IMU-based outdoor running forefoot abduction detection method
By collecting data in the forefoot region of the subject's foot using an IMU, performing gait cycle segmentation and yaw angle calculation, the problem of poor portability and high cost of motion capture systems is solved, achieving low-cost and efficient forefoot abduction detection.
Patent Information
- Application Number
- CN202511043338.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-07-28
- Publication Date
- 2025-11-07
AI Technical Summary
Existing motion capture systems are inadequate in terms of portability, ease of use, and cost, and cannot be widely used for forefoot abduction detection in outdoor running.
An inertial measurement unit (IMU) was fixed to the forefoot region of the subject's foot. By collecting acceleration and angular velocity data, gait cycle segmentation and yaw angle calculation were performed to determine the forefoot abduction angle.
It achieves low-cost, portable, and efficient forefoot abduction detection, with results that are highly consistent with motion capture systems, and is suitable for scenarios where motion capture systems cannot or are not suitable.
Smart Images
Figure CN120913274A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the technical field of action recognition, in particular to an IMU-based detection method for outdoor running forefoot abduction. BACKGROUND
[0002] Currently, human motion analysis through a motion capture system is a common means, but such a system has several limitations in practical application. First, the motion capture system is equipped with multiple cameras, and the device is large in size, heavy in weight, and poor in portability. Once installed, it can only be used in fixed situations. The camera is sensitive to environmental light, and once disturbed, the collection result will have large distortion, and it requires a site condition. Second, the motion capture system requires a large amount of time in the preparation stage before use and in the collection stage during use, and requires the operator to have rich professional knowledge. It is not only inconvenient to use, but also requires the operator. Finally, the motion capture system is expensive and is not conducive to popularization to the public. SUMMARY
[0003] Therefore, the embodiments of the present application provide an IMU-based detection method for outdoor running forefoot abduction and related equipment to efficiently and low-cost detect forefoot abduction.
[0004] An aspect of the embodiments of the present application provides an IMU-based detection method for outdoor running forefoot abduction, which comprises the following steps:
[0005] Obtaining acceleration and angular velocity collected by an IMU during outdoor running of a subject; wherein the IMU is fixed to a forefoot region of a foot of the subject;
[0006] Performing gait cycle segmentation on the acceleration and the angular velocity to obtain a plurality of gait cycle data;
[0007] Determining a yaw angle of the IMU in each of the gait cycle data;
[0008] Determining a forefoot abduction angle of the subject during running according to each of the yaw angles.
[0009] In some embodiments, the performing gait cycle segmentation on the acceleration and the angular velocity to obtain a plurality of gait cycle data comprises the following steps:
[0010] Low-pass filtering the acceleration and the angular velocity and a posture quaternion obtained from the acceleration and the angular velocity by a preset algorithm;
[0011] Drawing a corresponding first curve according to the filtered angular velocity;
[0012] Obtaining a time of foot landing and a time of foot leaving of the subject according to the first curve.
[0013] The acceleration, the angular velocity and the attitude quaternion between the time when the foot touches the ground and the time when the next foot of the subject touches the ground are taken as the gait cycle data.
[0014] In some embodiments, the determination of the yaw angle of the IMU in each of the gait cycle data comprises the following steps:
[0015] A rotation matrix is established according to the attitude quaternion in each of the gait cycle data;
[0016] The rotation matrix is:
[0017] ;
[0018] Wherein, R LS is the rotation matrix;
[0019] The yaw angle is calculated according to the rotation matrix;
[0020] The yaw angle is:
[0021] ;
[0022] Wherein, is the yaw angle.
[0023] In some embodiments, the determination of the forefoot abduction angle of the subject during running according to each of the yaw angles comprises the following steps:
[0024] The yaw angle corresponding to the support period is extracted; wherein the support period is the period from the time when the foot touches the ground to the time when the foot leaves the ground in one gait cycle of the subject;
[0025] A corresponding second curve is drawn based on the yaw angle corresponding to each of the support periods;
[0026] The forefoot abduction angle is determined according to each of the second curves.
[0027] In some embodiments, the determination of the forefoot abduction angle according to each of the second curves comprises the following steps:
[0028] The starting value of each of the second curves is subtracted by the minimum value of the corresponding second curve, and a plurality of forefoot abduction maximum angle change values are obtained;
[0029] The average value of each of the forefoot abduction maximum angle change values is taken as the forefoot abduction angle.
[0030] In some embodiments, the method further comprises the following steps before the step of obtaining the acceleration and the angular velocity collected by the IMU when the subject runs outdoors:
[0031] obtaining the acceleration and the angular velocity collected by the IMU at a fixed sampling rate when the subject runs.
[0032] In some embodiments, the method further comprises the following steps before the step of obtaining the acceleration and the angular velocity collected by the IMU when the subject runs outdoors:
[0033] placing the IMU still for a set time after starting the IMU, so as to align the IMU with the local coordinate system.
[0034] Another aspect of the embodiments of the present application further provides an IMU-based forefoot abduction detection system for outdoor running, which comprises:
[0035] a data acquisition unit configured to obtain the acceleration and the angular velocity collected by the IMU when the subject runs outdoors, wherein the IMU is fixed to the forefoot region of the foot of the subject;
[0036] a gait segmentation unit configured to segment the acceleration and the angular velocity by gait cycle to obtain a plurality of gait cycle data;
[0037] a yaw angle calculation unit configured to determine the yaw angle of the IMU in each of the gait cycle data;
[0038] a forefoot abduction angle calculation unit configured to determine the forefoot abduction angle of the subject during running according to each of the yaw angles.
[0039] Another aspect of the embodiments of the present application further provides an electronic device comprising a processor and a memory;
[0040] the memory is configured to store a program;
[0041] the processor executes the program to implement the method of any one of the above aspects.
[0042] Another aspect of the embodiments of the present application further provides a computer readable storage medium, which stores a program, and the program is executed by a processor to implement the method of any one of the above aspects.
[0043] The present application at least has the following beneficial effects:
[0044] The application can obtain acceleration and angular velocity collected by an IMU when a subject runs outdoors, wherein the IMU is fixed to the forefoot region of the subject's foot; the acceleration and angular velocity are subjected to gait cycle segmentation to obtain gait cycle data; the yaw angle of the IMU in the support phase in each gait cycle data is determined; and the forefoot abduction angle of the subject in the running process is determined according to each yaw angle. The application can overcome the shortcomings of poor portability, inconvenience of use and high price of the existing motion capture system, and the IMU is small in size, easy to carry, simple to use, does not require professional knowledge and is inexpensive, and the results of measurement and calculation by the IMU have strong consistency with the motion capture system, which proves the feasibility of using the IMU to replace the motion capture system. The application provides another effective solution for scenarios where the motion capture system cannot be used or cannot function. BRIEF DESCRIPTION OF DRAWINGS
[0045] In order to more clearly illustrate the technical solutions in the embodiments of the application, the drawings needed in the embodiment description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the application, and other drawings can be obtained by those skilled in the art without creative labor.
[0046] Figure 1 An IMU attitude angle example diagram provided for the embodiments of the application;
[0047] Figure 2 A forefoot abduction angle diagram provided for the embodiments of the application;
[0048] Figure 3 A flowchart of the IMU-based outdoor running forefoot abduction detection method provided for the embodiments of the application;
[0049] Figure 4 An example flowchart of the IMU-based outdoor running forefoot abduction detection method provided for the embodiments of the application;
[0050] Figure 5 An example diagram of a gait cycle curve provided for the embodiments of the application;
[0051] Figure 6 An example diagram of a yaw angle curve provided for the embodiments of the application;
[0052] Figure 7 An example diagram of an optional specific implementation of the embodiments of the application;
[0053] Figure 8 A structural block diagram of the IMU-based outdoor running forefoot abduction detection system provided for the embodiments of the application. DETAILED DESCRIPTION
[0054] In order to make the purposes, technical solutions and advantages of the present application clearer, the present application will be further described in detail below with reference to the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and not intended to limit the present application.
[0055] Before the embodiments of the present application are described in detail, first, some related technologies involved in the embodiments of the present application are described as follows:
[0056] Joint angle: refers to the angle generated when the human joint moves.
[0057] Biomechanics: in the present application, biomechanics specifically refers to lower limb kinematics and lower limb dynamics, lower limb kinematics refers to the joint angle (degree) of the lower limb of the human body, angular velocity (degree / second) and the like, and lower limb dynamics refers to the force (Newton) and moment (Newton*m) received by the joint of the lower limb of the human body.
[0058] Forefoot abduction: the foot of the human body can be divided into forefoot, midfoot and hindfoot, and forefoot abduction refers to the angle of rotation of the forefoot in the horizontal plane to the outside of the body.
[0059] IMU: Inertial Measurement Unit (IMU).
[0060] Gyroscope: a device for measuring angular motion, which can detect the angular velocity of rotation around its XYZ axes respectively.
[0061] Accelerometer: a device for measuring linear acceleration, which can detect acceleration along its XYZ axes respectively.
[0062] Hz: unit of frequency, 60 Hz = 60 sample points per second.
[0063] Gait cycle: the gait cycle is the time experienced from the heel of one foot touching the ground to the next heel touch of the same foot, and in a gait cycle, it is often divided into a support period (from the heel touching the ground to the toe leaving the ground) and a swing period (from the toe leaving the ground to the next heel touch in the air).
[0064] Attitude calculation: the current attitude of the IMU is calculated by using the acceleration and angular velocity output by the IMU.
[0065] Yaw angle, pitch angle, roll angle: yaw angle, pitch angle and roll angle are collectively referred to as attitude angle. The attitude angle is the relative rotation angle of the body coordinate system relative to the local coordinate system. An example of the attitude angle of an IMU is shown in FIG. Figure 1
[0066] The existing optical motion capture system is a system for acquiring the motion trajectory of a human body or an object. The system is composed of multiple infrared cameras, and the field of view constructed by the cameras covers a specific measurement area. Each camera is equipped with a near-infrared LED light array around it, which is used to irradiate reflective marker points attached to the surface of the measured object. The two-dimensional image information of the reflected light acquired by the camera is used for the reconstruction of spatial three-dimensional coordinates. Through the observation of the same reflective marker by multiple cameras, the accurate calculation of its position in three-dimensional space is realized, thereby completing the continuous capture, image acquisition, processing and analysis of the motion of the measured object, and realizing the real-time recording of the motion process.
[0067] In the study of running biomechanics, researchers can record key indicators such as joint angles of subjects in real time through high-precision three-dimensional motion capture systems, thereby deeply understanding the biomechanical mechanisms in the process of running, and providing data support for clinical diagnosis and rehabilitation treatment.
[0068] Abnormality of the forefoot abduction angle (such as Figure 2 θ) is a characteristic feature of flat foot running biomechanics. Compared with people with normal arch height, the forefoot abduction angle in the gait of flat foot people is larger. The current method for measuring forefoot abduction in gait is to reconstruct the three-dimensional motion of the forefoot in gait and then calculate the forefoot abduction through a motion capture system.
[0069] In view of the problems existing in the prior art, with reference to Figure 3 The embodiments of the present application provide an outdoor running forefoot abduction detection method based on an IMU, which specifically includes the following steps S300-S330:
[0070] S300: acquiring acceleration and angular velocity collected by an IMU during outdoor running of a subject; wherein the IMU is fixed to the forefoot region of the foot of the subject;
[0071] S310: performing gait cycle segmentation on the acceleration and the angular velocity to obtain multiple gait cycle data;
[0072] S320: determining the yaw angle of the IMU in each of the gait cycle data;
[0073] S330: determining the forefoot abduction angle of the subject in the running process according to each of the yaw angles.
[0074] Optionally, the gait cycle segmentation on the acceleration and the angular velocity to obtain multiple gait cycle data includes the following steps:
[0075] Low-pass filtering the acceleration and the angular velocity and the attitude quaternion obtained from the acceleration and the angular velocity by a preset algorithm;
[0076] According to the angular velocity after filtering, a corresponding first curve is drawn;
[0077] According to the first curve, a time of foot contact and a time of foot off ground of the subject are driven;
[0078] The acceleration, the angular velocity and the attitude quaternion between the time of foot contact and the time of foot contact of the next foot are taken as the gait cycle data.
[0079] Optionally, the yaw angle of the IMU in each of the gait cycle data is determined, comprising the following steps:
[0080] According to the attitude quaternion in each of the gait cycle data, a rotation matrix is established;
[0081] The rotation matrix is:
[0082] ;
[0083] Wherein, R LS is the rotation matrix;
[0084] The yaw angle is calculated according to the rotation matrix;
[0085] The yaw angle is:
[0086] ;
[0087] Wherein, is the yaw angle.
[0088] Optionally, the forefoot abduction angle of the subject during running is determined according to each of the yaw angles, comprising the following steps:
[0089] The yaw angle corresponding to the support period is extracted; wherein the support period is the period from the time of foot contact to the time of foot off ground in one gait cycle of the subject;
[0090] According to the yaw angle corresponding to each of the support periods, a corresponding second curve is drawn;
[0091] According to each of the second curves, the forefoot abduction angle is determined.
[0092] Optionally, the forefoot abduction angle is determined according to each of the second curves, comprising the following steps:
[0093] The starting value of each of the second curves is subtracted from the minimum value of the corresponding second curve, and a plurality of forefoot abduction maximum angle change values are obtained;
[0094] Average the maximum forefoot abduction angle change values of each of the forefoot abduction angles to obtain a forefoot abduction angle.
[0095] Optionally, the method further comprises the following steps before the step of obtaining the acceleration and angular velocity collected by the IMU when the subject runs outdoors:
[0096] Obtaining the acceleration and angular velocity collected by the IMU at a fixed sampling rate when the subject runs.
[0097] Optionally, the method further comprises the following steps before the step of obtaining the acceleration and angular velocity collected by the IMU when the subject runs outdoors:
[0098] After the IMU is turned on, it is placed still for a set time, and then the IMU is aligned with the local coordinate system.
[0099] Next, the scheme of the embodiments of the present application will be described and explained in detail in combination with specific application examples.
[0100] An inertial measurement unit (IMU) is a portable device that is gradually applied to human motion biomechanics research due to its small size, light weight, and low cost. The IMU can collect motion parameters and other biomechanics information by combining a gyroscope and an accelerometer, and can realize human motion analysis in multiple outdoor scenarios. The present embodiment will rely on the IMU to replace the motion capture system to realize long-distance running forefoot abduction angle monitoring outdoors. The method flow of the present embodiment is shown in Figure 4 .
[0101] Wearing the IMU to collect data: This step is to collect the forefoot acceleration and angular velocity of the subject when running. The specific operation is as follows: ① After turning on the IMU, place it still for about 30 seconds and align it with the local coordinate system. ② Fix the IMU on the forefoot area of the subject's foot through a tight belt or other means, and then put on socks and running shoes. The IMU will continuously record data at a fixed sampling rate (unit: Hz) during the subject's running, and the data is saved in the IMU in the form of acceleration and angular velocity.
[0102] Performing gait cycle segmentation: This step is to divide all the data recorded during the subject's running into multiple gait cycle data. The specific operation is as follows: ① Export the data saved by the IMU (acceleration, angular velocity, and attitude quaternion obtained by the built-in algorithm), perform non-lagged low-pass filtering, and use a 2nd order Butterworth low-pass filter with a cutoff frequency of 10 Hz to filter the acceleration and angular velocity, respectively, to filter out high-frequency interference in the data. ② Divide the gait cycle, and the filtered angular velocity shows obvious regular changes (as shown in Figure 5 ).
[0103] Figure 5 The peak in the square box occurs at the moment of foot contact with the ground, and the peak in the circle occurs at the moment of foot off the ground. The data between the two boxes is all the data in a gait cycle, and the data between a box and the subsequent circle is all the data in the corresponding support period in the gait cycle. The divided gait cycle data is saved separately (acceleration, angular velocity, and attitude quaternion obtained by the built-in algorithm).
[0104] Solving the IMU attitude: This step is to calculate the attitude angle of the IMU body coordinate system. The specific operation is as follows:
[0105] ① The attitude quaternion in each gait cycle data is established into a rotation matrix, and the rotation matrix (RLS) is as follows:
[0106] ;
[0107] ② The IMU attitude angle is calculated by the following formula:
[0108] ;
[0109] The yaw angle of the IMU in each gait cycle is calculated by the above formula.
[0110] Calculate the forefoot abduction angle: This step is to calculate the maximum change of the forefoot abduction angle in the support period in the gait cycle. The specific operation is as follows: ① The yaw angle of the IMU in each gait cycle can be obtained by solving the IMU attitude. The part corresponding to the support period is extracted, and the curve shown in FIG. 8 is drawn. The maximum angle change of the forefoot abduction in the support period is obtained by subtracting the minimum value in the support period from the starting value of the support period. ② The maximum angle change of the forefoot abduction in each gait cycle is calculated and averaged to obtain the forefoot abduction angle of the subject during running. Figure 6
[0111] More specifically, one optional embodiment of the present embodiment is as shown in FIG. 8. Figure 7
[0112] The beneficial effects of the present embodiment include:
[0113] The present embodiment overcomes the shortcomings of poor portability, inconvenience of use, and high price of the motion capture system. The IMU is small in size, easy to carry, simple to use, does not require professional knowledge, and is inexpensive. On this basis, the results calculated by the IMU measurement are highly consistent with the motion capture system, which illustrates the feasibility of using the IMU to replace the motion capture system. The present embodiment provides another effective solution for scenarios where the motion capture system cannot be afforded or cannot function.
[0114] ReferenceFigure 8 The embodiment of the application provides an outdoor running forefoot abduction detection system based on an IMU, which comprises:
[0115] a data acquisition unit configured to acquire acceleration and angular velocity collected by an IMU during outdoor running of a subject, wherein the IMU is fixed to a forefoot region of the foot of the subject;
[0116] a gait segmentation unit configured to segment gait cycles of the acceleration and the angular velocity to obtain a plurality of gait cycle data;
[0117] a yaw angle calculation unit configured to determine a yaw angle of the IMU in each of the gait cycle data;
[0118] a forefoot abduction angle calculation unit configured to determine a forefoot abduction angle of the subject during running according to each of the yaw angles.
[0119] It can be understood that the contents in the method embodiment are applicable to the system embodiment, the system embodiment specifically implements the functions same as those of the method embodiment, and achieves the same beneficial effects as those of the method embodiment.
[0120] In some alternative embodiments, the functions / operations mentioned in the block diagram can not occur in the order mentioned in the operation diagram. For example, depending on the functions / operations involved, two blocks shown in succession can actually be executed substantially simultaneously or the blocks can sometimes be executed in reverse order. In addition, the embodiments presented and described in the flowcharts of the present application are provided by way of example, and the purpose is to provide a more comprehensive understanding of the technology. The disclosed method is not limited to the operations and logical flows presented herein. Alternative embodiments are contemplated in which the order of various operations is changed and in which sub-operations described as part of larger operations are independently executed.
[0121] Furthermore, although the present application is described in the context of functional modules, it is understood that one or more of the functions and / or features described can be integrated in a single physical device and / or software module, or one or more functions and / or features can be implemented in separate physical devices or software modules. It is also understood that a detailed discussion of the actual implementation of each module is unnecessary to an understanding of the present application. Rather, the actual implementation is within the routine of an engineer in the art, given the property, function and internal relationships of the various functional modules disclosed herein. Accordingly, the present application is not limited to purely hardware or software implementations, since combinations of hardware and software embodiments are also within the scope of the present application. It is also understood that the particular concepts disclosed are merely illustrative and that the scope of the present application is not limited to the specific embodiments described herein, but rather only to the scope of the appended claims and their equivalents.
[0122] If the functions are implemented in software, the functions can be stored in or implemented as one or more computer program products, which can be incorporated into a computer-readable medium for use by or in connection with an instruction execution system, apparatus, or device, such as a computer-based system, processor- containing system, or other system that can fetch the instructions from the instruction execution system, apparatus, or device and execute the instructions. In the context of this specification, a "computer-readable medium" can be any means that can contain, store, communicate, propagate, or transport the program for use by or in connection with the instruction execution system, apparatus, or device. The computer-readable medium can be, for example but not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, device, or propagation medium.
[0123] The logic and / or steps represented in the flowcharts and / or described herein, for example, can be considered as a sequence of instructions to implement logic functions, and can be embodied in any computer-readable medium for use by or in connection with an instruction execution system, apparatus, or device, such as a computer-based system, processor-containing system, or other system that can fetch the instructions from the instruction execution system, apparatus, or device and execute the instructions. In the context of this specification, a "computer-readable medium" can be any means that can contain, store, communicate, propagate, or transport the program for use by or in connection with the instruction execution system, apparatus, or device.
[0124] More specific examples (a non-exhaustive list) of the computer-readable medium include the following: an electrical connection (electronic) having one or more wires, a portable computer diskette (magnetic), a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or Flash memory), an optical fiber, and a portable compact disc read-only memory (CDROM). Additionally, the computer-readable medium can also be paper or another suitable medium upon which the program is printed, as the program can be electronically captured, for example, via optical scanning of the paper or other medium, then compiled, interpreted, or otherwise processed in a suitable manner, if necessary, and then stored in a computer memory.
[0125] It should be understood that aspects of the application can be implemented in hardware, software, firmware or combinations thereof. In the above embodiments, various steps or methods can be implemented in software or firmware that is stored in memory and executed by a suitable instruction execution system. For example, if implemented in hardware, as in another embodiment, any of the following technologies, known in the art, or combinations thereof, can be used: a discrete logic circuit having logic gates for implementing logic functions upon data signals, an application specific integrated circuit having appropriate combinational logic gates, a programmable gate array (PGA), a field programmable gate array (FPGA), or the like.
[0126] In the description of the specification, the description of the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" and the like means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In the specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.
[0127] Although embodiments of the present application have been shown and described, it would be recognized by those of ordinary skill in the art that various changes, modifications, alternatives, and variations can be made to the embodiments without departing from the principles and spirit of the application, and that the scope of the present application is defined by the claims and their equivalents.
[0128] The above is a specific description of the preferred embodiments of the present application, but the present application is not limited to the described embodiments, and those skilled in the art can make various equivalent modifications or replacements without departing from the spirit of the present application, and these equivalent modifications or replacements are all included in the scope defined by the claims of the present application.
Claims
1. An IMU-based outdoor running prefoot abduction detection method, characterized in that, The method comprises the following steps: Obtaining acceleration and angular velocity collected by an IMU when a subject runs outdoors, wherein the IMU is fixed to the forefoot region of the subject's foot; Segmenting the acceleration and the angular velocity by gait cycle to obtain a plurality of gait cycle data; Determining the yaw angle of the IMU in each of the gait cycle data; Determining the forefoot abduction angle of the subject during running according to each of the yaw angles.
2. The IMU-based outdoor run forefoot splay detection method of claim 1, wherein, The step of segmenting the acceleration and the angular velocity by gait cycle to obtain a plurality of gait cycle data comprises the following steps: Low-pass filtering the acceleration, the angular velocity, and the attitude quaternion obtained from the acceleration and the angular velocity by a preset algorithm; Drawing a corresponding first curve according to the filtered angular velocity; Obtaining the time when the subject's foot touches the ground and the time when the foot leaves the ground according to the first curve; Taking the acceleration, the angular velocity, and the attitude quaternion between the time when the foot touches the ground and the time when the next foot touches the ground as the gait cycle data.
3. The IMU-based outdoor run forefoot splay detection method of claim 2, wherein, The step of determining the yaw angle of the IMU in each of the gait cycle data comprises the following steps: Establishing a rotation matrix according to the attitude quaternion in each of the gait cycle data; The rotation matrix is: ； wherein R LS is the rotation matrix; Calculating the yaw angle according to the rotation matrix; The yaw angle is: ； wherein, is the yaw angle.
4. The IMU-based outdoor run forefoot splay detection method of claim 1, wherein, The step of determining the forefoot abduction angle of the subject during running according to each of the yaw angles comprises the following steps: Extracting the yaw angle corresponding to the support period, wherein the support period is the period from the time when the subject's foot touches the ground to the time when the foot leaves the ground in one gait cycle; Drawing a corresponding second curve based on the yaw angle corresponding to each of the support periods; Determining the forefoot abduction angle according to each of the second curves.
5. The IMU-based outdoor run forefoot splay detection method of claim 4, wherein, The step of determining the forefoot abduction angle according to each of the second curves comprises the following steps: Subtracting the minimum value of each of the second curves from the starting value of each of the second curves to obtain a plurality of maximum forefoot abduction angle change values; Taking the average of each of the maximum forefoot abduction angle change values as the forefoot abduction angle.
6. The IMU-based outdoor run forefoot splay detection method of claim 1, wherein, The step of obtaining the acceleration and angular velocity collected by an IMU when a subject runs outdoors comprises the following steps: Obtaining the acceleration and the angular velocity collected by the IMU at a fixed sampling rate when the subject runs.
7. The IMU-based outdoor run foot abduction detection method according to any one of claims 1 to 6, characterized in that, Before the step of obtaining the acceleration and angular velocity collected by an IMU when a subject runs outdoors, the method further comprises the following steps: After turning on the IMU, placing it still for a set time to align the IMU with the local coordinate system.
8. An IMU-based outdoor running prefoot eversion detection system, characterized in that, The system comprises: A data acquisition unit for obtaining acceleration and angular velocity collected by an IMU when a subject runs outdoors, wherein the IMU is fixed to the forefoot region of the subject's foot; A gait segmentation unit for segmenting the acceleration and the angular velocity by gait cycle to obtain a plurality of gait cycle data; A yaw angle calculation unit for determining the yaw angle of the IMU in the support period in each of the gait cycle data; A forefoot abduction angle calculation unit is configured to determine a forefoot abduction angle of the subject during running according to the respective yaw angles.
9. An electronic device, comprising: The electronic device includes a processor and a memory; The memory is configured to store a program; The processor executes the program to implement the method according to any one of claims 1 to 7.
10. A computer-readable storage medium, characterized in that, The storage medium stores a program, and the program is executed by a processor to implement the method according to any one of claims 1 to 7.