An automatic endpoint camera shooting and image judging system based on UWB ranging

Abstract

This invention discloses an automatic finish line camera image interpretation system based on UWB ranging, belonging to the field of sports timing technology. The system includes: a starting sensor for capturing the race start trigger signal; a finish line camera timing unit for acquiring a sequence of finish line images; a UWB timing unit containing symmetrically arranged first and second base stations and electronic tags worn by athletes, employing multi-chip parallel ranging and linear fitting algorithms to calculate the finish line crossing time; and a data fusion and interpretation server that maps the UWB finish line crossing timestamp and identity information to image frames, generating a virtual auxiliary interpretation line. This invention achieves system-wide clock synchronization through a temperature-compensated crystal oscillator and time compensation mechanism, mapping the UWB-determined identity information and finish line crossing timestamp to high frame rate image frames to generate a virtual auxiliary interpretation line. This assists referees in quickly confirming results, effectively solving the recognition problems caused by overlapping occlusion, ambient light interference, and multi-lap races, achieving millisecond-level automatic image interpretation.

Description

Technical Field

[0001] This invention relates to the field of sports timing technology, and in particular to an automatic image interpretation system for finish line cameras based on UWB ranging. Background Technology

[0002] In competitive sports, automatic timing systems with finish line cameras are core tools for ensuring fairness and impartiality, playing an irreplaceable role, especially in high-speed sports such as cycling, speed skating, and track and field. These systems typically consist of a starting unit, an image acquisition unit, and a data processing and interpretation unit. During the race, the starting unit generates a start signal, prompting all modules of the system to begin timing synchronously, while the image acquisition unit continuously captures images of the finish line at an extremely high frame rate. Currently, advanced finish line camera systems can capture frames at up to 10,000 frames per second with a timing accuracy of 0.1ms, clearly reproducing the moment an athlete crosses the finish line, thus effectively reducing disputes during the race.

[0003] With the increasing demands for real-time performance evaluation in modern sports broadcasts, automatic image recognition-based evaluation methods have emerged. These methods improve the efficiency of performance evaluation to some extent by learning evaluation rules through edge detection or artificial neural networks. However, pure image recognition-based automatic evaluation technology still faces the following insurmountable obstacles in practical applications: overlapping lane marking issues, where athletes in the inner lane can easily obscure athletes in the outer lane when they are too close, leading to inaccurate evaluations or even missed evaluations; ambient lighting effects, where drastic changes in ambient light in outdoor competitions can cause images to be overexposed or underexposed, making it difficult for the system to accurately identify athlete edges; lane identification errors, where detached or obscured bib numbers or poor lighting often lead to lane identification errors, especially prominent in number-based events such as cycling and speed skating; and lapping issues, where leading athletes often lead trailing athletes by one or even several laps in long-distance lap events such as the 5000m and 10000m. When these athletes cross the finish line at the same time, the image-based automatic judgment algorithm cannot distinguish between athletes who have finished the race and those who have not, leading to errors in the results statistics.

[0004] Ultra-wideband (UWB) technology has demonstrated significant advantages in the field of wireless precision positioning. UWB positioning primarily employs the time-of-flight ranging principle, and its ranging results exhibit a linear relationship with distance, resulting in extremely high spatial resolution. To further eliminate errors caused by clock skew, the industry typically uses bilateral bidirectional ranging technology, improving accuracy by measuring signals back and forth between the remote base station and the tag in both directions. UWB technology inherently possesses the ability to distinguish different targets, enabling the assignment of a unique identifier to each athlete. Although finish line camera systems and UWB technology are widely used in timing and positioning respectively, how to organically combine their advantages to solve the challenge of automatic map interpretation in complex competition scenarios remains a key direction for current technological development. Summary of the Invention

[0005] The purpose of this invention is to provide an automatic image interpretation system for finish line cameras based on UWB ranging, in order to solve the problems of missed target recognition due to overlapping and obstruction of athletes, image recognition failure caused by drastic changes in ambient light, difficulty in identity recognition due to damaged or obstructed bib numbers, and difficulty in distinguishing between the leader and the lapped in long-distance circuit races.

[0006] To solve the above-mentioned technical problems, the present invention provides the following technical solution: On the one hand, an automatic image interpretation system for endpoint cameras based on UWB ranging includes: a starting sensor, an endpoint camera timing unit, a UWB timing unit, and a data fusion and interpretation server; The starting sensor is used to capture the trigger signal for the start of the race and synchronize the starting timestamp to the finish line camera timing unit and the UWB timing unit via a wired or wireless communication link. The finish line camera timing unit is deployed to the side of the finish line and configured to acquire a sequence of images of the finish line area at a preset high frame rate; The UWB timing unit includes a first base station, a second base station, and a UWB electronic tag worn by the athlete, all located on the extension lines on both sides of the finish line.

[0007] The first and second base stations in the UWB timing unit adopt a symmetrical layout. Each base station integrates a main control processor, a temperature-compensated crystal oscillator, and multiple sets of ultra-wideband (UWB) wireless transceiver modules. These modules interact bidirectionally with the main control processor via a serial peripheral interface. To address the data refresh rate bottleneck in high-concurrency scenarios, the multiple UWB modules in the first and second base stations are configured to operate in parallel on independent communication frequency bands. Specifically, the first UWB module operates on the first channel, the second on the second, and so on, up to the fifth module operating on the fifth channel. The main control processor, according to a preset polling algorithm, divides the UWB electronic tags belonging to the participating athletes into multiple logical groups based on their numbers. Each logical group corresponds to a specific communication channel. Specifically, each UWB module is only responsible for bilateral bidirectional ranging with a preset number of UWB electronic tags within its corresponding channel. This multi-chip parallel hardware topology increases the sampling frequency of individual tags to the millisecond level, thereby providing sufficiently dense discrete sampling points for subsequent line-fitting.

[0008] The UWB timing unit also includes a clock synchronization module, which uses a highly stable temperature-compensated crystal oscillator as the reference clock source, with a frequency stability better than ±0.5ppm. The main control processor receives synchronization pulses from the trigger sensor through the capture function of its internal timer and calculates the delay compensation value generated by the hardware transmission link. The delay compensation value is used to calibrate the local time axis of the UWB timing unit, ensuring that the timestamps of the UWB ranging data and the image frame timestamps of the endpoint camera timing unit are aligned under the same time base.

[0009] The UWB electronic tag uses a low-power microcontroller as its control core and integrates a dual-band communication module. The dual-band communication module includes an ultra-wideband unit for high-precision ranging and a low-power Bluetooth unit for data management and remote wake-up. In non-competition mode, the UWB electronic tag is in deep sleep mode, with its quiescent current maintained at the microamplitude level. When the first or second base station issues a wake-up command, the low-power Bluetooth unit receives the command and triggers the microcontroller to enter operating mode. The UWB electronic tag also has an internal power management circuit that monitors the battery voltage in real time and encapsulates the battery status in the ranging data packet, feeding it back to the base station.

[0010] The UWB timing unit accurately calculates the athlete's crossing time by executing a finish line determination algorithm. This algorithm is based on geometric criteria and linear interpolation fitting. The specific implementation process is as follows: First, the first and second base stations perform bilateral bidirectional ranging with the same UWB electronic tag, obtaining a first ranging value and a second ranging value. Since the first and second base stations are located on opposite sides of the finish line extension, the sum of the first and second ranging values ​​reaches its theoretical minimum when the athlete's UWB electronic tag is exactly on the finish line. The main control processor continuously monitors the changing trend of this sum of distances; when the sum of the determined distances changes from decreasing to increasing, the finish line crossing logic is triggered.

[0011] Furthermore, to eliminate the error caused by UWB discrete sampling points not accurately landing on the physical location of the finish line, the line-crossing determination algorithm uses a linear fitting method to calculate the precise time. The system selects the time of the sampling point before the sum of distances reaches its minimum value and its corresponding vertical distance, as well as the time of the first sampling point after reaching the minimum value and its corresponding vertical distance. The vertical distance refers to the displacement of the tag relative to the vertical plane of the finish line. Assuming the athlete is in a state of uniform motion for a very short time before and after crossing the line, the system uses a linear interpolation formula to calculate the precise time value when the displacement is zero, based on the time difference and displacement difference between two adjacent sampling points. This precise time value serves as the UWB reference line-crossing timestamp.

[0012] The data fusion and interpretation server receives reference crossing timestamps, athlete identification codes, lane information, and distance measurement error reference values ​​from the UWB timing unit via Ethernet or a long-range wireless communication module. Simultaneously, the server receives high-frame-rate image streams from the finish line camera timing unit. Internally, the data fusion and interpretation server runs fusion processing software that maps the UWB reference crossing timestamps to the corresponding image frame indices according to a timestamp alignment protocol. On the automatic image interpretation interface, the system generates a virtual auxiliary line at the corresponding image frame position and overlays the athlete's identification information and lane number beside the line.

[0013] For long-distance circuit races, the data fusion and interpretation server executes a lap count logic determination program. This program pre-sets the total number of laps for the race, and the UWB timing unit generates a crossing record each time an athlete passes the finish line area. The lap count logic determination program accumulates the number of crossings corresponding to each athlete's identification code and uses a time window filtering mechanism to exclude invalid triggers caused by athletes lingering near the finish line. Only when the count reaches the preset total number of laps does the system determine the current crossing timestamp as the final race result and trigger the automatic capture and saving of the finish line camera image.

[0014] Furthermore, the UWB timing unit also integrates a long-range dual-mode communication module, which supports the LoRa protocol and the 2.4GHz frequency band. In large-scale water sports scenarios such as rowing and canoeing, where the finish line is far from the starting point, the long-range dual-mode communication module is used to achieve cross-regional data relay and time synchronization command transmission. The module improves the signal's anti-interference capability through spread spectrum technology, ensuring that the starting synchronization signal can be accurately delivered to each subsystem in the finish line area even in complex electromagnetic environments.

[0015] On the other hand, an automatic image interpretation method for endpoint cameras based on UWB ranging, applied to the aforementioned automatic image interpretation system for endpoint cameras based on UWB ranging, includes the following steps: Step S1: Start synchronization and time reference establishment; The start sensor captures the trigger signal of the start of the race, generates a high-precision synchronization pulse, and sends it simultaneously to the finish line camera timing unit and the UWB timing unit through a wired or wireless communication link; The main control processor in the UWB timing unit uses the capture function of the internal timer to receive the synchronization pulse, combines the delay compensation value of the hardware transmission link to calibrate the local time axis, and uses a temperature-compensated crystal oscillator as the reference clock source to ensure that the timestamp of the UWB ranging data is aligned with the timestamp of the image frame of the finish line camera timing unit under the same time reference; Step S2: Multi-chip parallel ranging polling; Multiple sets of ultra-wideband wireless transceiver modules integrated within the first and second base stations work in parallel on independent communication frequency bands; The main control processor divides the UWB electronic tags worn by athletes into multiple logical groups according to their numbers based on the polling algorithm. Each logical group corresponds to a specific communication frequency band. Each ultra-wideband wireless transceiver module is only responsible for bilateral and bidirectional ranging with a preset number of UWB electronic tags in its corresponding channel, thereby increasing the sampling frequency of a single tag to the millisecond level. Step S3: Intelligent power consumption management and data feedback of the UWB electronic tag; In non-competition mode, the UWB electronic tag is in deep sleep mode, and the static current is maintained at the microamp level; When the first base station or the second base station issues a wake-up command, the low-power Bluetooth unit receives the command and triggers the tag to enter the working state; After the ranging is completed, the UWB electronic tag encapsulates the battery level, motion status and received signal strength indication in a feedback data packet through the low-power Bluetooth channel and sends it to the base station.

[0016] Step S4: Line crossing determination and timestamp fitting calculation; the first base station and the second base station respectively perform bilateral bidirectional ranging with the same UWB electronic tag to obtain the first ranging value and the second ranging value, and the main control processor calculates the sum of the two D; when the determination D changes from decreasing to increasing, the line crossing logic is triggered; the system selects the sampling point time t1 before D reaches the minimum value and the corresponding normal displacement D. t1 And the time t2 of the first sampling point after reaching the minimum value and the corresponding normal displacement Dt2 The precise time value t when the normal displacement is zero is calculated using the linear interpolation formula. Finish As a UWB reference line timestamp; Step S5, Data aggregation and long-distance wireless relay: The first base station and the second base station send the calculated crossing timestamp, athlete identification code, lane information and ranging error reference value to the data aggregation module through the long-distance dual-mode communication module; This module supports the LoRa protocol and the 2.4GHz frequency band, and uses spread spectrum technology to achieve reliable transmission at the kilometer level; After receiving the data, the data processing main control in the data aggregation module forwards it to the data fusion and interpretation server through the Ethernet interface; Step S6: Image fusion interpretation and result output; The data fusion interpretation server receives the UWB reference crossing timestamp, athlete identification code, lane information, and high frame rate image stream captured by the finish line camera timing unit; According to the timestamp alignment protocol, the UWB reference crossing timestamp is mapped to the corresponding image frame index, and the athlete's identification information and lane information are superimposed and displayed at the corresponding position on the interpretation interface, and a virtual auxiliary interpretation line is generated to assist the referee in quickly confirming the results.

[0017] Compared with the prior art, the beneficial technical effects of the present invention are as follows: This invention combines UWB high-precision ranging technology with finish line camera technology, effectively solving the limitations of traditional visual judgment in terms of occlusion, abnormal lighting, and difficulty in identification. UWB signals have extremely strong penetrability, so even when the inside lane athlete completely obscures the outside lane athlete, the UWB timing unit can still accurately obtain the finish line information of each athlete through radio waves, thus providing a reliable auxiliary basis for judgment.

[0018] The multi-chip parallel hardware topology adopted in this invention fundamentally solves the problem of insufficient refresh rate in traditional single-chip UWB systems under multi-target concurrent environments. By assigning different tags to different physical channels for parallel ranging, the system increases the effective sampling frequency by several times. Combined with the linear fitting algorithm, the reference score provided by the UWB unit achieves millisecond-level accuracy, enabling seamless matching with high frame rate camera systems.

[0019] This invention achieves a unified time base for the entire system through a hardware-level time compensation mechanism and a high-precision temperature-compensated crystal oscillator; the three stages of issuing commands, recording images, and measuring distances operate on the same clock axis, eliminating the cumulative error caused by system delay jitter and ensuring the legitimacy and authority of the results.

[0020] The lap count logic judgment and time window filtering mechanism provided by this invention greatly simplifies the judgment process for long-distance races; the system can automatically distinguish between the leader and the lapped, and automatically merge repeated trigger data, which significantly reduces the workload of manual map judgment and improves the automation level of race organization. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the physical deployment and geometric ranging principle of UWB base stations provided by the present invention; Figure 2 This is a schematic diagram of the UWB communication network topology and multi-band partitioning structure provided by the present invention; Figure 3 This is a schematic diagram of the timing logic for tag polling by a UWB base station provided by the present invention; Figure 4 A schematic diagram of the high-precision linear fitting algorithm for the finish line collision provided by this invention; Figure 5 This is a block diagram of the internal hardware structure of a UWB base station provided by the present invention; Figure 6 The UWB timing unit processing flowchart provided by this invention; Figure 7 The hardware circuit diagram of the UWB electronic tag provided by this invention; Figure 8 The present invention provides a flowchart of the intelligent wake-up and working logic of UWB electronic tags. Figure 9 This is a block diagram of the overall architecture of the endpoint camera automatic image interpretation system based on UWB ranging provided by the present invention; Figure 10 Hardware block diagram of the data aggregation module provided by this invention; Figure 11 This invention provides a timing diagram for the athlete crossing the finish line logic under a multi-lap race system. Figure 12 A schematic diagram illustrating the definition of the UWB unit-specific data frame format provided by this invention; Figure 13 This is a schematic diagram illustrating the specific steps of the automatic image interpretation method for endpoint cameras based on UWB ranging provided by the present invention. Detailed Implementation

[0022] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0023] Please refer to Figure 1 , Figure 1 This is a schematic diagram illustrating the physical deployment and geometric ranging principle of UWB base stations provided in this embodiment of the invention, demonstrating the application deployment of this invention in a real competitive sports scenario. In the finish line area of ​​a track and field stadium or race car, the first base station and the second base station are respectively erected on both sides of the extended finish line, with the center line connecting them completely coinciding with the physical finish line. Athletes A, B, C, etc., wearing UWB electronic tags, sprint towards the finish line within their respective tracks. Please refer to... Figure 9 , Figure 9 The diagram shows the overall architecture of the timing system provided in this embodiment of the invention. The entire system mainly consists of a starting sensor, a finish line camera timing unit, a UWB timing unit, and a data fusion and interpretation server.

[0024] At the start of the competition, step S1, "Starting Synchronization and Time Base Establishment," is executed. A starting sensor is installed at the starting gun position. When the starting sound or electronic starting signal is triggered, the sensor generates a high-precision synchronization pulse signal. This signal is simultaneously transmitted via shielded transmission cable to the first and second base stations in the finish line camera timing unit and the UWB timing unit. Please refer to... Figure 5 , Figure 5 This is a block diagram of the internal hardware structure of a UWB base station provided in an embodiment of the present invention. The main control processor inside the first base station uses a CH32V307 chip, which is equipped with a high-precision timer capture channel. When the main control processor senses the command synchronization pulse, it immediately reads the system clock count value driven by the temperature-compensated crystal oscillator. The temperature-compensated crystal oscillator is a DSB3221SDN model, which provides a frequency stability of ±0.5ppm, ensuring that the clock drift of the entire system is controlled within the microsecond level during long-term competitions. The main control processor calculates the transmission delay from command triggering to signal reception and executes a delay compensation algorithm to strictly align the zero point of the local clock axis with the moment of command.

[0025] Then, step S2, multi-chip parallel ranging polling, is executed. To address the data refresh rate issue when multiple athletes cross the finish line concurrently, this invention integrates five ultra-wideband wireless transceiver modules in both the first and second base stations. Please refer to... Figure 2 and Figure 3 , Figure 2 This is a schematic diagram of the UWB communication network topology and multi-band partitioning structure provided in an embodiment of the present invention. Figure 3This is a timing logic diagram of tag polling by a UWB base station according to an embodiment of the present invention. The main control processor controls the five ultra-wideband wireless transceiver modules through the serial peripheral interface SPI0 and the corresponding chip select signals CS1 to CS5. Each ultra-wideband wireless transceiver module is configured to operate on a different communication channel, thereby realizing frequency division multiplexing at the physical layer. The main control processor assigns all participating UWB electronic tags to different channel groups according to their numbers. For example, tags numbered one to three are assigned to the first channel, and the first ultra-wideband wireless transceiver module is responsible for ranging. During the polling process, the base station first initiates a ranging request to tag 1. If tag 1 is within the coverage area, the round-trip time is obtained through a bilateral bidirectional ranging method. If tag 1 does not respond due to excessive distance, the base station immediately switches to polling tag 2 after waiting for a preset timeout period. This parallel processing mechanism shortens the sampling period of a single tag to less than four milliseconds, providing high-density raw data support for subsequent high-precision line fitting.

[0026] Next, step S3, intelligent power consumption management and data feedback for the UWB electronic tag, is executed. Please refer to... Figure 7 and Figure 8 , Figure 7 This is a block diagram of the hardware circuit principle of the UWB electronic tag provided in the embodiment of the present invention; Figure 8 This is a flowchart illustrating the intelligent wake-up and operational logic of a UWB electronic tag provided in this embodiment of the invention. The core of the UWB electronic tag consists of a tag master controller and an ultra-wideband transceiver module. The tag master controller integrates a low-power Bluetooth unit, configured to be in deep sleep mode during non-competition periods, at which time the static current is only four microamps. The tag also integrates a three-axis accelerometer. When the accelerometer detects that an athlete has begun vigorous warm-up or starting a run, it triggers the interrupt pin of the tag master controller, causing the system to enter a pre-operation state. When the tag receives a Bluetooth broadcast command from the base station, the tag master controller powers on the ultra-wideband module and completes register initialization, then begins responding to the base station's ranging pulses. After ranging is completed, the UWB electronic tag encapsulates its battery level, movement status, and Received Signal Strength Indication (RSSI) in a feedback data packet and sends it to the base station via the low-power Bluetooth channel. The base station then combines this auxiliary information with the ranging value for processing.

[0027] As the athlete approaches the finish line, step S4, the finish line determination and timestamp fitting calculation, is performed. Please refer to... Figure 4 , Figure 4 This is a schematic diagram of the high-precision linear fitting algorithm for the finish line crossing provided in this embodiment of the invention, as shown below. Figure 4 As shown, the distance between UWB base station 1 and base station 2 is d. sta At time t1, the distances from UWB electronic tag 3 to the first base station 1 and the second base station 2 were measured to be d1 and d1, respectively. t1、 d2t1， The normal distance to the finish line is D t1 The distances measured at time t2 are d1 and d2, respectively. t2、 d2 t2， The normal distance is D t2 The system monitors in real time the distance d1 from the UWB electronic tag to the first base station and the distance d2 to the second base station. The sum of the distances D, calculated by the main control processor, can be obtained from the formula:

[0028] According to geometric principles, when D reaches its minimum value, the UWB electronic tag is closest to the finish line on the geometric plane. To achieve timing accuracy beyond the sampling frequency limit, the main control processor executes a linear fitting algorithm. At time t1, the system measures the sum of distances as D1 and calculates the normal displacement D of the tag relative to the finish line. t1 At time t2, the sum of the measured distances is D2, and the normal displacement D is calculated. t2 According to the formula, combined with the base station spacing d sta D can be accurately calculated using trigonometric relationships. t1 and D t2：

[0029] Let t be the time interval from time t1 to time t2. 2-1 The distance the label traveled was D. t2-t1 From the formula, we can obtain:

[0030] Since the interval between t1 and t2 is extremely short, it can be approximated that the athlete is moving at a constant speed. Therefore, the exact moment t when the displacement is zero can be calculated by linear interpolation using the formula. Finish：

[0031] This algorithm achieves a line crossing time determination accuracy of 0.1ms by performing a weighted average fitting of the sampling points before and after the line crossing, effectively eliminating discrete sampling errors.

[0032] Then proceed to step S5: data aggregation and long-distance wireless relay. Please refer to... Figure 10 , Figure 10This is a hardware block diagram of the data aggregation module provided in this embodiment of the invention. The first base station and the second base station send the calculated crossing timestamp, athlete number, and error reference value to the data aggregation module via a long-distance dual-mode communication module (LR1121). The long-distance dual-mode communication module is configured to operate in the 400 MHz frequency band and uses LoRa spread spectrum technology to achieve reliable transmission at the kilometer level, which has significant advantages in large-scale venues such as rowing or marathons. After receiving the data, the data processing main controller inside the data aggregation module forwards the information to the data fusion and interpretation server via an Ethernet interface.

[0033] Finally, perform step S6: image fusion interpretation and result output. Please refer to... Figure 12 , Figure 12 This is a schematic diagram illustrating the definition of a dedicated data frame format for the UWB unit provided in this embodiment of the invention. The data output by the UWB timing unit adopts a specific frame format, including the firing timestamp, athlete number, lane number, finish line crossing timestamp, and error bytes. After receiving this data, the data fusion and interpretation server aligns it with the high frame rate image stream acquired by the finish line camera timing unit. The finish line camera timing unit acquires finish line images at a rate of 10,000 frames per second, with each frame containing a timestamp relative to the starting signal. Based on the finish line crossing timestamp provided by UWB, the interpretation server automatically locates the corresponding image frame and draws an auxiliary interpretation line at the finish line position on the display interface, while simultaneously overlaying and displaying the athlete's identity information.

[0034] For long-distance circuit race scenarios, please refer to Figure 11 , Figure 11 This is a timing diagram of the athlete crossing the finish line logic under a multi-lap race system provided in this embodiment of the invention. The system executes a lap count logic discrimination algorithm. In a 5,000-meter or 10,000-meter race, athletes need to cross the finish line multiple times. The data fusion and interpretation server sets up an independent counter for each athlete's number. When an athlete crosses the finish line area, the system first determines whether the current time relative to the starting time is less than a preset filtering threshold. If it is less than the threshold, it is determined to be an invalid trigger, eliminating interference caused by the starting point being too close to the finish line. During the subsequent laps, the system records the timestamp of each time the athlete crosses the finish line. Only when the number of times the athlete crosses the finish line reaches the total number of laps set for the race, does the system determine the timestamp of the last time the athlete crosses the finish line as the official result and link the finish line camera to capture a close-up image of the athlete crossing the finish line at that moment.

[0035] In this embodiment, the parallel polling algorithm executed by the main control processor also includes a dynamic weight allocation mechanism. When the system determines, based on RSSI intensity, that an athlete is less than ten meters from the finish line, the main control processor automatically increases the polling frequency of the athlete's tag, allocating more communication time slots to the tag about to cross the finish line, thereby ensuring the highest data sampling density at the crucial moment of crossing the line. Simultaneously, the ultra-wideband wireless transceiver module performs channel impulse response analysis, extracting the arrival time of the first path signal and eliminating multipath interference signals generated by reflections from the stadium stands, ensuring ranging stability in complex physical environments.

[0036] Regarding data security, the verification mechanism shown in step S12 is implemented. Each frame of data output by the UWB unit includes a data length field and a checksum field. After receiving the data, the data fusion and interpretation server performs cyclic redundancy check. If the data packet is found to be damaged during wireless transmission, a retransmission request is initiated to the base station through the long-distance dual-mode communication module. This closed-loop confirmation mechanism ensures the absolute reliability of the competition data and avoids the loss of results due to radio interference.

[0037] This invention achieves a highly cohesive and loosely coupled judgment system through the deep integration of the aforementioned hardware architecture and algorithmic logic. The finish line camera timing unit provides intuitive visual evidence, while the UWB timing unit provides precise identification and time indexing. In extreme cases where athletes overlap and obscure each other, referees do not need to manually search for targets in tens of thousands of images; they can quickly locate the crossing frame simply by referring to the reference lines automatically marked by the UWB system, greatly improving the real-time performance and accuracy of the judgment. Furthermore, each unit of the system works independently and serves as a backup for the others. Even if the camera system causes blurry images due to overexposure of ambient light, the score data packets independently generated by the UWB timing unit can still serve as valid judgment criteria, ensuring the continuity of event timing.

[0038] In terms of hardware implementation, the power management module of the first base station is configured to support dual power supply modes of AC power and built-in lithium battery, and integrates an equalization charging circuit to protect battery life. Optocouplers are used for electrical isolation between the main control processor and various peripheral modules to prevent damage to the core logic circuitry from outdoor lightning or static electricity. The LR1121 module connects to the main control via the SPI1 interface, and its chip select pins CS11 and CS12 are directly driven by the main control's general purpose input / output (GPIO) interface, achieving millisecond-level response to long-distance relay signals. This refined hardware design, combined with advanced linear fitting algorithms, makes this system superior to existing single-vision image judgment schemes in terms of timing accuracy, concurrent processing capability, and environmental adaptability.

[0039] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

[0040] In conclusion, the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. 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. An automatic image interpretation system for endpoint cameras based on UWB ranging, characterized in that, This includes a starting sensor, a finish line camera timing unit, a UWB timing unit, and a data fusion and interpretation server; The starting sensor is used to capture the trigger signal for the start of the race and synchronize the starting timestamp to the finish line camera timing unit and the UWB timing unit; The finish line camera timing unit is deployed to the side of the finish line and configured to acquire a sequence of images of the finish line area; The UWB timing unit includes a first base station, a second base station, and a UWB electronic tag worn by the athlete, all located on the extended lines on both sides of the finish line. The data fusion interpretation server receives the line-crossing timestamp and identity information from the UWB timing unit, and maps the line-crossing timestamp and identity information of the UWB timing unit to the image frame index corresponding to the sequence image, generating a virtual auxiliary interpretation line.

2. The endpoint camera automatic image interpretation system based on UWB ranging according to claim 1, characterized in that, Both the first base station and the second base station integrate a main control processor, a temperature-compensated crystal oscillator, and multiple sets of ultra-wideband wireless transceiver modules. The multiple sets of ultra-wideband wireless transceiver modules are electrically connected to the main control processor through a serial peripheral interface. The multiple sets of ultra-wideband wireless transceiver modules are configured to work in parallel on mutually independent communication frequency bands. The main control processor divides the UWB electronic tags into multiple logical groups according to their numbers based on a polling algorithm. Each logical group corresponds to a specific communication frequency band.

3. The endpoint camera automatic image interpretation system based on UWB ranging according to claim 2, characterized in that, The frequency stability of the temperature-compensated crystal oscillator is ±0.5ppm; the main control processor receives the synchronization pulse from the starting sensor through an internal timer and calibrates the local time axis according to the delay compensation value of the hardware transmission link to ensure that the timestamp of the UWB ranging data is aligned with the timestamp of the image frame of the endpoint camera timing unit under the same time reference.

4. The automatic image interpretation system for endpoint cameras based on UWB ranging according to claim 1, characterized in that, The UWB electronic tag includes a low-power Bluetooth unit and an ultra-wideband unit; the low-power Bluetooth unit receives a wake-up command from the first base station or the second base station and triggers the UWB electronic tag to enter the working state; the static current of the UWB electronic tag in the non-working state is maintained at the microamp level.

5. The endpoint camera automatic image interpretation system based on UWB ranging according to claim 1, characterized in that, The UWB timing unit integrates a long-distance dual-mode communication module; the long-distance dual-mode communication module supports the LoRa protocol and the 2.4GHz frequency band, and improves the anti-interference capability of the signal through spread spectrum technology, realizing cross-regional relay of command signals and the issuance of time synchronization commands; The UWB timing unit is equipped with a line-crossing determination algorithm; the first base station and the second base station respectively perform bilateral bidirectional ranging with the same UWB electronic tag to obtain a first ranging value and a second ranging value; the main control processor calculates the sum D of the distance between the first ranging value and the second ranging value, and triggers the line-crossing logic determination when it determines that the sum D of the distance changes from decreasing to increasing.

6. The endpoint camera automatic image interpretation system based on UWB ranging according to claim 5, characterized in that, The collision determination algorithm uses a linear fitting method to calculate the crossing timestamp; the system selects the time t1 of the sampling point before the sum of the distances reaches its minimum value and the first normal displacement D corresponding to t1. t1 And the first sampling point time t2 after reaching the minimum value and the corresponding second normal displacement D. t2 The system uses a linear interpolation formula to calculate the precise time value t when the normal displacement is zero, based on the time difference and displacement difference between two adjacent sampling points. Finish And use the precise time value as the UWB reference line timestamp.

7. The automatic image interpretation system for endpoint cameras based on UWB ranging according to claim 6, characterized in that, The data fusion interpretation server receives the UWB reference crossing timestamp, athlete identification code, lane information, and distance measurement error reference value from the UWB timing unit. The data fusion interpretation server maps the UWB reference crossing timestamp to the corresponding image frame index in the sequence image according to the timestamp alignment protocol, and overlays and displays the athlete's identification information and lane information at the corresponding position on the image interpretation interface.

8. The automatic image interpretation system for endpoint cameras based on UWB ranging according to claim 1, characterized in that, The data fusion and interpretation server is configured with a lap count logic discrimination program; the lap count logic discrimination program accumulates the number of times each athlete's identification code crosses the finish line, and combines a time window filtering mechanism to exclude invalid trigger signals within a preset time threshold after the start of the race; when the count value reaches the preset total number of laps, the system determines the current finish line timestamp as the final race result, and triggers the automatic capture and saving of the finish line camera image.

9. The endpoint camera automatic image interpretation system based on UWB ranging according to claim 2, characterized in that, The main control processor is also equipped with a dynamic weight allocation mechanism, which determines the distance between the athlete and the finish line based on the received signal strength indication of the UWB electronic tag. When it is determined that an athlete is less than the preset distance threshold from the finish line, the polling frequency of the UWB electronic tag to which the athlete belongs is automatically increased to obtain higher density ranging data. The multiple sets of ultra-wideband wireless transceiver modules are also configured to extract the arrival time of the first path signal by analyzing the channel impulse response curve, and suppress multipath interference caused by reflection from the ground or stands.

10. A method for automatic image interpretation of endpoint cameras based on UWB ranging, applied to the automatic image interpretation system for endpoint cameras based on UWB ranging as described in any one of claims 1 to 9, characterized in that, Includes the following steps: Step S1: The trigger sensor captures the trigger signal and generates a synchronization pulse, which is sent to the endpoint camera timing unit and the UWB timing unit; the UWB timing unit uses a temperature-compensated crystal oscillator and compensates for transmission delay, and is aligned with the time reference of the camera unit; Step S2: Multiple sets of ultra-wideband wireless transceiver modules inside the first and second base stations work in parallel on independent communication frequency bands. The main control processor divides the UWB electronic tags into multiple logical groups according to the polling algorithm. Each group corresponds to a communication frequency band for bilateral bidirectional ranging. Step S3: When not in competition mode, the UWB electronic tag is in deep sleep mode. After receiving the wake-up command from the base station, it enters working mode. After the ranging is completed, it feeds back the battery level, motion status and signal strength via Bluetooth Low Energy. Step S4: The first base station and the second base station perform bilateral bidirectional ranging with the same tag respectively, calculate the sum of distances D, and trigger the line crossing judgment when D changes from decreasing to increasing; Select the time and normal displacement of the adjacent sampling points before and after the minimum value of D, and use linear interpolation to calculate the precise time when the normal displacement is zero, which is used as the UWB reference crossing timestamp; Step S5: The base station sends the crossing timestamp, athlete identification, lane number, and error reference value to the data aggregation module through the long-distance dual-mode communication module, and then forwards them to the data fusion and interpretation server via Ethernet; Step S6: The data fusion interpretation server maps the UWB reference line timestamp to the corresponding image frame index, overlays and displays the athlete's identity information and lane information on the interpretation interface, and generates a virtual auxiliary interpretation line.

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