A ranging communication fusion system and method based on spot centroid position offset

Abstract

The application discloses a ranging communication fusion system and method based on spot centroid position offset, and belongs to the technical field of optical ranging and optical communication integration. The system transmits two laser signals and performs PPM modulation, and the modulated signals form spatially distinguishable spots on the imaging surface of an array detector after optical focusing; the spot spatial position information and photon arrival timestamp data are collected, the target distance is calculated based on the spot centroid position offset, laser ranging without echo time is realized, the PPM modulated signal is decoded based on the photon arrival timestamp data to extract communication data, and the fusion of ranging and communication functions is realized. The system of the application supports fixed or adjustable imaging structure, can be flexibly configured between system integration and ranging accuracy according to application requirements, effectively avoids the distance ambiguity problem under the condition of high repetition frequency laser emission, improves the adaptability to high frequency laser emission and high speed modulation, and has compact structure and high integration.

Description

Technical Field

[0001] This invention belongs to the field of integrated optical ranging and optical communication technology, specifically relating to a ranging and communication fusion system and method based on the offset of the centroid position of a light spot. Background Technology

[0002] With the development of modern communication and ranging technologies, laser sensing systems are evolving towards higher precision, lower power consumption, and higher integration. This is especially true in short-to-medium distance applications such as smart terminals, human-computer interaction, and autonomous driving, where higher demands are placed on fusion systems that simultaneously possess ranging and communication capabilities. However, in existing technologies, ranging and communication functions are mostly built as independent modules, occupying different transmission and reception paths. This results in complex system architecture, redundant resource allocation, and hinders functional integration and overall performance optimization. Furthermore, traditional laser ranging methods largely rely on the pulse time-of-flight principle, calculating target distance by recording the time difference between laser signal transmission and reception. However, under high repetition frequency laser emission conditions, this is prone to distance ambiguity, limiting the system's ranging accuracy and stability.

[0003] Some scholars have proposed a synchronization method for single-photon communication using M-order PPM modulation. This method improves the robustness and synchronization accuracy of single-photon communication under low-light conditions by adding a frame synchronization code and a time slot synchronization header at the transmitting end, and sequentially performing time slot synchronization, clock synchronization, and frame synchronization at the receiving end. However, this scheme only addresses the communication link synchronization problem and does not involve the coupling and utilization of communication modulation and ranging information.

[0004] One scholar proposed a laser ranging method, system, lidar, and radar product. In each ranging cycle, the trigger count of the photosensitive receiver array pixels is counted to form a grayscale image of the light spot and the centroid position is calculated. Then, referring to the calibrated centroid-distance relationship, the peak range of the Direct Time-of-Flight (DTOF) ranging histogram is determined, and peak fitting is performed to obtain the ranging time and distance values. This scheme effectively utilizes the mapping relationship between the spatial domain centroid and the time domain histogram, but it does not involve the embedding and synchronous extraction of communication data, and does not achieve integrated ranging and communication on a unified link.

[0005] Another researcher designed a ranging calibration method that acquires a target image containing a laser spot while measuring the distance, calculates the deviation between the spot center and the imaging system's field of view center, and determines the deviation angle based on the image deviation and the image-side focal length, thereby calibrating the first distance value to obtain a more accurate second distance value. However, this technique mainly improves ranging accuracy and consistency, without involving the synchronous extraction of ranging communication information.

[0006] In summary, existing technologies still have room for improvement in terms of simultaneous extraction of ranging and communication data, distance accuracy and stability under high repetition frequency conditions, and system integration. Therefore, it is necessary to design a fusion system that can achieve simultaneous extraction of ranging and communication data under a unified optical path structure, reducing dependence on echo time information while improving communication modulation efficiency and system integration capabilities. Summary of the Invention

[0007] To address the aforementioned technical problems, this invention provides a ranging and communication fusion system and method based on the offset of the laser spot centroid position. The system is based on geometric optics principles, constructing a mapping relationship between the offset of the laser spot centroid position and the target distance. It embeds communication data into the laser signal using pulse position modulation (PPM), acquires data signals containing position and modulation information through an array detection module, and combines this with a signal processing module to calculate the target distance and decode the communication data, achieving simultaneous extraction of ranging and communication information. This system is suitable for low-latency applications and has advantages such as simple structure, low power consumption, and easy scalability.

[0008] To achieve the above objectives, the present invention adopts the following technical solution:

[0009] In a first aspect, the present invention provides a ranging and communication fusion system based on the offset of the centroid position of a light spot, the system comprising a laser emission module, a pulse modulation module, an optical focusing module, an array detection module, a signal processing module, and a data output module;

[0010] The laser emitting module is used to generate two laser signals;

[0011] The pulse modulation module is used to perform PPM modulation on the two laser signals to obtain a PPM modulated signal; the PPM modulated signal carries communication data.

[0012] The optical focusing module is used to focus the PPM modulation signal onto the imaging surface of the array detection module to form a spatially distinguishable light spot;

[0013] The array detection module is used to receive the focused PPM modulation signal and output a data signal; the data signal includes the spatial position information of the light spot and the photon arrival time stamp data.

[0014] The signal processing module is used to calculate the target distance based on the data signal and extract the communication data;

[0015] The data output module is used to output the target distance and the communication data to an external device.

[0016] Furthermore, the pulse modulation module performs M-PPM modulation on the two laser signals respectively. Each PPM symbol consists of M equal-length time slots. Only one time slot in the M equal-length time slots carries a pulse to represent the modulation information corresponding to the PPM symbol. A protection time slot is set at the beginning of each PPM symbol to prevent pulse crosstalk between adjacent symbols and improve the stability of modulation and demodulation.

[0017] Furthermore, the array detection module uses a photon counting type two-dimensional array detector, including a multi-pixel photon counter (MPPC) array or a single photon avalanche diode (SPAD) array, to output the spatial location information of the light spot and the photon arrival timestamp data.

[0018] Furthermore, the imaging surface of the array detection module adopts a fixed imaging structure or an adjustable imaging structure, which is selected and configured according to the spatial compactness requirements or ranging accuracy requirements of the system. Specifically, when the imaging surface adopts a fixed imaging structure, the imaging surface is set at a preset fixed position after the optical focusing module to obtain a diffuse spot image. When the imaging surface adopts an adjustable imaging structure, the imaging surface is adjusted to the focusing plane position of the optical focusing module by a motion component to obtain a clear focused spot image.

[0019] Furthermore, the signal processing module includes a spot centroid extraction and distance calculation unit. This unit extracts the spot centroid based on the spot's spatial location information, calculates the spot centroid position offset, and establishes a target distance calculation model based on the spot centroid position offset, based on the system's structural parameters and geometric imaging characteristics. To calculate the target distance; wherein, Indicates the distance to the target. This indicates the offset of the centroid position of the light spot. This represents the target distance calculation function.

[0020] Furthermore, the signal processing module also includes a timestamp decoding and boundary judgment unit, which is used to decode the PPM modulation signal and identify the PPM symbol boundary position based on the photon arrival timestamp data and the time characteristics in PPM modulation, and extract the corresponding communication data according to the PPM symbol boundary position.

[0021] Furthermore, the system supports channel expansion. The laser emission module adopts a multi-channel laser array structure, which includes multiple independently controllable laser emission units. The laser signal emission direction and modulation method of each channel can be set independently. The array detection module has two-dimensional imaging capability and can simultaneously receive and distinguish the light spots formed by laser signals from different channels. The signal processing module has parallel processing capability and supports synchronous calculation of target distances across multiple channels and independent extraction of communication data.

[0022] Secondly, the present invention provides a ranging and communication fusion method based on spot centroid position offset, applied to the aforementioned ranging and communication fusion system based on spot centroid position offset, the method comprising:

[0023] Step 1: The laser emitting module generates two laser signals;

[0024] Step 2: The pulse modulation module modulates the two laser signals using PPM modulation to obtain a PPM modulated signal; the PPM modulated signal carries communication data.

[0025] Step 3: The optical focusing module focuses the PPM modulation signal onto the imaging surface of the array detection module to form a spatially distinguishable light spot;

[0026] Step 4: The array detection module receives the focused PPM modulation signal and outputs a data signal; the data signal includes the spatial position information of the light spot and the photon arrival time stamp data;

[0027] Step 5: The signal processing module calculates the target distance based on the data signal and extracts the communication data;

[0028] Step 6: The data output module outputs the target distance and the communication data.

[0029] Further, in step 5, the signal processing module calculates the target distance based on the data signal, including: the signal processing module extracts the centroid of the light spot based on the spatial position information of the light spot, calculates the offset of the position of the light spot centroid, and establishes a target distance calculation model based on the offset of the position of the light spot centroid based on the structural parameters and geometric imaging characteristics of the system. To calculate the target distance; wherein, Indicates the distance to the target. This indicates the offset of the centroid position of the light spot. This represents the target distance calculation function.

[0030] Further, in step 5, the signal processing module extracts the communication data based on the data signal, including: the signal processing module decodes the PPM modulation signal and identifies the PPM symbol boundary position based on the photon arrival timestamp data and the time characteristics in PPM modulation, and extracts the corresponding communication data based on the PPM symbol boundary position.

[0031] The beneficial effects of this invention are as follows:

[0032] 1. A distance calculation model based on the mapping relationship between the position offset of the spot centroid and the target distance is constructed. The position offset of the spot centroid is used as the key variable for ranging, realizing laser ranging without echo time, which effectively reduces the system response delay and improves the ranging robustness.

[0033] 2. By adopting M-PPM pulse modulation technology and combining it with a photon counting array detector to collect data signals containing light spot position information and modulation information, the system achieves efficient integration of ranging and communication functions, enhancing the system's information processing efficiency and functional synergy capabilities.

[0034] 3. It adopts a spatial decoupling design of multi-channel laser modulation and array detector, which can realize the parallel capture and processing of multiple light spots on the same optical imaging surface. It supports fixed and adjustable imaging structure configurations, and can flexibly choose between integration and accuracy requirements. It has the advantages of compact structure, stable optical path and strong scalability, and is suitable for a variety of medium and short distance fusion application scenarios. Attached Figure Description

[0035] Figure 1 This is a structural block diagram of the ranging and communication fusion system based on the centroid offset of the spot, according to the present invention.

[0036] Figure 2 This is a flowchart of the ranging and communication fusion method based on the centroid position offset of the spot according to the present invention.

[0037] Figure 3 This is a schematic diagram illustrating the optical path structure and the centroid position shift of the dual-channel light spot under a fixed imaging structure according to an embodiment of the present invention.

[0038] Figure 4 This is a schematic diagram illustrating the optical path structure and the centroid position shift principle of the adjustable imaging structure system according to an embodiment of the present invention. Detailed Implementation

[0039] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0040] The term “exemplary” as used herein means “serving as an example, embodiment, or illustration.” Any embodiment illustrated herein as “exemplary” is not necessarily to be construed as superior to or better than other embodiments.

[0041] The terms “first”, “second”, etc., are used to distinguish similar objects, not to describe or indicate a specific order or sequence.

[0042] The term "comprising" or any other similar term is intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus / device that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent in such process, method, article, or apparatus / device.

[0043] Furthermore, to better illustrate the present invention, numerous specific details are provided in the following detailed embodiments. Those skilled in the art should understand that the present invention can be practiced without certain specific details. In some instances, methods, means, elements, and circuits well known to those skilled in the art have not been described in detail in order to highlight the spirit of the invention.

[0044] Figure 1 The diagram shows the structural block diagram of the ranging and communication fusion system based on spot centroid position offset of the present invention, as follows: Figure 1 As shown, the system includes a laser emission module, a pulse modulation module, an optical focusing module, an array detection module, a signal processing module, and a data output module.

[0045] The laser emitting module is used to generate two laser signals.

[0046] The pulse modulation module is used to perform PPM modulation on the two laser signals generated by the laser emission module to obtain a PPM modulated signal; the PPM modulated signal carries communication data.

[0047] For example, the pulse modulation module performs M-PPM modulation on the two laser signals respectively. Each PPM symbol consists of M equal-length time slots, where M is an integer greater than 1. Only one of these M time slots carries a pulse (the rest are empty), representing the modulation information corresponding to the PPM symbol. The time slot index of the pulse indicates the symbol value carried by the PPM symbol. To avoid crosstalk caused by pulse transmission between adjacent symbols and to improve the robustness and stability of the system's modulation and demodulation, a guard time slot is set at the beginning of each PPM symbol. This guard slot is used to identify symbol boundaries and reduce the probability of symbol recognition errors caused by timing jitter under high-speed modulation.

[0048] An optical focusing module is used to focus the PPM modulation signal onto the imaging surface of the array detection module to form a spatially distinguishable light spot.

[0049] For example, the optical focusing module is implemented using a convex lens.

[0050] The array detection module is used to receive the focused PPM modulation signal and output a data signal; the data signal includes the spatial position information of the light spot and the photon arrival time stamp data.

[0051] For example, the array detection module uses a photon-counting two-dimensional array detector to capture a two-dimensional spatial spot image and photon arrival timestamp information after the PPM modulated signal is optically focused. Specifically, the array detection module includes an MPPC array or a SPAD array, which can output photon arrival timestamp data for PPM symbol decoding and a two-dimensional spatial spot image (i.e., spot spatial location information) for ranging calculation at high time resolution.

[0052] For example, to adapt to different requirements of system integration and ranging accuracy, the imaging surface of the array detection module can adopt a fixed imaging structure or an adjustable imaging structure. The fixed imaging structure sets the imaging surface at a preset fixed position after the optical focusing module, eliminating the need for additional adjustment mechanisms. This facilitates system integration and assembly, and is suitable for scenarios with limited space or low accuracy requirements. However, in a fixed imaging structure, the light spot exhibits a certain degree of dispersion due to the imaging surface being offset from the focusing plane, resulting in limited accuracy in locating the spot centroid. The adjustable imaging structure, on the other hand, uses motion components to adjust the imaging surface along the optical axis to the focusing plane, thereby obtaining a clear, focused light spot image and significantly improving the accuracy of extracting the spot centroid position. This is suitable for applications with high ranging accuracy requirements, but the system structure is relatively more complex, requiring additional motion components. In practical applications, the choice between a fixed or adjustable imaging structure for the array detection module's imaging surface can be made based on the system's space compactness requirements or ranging accuracy needs.

[0053] The signal processing module is used to calculate the target distance based on the data signal and extract the communication data.

[0054] The signal processing module includes a spot centroid extraction and distance calculation unit, as well as a timestamp decoding and boundary judgment unit.

[0055] The spot centroid extraction and distance calculation unit is used to extract the spot centroid based on the spot's spatial location information, calculate the spot centroid position offset, and establish a target distance calculation model based on the spot centroid position offset, based on the system's structural parameters and geometric imaging characteristics. To calculate the target distance; where, Indicates the distance to the target. This indicates the offset of the centroid position of the light spot. This represents the target distance calculation function.

[0056] The target distance calculation model represents the mapping relationship between the offset of the spot centroid position and the target distance. This model can be derived from an image geometric model or obtained through experimental calibration. It effectively improves the system's ranging accuracy and real-time performance, enhances anti-interference capabilities, and is suitable for multi-channel ranging and communication fusion systems. Based on the above mapping relationship, the target distance can be calculated.

[0057] The timestamp decoding and boundary judgment unit is used to decode the PPM modulation signal and identify the PPM symbol boundary positions based on photon arrival timestamp data and the time characteristics in PPM modulation, and extract the corresponding communication data according to the PPM symbol boundary positions. The specific process is as follows: First, photon arrival timestamp data is collected for each channel. Then, PPM symbol boundary judgment is performed. When a continuous period without pulses reaches the protection time slot, the position is marked as a candidate boundary, and a window is opened at the candidate position according to the "protection time slot + one complete PPM symbol length". When only one pulse appears within this window, it is confirmed as the symbol start boundary. To avoid misjudgments caused by empty time slots, it is further required that the interval between two adjacent confirmed boundaries is consistent with "protection time slot + one complete PPM symbol length" (allowing for small tolerances). If this is not met, the candidate is discarded and the process continues. Finally, the time slot position of the PPM symbol containing the pulse is mapped to the corresponding symbol and bit sequence, and the communication data is obtained after framing and verification.

[0058] In this way, the target distance can be calculated by extracting the centroid of the light spot and calculating the distance, while the communication data can be extracted by the timestamp decoding and boundary judgment unit, thus realizing the fusion processing of ranging and communication.

[0059] The data output module is used to output the calculated target distance and the extracted communication data to external devices.

[0060] For example, the system of the present invention supports channel expansion. The laser emission module can adopt a multi-channel laser array structure, which includes multiple independently controllable laser emission units. The laser signal emission direction and modulation method of each channel can be set independently. The array detection module has two-dimensional imaging capability and can simultaneously receive and distinguish the light spots formed by laser signals from different channels. The signal processing module has parallel processing capability and supports the synchronous calculation of target distances of multiple channels and the independent extraction of communication data.

[0061] This invention relates to a ranging and communication fusion system based on spot centroid position offset. A laser emission module emits two laser signals, and a pulse modulation module performs PPM modulation on these two pulse signals. The modulated signals, after passing through an optical focusing module, form a spatially distinguishable spot on the imaging surface of an array detection module. The array detection module acquires a data signal containing both spot position information and modulation information. A signal processing module establishes a target distance calculation model based on the spot centroid position offset, achieving laser ranging without echo time. Simultaneously, it decodes PPM symbols based on photon arrival timestamps to extract communication data, thus integrating ranging and communication functions. The system supports fixed or adjustable imaging structures, allowing for flexible configuration between system integration and ranging accuracy according to application requirements. It effectively avoids distance ambiguity under high repetition frequency laser emission conditions, improves adaptability to high-frequency laser emission and high-speed modulation, and features a compact structure, high integration, simple structure, low power consumption, and easy expansion. It is suitable for applications such as smart terminals and vehicle-mounted LiDAR.

[0062] This invention also proposes a ranging and communication fusion method based on the offset of the spot centroid position, which is executed by the above-mentioned ranging and communication fusion system based on the offset of the spot centroid position. Figure 2 A flowchart illustrating the ranging and communication fusion method based on spot centroid position offset of the present invention is shown, as follows: Figure 2 As shown, the method includes:

[0063] Step 1: The laser emitting module generates two laser signals;

[0064] Step 2: The pulse modulation module modulates the two laser signals using PPM modulation to obtain a PPM modulated signal; the PPM modulated signal carries communication data.

[0065] Step 3: The optical focusing module focuses the PPM modulation signal onto the imaging surface of the array detection module to form a spatially distinguishable light spot;

[0066] Step 4: The array detection module receives the focused PPM modulation signal and outputs a data signal; the data signal includes the spatial position information of the light spot and the photon arrival time stamp data;

[0067] Step 5: The signal processing module calculates the target distance based on the data signal and extracts the communication data;

[0068] Step 6: The data output module outputs the target distance and the communication data.

[0069] For example, in step 5, the signal processing module extracts the centroid of the light spot based on the spatial location information of the light spot, calculates the offset of the centroid position, and establishes a target distance calculation model based on the offset of the centroid position based on the structural parameters and geometric imaging characteristics of the system. To calculate the target distance; where, Indicates the distance to the target. This indicates the offset of the centroid position of the light spot. This represents the target distance calculation function.

[0070] For example, in step 5, the signal processing module decodes the PPM modulation signal and identifies the PPM symbol boundary position based on the photon arrival timestamp data and the time characteristics in PPM modulation, and extracts the corresponding communication data according to the PPM symbol boundary position.

[0071] The following sections will provide a detailed description of the ranging and communication fusion system and method based on the offset of the spot centroid position, using examples of a fixed imaging structure and an adjustable imaging structure for the imaging surface of the array detection module.

[0072] Example 1:

[0073] This embodiment addresses the need for compact applications. The array detection module employs an MPPC array, and the imaging surface uses a fixed imaging structure. It provides a ranging and communication fusion system and method based on dual-channel laser emission. The principle of the system's optical path structure and the centroid position shift of the dual-channel laser spot under the fixed imaging structure is as follows: Figure 3 As shown. This system uses two lasers with identical parameters (i.e., Figure 3 Laser 1 and Laser 2 serve as the light sources for channels 1 and 2, respectively, with a center wavelength of 905 nm and a pulse width of 5 ns. The lasers are arranged vertically with a center-to-center spacing of 2h (the distance between laser 1 and laser 2 and the optical axis is h). The two lasers operate synchronously, using 4-PPM modulation to load communication data. Each PPM symbol contains four time slots with a width of 40 ns. A 40 ns guard time slot is set at the beginning of the symbol to effectively suppress inter-symbol pulse crosstalk. The single-channel communication rate is 10 Mbps, and the total dual-channel communication rate reaches 20 Mbps.

[0074] The laser beams emitted by lasers 1 and 2 are focused by a convex lens onto the imaging surface of the MPPC array, forming two spatially distinguishable upper and lower light spots. The MPPC array is positioned behind the convex lens at a distance... At this location, the array resolution is 32×32, and the single pixel size is 25µm×25µm, providing high temporal and spatial resolution. The fixed imaging structure fixes the imaging surface at a non-real focal point, simplifying the system's optical path and structural packaging, making it suitable for short-to-medium range compact ranging and communication integration scenarios. As the target distance changes, the dual-channel light spot experiences an observable centroid position shift in the direction perpendicular to the imaging surface. The signal processing module establishes a target distance calculation model based on the similar triangle model and the offset of the spot centroid position. When the laser is located at a distance from the convex lens Location (i.e., where the laser is located) Figure 3 (reference plane in the middle) and distance convex lens Location (i.e., where the laser is located) Figure 3 When measuring the plane (in the middle), the centroid heights of the imaging spot on the MPPC array imaging plane are respectively... and The offset of the centroid position of the light spot is After sorting, the target distance calculation model can be obtained as follows: The MPPC array synchronously outputs the spot image and photon arrival timestamp information, and the signal processing module extracts the centroid coordinates of the spot in real time and calculates... Simultaneously, by combining the time characteristics in PPM modulation to decode PPM symbols and complete boundary identification, the ranging results and communication data are synchronously calculated. The final result is uploaded to the main control system through the data output module, completing the fusion of high repetition rate and high robustness dual-channel ranging and communication.

[0075] Example 2:

[0076] This embodiment addresses the high-precision application requirements by employing an MPPC array for the array detection module and an adjustable imaging structure for the imaging surface, providing a ranging and communication fusion system and method based on dual-channel laser emission. The principle of the system optical path structure and the centroid position shift of the dual-channel laser spot under the adjustable imaging structure is as follows: Figure 4 As shown. This system uses two lasers with identical parameters (i.e., Figure 4 Laser 1 and Laser 2 serve as the light sources for channels 1 and 2, respectively, with a center wavelength of 905 nm and a pulse width of 5 ns. The lasers are arranged vertically with a center-to-center spacing of 2h (the distance between laser 1 and laser 2 and the optical axis is h). The two lasers operate synchronously, using 4-PPM modulation to load communication data. Each PPM symbol contains four time slots with a width of 40 ns. A 40 ns guard time slot is set at the beginning of the symbol to effectively suppress inter-symbol pulse crosstalk. The single-channel communication rate is 10 Mbps, and the total dual-channel communication rate reaches 20 Mbps.

[0077] The laser beams emitted by lasers 1 and 2 are focused by a convex lens onto the imaging surface of the MPPC array, forming two spatially distinguishable upper and lower light spots. The position of the MPPC array is adjustable, with an array resolution of 32×32 and a single pixel size of 25µm×25µm, providing high temporal and spatial resolution. The adjustable imaging structure, through the inclusion of a motion component, allows the imaging surface of the MPPC array detector to move along the optical axis to the actual focusing plane of the laser beam, thereby achieving dual-channel spot imaging at the focal point and obtaining a clear imaging effect, suitable for high-precision ranging applications. As the target distance changes, the dual-channel light spots exhibit observable centroid position shifts in the vertical direction of the MPPC array imaging surface at different focusing plane positions. The signal processing module establishes a target distance calculation model based on the similar triangle model and the offset of the spot centroid position. When the laser is located at a distance from the convex lens Location (i.e., where the laser is located) Figure 4 (reference plane in the middle) and distance convex lens Location (i.e., where the laser is located) Figure 4 When measuring the plane (in the middle), the centroid heights of the imaging spot on the MPPC array imaging plane are respectively... and The offset of the centroid position of the light spot After sorting, the target distance calculation model can be obtained as follows: The MPPC array synchronously outputs the spot image and photon arrival timestamp information, and the signal processing module extracts the centroid coordinates of the spot in real time and calculates... Simultaneously, by combining the time characteristics in PPM modulation to decode PPM symbols and complete boundary identification, the ranging results and communication data are synchronously calculated. The final result is uploaded to the main control system through the data output module, completing the fusion of high repetition rate and high robustness dual-channel ranging and communication.

[0078] The contents not described in detail in this specification are existing technologies known to those skilled in the art.

[0079] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above descriptions are merely specific embodiments of the present invention and are not intended to limit the present invention. The above descriptions are exemplary and not exhaustive. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A ranging and communication fusion system based on the offset of the centroid position of a light spot, characterized in that, The system includes a laser emission module, a pulse modulation module, an optical focusing module, an array detection module, a signal processing module, and a data output module; The laser emitting module includes two lasers with identical parameters, used to synchronously generate two laser signals; The pulse modulation module is used to perform PPM modulation on the two laser signals to obtain a PPM modulated signal; the PPM modulated signal carries communication data; wherein, the pulse modulation module performs M-PPM modulation on the two laser signals respectively, each PPM symbol in the PPM modulated signal is composed of M equal-length time slots, and only one time slot in the M equal-length time slots carries a pulse to represent the modulation information corresponding to the PPM symbol; a guard time slot is set at the beginning position of each PPM symbol to prevent pulse crosstalk between adjacent symbols and improve the stability of modulation and demodulation; The optical focusing module is used to focus the PPM modulation signal onto the imaging surface of the array detection module to form a spatially distinguishable light spot; The array detection module is used to receive the focused PPM modulation signal, acquire and output data signals; the data signals include both spot spatial position information and photon arrival timestamp data; wherein, the array detection module uses a photon counting type two-dimensional array detector, including an MPPC array or a SPAD array, to output the spot spatial position information and the photon arrival timestamp data; the spot spatial position information is represented by a two-dimensional spatial spot image and used for ranging calculation; the photon arrival timestamp data is used for PPM symbol decoding; The signal processing module includes a spot centroid extraction and distance calculation unit and a timestamp decoding and boundary judgment unit, which are used to calculate the target distance based on the data signal and extract the communication data at the same time. The spot centroid extraction and distance calculation unit is used to extract the spot centroid based on the spot's spatial location information, calculate the spot centroid position offset, and establish a target distance calculation model based on the spot centroid position offset based on the system's structural parameters and geometric imaging characteristics. To calculate the target distance; wherein, Indicates the distance to the target. This indicates the offset of the centroid position of the light spot. This represents the target distance calculation function; The timestamp decoding and boundary judgment unit is used to decode the PPM modulation signal and identify the PPM symbol boundary position based on the photon arrival timestamp data, combined with the protection time slot and a complete PPM symbol length, and map the time slot position where the pulse is located to the corresponding symbol and bit sequence according to the identified PPM symbol boundary, so as to extract the communication data. The data output module is used to output the target distance and the communication data to an external device.

2. The ranging and communication fusion system based on spot centroid position offset according to claim 1, characterized in that, The imaging surface of the array detection module can be a fixed imaging structure or an adjustable imaging structure, selected and configured according to the spatial compactness requirements or ranging accuracy requirements of the system. When the imaging surface is a fixed imaging structure, it is positioned at a preset fixed position after the optical focusing module to obtain a diffuse spot image. When the imaging surface is an adjustable imaging structure, a motion component adjusts the imaging surface to the focusing plane position of the optical focusing module to obtain a clearly focused spot image.

3. The ranging and communication fusion system based on spot centroid position offset according to claim 1, characterized in that, When the timestamp decoding and boundary judgment unit identifies the PPM symbol boundary position, if it detects that the continuous pulse-free time reaches the protection time slot, it marks the position as a candidate boundary and opens a window at the candidate boundary according to "protection time slot plus the length of a complete PPM symbol". The window has a window size. When only one pulse appears in the window, it is confirmed as the PPM symbol start boundary. It is further required that the interval between two adjacent confirmed boundaries is consistent with "protection time slot plus the length of a complete PPM symbol". If it does not meet the requirement, the candidate boundary is discarded and the sliding continues. Finally, the time slot position of the PPM symbol where the pulse is located is mapped to the corresponding symbol and bit sequence. After framing and verification, the communication data is obtained.

4. The ranging and communication fusion system based on spot centroid position offset according to any one of claims 1-3, characterized in that, The system supports channel expansion. The laser emission module adopts a multi-channel laser array structure, which contains multiple independently controllable laser emission units. The laser signal emission direction and modulation method of each channel can be set independently. The array detection module has two-dimensional imaging capability, and can simultaneously receive and distinguish light spots formed by laser signals from different channels; The signal processing module has parallel processing capabilities, supporting synchronous calculation of target distances across multiple channels and independent extraction of communication data.

5. A ranging and communication fusion method based on spot centroid position offset, applied to the ranging and communication fusion system based on spot centroid position offset as described in any one of claims 1-4, characterized in that, The method includes: Step 1: The laser emitting module synchronously generates two laser signals using two lasers with identical parameters; Step 2: The pulse modulation module modulates the two laser signals using PPM modulation to obtain a PPM modulated signal. The PPM modulated signal carries communication data. Specifically, the pulse modulation module performs M-PPM modulation on the two laser signals respectively. Each PPM symbol in the PPM modulated signal consists of M equal-length time slots. Only one time slot in the M equal-length time slots carries a pulse, used to represent the modulation information corresponding to that PPM symbol. A guard time slot is set at the beginning of each PPM symbol to prevent pulse crosstalk between adjacent symbols and improve the stability of modulation and demodulation. Step 3: The optical focusing module focuses the PPM modulation signal onto the imaging surface of the array detection module to form a spatially distinguishable light spot; Step 4: The array detection module receives the focused PPM modulation signal, acquires and outputs a data signal; the data signal includes both the spatial position information of the light spot and the photon arrival timestamp data; wherein, the array detection module uses a photon counting type two-dimensional array detector, including an MPPC array or a SPAD array, to output the spatial position information of the light spot and the photon arrival timestamp data; the spatial position information of the light spot is represented by a two-dimensional spatial light spot image and is used for ranging calculation; the photon arrival timestamp data is used for PPM symbol decoding; Step 5: The signal processing module calculates the target distance based on the data signal and extracts the communication data simultaneously; Step 6: The data output module outputs the target distance and the communication data; In step 5, the signal processing module calculates the target distance based on the data signal, including: The spot centroid extraction and distance calculation unit in the signal processing module extracts the spot centroid based on the spot's spatial location information, calculates the spot centroid position offset, and establishes a target distance calculation model based on the spot centroid position offset based on the system's structural parameters and geometric imaging characteristics. To calculate the target distance; wherein, Indicates the distance to the target. This indicates the offset of the centroid position of the light spot. This represents the target distance calculation function; In step 5, the signal processing module extracts the communication data based on the data signal, including: The timestamp decoding and boundary judgment unit in the signal processing module decodes the PPM modulation signal and identifies the PPM symbol boundary position based on the photon arrival timestamp data, combined with the guard time slot and a complete PPM symbol length. It then maps the pulse time slot position to the corresponding symbol and bit sequence according to the identified PPM symbol boundary to extract the communication data.

6. The ranging and communication fusion method based on spot centroid position offset according to claim 5, characterized in that, In step 5, when the timestamp decoding and boundary judgment unit identifies the PPM symbol boundary position, if it detects that the continuous pulse-free time reaches the protection time slot, it marks the position as a candidate boundary and opens a window at the candidate boundary according to "protection time slot plus the length of a complete PPM symbol". The window has a window size. When only one pulse appears in the window, it is confirmed as the starting boundary of the PPM symbol. It is further required that the interval between two adjacent confirmed boundaries is consistent with "protection time slot plus the length of a complete PPM symbol". If it is not satisfied, the candidate boundary is discarded and sliding continues. Finally, the time slot position of the PPM symbol where the pulse is located is mapped to the corresponding symbol and bit sequence. After framing and verification, the communication data is obtained.

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