Running machine with running posture analysis function and running board counter-acting force analysis method

Abstract

The invention relates to the technical field of treadmills, in particular to a treadmill with a running posture analysis function and a running board counter-acting force analysis method. The running board counter-acting force analysis method comprises the following steps: acquiring real-time air pressure data of a left air bag and a right air bag and respectively generating air pressure time sequence curves; distinguishing a left foot landing data segment, a right foot landing data segment and a double-foot flying data segment based on the air pressure time sequence curve; and intercepting a left foot landing data segment and / or a right foot landing data segment used for counter-acting force analysis, and reversely deducing the pressure of the user on the running board in the running process according to the wave crest air pressure data so as to calculate a landing peak value. The data source is direct representation of the contact between the sole and the running board and the acting force of the running board, the grounding peak value and the impact load rate of the user can be intuitively represented, and the method does not need to wear and does not affect the daily running habit of the user.

Description

Technical Field

[0001] 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. Background Art

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

[0003] For example, a Chinese patent document (CN113457106A) discloses an intelligent treadmill used in conjunction 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 acceleration value of the instep during exercise is collected to indirectly analyze the running posture data. 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 studied.

[0004] For example, a Chinese patent document (CN109331406A) discloses a quantitative evaluation method for lower limb motor ability based on a treadmill force platform. The evaluation method is based on a thin film pressure sensor on the insole. Although the pressure insole directly collects sole data, the insole, as a wearable device, needs to directly contact the sole of the foot and requires an external signal transmitter. This method is mostly used for scientific research and is extremely inconvenient to wear during daily fitness. Wearing it directly on the sole of the foot affects the user's daily running habits. In addition, hundreds of sensors and signal lines in the insole are easily squeezed and bent during exercise, resulting in failure.

[0005] Although the prior art has shown that a shock-absorbing airbag is arranged between the treadmill base frame and the running board, the application of the shock-absorbing airbag is currently limited to utilizing its compression deformation to achieve the functions of cushioning and shock absorption and adjusting the softness and hardness, and there is no public method for analyzing the running posture including the reaction force using the pressure change of the shock-absorbing airbag.

[0006] The peak contact force and impact load rate are indicators used to measure and reflect the ground reaction force on the sole of the foot during exercise, because the ground reaction force during exercise is one of the potential factors causing sports injuries. That is, maintaining a high peak contact force and impact load rate for a long time and being exposed to a long exercise time will greatly increase the probability of injury. The peak contact force is used to evaluate the maximum value of the ground reaction force on the sole of the foot during the foot contact process during exercise, usually expressed as a multiple of body weight (BW); the impact load rate represents the speed of increase of the ground reaction force on the sole of the foot when 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 wearing, 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: The running board reaction force analysis method includes the following steps: S1, obtaining real-time air pressure data of the left airbag and the right airbag and generating air pressure time series curves respectively; 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; S3, intercepting the left foot landing data segment and / or the right foot landing data segment for reaction force analysis, and calculating the ground contact peak value by inferring the pressure applied to the running board by the user during running according to the peak air pressure data.

[0009] Preferably, the distinguishing method in step S2 is specifically as follows: calling the air pressure timing 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, the left foot is on the ground, if the difference is negative, the right foot is on the ground, and if the difference is zero, both feet are in the air; the difference formula is: .

[0010] 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 touched the ground, and 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 touched the ground.

[0011] Preferably, the peak contact back-calculation formula group of step S3 is as follows: ; ; ; ; Where P G is the peak value of ground contact; F P is the running board pressure at the peak point; W is the user's weight; V ref V is the air pressure data; P is the peak air pressure data; α is the slope of the relationship curve of running board pressure / air pressure; β is the intercept of the relationship curve of running board pressure / air pressure; K1 is the slope of the relationship curve of slope α / initial air pressure; K2 is the slope of the relationship curve of intercept β / initial air pressure; B1 is the intercept of the relationship curve of slope α / initial air pressure; B2 is the intercept of the relationship curve of intercept β / initial air pressure.

[0012] Preferably, the method for establishing the relationship curve of the slope α / initial air pressure is: collecting air pressure data of air bags with different initial air pressures when subjected to different running board pressures under breath-holding conditions, and fitting to obtain multiple running board pressure / air pressure relationship curves; and fitting to obtain the relationship curve of the slope α / initial air pressure based on the slopes of the above multiple running board pressure / air pressure relationship curves.

[0013] Preferably, the method for establishing the intercept β / initial air pressure relationship curve is: collecting air pressure data of air bags with different initial air pressures when subjected to different running board pressures under breath-holding conditions, and fitting to obtain multiple running board pressure / air pressure relationship curves; and fitting to obtain the intercept β / initial air pressure relationship curve based on the intercepts of the multiple running board pressure / air pressure relationship curves.

[0014] Preferably, the running board reaction force analysis method further includes step S4: based on the formula The impact load rate F is obtained by reverse calculation V , where F V is the impact load rate; P G is the peak value of touchdown; △t is the time difference between peak and valley.

[0015] Preferably, step S1 also includes filtering and denoising the real-time air pressure data.

[0016] The present invention also provides a treadmill with a running posture analysis function, including a treadmill body and a controller, the controller including a memory, a processor and a computer program stored in the memory and running on the processor, and the processor implements the steps of the above method when executing the computer program; the left airbag and the right airbag are respectively connected to each other and are provided with air pressure sensors for monitoring the air pressure inside the airbags, 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.

[0017] 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 heavy, if the peak fluctuation amplitude of the left foot is less than the peak fluctuation amplitude of the right foot, the right foot is heavy, 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.

[0018] Compared with the prior art, the present invention has the following beneficial effects: The present invention utilizes the left side airbag and the right side airbag that directly act on the left and right sides of the running board, collects the internal air pressure data changes caused by the degree of squeezing of the left side airbag and the right side airbag by the running board in real time, and uses the left and right air pressure difference or the left and right peak-to-valley ratio difference from the left side air pressure timing curve and the right side air pressure timing curve to analyze and distinguish the different data segments of the left foot landing, the right foot landing and both feet in the air pressure timing curve 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 reversely infers the pressure applied to the running board by the user during running according to the peak air pressure data to calculate the ground contact peak value and the impact load rate.

[0019] 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 wearing and does not affect the user's daily running habits. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is a flow chart of the reaction force analysis of the running board of the present invention.

[0021] Figure 2 It is a principle block diagram of the air pressure sensor and controller of the present invention.

[0022] Figure 3 This is a schematic diagram of the principle of differentiating left and right feet by difference in the present invention.

[0023] Figure 4 This is a waveform diagram of the present invention for distinguishing left and right feet by difference.

[0024] Figure 5 The following is a table of air pressure data when air bags with different initial air pressures are subjected to different running board pressures under breath-holding conditions.

[0025] Figure 6 It is a relationship curve diagram of multiple running board pressures / air pressures of the present invention.

[0026] Figure 7 It is the relationship curve of slope α / initial air pressure.

[0027] Figure 8 This is the relationship curve of intercept β / initial air pressure.

[0028] Fig. 9 This is a left-right balance judgment logic diagram of the present invention.

[0029] Fig.10 It is a schematic diagram of the corresponding band curve in the left-right balance judgment of the present invention. DETAILED DESCRIPTION

[0030] In order to make the above features and advantages of the present invention more obvious and easy to understand, embodiments are given below with reference to the accompanying drawings for detailed description as follows.

[0031] The present 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 the present embodiment includes a chassis, a running board, and a left airbag and a right airbag located on the left and right sides between the chassis and the running board. The installation structure of the left airbag and the right airbag between the chassis and the running board is not limited. During running, the left airbag and the right airbag respectively support and withstand the impact of the running board to produce a shock-absorbing effect. The left airbag and the right airbag of the present embodiment are respectively connected to an air pressure sensor for monitoring the air pressure inside the airbag. The air pressure sensor is 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 FIG. Figure 2 .

[0032] like Figure 1 As shown, when the processor executes the computer program, the running board reaction force analysis steps are implemented, specifically: S1. Obtain the real-time air pressure data of the left and right air bags and generate air pressure timing curves respectively. The acquisition frequency of the air pressure sensor is once every 8 to 50 milliseconds, and the more preferred acquisition frequency is once every 10 to 25 milliseconds. Before generating the air pressure timing curve, the real-time air pressure data is subjected to conventional IIR filtering and denoising. It should be noted that since the left and right air bags are installed below the left and right sides of the running board, when the left foot is supported, the left air bag will be compressed to produce pressure changes, and the right air bag will also be compressed to produce different degrees of pressure changes. Similarly, when the right foot is supported, the left and right air bags will also produce pressure changes. This also results in the need to perform step S2 to distinguish which section of the air pressure timing curves on the left and right sides belongs to the left foot landing, the right foot landing, and both feet in the air.

[0033] S2. Distinguish 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 timing curve.

[0034] One of the distinguishing methods in step S2 is: Figure 3 to Figure 4As shown, the air pressure timing curves on the left and right sides are called and the difference waveform at the same time is obtained based on the following difference formula. If the difference is positive, the left foot is on the ground, and if the difference is negative, the right foot is on the ground; the difference formula is: .

[0035] The second distinguishing method in step S2 is: calling the air pressure time series 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 the left foot has touched the ground, and if the peak-to-valley ratio on the right side is greater than the peak-to-valley ratio on the left side, it means the right foot has touched the ground.

[0036] S3, intercepting the left foot landing data segment and / or the right foot landing data segment for reaction force analysis, and calculating the ground contact peak value by inferring the pressure applied to the running board by the user during running according to the peak air pressure data.

[0037] The peak contact back-calculation formula is as follows: ; ; ; ; Where P G is the peak value of ground contact; F P is the running board pressure at the peak point; W is the user's weight, which is input by the user in the interactive module of the controller or obtained by the controller from the cloud server or the local server using the communication interface; V ref V is the air pressure data; P is the peak air pressure data; α is the slope of the relationship curve of running board pressure / air pressure; β is the intercept of the relationship curve of running board pressure / air pressure; K1 is the slope of the relationship curve of slope α / initial air pressure; K2 is the slope of the relationship curve of intercept β / initial air pressure; B1 is the intercept of the relationship curve of slope α / initial air pressure; B2 is the intercept of the relationship curve of intercept β / initial air pressure.

[0038] The slope α / initial air pressure relationship curve is established by collecting air pressure data of air bags with different initial air pressures under breath-holding conditions and subjected to different running board pressures (e.g. Figure 5 ), and fitted to obtain multiple running board pressure / air pressure relationship curves (such as Figure 6 According to the slopes of the above-mentioned multiple running board pressure / air pressure relationship curves, a slope α / initial air pressure relationship curve is fitted (as shown in Figure 7 As shown), the relationship is: It should be noted that this relationship is only the data collected and fitted this time. Different running boards will have different relationship in specific applications. Therefore, the relationship curves of slope α and initial air pressure of different treadmills should be collected and fitted based on the establishment method described in this article.

[0039] The method for establishing the relationship curve of intercept β / initial air pressure is as follows: collecting air pressure data of air bags with different initial air pressures under breath-holding conditions subjected to different running board pressures (e.g. Figure 5 ), and fitted to obtain multiple running board pressure / air pressure relationship curves (such as Figure 6 According to the intercepts of the above-mentioned multiple running board pressure / air pressure relationship curves, the intercept β / initial air pressure relationship curve is fitted (as shown in Figure 8 As shown), the relationship is: It should be noted that this relationship is only the data collected and fitted this time. Different running boards will have different relationship in specific applications. Therefore, the intercept β / initial air pressure relationship curves of different treadmills should be collected and fitted based on the establishment method described in this article.

[0040] Furthermore, the running board reaction force analysis method further includes step S4: based on the formula The impact load rate F is obtained by reverse calculation V , where F V is the impact load rate; P G is the peak value of touchdown; △t is the time difference between peak and valley.

[0041] Furthermore, when the processor executes the computer program, it also implements left-right balance judgment, and the specific judgment method is: Figures 9 and 10 As shown, the corresponding peak air pressure data is analyzed in the corresponding bands of the left and right feet, and the peak fluctuation amplitudes of the left and right feet are compared to determine the balance of the left and right feet landing. If the peak fluctuation amplitude of the left foot is greater than the peak fluctuation amplitude of the right foot, the left foot is heavy, if the peak fluctuation amplitude of the left foot is less than the peak fluctuation amplitude of the right foot, the right foot is heavy, and 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. The peak fluctuation amplitude is the pressure change value between the peak point and the trough point.

[0042] 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 to the above embodiments. The above embodiments and descriptions are only for illustrating the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, which shall fall within the scope of the present invention to be protected. The scope of protection of the present invention shall be defined by the attached claims and their equivalents.

Claims

1. A running board reaction force analysis method, characterized in that: The steps include: S1, obtaining real-time air pressure data of the left airbag and the right airbag and generating air pressure time series curves respectively; 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; S3, intercepting the left foot landing data segment and / or the right foot landing data segment for reaction force analysis, and calculating the ground contact peak value by inferring the pressure applied to the running board by the user during running according to the peak air pressure data.

2. The running board reaction force analysis method according to claim 1, characterized in that: The distinguishing method in step S2 is specifically as follows: calling the air pressure timing 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, the left foot is on the ground, if the difference is negative, the right foot is on the ground, and if the difference is zero, both feet are in the air; the difference formula is: .

3. The running board reaction force analysis method according to claim 1, characterized in that: 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 touched the ground, and 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 touched the ground.

4. The running board reaction force analysis method according to claim 1, characterized in that: The peak contact back-calculation formula group of step S3 is as follows: ； ； ； ； Where P G is the peak value of ground contact; F P is the running board pressure at the peak point; W is the user's weight; V ref V is the air pressure data; P is the peak air pressure data; α is the slope of the relationship curve of running board pressure / air pressure; β is the intercept of the relationship curve of running board pressure / air pressure; K1 is the slope of the relationship curve of slope α / initial air pressure; K2 is the slope of the relationship curve of intercept β / initial air pressure; B1 is the intercept of the relationship curve of slope α / initial air pressure; B2 is the intercept of the relationship curve of intercept β / initial air pressure.

5. The running board reaction force analysis method according to claim 4, characterized in that: The method for establishing the slope α / initial air pressure relationship curve is as follows: air pressure data of air bags with different initial air pressures when subjected to different running board pressures under breath-holding conditions are collected, and multiple running board pressure / air pressure relationship curves are obtained by fitting; and the slope α / initial air pressure relationship curve is obtained by fitting based on the slopes of the multiple running board pressure / air pressure relationship curves.

6. The running board reaction force analysis method according to claim 4, characterized in that: The method for establishing the intercept β / initial air pressure relationship curve is as follows: air pressure data of air bags with different initial air pressures when subjected to different running board pressures under breath-holding conditions are collected, and multiple running board pressure / air pressure relationship curves are obtained by fitting; and based on the intercepts of the multiple running board pressure / air pressure relationship curves, the intercept β / initial air pressure relationship curve is obtained by fitting.

7. The running board reaction force analysis method according to claim 4, characterized in that: The running board reaction force analysis method further includes step S4: based on the formula The impact load rate F is obtained by reverse calculation V , where F V is the impact load rate; P G is the peak value of touchdown; △t is the time difference between peak and valley.

8. The running board reaction force analysis method according to claim 1, characterized in that: Step S1 also includes filtering and denoising the real-time air pressure data.

9. 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, and the processor implements the steps of the method as claimed in any one of claims 1 to 8 when executing the computer program; the left airbag and the right airbag are respectively connected to each other with an air pressure sensor for monitoring the air pressure inside the airbag, 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.

10. The treadmill with running posture analysis function according to claim 9, characterized in that: 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 heavy, if the peak fluctuation amplitude of the left foot is less than the peak fluctuation amplitude of the right foot, the right foot is heavy, 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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