Treadmill with running posture analysis function and method for analyzing reaction force of running board

Abstract

The present invention relates to the technical field of treadmills, and in particular to a treadmill with a running posture analysis function and a running board reaction force analysis method. The running board reaction force analysis method comprises the following steps: obtaining real-time air pressure data of the left airbag and the right airbag and generating air pressure time series curves respectively; distinguishing the left foot landing data segment, the right foot landing data segment and the two-foot-in-the-air data segment based on the air pressure time series curve; intercepting the left foot landing data segment and / or the right foot landing data segment used for reaction force analysis, and calculating the ground contact peak value by inferring the pressure exerted on the running board by the user during running based on the peak air pressure data. The data source of the present invention is the direct reflection of the force exerted by the running board on the sole of the foot, which can intuitively reflect the user's ground contact peak value and impact load rate. Moreover, the method does not require wearing and does not affect the user's daily running habits.

Description

Technical Field

[0001] The present invention relates to the technical field of treadmills, and particularly to a treadmill with a running posture analysis function and a method for analyzing the reaction force of a running board. Background Art

[0002] As an aerobic fitness equipment that is not affected by the weather and can conveniently control the exercise intensity by adjusting the speed and slope, electric treadmills are increasingly entering families to meet the needs of home fitness exercises. Since runners lack professional guidance, incorrect running postures often occur, resulting in poor exercise effects or exercise injuries. For this reason, various treadmills with running posture analysis functions have also emerged in the prior art.

[0003] For example, Chinese Patent Publication No. CN113457106A discloses an intelligent treadmill that is used in cooperation with an intelligent wearable device, and proposes a running posture detection method based on the intelligent wearable device. By integrating a three-axis acceleration sensor, the running posture data is indirectly analyzed by collecting the acceleration value of the instep during the movement process. The running posture data obtained in this way has its own limitations, because the data source is not directly related to the sole data, but is inferred through other data, so the accuracy needs to be investigated.

[0004] For example, Chinese Patent Publication No. CN109331406A discloses a method for quantitatively evaluating the lower limb motor ability based on a treadmill force platform. The evaluation method is based on a thin film pressure sensor on an insole. Although the pressure insole directly collects the sole data, as a wearable device, the insole needs to be in direct contact with the sole and requires an external signal transmitter. This method is mostly used for scientific research and is extremely inconvenient to wear during daily fitness exercises. In addition, wearing it directly on the sole affects the user's daily running habits; moreover, hundreds of sensors and signal lines in the insole are easily squeezed and bent during the movement, resulting in malfunctions.

[0005] Although shock-absorbing airbags have been provided between the treadmill chassis and the running board in the prior art, the current application of shock-absorbing airbags is limited to using their compression deformation to achieve the functions of buffering, shock absorption, and adjusting softness and hardness, but no analysis method for running postures including reaction forces using the pressure change of the shock-absorbing airbags has been disclosed.

[0006] Peak contact force and impact load rate are indicators used to measure and reflect the ground reaction force exerted on the plantar surface of the foot during exercise. Ground reaction force is a potential factor in sports injuries. Sustained high peak contact force and impact load rate, along with prolonged exercise, significantly increase the likelihood of injury. Peak contact force measures the maximum ground reaction force exerted on the plantar surface during foot contact, typically expressed as a multiple of body weight (BW). Impact load rate represents the rate of increase in the ground reaction force exerted on the plantar surface of the foot upon landing. Summary of the Invention

[0007] The purpose of the present invention is to provide a running board reaction force analysis method, which can intuitively reflect the impact force of the user's footfall on the running board, does not require wear and does not affect the user's daily running habits.

[0008] To achieve the above object, the technical solution adopted by the present invention is:

[0009] The running board reaction force analysis method includes the following steps:

[0010] S1, obtaining real-time air pressure data of the left airbag and the right airbag and generating air pressure time series curves respectively;

[0011] S2. distinguishing a left foot landing data segment, a right foot landing data segment, and a two-foot-in-the-air data segment based on the air pressure time series curve;

[0012] S3. Intercept the left foot landing data segment and / or the right foot landing data segment for reaction force analysis, and calculate the ground contact peak value by inferring the pressure applied to the running board by the user during running based on the peak air pressure data.

[0013] Preferably, the distinguishing method in step S2 is specifically: calling the air pressure time series curves on the left and right sides and obtaining the difference waveform at the same time based on the following difference formula, if the difference is positive, it means the left foot has landed, if the difference is negative, it means the right foot has landed, and if the difference is zero, it means both feet are in the air; the difference formula is: .

[0014] Preferably, the distinguishing method of step S2 is specifically as follows: calling the air pressure timing curves on the left and right sides; respectively calculating the peak-to-valley ratios of the peak air pressure data and the trough air pressure data on the left and right sides in the same time period; if the peak-to-valley ratio on the left side is greater than the peak-to-valley ratio on the right side, it means that the left foot has landed; if the peak-to-valley ratio on the right side is greater than the peak-to-valley ratio on the left side, it means that the right foot has landed.

[0015] Preferably, the contact peak reverse calculation formula group in step S3 is as follows:

[0016] ;

[0017] ;

[0018] ;

[0019] ;

[0020] wherein, P G is the peak ground contact value; F P is the running board pressure at the peak point; W is the user's weight; V ref is the air pressure data during the airborne state; V P is the air pressure data at the peak; α is the slope of the relationship curve between the running board pressure and the air pressure; β is the intercept of the relationship curve between the running board pressure and the air pressure; K1 is the slope of the relationship curve between the slope α and the initial air pressure; K2 is the slope of the relationship curve between the intercept β and the initial air pressure; B1 is the intercept of the relationship curve between the slope α and the initial air pressure; B2 is the intercept of the relationship curve between the intercept β and the initial air pressure.

[0021] Preferably, the method for establishing the relationship curve between the slope α and the initial air pressure is as follows: collect the air pressure data of the airbag under different initial air pressures when it is closed and under different running board pressures, and fit to obtain multiple relationship curves between the running board pressure and the air pressure; based on the slopes of the above multiple relationship curves between the running board pressure and the air pressure, fit to obtain the relationship curve between the slope α and the initial air pressure.

[0022] Preferably, the method for establishing the relationship curve between the intercept β and the initial air pressure is as follows: collect the air pressure data of the airbag under different initial air pressures when it is closed and under different running board pressures, and fit to obtain multiple relationship curves between the running board pressure and the air pressure; based on the intercepts of the above multiple relationship curves between the running board pressure and the air pressure, fit to obtain the relationship curve between the intercept β and the initial air pressure.

[0023] Preferably, the running board reaction force analysis method further includes step S4: based on the formula calculate the impact load rate F V by inverse deduction, wherein in the formula, F V is the impact load rate; P G is the peak ground contact value; △t is the peak-valley time difference.

[0024] Preferably, in step S1, it further includes filtering and denoising the real-time air pressure data.

[0025] The present invention also provides a treadmill with a running posture analysis function, comprising a treadmill body and a controller, wherein the controller comprises a memory, a processor, and a computer program stored in the memory and running on the processor, and the steps of the above method are implemented when the processor executes the computer program; an air pressure sensor for monitoring the air pressure inside the air bag is respectively connected to the left air bag and the right air bag, and the air pressure sensor is electrically connected to the controller through an air pressure acquisition circuit to input real-time air pressure data to the controller.

[0026] Furthermore, when the processor executes the computer program, it also realizes left-right balance judgment. The specific judgment method is: analyze the corresponding peak air pressure data in the corresponding bands of the left and right feet, compare the peak fluctuation amplitudes of the left and right feet to judge the landing balance of the left and right feet, if the peak fluctuation amplitude of the left foot is greater than the peak fluctuation amplitude of the right foot, the left foot is heavier, if the peak fluctuation amplitude of the left foot is less than the peak fluctuation amplitude of the right foot, the right foot is heavier, if the peak fluctuation amplitude of the left foot is equal to the peak fluctuation amplitude of the right foot, the left and right are balanced.

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

[0028] The present invention utilizes the left and right airbags that directly interact with the left and right sides of the running board. By real-time collecting the internal air pressure data changes caused by the degree of compression of the left and right airbags by the running board during running, the left and right air pressure time series curves and the right air pressure time series curves are used to analyze and distinguish the different data segments of the left foot landing, right foot landing and both feet in the air pressure time series curves of each airbag, thereby analyzing the corresponding air pressure data in the left foot landing data segment and / or the right foot landing data segment, and inferring the pressure applied to the running board by the user during running based on the peak air pressure data to calculate the ground contact peak value and impact load rate.

[0029] The data source of the present invention is the contact between the sole of the foot and the running board, which is a direct reflection of the force exerted by the running board. It can intuitively reflect the user's ground contact peak and impact load rate. In addition, this method does not require wearable devices and does not affect the user's daily running habits. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 This is a flow chart of the running board reaction force analysis of the present invention.

[0031] Figure 2 This is a principle block diagram of the air pressure sensor and controller of the present invention.

[0032] Figure 3 This is a schematic diagram of the principle of differentiating left and right feet using difference values in the present invention.

[0033] Figure 4 This is a waveform diagram of the present invention for distinguishing left and right feet by difference.

[0034] Figure 5 Air pressure data table of airbags with different initial air pressures when subjected to different running board pressures under airtight conditions.

[0035] Figure 6 Relationship curve graph of multiple running board pressures / air pressures of the present invention.

[0036] Figure & Relationship curve graph of slope α / initial air pressure.

[0037] Figure 8 Relationship curve graph of intercept β / initial air pressure.

[0038] Figure 9 Left - right balance judgment logic diagram of the present invention.

[0039] Figure 10 Schematic diagram of corresponding band curves in left - right balance judgment of the present invention. Detailed implementation mode

[0040] In order to make the above - mentioned features and advantages of the present invention more obvious and understandable, specific embodiments are given below and described in detail in conjunction with the accompanying drawings.

[0041] This embodiment provides a treadmill with a running posture analysis function, including a treadmill body and a controller. The controller includes a memory, a processor, and a computer program stored in the memory and running on the processor. The treadmill body of this embodiment includes a chassis, a running board, and left and right airbags on both left and right sides between the chassis and the running board. The installation structure of the left and right airbags between the chassis and the running board is not limited. During running, the left and right airbags respectively support and bear the impact of the running board to produce a shock - absorbing effect. Pressure sensors for monitoring the internal air pressure of the airbags are respectively connected to the left and right airbags of this embodiment. The pressure sensors are electrically connected to the controller through a conventional air pressure acquisition circuit to input real - time air pressure data to the controller. The principle block diagram is shown in Figure 2 .

[0042] As Figure 1 shown, when the processor executes the computer program, it realizes the running board reaction force analysis step, specifically as follows:

[0043] S1. Obtain the real-time air pressure data of the left airbag and the right airbag, and generate air pressure time series curves respectively. The acquisition frequency of the air pressure sensor is once every 8 milliseconds to 50 milliseconds, and a more preferable acquisition frequency is once every 10 milliseconds to 25 milliseconds. Before generating the air pressure time series curve, perform conventional IIR filtering and denoising on the real-time air pressure data. It should be noted that since the left airbag and the right airbag are installed under the left and right sides of the running board, when the left foot supports, the left airbag will be compressed to generate a pressure change, and at the same time, the right airbag will also be compressed to generate pressure changes of different degrees. Similarly, when the right foot supports, both the left airbag and the right airbag will generate pressure changes. Thus, it is necessary to perform step S2 to distinguish which segments in the air pressure time series curves of the left and right sides belong to the left foot landing, the right foot landing, and both feet in the air.

[0044] S2. Based on the air pressure time series curve, distinguish the left foot landing data segment, the right foot landing data segment, and the both feet in the air data segment.

[0045] One of the distinguishing methods in this step S2 is: as Figures 3 to 4 shown, call the air pressure time series curves of the left and right sides and obtain the difference waveform at the same moment based on the following difference formula. If the difference is positive, it is the left foot landing; if the difference is negative, it is the right foot landing; the difference formula is: .

[0046] Another distinguishing method in this step S2 is: call the air pressure time series curves of the left and right sides; calculate the peak-valley ratios of the peak air pressure data and the valley air pressure data on the left and right sides respectively within the same time period; if the peak-valley ratio on the left is greater than the peak-valley ratio on the right, it is the left foot landing; if the peak-valley ratio on the right is greater than the peak-valley ratio on the left, it is the right foot landing.

[0047] S3. Intercept the left foot landing data segment and / or the right foot landing data segment for ground reaction force analysis, and calculate the touchdown peak value by inversely inferring the magnitude of the pressure exerted by the user on the running board during running based on the peak air pressure data.

[0048] The touchdown peak value inverse inference formula group is as follows:

[0049] ;

[0050] ;

[0051] ;

[0052] ;

[0053] In the formula, P G is the touchdown peak value; F Pis the peak point running board pressure; W is the user's weight, which is input by the user in the interaction module of the controller or obtained by the controller from the cloud server or local server through the communication interface; V ref is the air pressure data during takeoff; V P is the air pressure data at the peak of the wave; α is the slope of the relationship curve between the running board pressure and air pressure; β is the intercept of the relationship curve between the running board pressure and air pressure; K1 is the slope of the relationship curve between the slope α and the initial air pressure; K2 is the slope of the relationship curve between the intercept β and the initial air pressure; B1 is the intercept of the relationship curve between the slope α and the initial air pressure; B2 is the intercept of the relationship curve between the intercept β and the initial air pressure.

[0054] The method for establishing the relationship curve between the slope α and the initial air pressure is as follows: Collect the air pressure data of the airbag under different initial air pressures when it is under airtight conditions and subjected to different running board pressures (as Figure 5 shown), and fit to obtain multiple relationship curves between the running board pressure and air pressure (as Figure 6 shown); Based on the slopes of the above multiple relationship curves between the running board pressure and air pressure, fit to obtain the relationship curve between the slope α and the initial air pressure (as Figure 7 shown), and the relationship formula is: . It should be noted that this relationship formula is only for the data collected and fitted in this time. In specific applications, different running boards will have different relationship formulas. Therefore, the relationship curve between the slope α and the initial air pressure of different treadmills should be collected and fitted based on the establishment method described in this article.

[0055] The method for establishing the relationship curve between the intercept β and the initial air pressure is as follows: Collect the air pressure data of the airbag under different initial air pressures when it is under airtight conditions and subjected to different running board pressures (as Figure 5 shown), and fit to obtain multiple relationship curves between the running board pressure and air pressure (as Figure 6 shown); Based on the intercepts of the above multiple relationship curves between the running board pressure and air pressure, fit to obtain the relationship curve between the intercept β and the initial air pressure (as Figure 8 shown), and the relationship formula is: . It should be noted that this relationship formula is only for the data collected and fitted in this time. In specific applications, different running boards will have different relationship formulas. Therefore, the relationship curve between the intercept β and the initial air pressure of different treadmills should be collected and fitted based on the establishment method described in this article.

[0056] Further, the running board reaction force analysis method further includes step S4: Based on the formula inversely calculate to obtain the impact load rate F V , where F V is the impact load rate; P G is the peak value at touchdown; △t is the peak-valley time difference.

[0057] Further, when the processor executes the computer program, it also implements left-right balance judgment. The specific judgment method is as follows: Figures 9 to 10 As shown, analyze the peak air pressure data corresponding to the left and right feet in the corresponding frequency bands, and compare the peak fluctuation amplitudes of the left and right feet to judge the left-right landing balance. If the peak fluctuation amplitude of the left foot is greater than that of the right foot, the left foot is heavier; if the peak fluctuation amplitude of the left foot is less than that of the right foot, the right foot is heavier; if the peak fluctuation amplitude of the left foot is equal to that of the right foot, the left and right are balanced. The peak fluctuation amplitude is the air pressure change value between the peak point and the trough point.

[0058] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited by the above embodiments. The above embodiments and the descriptions in the specification only illustrate the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention will have various changes and improvements, and these changes and improvements all fall within the scope of the present invention claimed. The scope of the present invention claimed is defined by the appended claims and their equivalents.

Claims

1. Method for analyzing reaction force of running board, characterized in that It includes the following steps: S1. Obtain the real-time air pressure data of the left airbag and the right airbag and generate air pressure time series curves respectively; S2. Based on the air pressure time series curves, distinguish the left foot touchdown data segment, the right foot touchdown data segment, and the double-foot airborne data segment; S3. Intercept the left foot touchdown data segment and / or the right foot touchdown data segment for ground reaction force analysis, and calculate the touchdown peak value by inversely inferring the magnitude of the pressure on the running board during the user's running process according to the peak air pressure data; The touchdown peak value inverse inference formula group in step S3 is as follows: ； ； ； ； Wherein, P G is the peak ground contact value; F P is the running board pressure at the peak point; W is the user's weight; V ref is the air pressure data during the airborne phase; V P is the air pressure data at the peak; α is the slope of the relationship curve between the running board pressure and the air pressure; β is the intercept of the relationship curve between the running board pressure and the air pressure; K1 is the slope of the relationship curve between the slope α and the initial air pressure; K2 is the slope of the relationship curve between the intercept β and the initial air pressure; B1 is the intercept of the relationship curve between the slope α and the initial air pressure; B2 is the intercept of the relationship curve between the intercept β and the initial air pressure.

2. The method for analyzing the reaction force of the running board according to claim 1, characterized in that: The specific method for distinguishing in step S2 is as follows: Call the air pressure time series curves on the left and right sides and obtain the difference waveform at the same moment based on the following difference formula. If the difference is positive, it means the left foot is on the ground; if the difference is negative, it means the right foot is on the ground; if the difference is zero, it means both feet are off the ground. The difference formula is: .

3. The method for analyzing the reaction force of the running board according to claim 1, characterized in that: The specific method for distinguishing in step S2 is: call the air pressure time series curves on the left and right sides; calculate the peak-to-valley ratios of the peak air pressure data and the valley air pressure data on the left and right sides in the same time period respectively; if the peak-to-valley ratio on the left side is greater than the peak-to-valley ratio on the right side, it is a left foot touchdown, and if the peak-to-valley ratio on the right side is greater than the peak-to-valley ratio on the left side, it is a right foot touchdown.

4. The method for analyzing the reaction force of the running board according to claim 1, wherein: The method for establishing the relationship curve of the slope α / initial air pressure is: collect the air pressure data of the airbag with different initial air pressures under the condition of holding breath when subjected to different running board pressures, and fit to obtain multiple relationship curves of running board pressure / air pressure; according to the slopes of the above multiple relationship curves of running board pressure / air pressure, fit to obtain the relationship curve of the slope α / initial air pressure.

5. The method for analyzing the reaction force of the running board according to claim 1, characterized in that: The method for establishing the relationship curve of the intercept β / initial air pressure is: collect the air pressure data of the airbag with different initial air pressures under the condition of holding breath when subjected to different running board pressures, and fit to obtain multiple relationship curves of running board pressure / air pressure; according to the intercepts of the above multiple relationship curves of running board pressure / air pressure, fit to obtain the relationship curve of the intercept β / initial air pressure.

6. The running board reaction force analysis method according to claim 1, characterized in that: The running board reaction force analysis method further includes step S4: Based on the formula back-calculate to obtain the impact load rate F V , where F V is the impact load rate; P G is the peak ground contact force; △t is the peak-valley time difference.

7. The method for analyzing the reaction force of the running board according to claim 1, characterized in that: In step S1, it also includes filtering and denoising the real-time air pressure data.

8. A treadmill with a running posture analysis function, comprising a treadmill body and a controller, characterized in that: The controller includes a memory, a processor, and a computer program stored in the memory and running on the processor. When the processor executes the computer program, it implements the steps of the method according to any one of claims 1 to 7; pressure sensors for monitoring the internal air pressure of the airbag are respectively connected and arranged on the left airbag and the right airbag, and the pressure sensors are electrically connected to the controller through an air pressure acquisition circuit to input real-time air pressure data to the controller.

9. The treadmill with a running posture analysis function according to claim 8, characterized in that: When the processor executes the computer program, it also implements left-right balance judgment. The specific judgment method is: analyze the corresponding peak air pressure data in the corresponding wave bands of the left and right feet, compare the peak fluctuations of the left and right feet to judge the left-right landing balance. If the peak fluctuation amplitude of the left foot is greater than the peak fluctuation amplitude of the right foot, the left foot is heavier; if the peak fluctuation amplitude of the left foot is less than the peak fluctuation amplitude of the right foot, the right foot is heavier; if the peak fluctuation amplitude of the left foot is equal to the peak fluctuation amplitude of the right foot, the left and right are balanced.

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