An infrared positioning system

Abstract

This invention discloses an infrared positioning system, including an electronic tag, a camera base station, and a processor. The camera base station includes a first camera, a second camera, and a filtering device. The filtering device includes a switching component and a narrowband filter. The narrowband filter and the switching component are connected and can move under the action of the switching component. The electronic tag is used to periodically radiate infrared encoded information. The first camera is used to capture a first visible light image. The second camera is used to capture a second visible light image when the narrowband filter is located to one side of the second camera, and to capture an infrared image when the narrowband filter is in front of it, so as to capture a target carrying an electronic tag. The processor is used to obtain the mapping relationship between the pixel position coordinates of the infrared image and the first visible light image, and to process the infrared image to obtain the center pixel coordinates of the target and the number of the carried electronic tag, thereby obtaining the position of the target according to the mapping relationship and the center pixel coordinates of the target.

Description

Technical Field

[0001] This invention relates to the field of positioning technology, and more specifically to an infrared positioning system. Background Technology

[0002] In recent years, with the development of the mobile internet, location awareness and target encoding have become increasingly important. Location-based services have significant demand and market potential in fields such as learning, rescue, healthcare, and surveillance. It is well known that global satellite navigation systems provide positioning outdoors, but the accuracy is only at the meter level, and due to obstructions, it cannot be applied to indoor positioning. Therefore, indoor positioning technology has become a research hotspot and focus.

[0003] Numerous indoor positioning technologies have emerged, including WiFi indoor positioning, RFID indoor positioning, Bluetooth indoor positioning, mobile communication network-assisted indoor positioning, UWB ultra-wideband indoor positioning, ZigBee indoor positioning, ultrasonic positioning, computer vision indoor positioning, and traditional infrared positioning. While wireless positioning technologies such as WiFi, RFID, Bluetooth, and UWB offer strong penetration, they employ complex chip hardware, sophisticated algorithms, and are costly. Ultrasonic positioning requires the deployment of numerous base stations and has a limited range, making it unsuitable for locating multiple targets; therefore, ultrasound is suitable for distance positioning but not for multi-target planar positioning. Machine vision positioning requires complex visual tracking algorithms, significantly increasing the demand for hardware computing power. Traditional infrared indoor positioning typically involves attaching an infrared-emitting electronic tag to the target object and using multiple infrared receivers placed indoors and outdoors to measure the distance or angle of the signal source to calculate the object's location. Alternatively, it may use an infrared network of multiple transmitters and receivers to cover the target space. However, all these methods require a large number of densely deployed sensors, resulting in high hardware and construction costs. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide an infrared positioning system that is simple in hardware and algorithm, low in cost, and can achieve accurate positioning.

[0005] To address the aforementioned technical problems, this invention provides an infrared positioning system, comprising at least one electronic tag, at least one camera base station, and a processor. The camera base station includes a first camera and a second camera arranged side-by-side. A filtering device is disposed on one side of the second camera. The filtering device includes a switching component and a narrowband filter for allowing infrared light to pass through. The narrowband filter is connected to the switching component and can move to the front of or to the side of the second camera under the action of the switching component.

[0006] The electronic tag has infrared light of a specific wavelength, which is used to periodically radiate infrared encoded information;

[0007] The first camera is used to capture a first visible light image in real time;

[0008] The second camera is used to capture a second visible light image when the narrowband filter is located to one side of the second camera, and is also used to capture an infrared image in real time when the narrowband filter is located in front of the second camera, so as to capture a target carrying an electronic tag;

[0009] The processor is connected to the first camera and the second camera, and is used to map the specified pixel coordinates in the second visible light image to the first visible light image to obtain the mapping relationship between the pixel position coordinates of the infrared image and the first visible light image. It also processes the infrared image from the second camera to obtain the center pixel coordinates of the target in the infrared image and the number of the electronic tag it carries. Based on the mapping relationship between the pixel position coordinates of the infrared image and the first visible light image and the center pixel coordinates of the target, it obtains the actual physical location of the target.

[0010] The further technical solution is as follows: the processor includes:

[0011] The communication module is used to receive a first visible light image from the first camera and a second visible light image and an infrared image from the second camera;

[0012] The calibration mapping module is used to select specified pixel coordinates at multiple corresponding specific locations in the second visible light image and the first visible light image, obtain the relationship between the specified pixel coordinates in the second visible light image and the specified pixel coordinates at corresponding specific locations in the first visible light image, thereby obtaining the mapping relationship between the pixel position coordinates of the infrared image and the first visible light image;

[0013] The processing module is used to process the infrared image from the second camera to obtain the center pixel coordinates of the target in the infrared image and the number of the electronic tag it carries.

[0014] The coordinate positioning module is used to obtain the actual physical position of the target based on the mapping relationship between the pixel position coordinates of the infrared image and the first visible light image and the center pixel coordinates of the target.

[0015] The further technical solution is as follows: the processing module includes:

[0016] The image processing unit is used to filter the infrared image from the second camera, and perform binarization processing on the filtered infrared image to obtain a black and white image, so as to separate the electronic tag from the black background and obtain the center pixel coordinates of the electronic tag in the infrared image.

[0017] The decoding unit is used to continuously and in real time collect the flashing information of the electronic tag in the infrared image according to the preset bit transmission duration of the electronic tag and the preset sampling frequency of the camera base station, and obtain the infrared encoding information radiated by the electronic tag based on the collected flashing information, thereby obtaining the electronic tag number.

[0018] The further technical solution is as follows: the processor also includes a storage module, which stores a first visible light image, a second visible light image, an infrared image, the obtained center pixel coordinates of the target, and the number of the electronic tag carried by the target.

[0019] The further technical solution is as follows: the communication module includes a 4G module and / or a WiFi module and / or a USB module and / or a DVP module.

[0020] The further technical solution is as follows: the processor is also used to calculate the target displacement based on the number of the electronic tag carried by the target, the target's moving speed, and the shooting speed of the second camera, thereby tracking the target.

[0021] The further technical solution is as follows: the infrared positioning system also includes a server, which is used to receive a first visible light image, the actual physical location of the target and the number of the electronic tag carried by the target, so as to mark and display the actual physical location of the target and the number of the electronic tag carried in the first visible light image.

[0022] The further technical solution is as follows: the infrared positioning system includes two camera base stations, and the two camera base stations respectively capture images of two mutually perpendicular planes.

[0023] The beneficial technical effects of this invention are as follows: Compared with the prior art, the infrared positioning system of this invention is equipped with a switching component. By moving the position of the narrowband filter connected to it, the second camera can capture a second visible light image or an infrared image. Furthermore, the pixel position of the infrared image captured by the second camera is calibrated using the second visible light image and the first visible light image captured by the first camera. Specifically, the specified pixel coordinates in the second visible light image are mapped to the first visible light image to obtain the mapping relationship between the pixel position coordinates of the infrared image and the first visible light image. The infrared image from the second camera can be processed to obtain the center pixel coordinates of the target in the infrared image and the number of the carried electronic tag. Based on the mapping relationship between the pixel position coordinates of the infrared image and the first visible light image and the center pixel coordinates of the target, the actual physical location of the target is obtained. Therefore, the infrared positioning system of this invention can accurately locate multiple targets in a plane and obtain the electronic tag number using only the first and second cameras. Thus, in certain situations, such as when rescuing a specific target, the location of the specific target can be obtained through the electronic tag number for one-to-one communication. The hardware is simple, the algorithm is simple, and there is no need for a large number of densely deployed components, resulting in lower costs. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of a specific embodiment of the infrared positioning system of the present invention.

[0025] Figure 2 This is a schematic diagram of the specific structure of the processor in the infrared positioning system of the present invention.

[0026] Figure 3 It is the infrared encoding information of an electronic tag in the infrared positioning system of this invention.

[0027] Figure 4 This describes the working mode of the decoding unit in the infrared positioning system of this invention. Detailed Implementation

[0028] To enable those skilled in the art to more clearly understand the purpose, technical solution, and advantages of the present invention, the present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0029] Reference Figure 1 , Figure 1This is a schematic diagram of a specific embodiment of the infrared positioning system of the present invention. The infrared positioning system includes at least one electronic tag, at least one camera base station, and a processor 12. The camera base station includes a first camera 111 and a second camera 112 arranged in parallel. A filter device is provided on one side of the second camera 112. The filter device includes a switching component and a narrowband filter for allowing infrared light to pass through. The narrowband filter is connected to the switching component so that it can move to the front of or to the side of the second camera 112 under the action of the switching component.

[0030] The electronic tag has infrared light of a specific wavelength for periodically radiating infrared encoded information. The first camera 111 is used to capture a first visible light image in real time. The second camera 112 is used to capture a second visible light image when the narrowband filter is located to one side of the second camera 112, and also to capture an infrared image in real time when the narrowband filter is located in front of the second camera 112, so as to capture the target carrying the electronic tag. The processor 12 is connected to the first camera 111 and the second camera 112, and is used to map the specified pixel coordinates in the second visible light image to the first visible light image to obtain the mapping relationship between the pixel position coordinates of the infrared image and the first visible light image. It also processes the infrared image from the second camera 112 to obtain the center pixel coordinates of the target in the infrared image and the number of the carried electronic tag, and obtains the actual physical position of the target based on the mapping relationship between the pixel position coordinates of the infrared image and the first visible light image and the center pixel coordinates of the target. Understandably, the switching component can be a pan-tilt unit or other mechanical device that can move the narrowband filter, installed in a reserved indoor or outdoor mounting position, and its movement can be manually or automatically controlled by the processor 12. In this embodiment, the number of camera base stations is one, while in some other embodiments, the number of camera base stations can be two, and the two camera base stations can respectively capture two mutually perpendicular planes to locate the position of the target in three-dimensional space.

[0031] Based on the above design, the present invention can move the position of the narrowband filter connected to it so that the second camera 112 can capture a second visible light image or an infrared image. Then, the pixel position of the infrared image captured by the second camera 112 can be calibrated by using the second visible light image and the first visible light image captured by the first camera 111. That is, the specified pixel coordinates in the second visible light image are mapped to the first visible light image to obtain the mapping relationship between the pixel position coordinates of the infrared image and the first visible light image. Thus, the pixel position coordinates of the infrared image captured by the second camera 112 mapped to the first visible light image can be obtained, thereby obtaining the actual physical position of the target. This method does not require a large number of densely deployed components, has simple hardware, simple algorithms, and low cost.

[0032] In some embodiments, such as Figure 2 As shown, the processor 12 includes a communication module 121, a calibration mapping module 122, a processing module 123, and a coordinate positioning module 124. The communication module 121 is used to receive a first visible light image from the first camera 111 and a second visible light image and an infrared image from the second camera 112. Preferably, the communication module 121 includes a 4G module and / or a Wi-Fi module and / or a USB module and / or a DVP module. The calibration mapping module 122 is used to select specified pixel coordinates at multiple corresponding specific locations in the second visible light image and the first visible light image, and obtain the relationship between the specified pixel coordinates in the second visible light image and the specified pixel coordinates at corresponding specific locations in the first visible light image, thereby obtaining the mapping relationship between the pixel position coordinates of the infrared image and the first visible light image. Understandably, the first camera 111 and the second camera 112 have differences in installation position, lens configuration, and acquisition field of view. This invention uses the first visible light image and the second visible light image to calibrate the infrared image. When calibration is required, the switching component moves the narrowband filter to the side of the second camera 112. At this time, both the first camera 111 and the second camera 112 acquire visible light images. Multiple corresponding specific locations (e.g., 4 or more) are selected in the first visible light image and the second visible light image for pixel calibration, thereby obtaining the position mapping relationship between the first camera 111 and the second camera 112. The processing module 123 is used to process the infrared image from the second camera 112 to obtain the center pixel coordinates of the target in the infrared image and the number of the electronic tag it carries; the coordinate positioning module 124 is used to obtain the actual physical location of the target based on the mapping relationship between the pixel position coordinates of the infrared image and the first visible light image and the center pixel coordinates of the target.

[0033] Further, in some embodiments, the processing module 123 includes an image processing unit 1231 and a decoding unit 1232. The image processing unit 1231 is used to filter the infrared image from the second camera 112, and perform binarization processing on the filtered infrared image to obtain a black and white image, so as to separate the electronic tag from the black background and obtain the center pixel coordinates of the electronic tag in the infrared image. The decoding unit 1232 is used to continuously and in real time collect the flashing information of the electronic tag in the infrared image according to the preset bit transmission duration of the electronic tag and the preset sampling frequency of the camera base station, and periodically obtain the infrared encoding information radiated by the electronic tag according to the collected flashing information, thereby obtaining the number of the electronic tag. The blinking information of the electronic tag is formed by the electronic tag emitting infrared light or stopping emitting infrared light according to the bit transmission duration and the encoded information bits, forming a series of binary data. For example, when the electronic tag is 'on', it radiates infrared light in all directions, and when it is 'off', it stops radiating infrared light, which represent binary data '1' and '0' respectively. The infrared image after binarization is a black background image. When there is an electronic tag 'on' in the field of view, a small white bright spot appears in the black background image. Understandably, in this embodiment, the infrared encoding information radiated by the electronic tag is determined based on the flashing information, and each electronic tag has its own unique number. Preferably, 8 bits of data are used for numbering (numbering 256 targets). Parity bits can also be set in specific bits of the binary data to verify whether it is a valid electronic tag number. A start bit '1' with a duration of 1 bit is added before the 8-bit number, a parity bit '1' or '0' with a duration of 1 bit is added after the 8-bit number, a stop bit '1' with a duration of 1 bit, and an idle bit '0' with a duration of 10 bits are added, thereby forming the infrared encoding information corresponding to the electronic tag.

[0034] Preferably, in this embodiment, the preset bit transmission duration is the duration of one bit of data in the infrared encoded information transmitted by the electronic tag, for example, it can be 100ms, and the infrared encoded information consists of a series of data bits; the preset sampling frequency is the number of times the images are captured within the bit transmission duration, for example, it can be 3 times, that is, 3 times are sampled within 100ms to obtain 3 frames of images. The number of the electronic tag carried by the target can be obtained by matching the infrared encoded information radiated by the electronic tag obtained from the flashing information of the electronic tag with the infrared encoded information of the pre-stored electronic tag. Since the electronic tag periodically radiates infrared encoded information, the number of the target can be obtained in real time.

[0035] For example, if a target at a certain location in an image carries an electronic tag with the number 10101010 (decimal 170), its periodic infrared coding information is as follows: Figure 3As shown, during decoding in this embodiment, the real-time acquired infrared image at this location, after at least 10 bits of '0' level (no infrared light cluster found at this location in 30 frames, indicating a rest period), once a '1' level is acquired (infrared light cluster detected), a counter is set for the target at that location, starting from 0. The counter increments by 1 for each subsequent frame acquired, skipping the 0th frame and using the '1' level at that location in the next 1st frame as the starting bit. Every two frames thereafter, one frame is sampled, using the level at that location as the valid data bit, until a stop bit is received, completing one acquisition of infrared encoded information. This process is repeated, and the decoded information, after parity checking, is the infrared encoded information of the electronic tag carried by the target. Figure 4 As shown, the start bit is received when the counter is 1, the 8-bit serial number data is received when the counter is 4, 7, 10, 13, 16, 19, 22, and 25, the parity bit is received when the counter is 28, and the stop bit is received when the counter is 31. After completion, the serial number data is checked using the parity bit. After the check passes, the quasi-target is upgraded to a valid target. By using this method of sampling one frame out of three frames, the received 8-bit serial number data is the number of the electronic tag carried by the target.

[0036] In some embodiments, the processor 12 is further configured to calculate the target displacement based on the number of the electronic tag carried by the target, the target's moving speed, and the shooting speed of the second camera 112, thereby tracking the target. Based on this design, the target's movement range is estimated according to the speed of the moving target and the shooting interval of the second camera 112, and the target displacement is calculated. Targets within the target displacement range can be preliminarily identified as the same target, thus effectively locating the moving target.

[0037] Furthermore, in some other embodiments, the processor may also include a storage module storing a first visible light image, a second visible light image, an infrared image, the obtained center pixel coordinates of the target, and the number of the electronic tag carried by the target. The infrared positioning system may also include a server, which receives the first visible light image, the actual physical location of the target, and the number of the electronic tag carried by the target, and marks and displays the actual physical location of the target and the number of the electronic tag in the first visible light image. Based on this design, human-computer interaction can be performed through the server. The electronic tag number can be obtained through the infrared encoding information of the electronic tag, thereby obtaining the corresponding target identity and establishing one-to-one individual communication with any target. Understandably, the processor 12 in the infrared positioning system may be located within the camera base station or on the server side.

[0038] The infrared positioning system of this invention operates as follows after installation: Initially, the switching component moves the narrowband filter to the side of the second camera 112, the second camera 112 captures a second visible light image in real time, and the first camera 111 captures a first visible light image in real time; the processor 12 maps the specified pixel coordinates in the second visible light image to the first visible light image to obtain the mapping relationship between the pixel position coordinates of the infrared image and the first visible light image; the switching component moves the narrowband filter to the front of the second camera 112, the second camera 112 captures an infrared image in real time to capture targets carrying electronic tags; the processor 12 then... The infrared images from the two cameras 112 are binarized to separate the electronic tag carried by the target from the background, obtain the center pixel coordinates of the target, and continuously collect the flashing information of the electronic tag in the infrared images in real time according to the preset transmission duration of the electronic tag and the preset sampling frequency of the camera base station. The infrared coding information radiated by the electronic tag is obtained based on the collected flashing information, thereby obtaining the electronic tag number. Then, based on the mapping relationship between the pixel position coordinates of the infrared image and the first visible light image and the center pixel coordinates of the target, the actual physical position of the specific target is obtained, and the moving target can be tracked by estimating the displacement range of the target.

[0039] In summary, the infrared positioning system of the present invention can accurately locate multiple targets in a plane and obtain electronic tag numbers through the first and second cameras. Thus, in certain situations, such as when a specific target needs to be rescued, one-to-one communication can be carried out between the target's location and the obtained electronic tag number. The hardware is simple, the algorithm is simple, there is no need for complex machine vision algorithms, there is no need for a large number of densely deployed components, and the cost is low.

[0040] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention in any way. Those skilled in the art can make various equivalent changes and improvements based on the above embodiments, and all equivalent variations or modifications made within the scope of the claims should fall within the protection scope of the present invention.

Claims

1. An infrared positioning system, characterized in that, The system includes at least one electronic tag, at least one camera base station, and a processor. The camera base station includes a first camera and a second camera arranged side-by-side. A filter device is disposed on one side of the second camera. The filter device includes a switching component and a narrowband filter for allowing infrared light to pass through. The narrowband filter is connected to the switching component and can move to the front or side of the second camera under the action of the switching component. The electronic tag has infrared light of a specific wavelength, which is used to periodically radiate infrared encoded information; The first camera is used to capture a first visible light image in real time; The second camera is used to capture a second visible light image when the narrowband filter is located to one side of the second camera, and is also used to capture an infrared image in real time when the narrowband filter is located in front of the second camera, so as to capture a target carrying an electronic tag; The processor is connected to the first camera and the second camera, and is used to map the specified pixel coordinates in the second visible light image to the first visible light image to obtain the mapping relationship between the pixel position coordinates of the infrared image and the first visible light image. It also processes the infrared image from the second camera to obtain the center pixel coordinates of the target in the infrared image and the number of the electronic tag it carries. Based on the mapping relationship between the pixel position coordinates of the infrared image and the first visible light image and the center pixel coordinates of the target, it obtains the actual physical location of the target.

2. The infrared positioning system as described in claim 1, characterized in that, The processor includes: The communication module is used to receive a first visible light image from the first camera and a second visible light image and an infrared image from the second camera; The calibration mapping module is used to select specified pixel coordinates at multiple corresponding specific locations in the second visible light image and the first visible light image, obtain the relationship between the specified pixel coordinates in the second visible light image and the specified pixel coordinates at corresponding specific locations in the first visible light image, thereby obtaining the mapping relationship between the pixel position coordinates of the infrared image and the first visible light image; The processing module is used to process the infrared image from the second camera to obtain the center pixel coordinates of the target in the infrared image and the number of the electronic tag it carries. The coordinate positioning module is used to obtain the actual physical position of the target based on the mapping relationship between the pixel position coordinates of the infrared image and the first visible light image and the center pixel coordinates of the target.

3. The infrared positioning system as described in claim 2, characterized in that, The processing module includes: The image processing unit is used to filter the infrared image from the second camera, and perform binarization processing on the filtered infrared image to obtain a black and white image, so as to separate the electronic tag from the black background and obtain the center pixel coordinates of the electronic tag in the infrared image. The decoding unit is used to continuously and in real time collect the flashing information of the electronic tag in the infrared image according to the preset bit transmission duration of the electronic tag and the preset sampling frequency of the camera base station, and obtain the infrared encoding information radiated by the electronic tag based on the collected flashing information, thereby obtaining the electronic tag number.

4. The infrared positioning system as described in claim 2, characterized in that, The processor also includes a storage module that stores a first visible light image, a second visible light image, an infrared image, the obtained center pixel coordinates of the target, and the number of the electronic tag carried by the target.

5. The infrared positioning system as described in claim 2, characterized in that, The communication module includes a 4G module and / or a Wi-Fi module and / or a USB module and / or a DVP module.

6. The infrared positioning system as described in claim 1, characterized in that, The processor is also used to calculate the target displacement based on the number of the electronic tag carried by the target, the target's moving speed, and the shooting speed of the second camera, thereby tracking the target.

7. The infrared positioning system as described in claim 1, characterized in that, The infrared positioning system also includes a server, which is used to receive a first visible light image, the actual physical location of the target, and the number of the electronic tag carried by the target, so as to mark and display the actual physical location of the target and the number of the electronic tag carried in the first visible light image.

8. The infrared positioning system as described in claim 1, characterized in that, The infrared positioning system includes two camera base stations, which each capture images of two mutually perpendicular planes.

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