Three-point global intelligent swimming training automatic timing system adopting short-distance high-precision double sensors to assist long-distance wireless distance measurement

Abstract

The invention discloses a three-point global intelligent swimming training automatic timing system adopting short-distance high-precision double sensors to assist long-distance wireless distance measurement, and belongs to the technical field of intelligent exercise training equipment. The system comprises an athlete end intelligent wearing module and a coach end control processing unit, and is free of a base station, a beacon and a GPS, and the coach end can be flexibly deployed. According to the invention, a triple calibration system is adopted to automatically complete coordinate calibration of the endpoint and the midpoint of the swimming pool; the athlete end integrates underwater ultrasonic wave and millimeter wave radar double sensors, and is matched with medium self-adaption, attitude fusion and fault-tolerant algorithms to adapt to a water-air alternating scene. The system is provided with an intelligent control area, pre-start and pre-stop integrated control, false triggering prevention and accurate meter stop are realized, and two ranging modes of BLE 5.3 and UWB are supported. The system is high in timing precision, simple and convenient to deploy and stable in endurance, can adapt to swimming pools of multiple specifications, supports concurrent training of multiple athletes, and meets the precise training requirements of professional swimming teams of all levels.

Description

Technical Field

[0001] This invention belongs to the field of intelligent sports training equipment technology, specifically a three-point full-domain intelligent swimming training automatic timing system that uses short-range high-precision dual sensors to assist long-range wireless ranging. Background Technology

[0002] In the field of professional swimming training, automatic timing and positioning equipment is core equipment for improving training efficiency and ensuring timing accuracy. Currently, the mainstream automatic timing and positioning technologies for swimming training in the industry are mainly divided into two categories: motion parameter estimation schemes based on inertial sensors, and positioning schemes based on wireless base stations / beacons.

[0003] The first type of solution uses inertial sensors as its core, collecting head or torso movement data from athletes through components such as accelerometers and gyroscopes, and combining this data with algorithms to calculate swimming distance, number of laps, and turning movements. This type of equipment does not require additional hardware deployed around the pool, offering the advantage of flexible deployment. However, due to the cumulative error of inertial sensors, and factors such as swimming posture and water flow interference further affecting the calculation accuracy, the segmented timing results of this type of equipment in long-distance or long-duration training deviate from the actual situation, making it difficult to meet the requirements of professional training for accurate timing of standardized distances.

[0004] The second type of solution employs wireless ranging technology, deploying multiple base stations or beacons along the pool edge as positioning anchor points. The relative position of the athlete is calculated using signal arrival time or angle. Compared to inertial sensor solutions, the positioning results are more intuitive and less affected by motion posture. However, this type of solution requires the pre-deployment of a large number of anchor point modules at the training site, a time-consuming process. Furthermore, the fixed anchor point positions are difficult to adapt flexibly to different pool sizes (such as 25-meter, 50-meter, or non-standard pools), limiting the equipment's site versatility. In addition, both inertial sensor and wireless base station solutions rely heavily on the continuous changes in wireless signals or abrupt changes in motion parameters to indirectly estimate the athlete's arrival time at the edge, lacking direct measurement of the pool wall as a key reference point. This can easily lead to delays or inaccuracies in judgment during the athlete's head-first sprint, when the signal is easily attenuated.

[0005] In addition, existing equipment has shortcomings in terms of start triggering mechanism and coach end parameter configuration. For example, the equipment has a high false start trigger rate, and there is a start delay for effective starts. The industry has not yet formed a mature anti-false trigger logic that integrates multiple parameters such as displacement, attitude and position. Also, the coach end equipment usually requires manual measurement and input of the pool endpoint coordinates. Manual operation is not only cumbersome, but also prone to introducing measurement errors, affecting the accuracy and efficiency of system initialization. Summary of the Invention

[0006] The purpose of this invention is to provide a three-point, all-area intelligent swimming training automatic timing system that uses short-range, high-precision dual sensors to assist long-range wireless ranging, in order to solve the problems mentioned in the background art.

[0007] To achieve the above objectives, the present invention provides the following technical solution: a three-point full-domain intelligent swimming training automatic timing system using short-range high-precision dual sensors to assist long-range wireless ranging, including an athlete-end intelligent wearable sensing module and a coach-end control and processing unit;

[0008] The system has no base station, no beacon, no GPS, and no need to set up any additional positioning modules at end A and end B of the pool; the coach end control processing unit is the only fixed reference point of the system and can be deployed at any location around the pool.

[0009] The system is equipped with a triple calibration system consisting of "initial setup + dynamic iteration + fixed point backup" to automatically calibrate the spatial coordinates of the pool's A, B, and C ends.

[0010] The athlete-end smart wearable sensing module integrates short-range, high-precision dual sensors, which include an underwater ultrasonic ranging module and a 60GHz millimeter-wave radar module.

[0011] The system incorporates a media-adaptive, attitude fusion calibration algorithm and a sensor failure tolerance mechanism to filter valid ranging data and perform automatic timing under different media and attitudes.

[0012] A further preferred embodiment: The specific execution logic of the triple calibration system is as follows:

[0013] Initial establishment mechanism: After the athlete's first single-course swim, the system acquires the distance change curve through long-distance wireless continuous ranging, extracts the extreme points that satisfy the local extreme value conditions and the fluctuation stability conditions, and automatically calibrates the spatial coordinates of three reference points at the A, B and C ends of the pool through geometric back calculation, with a calibration error ≤ ±0.05 meters;

[0014] Dynamic and iterative calibration mechanism: When the athlete touches the pool wall at the end point, the absolute distance data between the athlete and the pool wall measured by dual sensors is correlated and matched with long-distance wireless ranging data. The reference value of the end point position is dynamically updated through geometric calculations to correct ranging errors caused by environmental changes, slight displacement of the coach's end point, and water ripples.

[0015] Fixed-point backup mechanism: A smart control zone of ≤5 meters is set up around the three benchmark points at the A, B and C ends of the pool. This zone has the functions of both pre-start zone and pre-stop zone. Entering the pre-start zone triggers the timing pre-start and anti-accidental touch verification. Entering the pre-stop zone wakes up the dual sensors to perform high-frequency distance measurement and execute the edge score judgment.

[0016] A further preferred method for determining the extreme points is:

[0017] Let the real-time straight-line distance be a function d(t), and the sampling interval be Δt = 0.01s. When the sampled data simultaneously satisfy:

[0018] (1) Local extremum condition: d(t) 0) ≤d(t0-Δt) and d(t0)≤d(t0+Δt);

[0019] (2) Wave stability condition: |d(t)-d(t0)|≤0.05m, ∀t∈[t0,t0+0.1s];

[0020] If the athlete's swimming motion deviates from the target, the system will automatically remove invalid data from the deviated segment and determine the extreme point based solely on the data from the straight swimming segment.

[0021] Further preferred: The athlete-end smart wearable sensing module is a temporal bone-attached vibration waterproof wearable structure, with a total weight of <40g and IPX8 waterproof capability;

[0022] Its front-end area integrates the aforementioned short-range, high-precision dual sensors. Both sensors are oriented towards the pool wall, physically isolated, and tilted downwards at a fixed angle of 5°–10° to accommodate the natural head-raising posture. The underwater ultrasonic ranging module is packaged in a 40kHz waterproof, miniaturized package with a beam angle ≥ ±20°, a ranging range of 0.01–5 meters, and an accuracy of ±0.02–0.03 meters.

[0023] The 60GHz millimeter-wave radar module has a beam angle of ≥±45°, a ranging range of 0.1~7 meters, and an accuracy of ±0.03 meters.

[0024] The module's outer shell is sealed to the internal components using a combination of ultrasonic welding and waterproof adhesive, and the two sensors are placed inside an independent sealed cavity.

[0025] Further preferred: The athlete-end smart wearable sensing module also includes a low-power main control MCU, a long-distance wireless ranging core module, a high-gain integrated antenna, a six-axis inertial sensor, a high-precision RTC real-time clock module, and an acoustic prompting and one-way voice broadcasting unit;

[0026] The long-range wireless ranging core module is configured as either a BLE 5.3 industrial-grade Bluetooth ranging module or a UWB ultra-wideband ranging module, both of which support continuous distance measurement.

[0027] The high-precision RTC real-time clock module is used to start timing immediately upon detecting a valid start signal.

[0028] A further preferred embodiment: The execution logic of the medium adaptation, attitude fusion calibration algorithm, and sensor failure tolerance mechanism is as follows:

[0029] Medium Adaptive: Real-time evaluation of the signal-to-noise ratio and data fluctuation characteristics of dual sensor signals. Ultrasonic data is selected as valid data in water, millimeter-wave radar data is selected as valid data in air, and the average value of the two data is taken as valid data in water / air transition medium.

[0030] Attitude fusion: Based on the six-axis inertial sensor to monitor the head pitch angle, when the beam of a single sensor deviates from the pool wall, the data weight of the millimeter-wave radar is increased, and when the attitude exceeds the theoretical limit range covered by the beams of the two sensors, it is temporarily switched to long-range wireless ranging data as an auxiliary reference.

[0031] Failure tolerance: When a sensor detects that its data has been invalid for an extended period or that its signal-to-noise ratio has been consistently below a preset threshold, the system automatically switches to another sensor for single-mode operation and issues a maintenance prompt.

[0032] A further preferred embodiment: The collaborative control logic of the intelligent control area is as follows:

[0033] Collaborative wake-up: When the long-distance wireless ranging core module determines that it has entered the ≤5-meter intelligent control zone, the main control MCU synchronously wakes up the dual sensors to measure the absolute distance to the pool wall at an adjustable frequency of 50-100Hz. After leaving the intelligent control zone and the distance exceeds 5.5 meters or after the edge-reaching result is locked, the dual sensors synchronously enter deep sleep mode.

[0034] Anti-false trigger verification (pre-start zone): The high-precision RTC real-time clock module is started to start timing when displacement is detected. If the athlete does not move forward continuously, sway, or retreat back to the pre-start zone within ≤5 meters after leaving the point, the timing is determined to be invalid and reset to zero, based on the change data of no significant increase in distance between the two sensors and the motion state data of angular velocity ≤0.01rad / s and acceleration ≤0.05m / s² of the six-axis inertial sensor.

[0035] Precise stop logic (pre-stop zone): The minimum point when the distance value changes from continuously decreasing to increasing is captured as the candidate stop time T0. Then, the stationary state within the preset time window is verified based on the data from the six-axis inertial sensor. After the verification is successful, T0 is locked as the final stop time and the endpoint coordinates are dynamically calibrated using the wall contact position data.

[0036] Further preferred: The system provides two implementation methods:

[0037] BLE 5.3 Bluetooth ranging version: Long-distance positioning accuracy ±1.5~3 meters, overall timing error <0.3 seconds;

[0038] UWB ultra-wideband ranging version: long-distance positioning accuracy ±0.073~0.125 meters, overall timing error ≤0.1 seconds;

[0039] Both versions only replace the long-range wireless ranging core module and the matching high-gain integrated antenna, sharing the same short-range high-precision dual sensors, hardware architecture and control logic, with edge detection accuracy reaching ±0.02 to 0.03 meters.

[0040] Further preferred: The coach-side control processing unit supports concurrent connections from ≤32 athlete-side devices;

[0041] It includes an industrial-grade main control unit, a wireless communication module, an input / output unit, and a power management unit;

[0042] The wireless communication module is matched one-to-one with the long-distance wireless ranging core module of the athlete's end, which is an industrial-grade BLE 5.3 Bluetooth module or an industrial-grade UWB ultra-wideband gateway module.

[0043] The input / output unit supports manual setting of pool length, visualization of training data, one-way voice broadcast from coach to athlete, and real-time monitoring of swimming status, distance measurement data, and performance data of multiple athletes.

[0044] The power management unit supports dual-mode power supply: built-in rechargeable lithium battery and external 220V AC power supply.

[0045] Further preferred: The system is suitable for training timing in 25-meter and 50-meter standard swimming pools and non-standard length swimming pools. It does not require manual measurement and input of pool endpoint coordinates, and fully relies on the triple calibration system to achieve fully automated endpoint identification, point calibration and training result locking.

[0046] Compared with the prior art, the beneficial effects of the present invention are:

[0047] 1. In this invention, the system constructs a triple calibration system of "initial establishment + dynamic repetition + fixed point backup". On the first swim, the system can automatically calibrate the three points of the pool (A, B, and C midpoints) by back-calculating from the extreme points, with a calibration error of ≤ ±0.05 meters. Subsequently, every time the swimmer touches the wall, the absolute distance to the pool wall measured by the dual sensors will dynamically correct the endpoint coordinates, achieving continuous optimization of accuracy. At the same time, combined with water / air medium adaptive dual-sensor collaborative ranging and the precise stop logic of "nearest point locking + static verification", it effectively solves the problems of blind spots, signal attenuation, and edge judgment deviation of existing equipment. The edge detection accuracy is stable at ±0.02~0.03 meters. The overall timing error of the UWB ultra-wideband ranging version is ≤0.1 seconds, and the overall timing error of the BLE 5.3 Bluetooth ranging version is <0.3 seconds, which is far superior to the timing accuracy of existing equipment and fully meets the precise timing requirements of professional swimming training at different levels, such as campus professional teams, provincial professional teams, and national teams.

[0048] 2. In this invention, the system adopts a minimalist architecture without base stations, beacons, or GPS, consisting only of an athlete-end smart wearable sensing module and a coach-end control and processing unit. No anchor point modules need to be deployed around the pool, nor is any modification to the pool required. The coach-end can be deployed as the sole fixed reference point at any location around the pool. Furthermore, there is no need for manual measurement and input of pool point parameters; the three-point calibration can be completed automatically with just one swim by the athlete. This completely solves the problems of time-consuming deployment, cumbersome manual operation, and susceptibility to human error associated with existing equipment, significantly improving deployment efficiency and ease of operation, and reducing the workload of coaches.

[0049] 3. In this invention, the athlete's end integrates a short-range, high-precision dual sensor consisting of an underwater ultrasonic ranging module and a 60GHz millimeter-wave radar module. Combined with media adaptation, attitude fusion calibration algorithms, and sensor failure tolerance mechanisms, it can automatically identify water, air, and water / air transition media and filter effective ranging data based on signal-to-noise ratio and data fluctuation characteristics. At the same time, it monitors the head pitch angle based on a six-axis inertial sensor and dynamically adjusts the sensor data weights, ensuring ranging effectiveness even if the head posture changes. The collaborative working logic of the dual sensors is perfectly adapted to the swimming scenario where the athlete's head alternates frequently in water / air media, effectively solving the problems of blind spots and signal interruptions in existing single-sensor devices. It is compatible with all swimming strokes such as breaststroke, backstroke, freestyle, and butterfly, achieving accurate ranging across the entire pool area without blind spots.

[0050] 4. In this invention, the system provides two implementation methods: BLE 5.3 Bluetooth ranging and UWB ultra-wideband ranging. Both only replace the long-range wireless ranging core module and the matching high-gain integrated antenna. The short-range high-precision dual sensors and the remaining hardware architecture, control logic, and workflow are completely identical, requiring no additional redesign. The BLE 5.3 Bluetooth ranging version offers a long-range positioning accuracy of ±1.5 to 3 meters, with low hardware cost and easy mass production, meeting the cost-effective training needs of professional teams in schools and general professional teams. The UWB ultra-wideband ranging version offers a long-range positioning accuracy of ±0.073 to 0.125 meters, meeting the extreme precision training needs of provincial professional teams and national teams. This achieves a balance between "cost-effective mass production" and "professional extreme precision," comprehensively covering the differentiated needs of different levels of swimming training.

[0051] 5. In this invention, an intelligent control zone of ≤5 meters is established around three points at the A, B, and C ends of the pool to achieve functional reuse of the pre-start and pre-stop zones. An integrated control logic of collaborative wake-up, anti-false trigger verification, and precise stop meter is designed. The pre-start zone adopts a dual anti-false trigger rule of "displacement trigger + dual sensor distance verification + inertial sensor motion state verification", which effectively reduces the false trigger rate caused by athlete micro-movements, water wave interference, etc., and solves the problems of high false trigger rate and effective start delay of existing equipment. The integrated control rule of pre-start / pre-stop also makes the system logic simpler and the equipment response faster, taking into account both the timeliness and accuracy of triggering.

[0052] 6. In this invention, the coach-side control processing unit supports concurrent connections of ≤32 athlete-side devices and is equipped with a multi-device concurrent polling algorithm, enabling simultaneous training and independent timing for multiple athletes. Each athlete-side module independently collects data and executes control logic without interference. The coach-side can receive and visualize the swimming status, distance measurement data, and performance data of all athletes in real time. After training, detailed data such as the split scores, total scores, and distances to the nearest edge for all athletes can be exported. It supports training effect analysis and archiving, eliminating the need for an independent control unit for each device. This significantly improves the coach's management efficiency for team-wide training and is suitable for the collective training needs of professional swimming teams.

[0053] 7. In this invention, the athlete-end smart wearable sensing module adopts a temporal bone-attached vibration waterproof wearable structure, with a total weight of <40g, eliminating wearing burden and meeting the ergonomic requirements of swimming training; the module has IPX8 underwater waterproof capability, and the wave-transparent material and the shell are double-sealed by ultrasonic welding + waterproof glue. The dual sensors and core hardware are placed in an independent sealed cavity, which is resistant to chlorine corrosion in swimming pools and has high reliability; at the same time, the dual sensors adopt a collaborative low-power mechanism of "wake-up-deep sleep", and the dual sensors go into sleep mode when not in the intelligent control area, reducing power consumption by more than 60%, meeting the battery life requirements of swimming pools for all-day underwater training.

[0054] 8. In this invention, the underwater ultrasonic ranging module and the 60GHz millimeter-wave radar module used in the system are both miniaturized and can be directly integrated into the front end of the athlete's module, sharing the modified polycarbonate wave-transparent area without the need for additional molding; there are no complex optical components or high-cost customized hardware, and the core hardware are all industrial-grade general-purpose components, making the hardware cost controllable, the mass production process simple, and suitable for large-scale promotion; at the same time, the system does not rely on a fixed-size pool and can be adapted to the training timing needs of 25-meter and 50-meter standard pools as well as non-standard length pools, without the need to adjust the hardware architecture, and can be adapted simply by setting the pool length on the coach's end, making it extremely versatile for different venues.

[0055] 9. In this invention, the system relies on a dynamic and iterative calibration mechanism, using the athlete's endpoint contact with the pool wall as the calibration trigger node. The absolute distance to the pool wall measured by dual sensors is used to continuously correct the endpoint reference value of long-distance wireless ranging. This can effectively resist interference from external factors such as environmental changes, water fluctuations, and slight displacement of the coach's end, achieving continuous optimization of accuracy. The ranging and timing accuracy of the equipment does not decay over long-term use, solving the problem of existing equipment being susceptible to external interference and accuracy degradation over long-term use, and ensuring the long-term working stability of the equipment.

[0056] 10. In this invention, the athlete end adopts a temporal bone-attached vibration waterproof wearable structure, which is different from the traditional ear-attached design that presses against the auricle and transmits sound through the air. When worn, it fits the temporal bone area without the pressure of the auricle. Moreover, the bone conduction / vibration sound transmission method transmits sound more clearly and has stronger anti-interference ability in the underwater environment. It perfectly matches the wearing comfort and acoustic prompting needs of swimming training, and avoids the problems of traditional ear-attached structures being easy to fall off and having sound transmission distortion underwater. Attached Figure Description

[0057] Figure 1 This is a block diagram of the overall architecture of a three-point full-domain intelligent swimming training automatic timing system that uses short-range high-precision dual sensors to assist long-range wireless ranging according to the present invention.

[0058] Figure 2 This invention provides the overall architecture and three-point layout diagram of a three-point intelligent swimming training automatic timing system that employs short-range high-precision dual sensors to assist long-range wireless ranging.

[0059] Figure 3 This is a block diagram of the intelligent wearable sensing module of the athlete end of a three-point full-domain intelligent swimming training automatic timing system that uses short-range high-precision dual sensors to assist long-range wireless ranging, according to the present invention.

[0060] Figure 4This is a block diagram of the coach-end control processing unit of a three-point full-domain intelligent swimming training automatic timing system that uses short-range high-precision dual sensors to assist long-range wireless ranging according to the present invention.

[0061] Figure 5 This is a flowchart illustrating the core working logic of a three-point, all-domain intelligent swimming training automatic timing system that employs short-range, high-precision dual-sensor-assisted long-range wireless ranging, according to the present invention. Detailed Implementation

[0062] 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.

[0063] Example 1

[0064] Please see Figure 1 - Figure 5 As shown, this embodiment is a three-point omnidirectional intelligent swimming training automatic timing system with a 50-meter standard swimming pool, a 50-meter training plan, and UWB ultra-wideband distance measurement. The specific implementation steps are as follows:

[0065] S1. System Deployment and Initialization: Deploy the coach-end control processing unit at any location around the 50-meter pool. Select either the built-in rechargeable lithium battery power supply or the external 220V AC power supply mode to complete the power-on. The system enters self-test mode to check whether the industrial-grade main control unit, wireless communication module, input / output unit, and power management unit are normal. After the self-test is completed, the coach manually sets "pool length = 50 meters" through the input / output unit of the control processing unit. The system completes initialization and enters the calibration state. At the same time, the wireless communication module is turned on, waiting to establish a pairing connection with the athlete-end smart wearable sensing module.

[0066] S2. Three-Point Automatic Calibration: After completing a waterproof check, the athlete enters the water wearing a smart wearable sensing module with a temporal bone-attached vibration waterproof structure. The module wirelessly pairs with the coach's device via acoustic prompts and a one-way voice broadcast unit, then completes a uniform one-way swim from end A to end B of the pool. During the swim, the module's UWB ultra-wideband ranging module maintains continuous wireless ranging with the coach's control and processing unit, uploading real-time straight-line distance data between the module and the coach's device at an adjustable 100Hz frequency. The coach's device receives and analyzes the continuous ranging data, generating a distance change curve between the module and the coach's device, and extracting extreme points that satisfy both local extremum and fluctuation stability conditions. Based on the distance data from these extreme points, combined with the preset 50-meter pool length parameter, the spatial coordinates of the midpoints of ends A, B, and C are automatically calculated using the Pythagorean theorem for right triangles, and permanently saved as initial reference values. The calibration error is ≤ ±0.05 meters.

[0067] S3. Pre-start Zone Triggering and Valid Start Judgment: After completing calibration, the athlete returns to the pre-start zone ≤ 5 meters from point A and remains stationary. The system detects a stationary signal (angular velocity ≤ 0.01 rad / s, acceleration ≤ 0.05 m / s²) via a six-axis inertial sensor and enters standby mode. Upon the athlete's starting motion, the UWB ultra-wideband ranging module detects the displacement in real time and immediately activates the high-precision RTC real-time clock module to begin timing. Simultaneously, the main control MCU wakes up the underwater ultrasonic ranging module and the 60 GHz millimeter-wave radar module. The dual sensors begin measuring the distance at an adjustable frequency of 75 Hz. The system measures the absolute distance to the pool wall and uploads the data in real time. The main control MCU uses a media adaptive algorithm to filter valid ultrasonic data. If the data shows that the distance to the pool wall is continuously increasing and the athlete has not returned to the pre-start area, the system determines it as a valid start and the timing continues. If the athlete moves in place or retreats within 5 meters of leaving end A, and the ultrasonic data shows that the distance has not increased significantly or has even decreased, the system, combined with the inertial sensor data, determines it as an invalid start, immediately resets the timing and returns to standby mode, and both sensors simultaneously enter deep sleep mode. The coach can issue start prompts to the athlete via one-way voice broadcast.

[0068] S4. Midpoint Pre-Stop Zone Segment Recording: As the athlete swims from point A to point B, the system acquires the athlete's position in real time via the UWB ultra-wideband ranging module. When the system determines that the athlete has entered the pre-stop zone ≤ 5 meters from the midpoint C, it immediately triggers a pre-pause state. Based solely on the position data continuously uploaded by the UWB ultra-wideband ranging module, combined with the coordinates of the three points obtained from the initial calibration, the system automatically records the moment the athlete passes through the midpoint C, generating a 25-meter segmented score, which is temporarily stored within the module. Since the athlete does not stop at the midpoint and continues swimming towards point B, the system does not execute the final stop operation, and the high-precision RTC real-time clock module continues timing. When the athlete leaves the pre-stop zone at the midpoint C by more than 5.5 meters, the system resumes normal swimming monitoring.

[0069] S5. Precise Edge Stop and Stop Timer in Endpoint Pre-Stop Zone: As the athlete swims towards End B, when the system determines through the UWB ultra-wideband ranging module that they have entered the ≤5-meter pre-stop zone at End B, it immediately triggers a pre-stop state. The main control MCU simultaneously wakes up the dual sensors and begins continuously collecting absolute distance data to the pool wall at an adjustable frequency of 75Hz. The system analyzes the distance data stream uploaded by the dual sensors in real time, establishes a distance-time curve, and when it detects that the distance value changes from continuously decreasing to increasing, it marks the time corresponding to the minimum value point as the candidate stop timer time T0 and caches the minimum distance value as the touch-the-wall position data. Subsequently, within a preset time window, the six-axis inertial sensor continuously collects and analyzes the motion. If the athlete's acceleration and angular velocity data are collected, and a stationary state is detected, T0 is confirmed as a valid stop time. The high-precision RTC real-time clock module is immediately stopped, and the 50-meter training total score is locked. At the same time, the 25-meter split scores, the 50-meter total score, and the touch-the-wall position data are uploaded to the coach's control processing unit. Using the absolute distance to the pool wall confirmed by the dual sensors at the moment of touch, combined with the distance data between the module and the coach's end measured by the UWB ultra-wideband ranging module at this time, the position reference value of the B end is dynamically updated through geometric calculations. After the score is locked and the data is uploaded, the dual sensors automatically enter deep sleep mode. The coach can send score prompts to the athlete through one-way voice broadcast.

[0070] Example 2

[0071] Please see Figure 1 - Figure 5 As shown, this embodiment is a three-point omnidirectional intelligent swimming training automatic timing system with a 25-meter standard swimming pool, a 25-meter training plan, and a BLE 5.3 Bluetooth ranging version. Its implementation steps are basically the same as those in Embodiment 1, with the only difference being:

[0072] S1. During system initialization, the coach manually sets "pool length = 25 meters" through the input / output unit of the coach terminal control processing unit;

[0073] S2. The athlete swims from end A / B toward the midpoint C. After entering the ≤5-meter pre-stopping zone at the midpoint C and coming to a stop, the system locks the total score of 25 meters through dual-sensor distance measurement. If there is a pool wall at the midpoint C, the ultrasonic distance measurement module directly measures the absolute distance to the pool wall. If there is no pool wall at the midpoint C, the calibrated coordinates of the midpoint C are used as a reference, and the score is locked by combining the data from the dual sensors.

[0074] S3. The core module for long-distance wireless ranging is a BLE 5.3 industrial-grade Bluetooth ranging module, with a long-distance positioning accuracy of ±1.5 to 3 meters and a timing error of <0.3 seconds.

[0075] S4. The coach terminal can be independently powered by a built-in rechargeable lithium battery, making it suitable for temporary training scenarios without an external power source.

[0076] Example 3

[0077] Please see Figure 1 - Figure 5 As shown, this embodiment is a three-point full-area intelligent swimming training automatic timing system with a 50-meter standard pool, a 100-meter training plan, and UWB ultra-wideband distance measurement. The implementation steps are based on embodiment 1, with the addition of a process where the athlete turns and swims towards end A from end B: After the athlete touches the wall and locks their score at end B, they turn and swim towards end A, repeating the process of "pre-start zone triggering and valid start determination - midpoint pre-stop zone segment recording - end point pre-stop zone precise edge arrival and stop timing". When swimming to the midpoint C, the 75-meter segment score is recorded. After swimming to end A and touching the wall and coming to a stop, the 100-meter total score is locked. At the same time, the absolute distance to the pool wall measured by dual sensors is used to correct the reference value of the position at end A. Throughout the process, the coach can issue turning prompts, sprint instructions, etc. in real time through one-way voice broadcast.

[0078] Example 4

[0079] Please see Figure 1 - Figure 5 As shown, this embodiment is a multi-athlete batch training scenario, employing a three-point full-domain intelligent swimming training automatic timing system with a 50-meter standard swimming pool, a 50-meter training plan, and UWB ultra-wideband distance measurement. The specific implementation steps are as follows:

[0080] S1. Multiple athletes wear smart wearable sensing modules with temporal bone-attached vibration waterproof wearable structure. After completing the waterproof check, they go into the water and wirelessly pair with the coach's control and processing unit. The coach selects an external 220V AC power supply mode to ensure continuous battery life when multiple devices are connected concurrently.

[0081] S2. After the coach-end control processing unit completes a three-point automatic calibration, all athletes start training simultaneously. Each athlete's smart wearable sensing module independently collects UWB ultra-wideband ranging data, dual-sensor ranging data, and inertial sensor data, independently executes pre-start / pre-stop control logic, and independently records segment / total scores without interfering with each other.

[0082] S3. The coach-side control and processing unit receives all athletes' swimming status, distance measurement data, and performance data in real time, and displays them visually in the input and output unit; the coach can issue training instructions to one or more athletes through one-way voice broadcast;

[0083] S4. After training, the coach-side control and processing unit exports detailed data of all athletes, including split scores, total scores, distance to the nearest edge, and valid start records, supporting training effect analysis and archiving.

[0084] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A three-point, all-area intelligent swimming training automatic timing system employing short-range, high-precision dual-sensor assisted long-range wireless ranging, characterized in that: This includes a smart wearable sensing module for athletes and a control and processing unit for coaches. The system has no base station, no beacon, no GPS, and no need to set up any additional positioning modules at end A and end B of the pool; the coach end control processing unit is the only fixed reference point of the system and can be deployed at any location around the pool. The system is equipped with a triple calibration system consisting of "initial setup + dynamic iteration + fixed point backup" to automatically calibrate the spatial coordinates of the pool's A, B, and C ends. The athlete-end smart wearable sensing module integrates short-range, high-precision dual sensors, including an underwater ultrasonic ranging module and a 60GHz millimeter-wave radar module. The system incorporates a media-adaptive, attitude fusion calibration algorithm and a sensor failure tolerance mechanism to filter valid ranging data and perform automatic timing under different media and attitudes.

2. The three-point, all-area intelligent swimming training automatic timing system according to claim 1, employing short-range, high-precision dual-sensor assisted long-range wireless ranging, is characterized in that... The specific execution logic of the triple calibration system is as follows: Initial establishment mechanism: After the athlete's first single-course swim, the system acquires the distance change curve through long-distance wireless continuous ranging, extracts the extreme points that satisfy the local extreme value conditions and the fluctuation stability conditions, and automatically calibrates the spatial coordinates of three reference points at the A, B and C ends of the pool through geometric back calculation, with a calibration error ≤ ±0.05 meters; Dynamic and iterative calibration mechanism: When the athlete touches the pool wall at the end point, the absolute distance data between the athlete and the pool wall measured by dual sensors is correlated and matched with long-distance wireless ranging data. The reference value of the end point position is dynamically updated through geometric calculations to correct ranging errors caused by environmental changes, slight displacement of the coach's end point, and water ripples. Fixed-point backup mechanism: A smart control zone of ≤5 meters is set up around the three benchmark points at the A, B and C ends of the pool. This zone has the functions of both pre-start zone and pre-stop zone. Entering the pre-start zone triggers the timing pre-start and anti-accidental touch verification. Entering the pre-stop zone wakes up the dual sensors to perform high-frequency distance measurement and execute the edge score judgment.

3. The three-point, all-area intelligent swimming training automatic timing system according to claim 2, employing short-range, high-precision dual-sensor assisted long-range wireless ranging, is characterized in that... The method for determining the extreme points is as follows: Let the real-time straight-line distance be a function d(t), and the sampling interval be Δt = 0.01s. When the sampled data simultaneously satisfy: (1) Local extremum condition: d(t0)≤d(t0-Δt) and d(t0)≤d(t0+Δt); (2) Wave stability condition: |d(t)-d(t0)|≤0.05m, ∀t∈[t0,t0+0.1s]; If the athlete's swimming motion deviates from the target, the system will automatically remove invalid data from the deviated segment and determine the extreme point based solely on the data from the straight swimming segment.

4. The three-point, all-area intelligent swimming training automatic timing system according to claim 1, characterized in that, The athlete-end smart wearable sensing module is a temporal bone-attached vibration waterproof wearable structure with a total weight of <40g and IPX8 waterproof capability. Its front-end area integrates the aforementioned short-range, high-precision dual sensors. The ranging directions of both sensors are both facing the pool wall, physically isolated, and use a fixed downward tilt angle of 5° to 10° to adapt to the natural head-raising posture. The underwater ultrasonic ranging module adopts a 40KHz waterproof miniaturized package, with a beam angle ≥ ±20°, a ranging range of 0.01 to 5 meters, and an accuracy of ±0.02 to 0.03 meters. The 60GHz millimeter-wave radar module has a beam angle of ≥±45°, a ranging range of 0.1~7 meters, and an accuracy of ±0.03 meters. The module's outer shell is sealed to the internal components using a combination of ultrasonic welding and waterproof adhesive, and the two sensors are placed inside an independent sealed cavity.

5. The three-point, all-area intelligent swimming training automatic timing system according to claim 1, characterized in that, The athlete-end smart wearable sensing module also includes a low-power main control MCU, a long-distance wireless ranging core module, a high-gain integrated antenna, a six-axis inertial sensor, a high-precision RTC real-time clock module, and an acoustic prompting and one-way voice broadcasting unit. The long-range wireless ranging core module is configured as either a BLE 5.3 industrial-grade Bluetooth ranging module or a UWB ultra-wideband ranging module, both of which support continuous distance measurement. The high-precision RTC real-time clock module is used to start timing immediately upon detecting a valid start signal.

6. The three-point, all-area intelligent swimming training automatic timing system according to claim 1, employing short-range, high-precision dual-sensor assisted long-range wireless ranging, is characterized in that... The execution logic of the medium adaptive, attitude fusion calibration algorithm and sensor failure tolerance mechanism is as follows: Medium Adaptive: Real-time evaluation of the signal-to-noise ratio and data fluctuation characteristics of dual sensor signals. Ultrasonic data is selected as valid data in water, millimeter-wave radar data is selected as valid data in air, and the average value of the two data is taken as valid data in water / air transition medium. Attitude fusion: Based on the six-axis inertial sensor to monitor the head pitch angle, when the beam of a single sensor deviates from the pool wall, the data weight of the millimeter-wave radar is increased, and when the attitude exceeds the theoretical limit range covered by the beams of the two sensors, it is temporarily switched to long-range wireless ranging data as an auxiliary reference. Failure tolerance: When a sensor detects that its data has been invalid for an extended period or that its signal-to-noise ratio has been consistently below a preset threshold, the system automatically switches to single-mode operation of another sensor and issues a maintenance prompt.

7. A three-point, all-area intelligent swimming training automatic timing system using short-range, high-precision dual-sensor assisted long-range wireless ranging as described in claim 2, characterized in that, The collaborative control logic of the intelligent control zone is as follows: Collaborative wake-up: When the long-distance wireless ranging core module determines that it has entered the ≤5-meter intelligent control zone, the main control MCU synchronously wakes up the dual sensors to measure the absolute distance to the pool wall at an adjustable frequency of 50-100Hz. After leaving the intelligent control zone and the distance exceeds 5.5 meters or after the edge-reaching result is locked, the dual sensors synchronously enter deep sleep mode. Anti-false trigger verification (pre-start zone): The high-precision RTC real-time clock module is started to start timing when displacement is detected. If the athlete does not move forward continuously, sway, or retreat back to the pre-start zone within ≤5 meters after leaving the point, the timing is determined to be invalid and reset to zero, based on the change data of no significant increase in distance between the two sensors and the motion state data of angular velocity ≤0.01rad / s and acceleration ≤0.05m / s² of the six-axis inertial sensor. Precise stop logic (pre-stop zone): The minimum point when the distance value changes from continuously decreasing to increasing is captured as the candidate stop time T0. Then, the stationary state within the preset time window is verified based on the data from the six-axis inertial sensor. After the verification is successful, T0 is locked as the final stop time and the endpoint coordinates are dynamically calibrated using the wall contact position data.

8. A three-point, all-area intelligent swimming training automatic timing system using short-range, high-precision dual-sensor assisted long-range wireless ranging as described in claim 5, characterized in that, The system provides two implementation methods: BLE 5.3 Bluetooth ranging version: Long-distance positioning accuracy ±1.5~3 meters, overall timing error <0.3 seconds; UWB ultra-wideband ranging version: long-distance positioning accuracy ±0.073~0.125 meters, overall timing error ≤0.1 seconds; Both versions only replace the long-range wireless ranging core module and the matching high-gain integrated antenna, sharing the same short-range high-precision dual sensors, hardware architecture and control logic, with edge detection accuracy reaching ±0.02 to 0.03 meters.

9. A three-point, all-area intelligent swimming training automatic timing system using short-range, high-precision dual-sensor assisted long-range wireless ranging as described in claim 1, characterized in that, The coach-side control and processing unit supports concurrent connections from ≤32 athlete-side devices; It includes an industrial-grade main control unit, a wireless communication module, an input / output unit, and a power management unit; The wireless communication module is matched one-to-one with the long-distance wireless ranging core module of the athlete's end, which is an industrial-grade BLE5.3 Bluetooth module or an industrial-grade UWB ultra-wideband gateway module. The input / output unit supports manual setting of pool length, visualization of training data, one-way voice broadcast from coach to athlete, and real-time monitoring of swimming status, distance measurement data, and performance data of multiple athletes. The power management unit supports dual modes: built-in rechargeable lithium battery power supply and external 220V AC power supply.

10. A three-point, all-area intelligent swimming training automatic timing system employing short-range, high-precision dual-sensor assisted long-range wireless ranging, as described in any one of claims 1 to 9, characterized in that, The system is suitable for training time in 25-meter and 50-meter standard swimming pools as well as non-standard length pools. It eliminates the need for manual measurement and input of pool endpoint coordinates, relying entirely on the triple calibration system to achieve fully automated endpoint identification, point calibration, and training result locking.

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