Intelligent lower limb training device for physical fitness detection and detection method thereof

Abstract

The invention discloses an intelligent lower limb training device for physical fitness detection and a detection method thereof, and relates to the technical field of physical fitness detection equipment.The intelligent lower limb training device comprises a lower limb training device body, the lower limb training device body comprises a base, a sliding limiting supporting seat is installed in the base, and a treadmill is installed in the supporting seat; the inclination angle of the treadmill is set through the inclination angle adjusting seat; the sensing detection system comprises a physiological parameter sensor and a motion parameter sensor; the intelligent control and processing system takes an embedded processor as a core, integrates a data acquisition module, a data storage module, a wireless communication module and a display driving module, and is internally provided with a self-adaptive damping adjustment algorithm, a physical ability evaluation algorithm based on a treadmill inclination angle and a motion posture analysis algorithm. The problem that a physical fitness detection lower limb training device cannot simulate the training states of a user at different inclination angles is solved.

Description

Technical Field

[0001] This invention relates to the field of physical fitness testing equipment technology, specifically to an intelligent lower limb training device for physical fitness testing and its testing method. Background Technology

[0002] A lower limb fitness testing device is a device that combines lower limb motor function with fitness testing function. It is usually equipped with heart rate monitoring, speed adjustment, and incline adjustment devices. When users perform exercises such as walking and running on the lower limb training device, the device can collect data such as exercise duration, distance, speed, heart rate, and calories burned in real time. Some high-end devices can also combine functions such as exercise posture analysis to comprehensively evaluate the user's cardiopulmonary function, endurance, exercise ability and other fitness indicators, providing a scientific basis for fitness guidance, health management or fitness testing.

[0003] However, existing physical fitness testing devices for lower limb training can only simulate the movement state when walking and running on flat ground, and their functions are relatively simple. They cannot simulate the training state of users at different inclination angles, so they are inaccurate in assessing cardiopulmonary function, lower limb strength, balance ability and fatigue state, and therefore do not meet the current needs. In response, we propose an intelligent lower limb training device for physical fitness testing and its testing method. Summary of the Invention

[0004] The purpose of this invention is to provide an intelligent lower limb training device and its testing method for physical fitness testing, so as to solve the problem mentioned in the background art that the lower limb training device for physical fitness testing cannot simulate the user's training state under different tilt angles.

[0005] To achieve the above objectives, the present invention provides the following technical solution: an intelligent lower limb training device for physical fitness testing, comprising a lower limb training device body, a damping and shock absorption component, a sensing and detection system, and an intelligent control and processing system;

[0006] The lower limb training device includes a base, inside which a sliding limit support seat is installed. Damping and shock absorption components are respectively arranged at the four corners between the base and the support seat. A running platform is installed inside the support seat. An inclination adjustment seat is installed on the inner side of the support seat and at the rear end of the running platform. The inclination angle of the running platform is set by the inclination adjustment seat. An auxiliary support mechanism is provided below the front end of the running platform. Brackets are fixedly installed on both sides of the front end of the base. A central control panel with a display panel is installed on the top of the brackets. Handrails are installed on both sides of the rear end of the central control panel.

[0007] The sensing and detection system includes physiological parameter sensors and motion parameter sensors. The physiological parameter sensors include a respiratory monitoring module and a heart rate monitoring module using millimeter-wave radar technology, and the respiratory monitoring module is mounted above the display panel via a mounting bracket. The motion parameter sensors include a high-precision encoder, a triaxial accelerometer, an inertial measurement unit, and a tilt angle sensor.

[0008] The intelligent control and processing system is based on an embedded processor and integrates a data acquisition module, a data storage module, a wireless communication module, and a display driver module. The system has built-in adaptive damping adjustment algorithm, physical fitness assessment algorithm based on treadmill tilt angle, and motion posture analysis algorithm.

[0009] Preferably, the running platform includes a frame, with triaxial accelerometers installed in the grooves on both sides of the upper surface of the frame. The two sides of the rear end of the frame are connected to the tilt adjustment seat via a rotating shaft, and a tilt angle sensor is installed on the rotating shaft. A transmission roller is rotatably mounted inside the frame, and a running belt is installed on the outside of the two transmission rollers. Two plates are welded and fixed inside the frame, one at the top and one at the bottom. The upper plate is the running board, used to bear the force generated by the user running, and the lower plate is the motor mounting plate, with a running belt motor installed on its upper end. A high-precision encoder is installed on the output shaft of the running belt motor. Pulleys are installed at the middle position of the front transmission roller and on the output shaft of the running belt motor, and the pulleys are connected by belt drive.

[0010] Preferably, each tilt adjustment seat has a worm gear rotatably mounted inside, and the shaft at one end of the worm gear is fixed to the rotating shaft at the rear end of the frame via a coupling. A transmission shaft rotatably connected to the tilt adjustment seat is mounted at the front end of the worm gear. A worm is mounted on the transmission shaft at the position corresponding to the worm gear, and the worm is threadedly connected to the worm gear. A drive shaft is provided at the rear end below the running platform, with both ends of the drive shaft extending into the interior of the tilt adjustment seat and connected to the tilt adjustment seat via bearings. One end of the drive shaft located inside the tilt adjustment seat is engaged with the bottom of the transmission shaft via a helical gear transmission. A driven gear is mounted at the middle position of the drive shaft. A tilt adjustment motor fixed to the base plate of the support seat is provided on one side of the rear end of the driven gear. A drive gear meshing with the driven gear is mounted on the output shaft of the tilt adjustment motor.

[0011] Preferably, the auxiliary support mechanism includes a limiting groove built into the front end of the frame, and the limiting groove has an inclined structure. A telescopic plate is slidably installed inside the limiting groove, and the bottom of the telescopic plate extends to the bottom of the frame. A servo motor is fixedly installed above the limiting groove. A stud is installed on the output shaft of the servo motor. The stud extends into the interior of the telescopic plate, and the external thread of the stud is threaded with the internal thread of the telescopic plate. A support plate is installed below the telescopic plate. The support plate and the telescopic plate are connected by a rotating shaft, and a pressure sensor is installed at the bottom of the support plate.

[0012] Preferably, the damping shock absorption assembly consists of a spring, a hydraulic shock absorber, a pressure sensor, a damping adjustment motor, and a controller. The pressure sensor monitors the pressure on the hydraulic shock absorber in real time. The damping adjustment motor changes the damping magnitude by adjusting the hydraulic oil flow orifice. The controller receives and processes the pressure data and controls the damping adjustment motor to adaptively adjust the shock absorption damping.

[0013] Preferably, the adaptive damping adjustment algorithm includes:

[0014] Data input and preprocessing: Input user weight, real-time running intensity, and real-time pressure fluctuation data of the shock absorption system;

[0015] Damping adjustment logic: A fuzzy PID control algorithm is adopted, taking the difference between the current damping and the ideal damping and the error change rate as input, and optimizing the K of the PID controller according to preset fuzzy rules. p ,K i ,K d Parameters are used to calculate the target damping coefficient and control the damping adjustment motor to adjust the damping of the hydraulic device.

[0016] Data feedback and evaluation: The controller records data such as pressure changes and damping adjustments of the shock absorption system. By analyzing parameters such as pressure peak, pressure curve symmetry, and pressure rise time, and combining these with motion parameters, it evaluates the user's lower limb strength and motor coordination.

[0017] Preferably, the physical fitness assessment algorithm based on the treadmill tilt angle includes:

[0018] Data input and preprocessing: Physiological parameter sensors and motion parameter sensors collect data at a set frequency, and the data from multiple sensors are synchronized in time using a hardware clock stamp;

[0019] Physical fitness assessment model: Calculates exercise load based on the load intensity calculation formula, predicts maximum oxygen uptake using the Balke formula, and assesses cardiopulmonary recovery capacity through heart rate recovery rate; calculates the symmetry of push-off force using data from left and right accelerometers, and assesses lower limb endurance and balance by analyzing gait stability and posture control indicators; constructs a fatigue classifier using a random forest algorithm, taking physiological parameters, exercise parameters, and environmental parameters as inputs, and outputs fatigue level to monitor the user's fatigue status;

[0020] Comprehensive scoring and feedback: Substitute each physical fitness indicator into the weighted comprehensive scoring formula to calculate the physical fitness score.

[0021] Preferably, uprights are welded and fixed to both sides of the base, and a crossbar is welded and fixed between the tops of the uprights. A protective belt retraction device is installed in the middle of the crossbar. The retraction device has a retraction roller with a torsion spring installed inside. A protective belt is wound around the outside of the retraction roller. A protective suit is sewn and fixed to the lower end of the protective belt. An inertial measurement unit and a heart rate monitoring module are respectively installed on both sides of the front end of the protective suit.

[0022] Preferably, the protective belt take-up and release device is equipped with a braking mechanism on both sides. The braking mechanism is provided with an internal toothed ring. A braking block is movably arranged inside the internal toothed ring. Two locking teeth are provided on one side of the outer side of the braking block. A connecting shaft is provided in the irregular inner cavity of the braking block. The connecting shaft is fixed to the shaft at one end of the take-up and release roller. A rotating rod is fixedly installed on one side of the connecting shaft.

[0023] The detection method for a smart lower limb training device for physical fitness testing includes the following steps:

[0024] Step 1, Initial Setup: Enter basic information such as age, gender, height, weight, and health status through the display panel of the lower limb training device. The system will then generate an initial physical fitness assessment model and set initial damping parameters for the shock absorption system.

[0025] Step 2, Exercise Detection Stage: Users select the treadmill tilt angle and exercise mode according to the training content. During the run, the sensor detection system collects physiological parameters, exercise parameters and posture data in real time. The adaptive damping adjustment mechanism automatically adjusts the shock absorption damping according to the user's weight and running intensity. The intelligent control and processing system uses built-in algorithms to analyze and process the collected data and evaluate the user's physical condition in real time.

[0026] Step 3, Results Feedback Stage: The system will provide real-time physical fitness assessment results and shock absorption adjustment status to the user through the display panel, and at the same time upload the test data to the cloud server for storage and management.

[0027] Compared with the prior art, the present invention has the following beneficial effects:

[0028] 1. This invention constructs a comprehensive physical fitness assessment model by integrating treadmill tilt angle, physiological parameters, and exercise parameter data. From cardiopulmonary function assessment through load intensity calculation, maximum oxygen uptake prediction, and heart rate recovery rate assessment, to lower limb endurance and balance assessment using indicators such as push-off force symmetry, cadence stability, and posture control, and finally to fatigue detection, it achieves a multi-dimensional assessment of the user's physical fitness. Compared to single-indicator testing, it can accurately reflect the user's true physical fitness status. Based on the physical fitness score calculated from individual user information and exercise data, the algorithm can generate personalized exercise suggestions and training plans for the user. Users with different fitness levels and exercise goals can receive targeted guidance, helping them to exercise scientifically.

[0029] 2. This invention can dynamically adjust the shock absorption damping in real time based on personalized data such as user weight and running intensity. Traditional fixed-damping shock absorption systems cannot adapt to dynamic changes during exercise, easily causing excessive pressure on joints and potentially leading to joint damage with long-term use. The adaptive damping adjustment mechanism continuously monitors and adjusts to maintain optimal shock absorption, effectively reducing the impact of running on joints, lowering the probability of sports injuries, and providing strong protection for the user's joint health. For heavier users, it can automatically increase damping to provide stronger support; when running at high intensity, it can also adjust the damping in time to effectively buffer the impact on joints during running. Different users can obtain shock absorption effects that suit their individual needs when using the lower limb training device, greatly improving exercise comfort and reducing discomfort caused by mismatched shock absorption.

[0030] 3. This invention incorporates a treadmill tilt adjustment mechanism. By activating the tilt adjustment motor, its output shaft drives the drive gear to rotate, which in turn meshes with the driven gear, causing the drive shaft to rotate. The helical gears at both ends of the drive shaft mesh with the helical gear at the bottom of the transmission shaft, thereby driving the worm gear to rotate. The contact surface between the worm gear and the worm wheel forms a spiral friction transmission surface. The rotation of the worm gear drives the worm wheel to rotate, which in turn drives the rotating shaft on the rear side of the treadmill to rotate, thus adjusting the treadmill tilt angle. Simultaneously, an auxiliary support mechanism is provided at the front end of the treadmill, with a support plate inside... Equipped with a pressure sensor, as the front end of the treadmill tilts up, the pressure at the bottom of the support plate disappears. At this time, the servo motor turns on, driving the stud to rotate. With the engagement of the threaded hole in the telescopic plate, the telescopic plate extends downwards towards the front end of the treadmill until the support plate contacts the base plate of the support seat again. On the one hand, users can freely switch between different inclines according to their own training goals and physical condition, effectively improving the targeting and training effect of the exercise. On the other hand, the auxiliary support mechanism and the treadmill tilt adjustment mechanism work together to provide stable support for the treadmill, preventing the treadmill from shaking or becoming unstable when tilted.

[0031] 4. This invention incorporates a safety protection mechanism, consisting of a protective belt wound around the take-up and release rollers and braking mechanisms located at both ends of the rollers. When the user slowly pulls the protective clothing to put it on, the protective belt gradually releases from the take-up and release rollers. The take-up and release rollers slowly drive the connecting shaft and rotating rod to rotate, which synchronously drives the brake block to move synchronously. At this time, the locking teeth will not engage with the inner toothed ring, making it easy for the user to put on the clothing after adjusting it to the appropriate position. When the user suddenly falls, the user pulls the protective clothing down rapidly, pulling on the connected protective belt and causing the connecting shaft and rotating rod to rotate rapidly. At this time, the brake block cannot keep up with the rotation of the rotating rod in time, causing one end of the rotating rod to compress and guide the irregular inner cavity of the brake block, resulting in the brake block being pushed out to one end. This causes the external locking teeth to engage with the inner toothed ring, and then the brake block locks the main rotating rod, preventing the connecting shaft from rotating. This allows the user wearing the protective clothing to stop quickly and avoid safety accidents caused by falls. Attached Figure Description

[0032] Figure 1 This is an overall perspective view of the present invention;

[0033] Figure 2 This is a perspective view of the lower limb training device of the present invention with the base removed;

[0034] Figure 3 This is a perspective view of the treadmill tilt adjustment mechanism of the present invention;

[0035] Figure 4 This is a perspective view of the treadmill transmission structure of the present invention;

[0036] Figure 5 This is a perspective view of the auxiliary support structure for the treadmill of the present invention;

[0037] Figure 6 This is a schematic diagram of the internal structure of the strap retraction device of the present invention;

[0038] Figure 7 This is a schematic diagram of the braking mechanism of the present invention.

[0039] In the diagram: 1. Base; 2. Support seat; 3. Tilt adjustment seat; 4. Running platform; 5. Bracket; 6. Central control panel; 7. Display panel; 8. Handrail; 9. Respiratory monitoring module; 10. Column; 11. Protective belt retraction device; 12. Protective belt; 13. Protective clothing; 14. Inertial measurement unit; 15. Heart rate monitoring module; 16. Damping and shock absorption assembly; 17. Drive shaft; 18. Tilt adjustment motor; 19. Drive gear; 20. Driven gear 21. Gear; 22. Helical gear; 23. Drive shaft; 24. Worm; 25. Worm wheel; 26. Frame; 27. Drive roller; 28. Running belt; 29. ​​Running belt motor; 30. Belt; 31. Stud; 32. Telescopic plate; 33. Support plate; 34. Servo motor; 35. Take-up and untake-off roller; 36. Braking mechanism; 37. Connecting shaft; 38. Rotating rod; 39. Brake block; 40. Gear; 41. Internal gear ring; 42. Triaxial accelerometer. Detailed Implementation

[0040] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0041] Please see Figure 1-7 The present invention provides an embodiment of an intelligent lower limb training device for physical fitness testing, comprising a lower limb training device body, a damping and shock absorption component 16, a sensing and detection system, and an intelligent control and processing system.

[0042] The lower limb training device includes a base 1, inside which a sliding limit support seat 2 is installed. Damping and shock absorption components are respectively located at the four corners between the base 1 and the support seat 2. A treadmill 4 is installed inside the support seat 2. An inclination adjustment seat 3 is installed on the inner side of the support seat 2 and at the rear end of the treadmill 4, allowing the treadmill 4 to be tilted. An auxiliary support mechanism is located below the front end of the treadmill 4. Brackets 5 are fixedly installed on both sides of the front end of the base 1. A central control panel 6 with a display panel 7 is installed above the brackets 5. Handrails 8 are installed on both sides of the rear end of the central control panel 6. The base 1 serves as the basic support structure, with the support seat 2 sliding and limiting inside, providing a mounting base for the treadmill 4. The damping and shock absorption components are distributed between the base 1 and the support seat 2, sensing and buffering the pressure transmitted by the treadmill 4 in real time. The inclination adjustment seat 3 adjusts the tilt angle of the treadmill 4 through an internal transmission structure according to control commands; the auxiliary support mechanism works in conjunction with the angle changes of the treadmill 4 to maintain overall stability. The bracket 5, the central control panel 6, the display panel 7 and the armrest 8 together constitute the operation and auxiliary structure. The display panel 7 is used to display information, and the armrest 8 is for users to hold on to.

[0043] The sensing and detection system includes physiological parameter sensors and motion parameter sensors. The physiological parameter sensors include a respiratory monitoring module 9 and a heart rate monitoring module 15 using millimeter-wave radar technology. The respiratory monitoring module 9 is mounted above the display panel 7 via a mounting bracket. The motion parameter sensors include a high-precision encoder, a triaxial accelerometer 42, an inertial measurement unit 14, and a tilt angle sensor. The respiratory monitoring module 9 uses millimeter-wave radar technology to transmit and receive millimeter-wave signals, capturing the subtle rise and fall of the user's chest during breathing and converting it into respiratory frequency and depth data. The heart rate monitoring module 15 acquires the user's heart rate and heart rate variability data through photoelectric and electrocardiogram monitoring technologies. The high-precision encoder is mounted on the output shaft of the treadmill motor 29, accurately measuring the treadmill speed by detecting the motor shaft rotation pulses. The triaxial accelerometer 42 is mounted on the frame 26 of the treadmill 4, monitoring acceleration changes in three directions during running. The inertial measurement unit 14 is mounted on the protective clothing 13, detecting the user's upper body posture. The tilt angle sensor is mounted on the treadmill 4's rotating shaft, providing real-time feedback of the treadmill's tilt angle data. All sensor data are transmitted to the intelligent control and processing system. Multiple types of sensors work together to achieve comprehensive monitoring of the user's physiological and movement status;

[0044] The intelligent control and processing system, centered on an embedded processor, integrates a data acquisition module, a data storage module, a wireless communication module, and a display driver module. The system incorporates an adaptive damping adjustment algorithm, a fitness assessment algorithm based on the treadmill tilt angle, and a motion posture analysis algorithm. The data acquisition module receives various data from the sensor detection system and performs analog-to-digital conversion; the data storage module temporarily stores data acquired and processed during the acquisition process. The embedded processor runs the built-in algorithms: the adaptive damping adjustment algorithm controls the damping components to adjust damping based on user weight, running intensity, and other data; the fitness assessment algorithm based on the treadmill tilt angle combines multi-source data to assess user fitness; and the motion posture analysis algorithm determines the correctness of posture based on inertial measurement unit data. The processing results are displayed on display panel 7 via the display driver module.

[0045] Please see Figure 4 and Figure 5The running table 4 includes a frame 26. Three-axis accelerometers 42 are installed in the grooves on both sides of the upper surface of the frame 26. The two sides of the rear end of the frame 26 are connected to the tilt adjustment seat 3 through a rotating shaft, and a tilt angle sensor is installed on the rotating shaft. The frame 26 has a transmission roller 27 that rotates back and forth inside. The two transmission rollers 27 are mounted on the outside of the two transmission rollers 27. The frame 26 has two plates welded and fixed at the top and bottom. The upper plate is the running plate, which is used to bear the force generated by the user running. The lower plate is the motor mounting plate, and the running belt motor 29 is mounted on its upper end. A high-precision encoder is mounted on the output shaft of the running belt motor 29. Pulleys are mounted at the middle position of the front transmission roller 27 and on the output shaft of the running belt motor 29. The pulleys are connected by a belt 30.

[0046] After the running belt motor 29 starts, its output shaft drives the high-precision encoder and pulley to rotate. Through the belt 30, the front drive roller 27 rotates, which in turn drives the running belt 28 to run. The force generated by the user running on the running board is transmitted to the frame 26, and the three-axis acceleration sensor 42 monitors the motion acceleration. The rear end of the running platform 4 is connected to the tilt adjustment seat 3 through a rotating shaft. The tilt angle sensor detects the change in the tilt angle of the running platform in real time and transmits the data to the intelligent control and processing system.

[0047] Please see Figure 2 , Figure 3 and Figure 4 The tilt adjustment seat 3 is equipped with worm gears 25, and the shaft at one end of the worm gear 25 is fixed to the shaft at the rear end of the frame 26 by a coupling. The front end of the worm gear 25 is equipped with a transmission shaft 22 that is rotatably connected to the tilt adjustment seat 3. The transmission shaft 22 is equipped with a worm 24 at the position corresponding to the worm gear 25, and the worm 24 is threadedly connected to the worm gear 25. The rear end of the running table 4 is provided with a drive shaft 17. Both ends of the drive shaft 17 extend into the interior of the tilt adjustment seat 3 and are connected to the tilt adjustment seat 3 by bearings. The end of the drive shaft 17 located inside the tilt adjustment seat 3 is connected to the bottom of the transmission shaft 22 by a helical gear 21. The middle position of the drive shaft 17 is equipped with a driven gear 20. The rear end of the driven gear 20 is provided with a tilt adjustment motor 18 that is fixed to the bottom plate of the support seat 2. The output shaft of the tilt adjustment motor 18 is equipped with a drive gear 19 that meshes with the driven gear 20.

[0048] When the tilt adjustment motor 18 starts, its output shaft drives the drive gear 19 to rotate, which meshes with the driven gear 20, causing the drive shaft 17 to rotate. The drive shaft 17 drives the transmission shaft 22 to rotate via the helical gear 21. The worm 24 on the transmission shaft 22 rotates accordingly. The worm 24 is threadedly connected to the worm wheel 25, transmitting the rotation to the worm wheel 25. The worm wheel 25 drives the shaft connected to the rear rotating shaft of the frame 26 to rotate, thereby adjusting the tilt angle of the running table 4.

[0049] Please see Figure 4 and Figure 5 The auxiliary support mechanism includes a limiting groove built into the front end of the frame 26, and the limiting groove has an inclined structure. A telescopic plate 32 is slidably installed inside the limiting groove, and the bottom of the telescopic plate 32 extends to the bottom of the frame 26. A servo motor 34 is fixedly installed above the limiting groove. A stud 31 is installed on the output shaft of the servo motor 34. The stud 31 extends into the interior of the telescopic plate 32, and the external thread of the stud 31 mates with the internal thread of the telescopic plate 32. A support plate 33 is installed below the telescopic plate 32. The support plate 33 and... The telescopic plate 32 is connected by a rotating shaft, and a pressure sensor is installed at the bottom of the support plate 33. When the tilt angle of the running platform 4 changes and the front end tilts up, the pressure at the bottom of the support plate 33 disappears. The pressure sensor transmits the signal to the intelligent control and processing system. The system controls the servo motor 34 to start, and the output shaft drives the stud 31 to rotate. The stud 31 is threaded with the threaded hole in the telescopic plate 32, causing the telescopic plate 32 to extend downwards towards the front end of the running platform 4 until the support plate 33 contacts the bottom plate of the support base 2 again, maintaining the stability of the running platform 4.

[0050] Furthermore, the damping and shock absorption assembly 16 consists of a spring, a hydraulic shock absorber, a pressure sensor, a damping adjustment motor, and a controller. The pressure sensor monitors the pressure on the hydraulic shock absorber in real time. The damping adjustment motor changes the damping magnitude by adjusting the hydraulic oil flow orifice. The controller receives and processes the pressure data, and controls the damping adjustment motor to adaptively adjust the shock absorption damping. The pressure sensor monitors the pressure on the hydraulic shock absorber in real time and transmits the data to the controller. Based on a preset algorithm, combined with the user's weight and real-time pressure data, the controller calculates the optimal shock absorption damping value required at the moment, and then controls the damping adjustment motor to rotate, adjusting the hydraulic oil flow orifice to change the damping magnitude of the hydraulic shock absorber, thereby achieving adaptive adjustment of the shock absorption damping.

[0051] The adaptive damping adjustment algorithm includes:

[0052] Data input and preprocessing:

[0053] Enter the user's weight W (kg);

[0054] Real-time running intensity I: Calculated from the running belt speed v (m / s) and the treadmill tilt angle θ (°), the formula is: I=k1*v+k2*sinθ, where k1 and k2 are weight coefficients (which can be optimized through training based on user exercise data);

[0055] Real-time pressure fluctuation F(t) of the shock absorption system: collected by the pressure sensor of the shock absorption device, in N;

[0056] Preprocessing: F(t) is subjected to moving average filtering to remove high-frequency noise and obtain a smoothed pressure signal F(t).

[0057] Damping adjustment model:

[0058] Objective function: Minimize the joint impact coefficient C, the formula is: Where ΔF is the peak value of the pressure fluctuation, and α ⊥ Reflects impact intensity; it is the vertical acceleration (obtained by a triaxial accelerometer), and α and β are weighting coefficients (prioritizing minimizing impact intensity);

[0059] Damping adjustment logic:

[0060] The fuzzy PID control algorithm is used to calculate the target damping coefficient D based on the current W, I, and F(t). target ;

[0061] Fuzzy controller input: error e = D curren tD optimal (Difference between current damping and ideal damping), rate of change of error

[0062] Fuzzy rules: If the user is heavy and the running intensity is high, the damping is dynamically adjusted to enhance support; if the pressure fluctuations are severe (large impact), the damping is dynamically reduced to buffer the impact.

[0063] PID Tuning: Real-time optimization of the PID controller's K-axis using fuzzy rules. p ,K i ,K d The parameters are output to the damping adjustment motor, which adjusts the flow orifice diameter of the hydraulic device to achieve dynamic adjustment of the damping D.

[0064] Dynamic update: Sensor data is collected every 0.5 seconds, and I and F(t) are updated in real time; when the user's motion state changes abruptly, rapid damping adjustment is triggered.

[0065] The algorithm for assessing lower limb strength and motor coordination includes:

[0066] Data input:

[0067] Shock absorption system feedback data: Peak pressure F peak : Maximum pressure during a single running push-off; Pressure curve symmetry S: Absolute difference in pressure peak values ​​between the left and right shock absorbers, reflecting the balance of force exertion by both legs; Pressure rise time t r The time it takes for the pressure to rise from its minimum to its peak during the push-off phase reflects the speed of force exertion.

[0068] Motion parameters: Step frequency f: calculated from accelerometer data; Posture stability σ θ Standard deviation of upper body pitch angle (calculated from IMU data).

[0069] Lower limb strength assessment model;

[0070] Explosive power index: (Power of push-off per unit body weight reflects the explosive power of the lower limbs);

[0071] Endurance rating: (Average ground pressure throughout the exercise reflects lower limb endurance.)

[0072] Motor coordination assessment model:

[0073] bilateral symmetry: (The closer the value is to 1, the more evenly the force is applied to the left and right legs);

[0074] Attitude stability: (The closer the value is to 1, the more stable the upper body posture).

[0075] Comprehensive assessment and feedback:

[0076] Establish a multilayer perceptron (MLP) model, with input index E. explosive E endurance C sym C posture Output a comprehensive score S score (0-100 points).

[0077] Fitness assessment algorithms based on treadmill tilt angle include:

[0078] Data input and preprocessing: Physiological parameter sensors and motion parameter sensors collect data at a set frequency, and the data from multiple sensors are synchronized in time using a hardware clock stamp;

[0079] Physical fitness assessment model:

[0080] Cardiopulmonary function assessment:

[0081] The tilt angle α directly affects the motion load, and the calculation formula is as follows: Where μ is the coefficient of friction of the treadmill (default 0.05); g is the acceleration due to gravity (9.8 m / s²). 2 ).

[0082] Cardiorespiratory endurance indicators:

[0083] Predicted maximum oxygen uptake (VO2 max) 2max The formula used is Balke's formula combined with tilt angle correction: VO2max = 3.5 + 0.2v + 0.9vsinα; (applicable to steady-state data of continuous motion for more than 3 minutes).

[0084] Heart rate recovery rate (HRR):

[0085] After a sudden change in tilt angle (e.g., from 10° to 0°), calculate the decrease in heart rate over 30 seconds: The higher the value, the stronger the cardiopulmonary recovery ability.

[0086] Lower limb endurance and balance assessment:

[0087] Tilt Angle Adaptability Index:

[0088] Symmetry of push-off force: The difference is calculated using data from acceleration sensors on both sides. If Symmetry decreases significantly when the tilt angle increases, it suggests insufficient lower limb balance.

[0089] Step frequency stability: Calculate the standard deviation σ of step frequency within 30 seconds before and after the change in tilt angle. f ; Stability decreases as the tilt angle increases, reflecting lower limb endurance fatigue.

[0090] Attitude control capability:

[0091] Pitch angle deviation: The ideal pitch angle θ under the set standard tilt angle. ideal =α + 5° (natural forward tilt angle of the human body), calculate the real-time deviation: Δθ = |θ - θ ideal |; When Δθ exceeds 10°, it indicates weak core muscle control.

[0092] Roll angle fluctuation:

[0093] Calculate the percentage of roll angles within ±5°. The larger the tilt angle, The higher the value, the better; otherwise, it indicates insufficient balance.

[0094] Fatigue detection model:

[0095] A fatigue classifier is constructed using the random forest algorithm. The input features include:

[0096] Physiological parameters: low-frequency components (LF) of HR, RR, and HRV;

[0097] Motion parameters: Aθ, Step frequency decrease rate (Δf / f0);

[0098] Environmental parameters: tilt angle, duration of motion

[0099] The output is the fatigue level (0 = awake, 1 = mild fatigue, 2 = moderate fatigue, 3 = severe fatigue).

[0100] Comprehensive scoring formula: Physical fitness score = w1·VO2max + w2·HRR + w3·Symmetry + w5·(1-fatigue level);

[0101] The weights are determined through training using user physical fitness test data.

[0102] Please see Figure 1 and Figure 6 The base 1 has columns 10 welded and fixed on both sides, and a cross frame welded and fixed between the tops of the columns 10. A protective belt retraction device 11 is installed in the middle of the cross frame. The retraction device 11 has a retraction roller 35 with a torsion spring installed inside. A protective belt 12 is wound around the outside of the retraction roller 35. A protective garment 13 is sewn and fixed to the lower end of the protective belt 12. An inertial measurement unit 14 and a heart rate monitoring module 15 are respectively installed on both sides of the front end of the protective garment 13.

[0103] Please see Figure 6 and Figure 7 Braking mechanisms 36 are installed on both sides of the protective belt retraction device 11. The internal gear ring 41 is provided inside the braking mechanism 36. A brake block 39 is movably arranged inside the internal gear ring 41. Two locking teeth 40 are provided on one side of the brake block 39. A connecting shaft 37 is provided in the irregular inner cavity of the brake block 39. The connecting shaft 37 is fixed to the shaft at one end of the retraction roller 35. A rotating rod 38 is fixedly installed on one side of the connecting shaft 37. When the user slowly pulls the protective clothing 13 to put it on, the protective belt 12 is gradually released from the retraction roller 35. The retraction roller 35 rotates slowly under the action of the torsion spring, driving the connecting shaft 37 and the rotating rod 38 to rotate. The rotating rod 38 drives the brake block 39 to move synchronously. At this time, the locking teeth 40 will not be locked into the internal gear ring 41. When a user suddenly falls, the protective belt 12 is pulled rapidly, causing the connecting shaft 37 and the rotating rod 38 to rotate rapidly. Due to inertia, the brake block 39 cannot keep up with the rotation speed of the rotating rod 38 in time. One end of the rotating rod 38 exerts pressure and guidance on the irregular inner cavity of the brake block 39, causing the brake block 39 to be pushed out. The locking tooth 40 engages with the inner toothed ring 41, and the brake block 39 locks the rotating rod 38, preventing the connecting shaft 37 from rotating, thus achieving an emergency stop for the protective clothing 13. The combination of the protective belt retraction device and the braking mechanism makes it convenient for users to put on the protective clothing during normal use without affecting their movement; in the event of a sudden fall, it can quickly brake, preventing further injury to the user and providing effective protection for the user's safety during exercise.

[0104] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

Claims

1. A smart lower limb training device for physical fitness testing, comprising a lower limb training device body, a damping and shock absorption assembly (16), a sensing and detection system, and an intelligent control and processing system, characterized in that: The lower limb training device includes a base (1), a sliding limit support seat (2) is installed inside the base (1), damping shock absorption components are respectively set at the four corners between the base (1) and the support seat (2), a running platform (4) is installed inside the support seat (2), an inclination adjustment seat (3) is installed on the inner side of the support seat (2) and at the rear end of the running platform (4), the inclination angle of the running platform (4) is set by the inclination adjustment seat (3), an auxiliary support mechanism is provided below the front end of the running platform (4), a bracket (5) is fixedly installed on both sides of the front end of the base (1), a central control panel (6) with a display panel (7) is installed above the bracket (5), and handrails (8) are installed on both sides of the rear end of the central control panel (6). The sensing and detection system includes physiological parameter sensors and motion parameter sensors. The physiological parameter sensors include a respiratory monitoring module (9) and a heart rate monitoring module (15) using millimeter-wave radar technology. The respiratory monitoring module (9) is mounted on the display panel (7) above the display panel via a mounting bracket. The motion parameter sensors include a high-precision encoder, a triaxial accelerometer (42), an inertial measurement unit (14), and a tilt angle sensor. The intelligent control and processing system is based on an embedded processor and integrates a data acquisition module, a data storage module, a wireless communication module, and a display driver module. The system has built-in adaptive damping adjustment algorithm, physical fitness assessment algorithm based on treadmill tilt angle, and motion posture analysis algorithm.

2. The intelligent lower limb training device for physical fitness testing according to claim 1, characterized in that: The running platform (4) includes a frame (26). Three-axis accelerometers (42) are installed in the grooves on both sides of the upper end face of the frame (26). The two sides of the rear end of the frame (26) are connected to the tilt adjustment seat (3) through a rotating shaft, and a tilt angle sensor is installed on the rotating shaft. The frame (26) is equipped with a transmission roller (27) that rotates back and forth inside. The two transmission rollers (27) are equipped with a running belt (28) on the outside. The frame (26) has two plates welded and fixed inside, one at the top and one at the bottom. The upper plate is the running board, which is used to bear the force generated by the user running. The lower plate is the motor mounting plate, and a running belt motor (29) is installed on its upper end. A high-precision encoder is installed on the output shaft of the running belt motor (29). Pulleys are installed at the middle position of the front transmission roller (27) and on the output shaft of the running belt motor (29), and the pulleys are connected by a belt (30).

3. The intelligent lower limb training device for physical fitness testing according to claim 2, characterized in that: The tilt adjustment seat (3) is equipped with a worm gear (25) inside each of them. The shaft at one end of the worm gear (25) is fixed to the rotating shaft at the rear end of the frame (26) by a coupling. The front end of the worm gear (25) is equipped with a transmission shaft (22) that is rotatably connected to the tilt adjustment seat (3). A worm (24) is installed on the transmission shaft (22) at the position corresponding to the worm gear (25), and the worm (24) is threadedly connected to the worm gear (25). A drive shaft (17) is provided at the rear end below the running table (4). Both ends of the drive shaft (17) extend to the tilt adjustment seat. The drive shaft (17) is located inside the tilt adjustment seat (3) and connected to the tilt adjustment seat (3) via a bearing. One end of the drive shaft (17) located inside the tilt adjustment seat (3) is connected to the bottom of the transmission shaft (22) via a helical gear (21). A driven gear (20) is installed at the middle position of the drive shaft (17). A tilt adjustment motor (18) fixed to the bottom plate of the support seat (2) is provided on one side of the rear end of the driven gear (20). The output shaft of the tilt adjustment motor (18) is equipped with a drive gear (19) that meshes with the driven gear (20).

4. The intelligent lower limb training device for physical fitness testing according to claim 3, characterized in that: The auxiliary support mechanism includes a limiting groove built into the front end of the frame (26), and the limiting groove is inclined. A telescopic plate (32) is slidably installed inside the limiting groove, and the bottom of the telescopic plate (32) extends to the bottom of the frame (26). A servo motor (34) is fixedly installed above the limiting groove. A stud (31) is installed on the output shaft of the servo motor (34). The stud (31) extends into the inside of the telescopic plate (32), and the external thread of the stud (31) is threaded with the internal thread of the telescopic plate (32). A support plate (33) is installed below the telescopic plate (32). The support plate (33) is connected to the telescopic plate (32) through a rotating shaft, and a pressure sensor is installed at the bottom of the support plate (33).

5. The intelligent lower limb training device for physical fitness testing according to claim 1, characterized in that: The damping shock absorber assembly (16) consists of a spring, a hydraulic shock absorber, a pressure sensor, a damping adjustment motor, and a controller. The pressure sensor monitors the pressure on the hydraulic shock absorber in real time. The damping adjustment motor changes the damping magnitude by adjusting the hydraulic oil flow orifice. The controller receives and processes the pressure data and controls the damping adjustment motor to adaptively adjust the damping.

6. The intelligent lower limb training device for physical fitness testing according to claim 5, characterized in that: The adaptive damping adjustment algorithm includes: Data input and preprocessing: Input user weight, real-time running intensity, and real-time pressure fluctuation data of the shock absorption system; Damping adjustment logic: A fuzzy PID control algorithm is adopted, taking the difference between the current damping and the ideal damping and the error change rate as input, and optimizing the K of the PID controller according to preset fuzzy rules. p ,K i ,K d Parameters are used to calculate the target damping coefficient and control the damping adjustment motor to adjust the damping of the hydraulic device. Data feedback and evaluation: The controller records data such as pressure changes and damping adjustments of the shock absorption system. By analyzing parameters such as pressure peak, pressure curve symmetry, and pressure rise time, and combining these with motion parameters, it evaluates the user's lower limb strength and motor coordination.

7. The intelligent lower limb training device for physical fitness testing according to claim 1, characterized in that: The physical fitness assessment algorithm based on the treadmill tilt angle includes: Data input and preprocessing: Physiological parameter sensors and motion parameter sensors collect data at a set frequency, and the data from multiple sensors are synchronized in time using a hardware clock stamp; Physical fitness assessment model: Calculates exercise load based on the load intensity calculation formula, predicts maximum oxygen uptake using the Balke formula, and assesses cardiopulmonary recovery capacity through heart rate recovery rate; calculates the symmetry of push-off force using data from left and right accelerometers, and assesses lower limb endurance and balance by analyzing gait stability and posture control indicators; constructs a fatigue classifier using a random forest algorithm, taking physiological parameters, exercise parameters, and environmental parameters as inputs, and outputs fatigue level to monitor the user's fatigue status; Comprehensive scoring and feedback: Substitute each physical fitness indicator into the weighted comprehensive scoring formula to calculate the physical fitness score.

8. The intelligent lower limb training device for physical fitness testing according to claim 1, characterized in that: The base (1) is welded and fixed with columns (10) on both sides. A cross frame is welded and fixed between the tops of the columns (10). A protective belt take-up and release device (11) is installed in the middle of the cross frame. The protective belt take-up and release device (11) is equipped with a take-up and release roller (35) with a torsion spring inside. A protective belt (12) is wrapped around the outside of the take-up and release roller (35). A protective garment (13) is sewn and fixed to the lower end of the protective belt (12). An inertial measurement unit (14) and a heart rate monitoring module (15) are respectively installed on both sides of the front end of the protective garment (13).

9. The intelligent lower limb training device for physical fitness testing according to claim 8, characterized in that: Braking mechanisms (36) are installed on both sides of the belt take-up and release device (11). The brake mechanism (36) has an internal toothed ring (41) inside. A brake block (39) is movably arranged inside the internal toothed ring (41). Two locking teeth (40) are provided on one side of the brake block (39). A connecting shaft (37) is provided in the irregular inner cavity of the brake block (39). The connecting shaft (37) is fixed to the shaft at one end of the take-up and release roller (35). A rotating rod (38) is fixedly installed on one side of the connecting shaft (37).

10. The detection method based on the intelligent lower limb training device for physical fitness testing as described in claim 1, characterized in that: The steps include: Step 1, Initial Setup: Enter basic information such as age, gender, height, weight, and health status through the display panel of the lower limb training device. The system will then generate an initial physical fitness assessment model and set initial damping parameters for the shock absorption system. Step 2, Exercise Detection Stage: Users select the treadmill tilt angle and exercise mode according to the training content. During the run, the sensor detection system collects physiological parameters, exercise parameters and posture data in real time. The adaptive damping adjustment mechanism automatically adjusts the shock absorption damping according to the user's weight and running intensity. The intelligent control and processing system uses built-in algorithms to analyze and process the collected data and evaluate the user's physical condition in real time. Step 3, Results Feedback Stage: The system will provide real-time physical fitness assessment results and shock absorption adjustment status to the user through the display panel, and at the same time upload the test data to the cloud server for storage and management.

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