, and then the angle ω can be accurately calculated.

Based on the above structure and principle, the present invention further provides an indoor positioning method, which is as follows:

In step S101, the rotating casing 4 is driven to rotate, so that the projection aperture 8 projected by the light source 2 onto the horizontal plane where the point to be positioned is located also rotates accordingly;

In step S102, the optical signal is sensed by the receiving end 7 located at the point to be located, and the projection aperture 8 where it is located is determined according to the optical signal, and then the connection line between the inner edge of the projection aperture 8 and the light source 2 and the location The angle θ ^r =r*α between the rotating shafts of the rotating housing 4, wherein, r is the number of projection apertures 8 inside the projection aperture 8 where the point to be located is located;

In step S103, according to the width of the special code bit 412 sensed by the receiving end 7, the angle Δθ ^r between the point to be positioned and the inner edge of the projection aperture 8 where it is located relative to the light source 2 is determined, and then the distance between the point to be positioned and the light source 2 is determined. Angle θ=θ ^r +Δθ ^r between the connecting line and the rotating shaft;

In step S104, when the light blocking sheet 31 passes through the card slot, the direction indicated by the projection of the end of the start bit and the end bit on the horizontal plane is the initial direction, and the frequency of the light source 2 is detected by the receiving end 7 The jump point and the end of the start bit and the end bit determine the angle ω ^r between the front c of the coding bit projection 81 where the point to be positioned is located and the initial direction; wherein, "front c" refers to the coding The edge where the bit projection is close to the original direction, "back edge d" refers to the edge where the encoded bit projection is away from the original direction.

In step S105, the included angle ^Δωr between the point to be located and the front edge of the projection of the code bit where it is located relative to the center of the projection aperture 8 is determined according to the light-transmitting code bit data collected continuously after the frequency jump point is detected by the receiving end 7 , and then determine the angle ω=ω ^r +Δω ^r between the point to be located and the initial direction;

In step S106, the position of the point to be located is determined according to the angle θ and the angle ω.

In the above-mentioned step S101, the projection aperture 8 is shown in Figure 5, and the light emitted by the light source 2 on the rotating housing 4 is projected onto the ground to form a projection aperture 8. Since the light source 2 is located at the center of the sphere of the rotating housing 4, each coding The angle α of 41 in the longitude direction is equal, therefore, the included angle between the inner edge and the outer edge of each projection aperture 8 relative to the light source 2 is also α. It can be understood that the included angle is the included angle between the inner edge and the outer edge in the longitude direction.

In the above steps S102 and S103, since the arrangement of the code bits 411 of each code ring 41 has its particularity, it can be determined which projection aperture 8 it is in according to the light signal induced by the receiving end 7, and then the projection aperture 8 can be determined. There are several projection apertures 8 inside the aperture 8, and then determine the angle θ ^r =r*α between the line between the inner edge of the projection aperture 8 and the light source 2 and the rotating shaft of the rotating housing 4, where r is The number of projection apertures 8 inside the projection aperture 8 where the point to be located is located. Further, the width of the projection 82 of the special coding bit 412 sensed by the receiving end 7 can determine the angle between the line connecting the point to be positioned and the light source 2 and the inner edge of the projection aperture 8 where it is located and the line connecting the light source 2 Δθ ^r is the angle between the inner edge of the coded bit projection 81 where the point to be positioned is located and the point to be positioned relative to the light source 2 . It can be understood that both the angles θ ^r and Δθ ^r are angles in the longitude direction. After obtaining these two angles, the angle θ=θ ^r +Δθ ^r between the line connecting the point to be positioned and the light source 2 and the rotation axis can be determined.

In the above step S104, usually the intersection of two vertically intersecting walls and the ground in the room is set as the origin, and the direction where the intersection line of one wall and the ground faces away from the origin is set as the initial direction, so as to provide more intuitive position coordinates.

In the above steps S104 and S105, when the light source 2 has a frequency jump, the receiving end 7 can detect the signal, and as the rotating housing 4 continues to rotate, the receiving end 7 can detect the end of the end bit, and the point to be positioned The angle ω relative to the initial orientation is another important parameter for positioning. Firstly, it is necessary to determine the angle ω ^{r between the front edge of the projection of the coding bit 81 where the point to be positioned is located and the initial direction, and then determine the angle Δω r between} the point to be positioned and the front edge relative to the center of the projection aperture 8 .

Wherein, ω ^r is determined in this way, during the period when the receiving end 7 detects the frequency jump point and the end of the end bit, the number n of coded bits that the rotating shell 4 turns over (including the coded bits where the receiving end 7 itself is located) can be determined , and then the above-mentioned included angle ω ^r can be determined. When the frequency jump occurs when the light blocking sheet 31 passes through the slot, that is, when the detection frequency changes from the first frequency to the second frequency, ω ^r =(n-1)*β , n is the number of coded bits that the rotating shell 4 turns over during the period when the receiving end 7 detects the frequency jump point and the end of the end bit, including the coded bits where the point to be positioned itself is located; when the frequency jump occurs at When the light blocking sheet 31 passes through the slot and continues to rotate for one code bit, that is, when the detected frequency changes from the second frequency to the first frequency, ω ^r =n*β.

Δω ^r is determined in this way, the width between the point to be located and the nearest projection of the non-transparent coding bit can be obtained according to the transparent coding bit information continuously collected after the receiving end 7 detects the frequency jump point, and according to the predicted The width of the bit 411 can determine how many coded bit projections are spaced between the point to be positioned and the nearest non-translucent coded bit projection, and the width la between the point to be positioned and the leading edge of the coded bit projection where it is located and the rear The width lb between the edges, Δω ^r =la/(la+lb)*β. It can be understood that the above-mentioned "width" is not limited to the concept of size, and may be the sampling times of the receiving end 7 . For each predetermined coded bit 411, the sampling times of the receiving end 7 is determined, so the above Δω ^r can be determined according to the amount of collected data.

Further, after obtaining the above angle θ and angle ω, in the preset coordinate system, the coordinates of the point to be positioned can be determined by combining the coordinates of the light source 2 and the vertical distance from the light source 2 to the horizontal plane where the point to be positioned is located.

Specifically referring to FIG. 6 , when the vertical height H from the light source 2 to the point to be positioned is known, and the coordinates (x ₀ , y ₀ , z ₀ ) of the light source 2 are known, the coordinates of the point to be positioned are :

(x ₀ +H*tan(θ)*sin(ω),y ₀ +H*tan(θ)*cos(ω),z ₀ -H).

When the vertical height of the light source 2 to the point to be positioned is unknown, and the coordinates (x ₀ , y ₀ , z ₀ ) of the light source 2 are known, two indoor positioning devices are used, and the irradiation surfaces of the two light sources 2 have intersecting areas, The point to be positioned is located in the intersection area, and the coordinates of the point to be positioned are determined by two known coordinates of the light source 2 and the included angle θ and ω. Assuming that the position of one of the light sources 2 is point A, the position of the other light source 2 is point C, and the point to be positioned is point B, the only straight line connecting the receiving end 7B from point A of the light source 2 can be determined, and the straight line passes through the rotating shell 45 The last point P(x ₁ ,y ₁ ,z ₁ ), the coordinates are (x ₀ +r*sin(θ)*sin(ω),y ₀ +r*sin(θ)*cos(ω),z ₀ - r*cos(θ)), it is also possible to determine the straight line connecting point C of the light source 2 to the receiving end 7B, which passes through a point Q(x ₃ , y ₃ , z ₃ ) on the rotating shell 4, where r is the already know the radius.

Knowing two points in the space, the equation L ₁ of the straight line AB can be established:

Equation L ₂ of straight line CB:

Combined with equations L ₁ and L ₂ , the coordinates of the receiving end 7B are calculated according to the least square method.

It can be understood that in actual positioning, it is necessary to determine a coordinate system, and then determine the initial direction, and the positioning coordinates are also coordinates in the coordinate system. As shown in Figure 4 and Figure 6, usually, the base 1 of the positioning device is fixed on the indoor ceiling, the base 1 cannot be rotated, the light source 2 illuminates downwards to cover the indoor space, and the rotating shell 4 rotates around its rotation axis, and the rotation axis starts from the light source 2, Pass through the apex of the rotating shell 4 and be perpendicular to the ground. In the three-dimensional indoor space, a right-handed rectangular coordinate system is established with a corner point on the indoor floor as the origin O(0,0,0), so that the X and Y axes coincide with two mutually perpendicular corner sides on the ground, and the Z axis It is perpendicular to the X and Y axes, and coincides with the corner edge pointing vertically to the roof, that is, the XOY plane coincides with the horizontal ground, and the Z axis points vertically to the roof. The initial direction of the rotating housing 4 is set to be parallel to the direction of the Y axis and point to the positive direction of the Y axis. That is, when the light blocking sheet 31 passes through the optical coupler 11 , the direction pointed by the end of the end bit is the positive direction of the Y axis. The coordinates (x ₀ , y ₀ , z ₀ ) of the light source 2 are known.

Further referring to FIG. 7 , the receiving end 7 may include a light sensor 71 mounted on a small circuit board 72 on which a processor 73 and a wireless transmission module 74 are also arranged. Or use a mobile device with a light sensor as a signal receiver.

In the embodiment of the present invention, since the data received by the receiving end 7 is mixed with environmental interference frequencies, multiple frequency components generated when the rotating housing 4 rotates, and other interference frequencies, etc., it needs to be processed in the following manner. First, the data passes through a band-pass filter to filter out signals that are less than the lowest frequency available to the light source 2 and signals that are greater than the highest frequency that can be used by the light source 2 (in this embodiment, filter out signals that are less than 20hz and greater than 350hz), and then filter After time-frequency transformation, such as wavelet time-frequency transformation, short-time Fourier time-frequency transformation (STFT) etc. (in this embodiment, wavelet time-frequency transformation is used), the final data is extracted from the time-frequency transformation result coefficient Encoding information of the outer shell circle, including the circle number code, the end bit code and the frequency jump point of the light source 22, etc.

The positioning device provided by the embodiment of the present invention can calculate the coordinates of a certain point in the indoor space by setting a rotating shell with a special structure, and designing the frequency jump rule of the light source, and sensing the optical signal through a signal receiving end. The device structure is simple and convenient. The positioning method is novel, accurate, and stable. It does not need to spend a lot of manpower and material resources to collect data such as fingerprints, and does not need to set a large number of reference points. It is not easily affected by the external environment. It has high precision, good stability, and low cost. It is suitable for indoor high-precision positioning. .

The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the present invention. Any modifications, equivalent replacements and improvements made within the spirit and principles of the present invention should be included in the protection of the present invention. within range.

Claims (10)

1. An indoor positioning device, characterized in that it comprises a base, a light source arranged on the base, a rotating member, a rotating housing arranged on the rotating member, and a controller; The rotating shell is a hemispherical shell or a shell circumscribed on a hemispherical surface formed by splicing a plurality of facets or annular surfaces; the luminous point of the light source is located at the center of the hemispherical surface; The rotating housing is divided into a plurality of coded circles parallel to the latitude, and the angle α of each coded circle relative to the light source in the longitude direction is known; each coded circle is divided into a plurality of coded bits, and the coded bits are relative to the The angle β of the central point of the coding circle is 360/N degrees, wherein N is the number of coding bits in one coding circle, and the coding bits of different coding circles are arranged in different ways; In each coding circle, several coding bits are in the light-transmitting state, and there are no consecutive two or more non-light-transmitting coding bits, and a number of coding bits arranged in a specific way constitute the start bit of the coding circle and end bit; Each coding circle includes a special coding bit having a shape different from other coding bits, and the width of the special coding bit has a preset variation law in the longitude direction; The base is also provided with an optical coupler with a slot, and the side of the rotating member facing the base is provided with a light-blocking sheet, and the rotating member drives the light-blocking sheet to pass through the slot once, so that The controller controls the light source to undergo a frequency jump; The indoor positioning device also includes a receiving end, which is used to sense the optical signal at the point to be located and detect the frequency jump point, and perform positioning according to the optical signal and the frequency jump point. 2. The indoor positioning device according to claim 1, wherein the edges on both sides of the special coding bit are not parallel to or coincident with the meridian, and the whole is triangular or trapezoidal, and the special coding bits of different coding circles are at the same longitude. 3 . The indoor positioning device according to claim 1 , wherein the start bit and the end bit are coded bits of a plurality of consecutive light-transmitting states. 4 . 4 . The indoor positioning device according to claim 3 , wherein the number of code bits contained in the start bit and the end bit in each code circle are the same, and the positions are the same. 5. The indoor positioning device according to claim 1, wherein the operating frequency of the light source is the first frequency and the second frequency, when the light blocking sheet passes through the slot, if the frequency of the light source If it is the first frequency, the controller controls the light source to jump to the second frequency. If the frequency of the light source is the second frequency, the controller controls the light source to rotate after the rotary housing continues to rotate one code bit. jump to the first frequency. 6. The indoor positioning device according to any one of claims 1 to 5, wherein the angles of each code circle in the longitude direction are equal, and the angles of each code bit in the latitude direction are all equal. 7. An indoor positioning method for an indoor positioning device, comprising the following steps: Driving the rotating housing to rotate, so that the projection aperture of the rotating housing projected from the light source to the horizontal plane where the point to be positioned is located also rotates accordingly; The light signal is sensed by the receiving end at the point to be positioned, and the projection aperture where it is located is determined according to the light signal, and then the angle between the line between the inner edge of the projection aperture and the light source and the rotation axis of the rotating housing is determined θ ^r =r*α, wherein, r is the number of projection apertures inside the projection aperture where the point to be located is located; Determine the angle Δθ ^r between the point to be positioned and the inner edge of the projection aperture relative to the light source according to the width of the special code bit sensed by the receiving end, and then determine the angle between the line between the point to be positioned and the light source and the rotation axis θ=θr + ^{Δθr ;} When the light blocking sheet passes through the card slot, the direction pointed to by the projection of the end of the start bit and the end bit on the horizontal plane is the initial direction, and the frequency jump point of the light source and the start bit and the start bit are detected by the receiving end. End the end of the bit, determine the angle ω ^r between the front edge of the coding bit projection where the point to be positioned is located and the initial direction; Determine the angle Δω ^r between the point to be positioned and the front edge of the projection of the code bit where it is located relative to the center of the projection aperture when the frequency jump occurs according to the continuously collected light-transmitting coded bit data after the frequency jump point is detected by the receiving end, and then determine the distance between the point to be positioned and the front edge of the projection aperture. The angle ω=ω ^r +Δω ^r between said initial directions; The position of the point to be located is determined according to the angle θ and the angle ω. 8. The indoor positioning method according to claim 7, wherein when the frequency hopping occurs when the light blocking sheet passes through the card slot, ω ^r =(n-1)*β, n is detected at the receiving end During the period between the frequency jump point and the end of the end bit, the number of code bits turned by the rotating shell, including the code bit where the point to be positioned itself is located; when the frequency jump occurs when the light shield passes through the slot and continues to rotate For one encoded bit, ω ^r =n*β. 9. The indoor positioning method according to claim 7, wherein when the vertical height H of the light source to the point to be positioned is known, and the coordinates (x ₀ , y ₀ , z ₀ ) of the light source are known When , the coordinates of the point to be located are: (x ₀ +H*tan(θ)*sin(ω),y ₀ +H*tan(θ)*cos(ω),z ₀ -H); When the vertical height of the light source to the point to be positioned is unknown and the coordinates (x ₀ , y ₀ , z ₀ ) of the light source are known, two indoor positioning devices are used, and the illuminated surfaces of the two light sources have An intersection area, where the point to be positioned is located in the intersection area, and the coordinates of the point to be positioned are determined by two known light source coordinates and the included angle θ and included angle ω. 10. The indoor positioning method according to claim 7, wherein the light source is set to work at the first frequency and the second frequency, and when the light blocking sheet passes through the slot, if the frequency of the light source is the first frequency , then control it to jump to the second frequency, if the frequency of the light source is the second frequency, then control the light source to jump to the first frequency after the rotating shell continues to rotate one code bit.