High-precision visible light positioning device based on image sensor

Abstract

The invention relates to the field of industrial internet, in particular to the technical field of indoor positioning in an intelligent scene, and discloses a visible light positioning device which comprises a visible light signal LED transmitting end, a visible light modulation unit circuit and an image sensor receiving end. The LED transmitting end is controlled to flicker at the frequency of 1200 Hz and broadcast visible light signals, the image sensor receiving end recognizes visible light ID information and LED contour information, and positioning is achieved through image information processing and calculation. According to the invention, flexible adjustment can be realized, visible light signals can be emitted, and high-precision visible light positioning can be realized.

Description

Technical Field

[0001] This invention relates to the field of industrial internet technology, and in particular to a high-precision visible light positioning device for smart scenes based on industrial internet. Background Technology

[0002] A smart factory is a facility that utilizes advanced information technology, automation technology, and digital technology to achieve intelligent, automated, and efficient production processes. It applies technologies such as the Internet of Things (IoT), big data analytics, and artificial intelligence (AI) to all aspects of the manufacturing process, enabling interconnectivity between equipment, real-time data collection and analysis, and automated control and optimization of the production process. This improves production efficiency, reduces costs, enhances product quality, and increases flexibility. The industrial internet (IIoT) is the infrastructure upon which information technology is applied in smart factory construction. As a product of the deep integration of manufacturing and the internet, the IIoT has become a key support for the new industrial revolution and a crucial cornerstone of intelligent manufacturing.

[0003] Indoor positioning uses various technologies to determine the precise location of people, equipment, and objects within an indoor environment. It provides positioning services and real-time data for smart scenarios through functions such as resource management and scheduling, security management, logistics and supply chain management, production process optimization, and employee efficiency optimization. Global Navigation Satellite Systems (GNSS) are currently the most mature and widely used positioning technology. However, satellite signals are easily blocked by buildings, making indoor positioning a blind spot for satellite positioning. Currently, indoor positioning has become crucial for providing comprehensive, high-precision positioning services. Indoor positioning technologies are currently in a phase of intense competition, and achieving a balance between positioning accuracy and cost remains a challenge. Therefore, low-cost, high-precision indoor positioning technology is of great significance for the realization of smart scenarios.

[0004] Visible light positioning falls under the category of indoor positioning. With its improved accuracy in recent years, indoor positioning provides highly accurate location data for industries such as retail, manufacturing, healthcare, and robotics, becoming a crucial foundation for the Internet of Things (IoT) era. Several important documents, including the State Council's "14th Five-Year Plan for Digital Economy Development" and the Ministry of Industry and Information Technology's "Three-Year Action Plan for the Construction of New IoT Infrastructure (2021-2023)," explicitly emphasize increasing efforts in tackling key core technologies such as high-precision positioning during the 14th Five-Year Plan period. Driven by strong policy support, my country's indoor positioning market has broad prospects.

[0005] Visible light positioning boasts high accuracy, attracting widespread attention and research from both academia and industry. Researchers have already implemented visible light positioning algorithms with accuracy within 5 centimeters using ordinary light sources and small luminous beacons. However, contrary to the continuous breakthroughs in visible light positioning performance, its application in real-world scenarios lags behind and still faces numerous challenges. This is because current research primarily validates its performance advantages in ideal environments such as laboratories, while real-world scenarios face more stringent hardware and software limitations and complex positioning environments. Furthermore, there is currently no highly available visible light positioning device that can flexibly adapt to the high-availability and easily deployable positioning needs of both laboratory and real-world application scenarios. Therefore, research is needed on high-precision visible light positioning devices for smart scenarios based on the Industrial Internet. Summary of the Invention

[0006] This invention proposes a high-precision visible light positioning device for smart scenarios based on the Industrial Internet. This device enables visible light positioning, improving the efficiency and accuracy of real-time positioning in smart scenarios and meeting the requirements of high-precision, low-latency, and easily deployable positioning services in smart scenarios. This application modifies LEDs as spatial beacons, transmitting visible light information via LEDs, and the receiving end uses a visual sensor to receive the information for positioning. This invention can achieve LED encoding through LED-driven serial ports, flexibly changing the ID information transmitted by the LEDs, thus realizing a highly available and easily deployable visible light positioning device.

[0007] This invention provides a high-precision visible light positioning device for smart scenarios based on the Industrial Internet, offering the following technical solution: The visible light positioning device includes a visible light signal LED transmitter, a visible light modulation unit circuit, and an image sensor receiver. The visible light modulation unit circuit consists of three functional modules: encoding, modulation, and driving. The encoding module assigns an ID to the LED using a self-designed encoding scheme. The modulation module further converts the digital signal into an analog signal, and finally, the driver chip inputs the amplified electrical signal to the LED lighting fixture to transmit the visible light signal. The image sensor receiver consists of functional modules for signal acquisition, signal processing, and positioning calculation. The signal acquisition module acquires visual signals by combining the image sensor with various interference factors such as ambient light intensity. It extracts and processes the visible light signal and visual geometric information separately through mechanisms such as dual-frame recognition, and achieves positioning through a visible light positioning algorithm based on the image sensor.

[0008] As an optimized solution of the present invention, the visible light modulation unit circuit also includes a serial port debugging port, which supports connection to a PC via a serial port debugging tool, and allows for one-click modification of LED ID allocation.

[0009] As an optimized embodiment of the present invention, the visible light signal LED emitting end is a circular or rectangular commercial lighting LED.

[0010] As an optimized embodiment of the present invention, the image sensor receiver includes, but is not limited to, smartphones, smart cars, smart robots, etc.

[0011] As an optimized embodiment of the present invention, the optical modulation unit circuit may include a microcontroller.

[0012] The beneficial effects of this invention are as follows: 1) This invention emits white light signals using LED light-emitting devices, and the light signal flicker frequency is approximately 1200Hz, which is imperceptible to the naked eye, meeting normal lighting needs. It is suitable for use in various smart scenarios in the Industrial Internet, such as large factories, warehouses, shopping malls, supermarkets, and exhibition halls. For example, when this invention is deployed for lighting in large shopping malls, customers and employees can achieve real-time positioning via smartphones, and intelligent robots can achieve self-positioning via image sensors.

[0013] 2) The serial port structure of this invention is simple and convenient to design. It can be connected to a computer via a debugging cable for ID allocation at any time. The allocation time is short and it supports a large number of IDs, which can meet the reuse needs of various indoor scenarios.

[0014] 3) The circuit structure of this invention is simple, low in cost, and highly integrated. It can be integrated into the LED lamp or directly connected to the existing LED fluorescent lamp and the live and neutral wires. The modification cost is low and it is easy to install indoors.

[0015] 4) This invention achieves positioning through a visual positioning algorithm, resulting in high positioning accuracy and small indoor positioning error. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of a visible light positioning system constructed according to the present invention;

[0017] Figure 2 This is a schematic diagram of the hardware system of the visible light positioning device of the present invention;

[0018] Figure 3 This is an optimized product diagram of the sending end of this invention;

[0019] Figure 4 This is a schematic diagram showing the correspondence between the encoding scheme at the transmitting end and the bright and dark stripe images at the receiving end of the present invention;

[0020] Figure 5 This is a schematic diagram illustrating the process of image decoding at the receiving end in this invention; Detailed Implementation

[0021] To enable those skilled in the art to more clearly understand and implement the present invention, the technical solutions of the embodiments of the present invention will be described in detail below with reference to the accompanying drawings and specific examples. However, the present invention is not limited to the following embodiments.

[0022] This invention discloses a visible light positioning device, such as... Figure 1 and Figure 2 As shown, this invention is based on visible light positioning technology. At the transmitting end, the LED lights are modulated and encoded with binary ID information. A control signal is input via a PC, and the binary code is burned into the control module. After digital-to-analog conversion, the signal is transmitted to the drive circuit to control the brightness changes of the LED lights, thus broadcasting the visible light signal. The mobile receiving end smart device captures the visible light signal through an image sensor, obtains images of bright and dark stripes of varying widths through the roller blind effect, identifies the visible light ID information through data processing, and achieves visible light positioning by processing the geometric information in the image.

[0023] In a specific embodiment, the hardware system implementation process of the visible light positioning device in this embodiment is as follows: Figure 2 As shown, it includes the following steps:

[0024] Step 1: Modulate the LED at the transmitting end, convert the digital signal into an analog signal, drive the LED lighting fixture to flash at a rate invisible to the naked eye, and broadcast a visible light signal.

[0025] In this embodiment, the ID information of the LED lighting fixture at the transmitting end is modulated. The microcontroller of the modulation module is connected to the PC. Through a serial port debugging tool, the binary sequence information composed of 0 and 1 sequences is encoded and encapsulated into frame data representing ID information through frame header design and written into the encoding module. The LED is assigned an ID through a self-designed encoding scheme. The digital signal is further converted into high and low level analog signals through the modulation module and input to the driving circuit through the enable terminal to control the working state of the driving circuit and realize digital modulation.

[0026] In this embodiment, the transmitter of the visible light positioning device is supplied with AC power from an external power source. After passing through a transformer module, the AC power is input into the drive circuit and converted into DC power that conforms to the LED's voltage-current characteristics, driving the LED to provide normal illumination and broadcasting visible light information.

[0027] In this embodiment, the LED lighting fixture flashes at a frequency of approximately 1200Hz when transmitting signals, which is invisible to the naked eye. Furthermore, the transmitted signals support hundreds of unique ID information, and a frame header is designed for each ID, resulting in a high recognition success rate.

[0028] An optimized solution of this embodiment is as follows: Figure 3As shown, the driver module can be connected to a PC via a serial port for modulation, enabling rapid modification of the lamp ID information. The diameter of the circular lamp is 25cm, and the communication distance can reach up to 6m under ideal conditions.

[0029] Step 2: The image sensor receiver uses dual-frame processing to acquire light source contour information, extracts the ROI, and achieves highly reliable recognition of visible light information based on the ROI.

[0030] The image sensor receiver is divided into modules for signal acquisition, signal processing, and positioning calculation according to its functions. The image acquisition module consists of a CMOS camera. The signal processing and positioning calculation modules are mobile computing units such as CPUs or Raspberry Pis mounted on mobile phones and vehicles. The positioning results are displayed in real time on the receiver's display screen and transmitted back to the server via a local area network.

[0031] like Figure 4 As shown, a dual-frame processing technique is designed using different exposure times. Figure 4 (a) is a frame with higher exposure. By performing preprocessing such as grayscale processing and image filtering on this image, geometric features are extracted to obtain the visual information ROI of the image contour. Figure 4 (b) To achieve ID information recognition through the aforementioned ROI, clear bright and dark stripes with a roller blind effect are obtained through grayscale processing and dynamic threshold binarization. The bright and dark stripes correspond to 0 and 1 sequences, and the stripe width corresponds to the number of repetitions of the 0 and 1 signals, thus achieving highly reliable ID beacon recognition. The specific image processing flow is as follows: Figure 5 As shown.

[0032] In this embodiment, the positioning calculation module uses a visible light positioning method based on visual geometric features to achieve actual positioning by combining visible light information with the geometric contour information of the lamp. Through various tests, this invention has verified that the positioning accuracy is within 10cm in multiple typical indoor scenarios.

[0033] The above-described embodiments illustrate some implementation methods of the present invention. The descriptions are relatively specific and detailed, and the purpose, technical solutions and beneficial effects of the present invention are explained in detail. However, they should not be construed as limiting the scope of the present invention. It should be noted that any modifications, variations and improvements made by the art without departing from the design and principles of the present invention should fall within the protection scope of the present invention.

Claims

1. A high-precision visible light positioning device based on an image sensor, characterized in that: It includes a visible light signal LED transmitter, a visible light modulation unit circuit, and an image sensor receiver. The visible light modulation unit circuit includes three functional modules: encoding, modulation, and driving. The visible light modulation unit encoding module assigns an ID to the LED through a self-designed encoding scheme, converts the digital signal into an analog signal through a serial port connection to the modulation module, and finally inputs the amplified electrical signal to the LED lighting fixture through the driving chip to realize the transmission of the visible light signal.

2. The visible light positioning device according to claim 1, characterized in that: The visible light positioning device also includes an image sensor receiver, which consists of functional modules such as signal acquisition, signal processing, and positioning calculation. The signal acquisition module acquires visual signals through the image sensor, extracts and processes visible light signals and visual geometric information separately through a dual-frame recognition mechanism, and achieves positioning through a visible light positioning algorithm based on the image sensor.

3. The visible light positioning device according to claim 1 or 2, characterized in that: The encoding module performs encoding via a PC and connects to a microcontroller via a serial debugging cable to perform programming. It also inputs signals to the EN enable terminal of a single-channel high-power LED constant current driver chip to control the chip's operating state. The power supply provides a 32V operating voltage to the driver chip through an adjustable boost DC-DC converter, driving the LED to send visible light signals.

4. The visible light positioning device according to claim 1, 2, or 3, characterized in that: The modulation module uses an Arduino UNO R3 or other MCU microcontroller unit.

5. The visible light positioning device according to claim 1, 2, or 3, characterized in that: The driving module consists of single-channel high-power LED constant current driving chips, such as DD311 and DD312.

6. The visible light positioning device according to claim 1, 2, or 3, characterized in that: The visible light signal LED emitter is a diode, and its shape is a circular or rectangular commercial lighting LED.

7. The visible light positioning device according to claim 1, 2, or 3, characterized in that: The visible light modulation unit circuit also includes a serial port debugging port, which supports connection to a PC via a serial port debugging tool, allowing for one-click modification of LED ID assignment.

8. The visible light positioning device according to claim 1, 2, or 3, characterized in that: Image sensor receivers include, but are not limited to, smartphones, smart cars, and smart robots.

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