A gait measurement system based on mobile platform and gait measurement method thereof

Abstract

The present invention relates to the field of gait detection and health monitoring technology, and in particular to a gait measurement system based on a mobile platform and a gait measurement method thereof, comprising a mobile platform, a gait data analysis and storage device, an image acquisition device and a visual marker, wherein the mobile platform is provided with a gait measurement space, the camera of the image acquisition device shoots the gait measurement space, and the gait data analysis and storage device comprises an image processing module electrically connected to the image acquisition device, a gait solution module electrically connected to the image processing module, a gait data storage module electrically connected to the gait solution module, and a communication module electrically connected to the gait data storage module. The present invention has low cost, is easy to use, measures multiple gait parameters, has high measurement accuracy, is not limited by the site, and can be used in different occasions. At the same time, the measurement data can be output in real time, providing real-time feedback to the person being measured, and providing rich and accurate gait information to data analysts.

Description

Technical Field

[0001] The present invention relates to the technical field of gait detection and health monitoring, and in particular to a gait measurement system and a gait measurement method based on a mobile platform. Background Art

[0002] In recent years, the number of people in my country who need walking training or gait correction has gradually increased due to aging, illness, accidents, sports injuries, and other reasons. The demand for quantitative measurement of human gait data is also increasing. For example, in the field of lower limb rehabilitation training, in order to make a correct diagnosis and prescribe accurate training prescriptions, doctors and rehabilitation therapists must accurately grasp the patient's gait characteristics. In addition, in order to quantify the intensity of rehabilitation training and evaluate the patient's rehabilitation status, real-time measurement of the patient's walking training volume and training intensity is also necessary. In the fields of gait correction, sports training, and activity monitoring of the elderly, gait measurement and monitoring are also indispensable.

[0003] The existing gait measurement equipment on the market can be divided into three categories. The first category is based on the inertial measurement unit (IMU) to measure the acceleration, angular velocity and geomagnetic information of certain parts of the patient's body, and calculate the patient's walking speed and walking distance and other motion parameters through filtering and integration. This method is limited by factors such as the measurement error of the sensor and the change of the indoor magnetic field. As time goes by, the measurement error accumulates in the integration algorithm, resulting in the error of long-term and long-distance measurement. Therefore, this method is not suitable for medium-long distance and medium-long time gait measurement. At the same time, the installation position and installation repeatability of the inertial measurement unit have a huge impact on the repeatability of the gait measurement results, increasing the difficulty of system configuration before each measurement. The second category is a motion capture system based on multiple infrared cameras fixed on the indoor wall. This type of system can realize real-time multi-point motion capture of the human body based on image processing and data fusion technology through infrared image information collected by infrared cameras. The multi-camera system can effectively avoid the visual occlusion problem caused by human posture. Therefore, this method can achieve high-precision human motion capture. The disadvantage of this solution is that the system is large, requires multiple dedicated camera equipment, is expensive and requires a specific measurement space. In order to expand the measurable space range, the number of cameras should be increased significantly. Due to the limitation of the camera shooting distance, the gait measurement process can only be confined to a fixed site, and the range of activities of the person being measured is greatly limited. At the same time, due to the problem of unmeasurable problems caused by occlusion, such systems are also difficult to meet the needs of multiple people using the same site at the same time, reducing the site utilization rate and the ability to receive patients in the rehabilitation center. The third category is the gait measurement method based on the pressure floor. This method can directly measure the foot pressure information that cannot be obtained in the first two methods. However, the basic principle of the pressure floor is to measure the change of the reaction force of the sole of the foot on the floor when pedaling through the pressure sensor, and then calculate the contact position and time of the foot and the floor according to the reaction force information. In order to accurately measure the magnitude of the reaction force, it is necessary to ensure that the pressure sensor is installed in a specific geometric position, and unify the sensitivity, linearity and offset of the sensor. This makes installation and debugging very difficult and costly. At the same time, the sensor itself is expensive. Usually, the gait measurement method based on this principle can only use a single or double pressure floor solution, so the range of activities of the user of the gait measurement is also greatly limited. In addition, the use of walking assistance tools such as walking frames also affects the measured values ​​of the pressure sensor, and therefore is not suitable for patients with lower limb disabilities who require the assistance of walking support devices.

[0004] In summary, the current gait measurement equipment has the following main disadvantages: few measurement parameters of gait data; low measurement accuracy, not suitable for long-term measurement; limited measurement site; not suitable for multiple people to use at the same time, low site utilization rate; complex structure and expensive equipment. Summary of the invention

[0005] In order to solve the above technical problems, the object of the present invention is to provide a gait measurement system and a gait measurement method based on a mobile platform, which have high gait measurement accuracy, can measure multiple gait characteristic parameters, and are not restricted by the measurement site.

[0006] In order to achieve the above object, the present invention adopts the following technical solution:

[0007] A gait measurement system based on a mobile platform comprises an image acquisition device, a mobile platform for supporting a person being measured to walk, a gait data analysis and storage device electrically connected to an output end of the image acquisition device, and visual markers fixed to the left and right feet of the person being measured to identify and locate the left and right feet. The mobile platform is provided with a gait measurement space. The camera of the image acquisition device photographs the left and right feet of the person being measured in the gait measurement space. The gait data analysis and storage device is used to perform gait analysis on the images acquired by the image acquisition device. The gait data analysis and storage device and the image acquisition device are both installed on the mobile platform. The gait data analysis and storage device comprises an image processing module electrically connected to the image acquisition device, a gait solution module electrically connected to the image processing module, a gait data storage module electrically connected to the gait solution module, and a communication module electrically connected to the gait data storage module.

[0008] Furthermore, the mobile platform includes a front guardrail, a left support frame and a right support frame, the left support frame and the right support frame are respectively connected to the two ends of the front guardrail, the front guardrail, the left support frame and the right support frame enclose a gait measurement space, the image acquisition device is installed on the front guardrail, and the camera of the image acquisition device is tilted toward the gait measurement space.

[0009] The present invention also provides a gait measurement method. The above-mentioned gait measurement system based on a mobile platform comprises the following steps:

[0010] 1) Fix the visual markers on the feet of the person being measured, and walk in the gait measurement space with the feet fixed with the visual markers;

[0011] 2) When the measured person's foot is deformed, the measured person fixes the visual mark at the appropriate position of the deformed surface and records the coordinates (x an ,y an ), the coordinates of the visual marker of the left foot and the coordinates of the visual marker of the right foot are: (x anL ,y anL ), (x anR ,y anR), and the angle θ between the line between the position point where the visual marker is fixed on the instep and the center point of the heel contour and the line between the tip of the middle toe and the center point of the heel contour an , the angles of the visual markers of the left foot and the right foot are: θ anL ,θ anR ; When the measured person's foot is not deformed, the center of the visual mark is fixed at the center of the projection of the soles of both feet on the ground plane, and the line connecting the point where the visual mark is fixed on the foot and the center of the heel contour is parallel to the line connecting the tip of the middle toe and the center of the heel contour. At this time: x anL =x anR =0,y anL =y anR =0,θ anL =θ anR =0, the above position coordinates are expressed in the coordinate system of the left foot and the right foot respectively;

[0012] 3) The image acquisition device is fixed at the center of the mobile platform, and the height h of the image acquisition device is adjusted. tu and pitch angle θ tu , the shooting range of the image acquisition device covers the gait measurement space to obtain the entire field of view of the movable range of the feet of the person being measured;

[0013] 4) The output end of the image acquisition device is connected to the input end of the gait data analysis and storage device, and the walking motion image information of the measured person is sent to the image processing module of the gait data analysis and storage device;

[0014] 5) The image processing module of the gait data analysis storage device processes the collected image data of the feet of the measured person when walking, and identifies the position coordinates and angle information of the visual mark in the image coordinate system at time t according to the color and shape characteristics of the selected visual mark. The information of the visual mark of the left foot is recorded as: The information of the visual mark of the right foot is recorded as:

[0015] 6) The gait analysis module of the gait data analysis and storage device performs coordinate transformation to transform the position coordinates of the visual markers in the image into the physical coordinate information of the plane coordinate system of the two feet on the ground plane. tu and pitch angle θ tu and the coordinates and angles of the visual markers [x an ,y an ,θ an ], the position coordinates and angle information of the visual markers fixed to the feet in the image: Transform to the plane physical coordinate system fixed on the plane where the feet of the person being measured are located, and obtain the actual physical space position information of the feet:

[0016] 7) The gait calculation module of the gait data analysis and storage device calculates the position information of both feet: Perform differential operation to obtain the movement speed information of both feet: The swing foot and the supporting foot are identified by the speed threshold method, and the swing phase of both feet at the start time is determined: T baiL (t), T baiR (t), the support phase of both feet at the start: T zhiL (t), T zhiR (t);

[0017] 8) The gait calculation module of the gait data analysis and storage device calculates the gait information of each foot in the swing phase period, and calculates the step length, step width, step speed, acceleration of the swing foot and foot deflection angle according to the measurement results;

[0018] 9) The gait calculation module of the gait data analysis and storage device integrates the step length at the end of the swing phase of each foot, calculates the walking distance of the measured person, and updates the gait data according to the total time of walking measurement;

[0019] 10) The gait data storage module of the gait data analysis and storage device records and stores the gait data obtained by the measurement in real time;

[0020] 11) The communication module of the gait data analysis and storage device sends the real-time measurement data to the mobile terminal, and the real-time gait data is displayed and the historical data is managed through the mobile terminal.

[0021] Furthermore, in step 1), the visual marker has information providing direction, and the number of the visual markers is two, and the two visual markers are respectively fixed at the center position of the projection plane where the soles of the feet of the person being measured are located or close to the center position of the projection plane.

[0022] Furthermore, the mobile platform-based gait measurement system also includes a shell, the image acquisition device and the gait data analysis and storage device are both installed in the shell to form an integrated structure, the shell is installed on the mobile platform, and the image acquisition device is electrically connected to the gait data analysis and storage device.

[0023] Furthermore, the image acquisition device is electrically connected to the gait data analysis and storage device via a cable.

[0024] Further, in step 6), the image-physical coordinate transformation unit in the gait solution module calculates the height h of the image acquisition device according to the image acquisition device.tu and pitch angle θ tu and the coordinates and angles of the visual markers: [x an ,y an ,θ an ], based on the position coordinates and angle information of the visual marker in the image coordinate system: Calculate the position information of the measured person's feet in the ground plane coordinate system:

[0025] Furthermore, in step 7), based on the position information of both feet obtained by real-time measurement and the sampling time, the speed information of the movement of both feet is calculated by a differential algorithm, and the position information of the movement of both feet is analyzed and judged by a speed threshold method to determine the state of the swinging foot and the supporting foot, as well as the starting time of the swinging phase and the supporting phase.

[0026] Further, in step 8), based on the starting time of the swing phase and the support phase as the time node, the position information and changes of the swing foot in the swing phase are selected, and the step length, left and right foot stride length, step width and foot deflection angle information are calculated, wherein the step length is the longitudinal movement distance of the swing foot, the left and right foot stride length is the longitudinal movement distance of each foot in a complete cycle of the support phase and the swing phase, the step width is the lateral distance between the two feet at the moment of switching between the swing phase and the support phase, and the foot deflection angle is the angle between the center line passing through the sole of one side and the forward direction. The position information of the swing foot is subjected to second-order differentiation to obtain the angular velocity information of the swing foot in the swing phase to obtain the relative position of the swing foot and the support foot.

[0027] Further, in step 9), the position information of the feet of the person being measured is recorded and the time information of the sampling of the position information of the feet is used, and the position information of the identified supporting foot is used as a reference point, and the total walking distance and total time are calculated by an integration algorithm, and then the average walking speed is calculated;

[0028] In step 10), the gait data storage module records and saves the calculated gait information and the original information of the image acquisition device in real time;

[0029] In step 11), the communication module is a wireless communication module, and the mobile terminal is a host computer. Real-time measurement data is sent to the host computer by wireless communication. The measurer monitors the real-time gait information of the person being measured through the host computer, and can also trace back the historical data of gait measurement and manage the result report of gait measurement.

[0030] The beneficial effects of the present invention are as follows: during actual work, the measured person walks in the gait measurement space under the support of the mobile platform, and the image acquisition device collects the measured person's footsteps image through the digital camera, and the information is processed in sequence by the image processing module, gait solution module, gait data storage module and communication module in the gait data analysis and storage device; wherein the image processing module identifies the position of the visual marks of the measured person's feet; the gait solution module calculates and obtains gait information including step length, step width, step speed, left and right foot speeds, acceleration, foot deflection angle, the switching time between the swinging foot (swinging foot) and the supporting foot (standing foot) state of the two feet, the swinging phase time period, the supporting phase time period, the walking movement time and the walking distance of the walker, and the gait information obtained by the solution is stored through the gait data storage module, and the gait information is sent to the upper computer through the communication module for real-time display and monitoring of the gait. The gait measurement system and the gait measurement method thereof have low cost, are easy to use, measure many gait parameters, have high measurement accuracy, are not limited by the site, and can be used in different occasions. At the same time, the measurement data can be output in real time to provide real-time feedback to the person being measured, and the measurement records can be saved in real time to provide data analysts with rich and accurate gait information, which is especially suitable for users with lower limb disabilities. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 It is a structural schematic diagram of the gait measurement system of the present invention.

[0032] Figure 2 Schematic diagram of visual markers fixed to the feet of the person being measured.

[0033] Figure 3 This is a schematic diagram of the projection of the visual marker on the coordinate system when it is fixed on the instep.

[0034] Figure 4 Schematic diagram of the projection of visual markers on the image coordinate system.

[0035] Figure 5 It is a flowchart of the working principle of the present invention.

[0036] Description of reference numerals:

[0037] 1. Mobile platform; 11. Gait measurement space; 12. Front guardrail; 13. Left support frame; 14. Right support frame; 2. Image acquisition device; 3. Gait data analysis and storage device; 31. Image processing module; 32. Gait solution module; 33. Gait data storage module; 34. Communication module; 4. Visual marker. DETAILED DESCRIPTION

[0038] In order to facilitate the understanding of those skilled in the art, the present invention is further described below in conjunction with embodiments and drawings. The contents mentioned in the implementation modes are not intended to limit the present invention.

[0039] Embodiment 1.

[0040] like Figures 1 to 5 As shown, the present invention provides a gait measurement system based on a mobile platform, which includes an image acquisition device 2, a mobile platform 1 for supporting a person being measured to walk, a gait data analysis and storage device 3 electrically connected to the output end of the image acquisition device 2, and a visual marker 4 fixed to the left foot and the right foot of the person being measured to identify and locate the left foot and the right foot. The mobile platform 1 is provided with a gait measurement space 11, and the camera of the image acquisition device 2 shoots the left foot and the right foot of the person being measured in the gait measurement space 11. The gait data analysis and storage device 3 is used to perform gait analysis on the image acquired by the image acquisition device 2. The gait data analysis and storage device 3 and the image acquisition device 2 are both installed on the mobile platform 1. The analysis and storage device 3 includes an image processing module 31 electrically connected to the image acquisition device 2, a gait solution module 32 electrically connected to the image processing module 31, a gait data storage module 33 electrically connected to the gait solution module 32, and a communication module 34 electrically connected to the gait data storage module 33. The gait data analysis and storage device 3 also includes a shell, and the image processing module 31, the gait solution module 32, the gait data storage module 33 and the communication module 34 are all built in the shell, and the shell is installed on the mobile platform 1. The image acquisition device 2 is equipped with a digital camera, and the shooting range of the digital camera covers the gait measurement space 11. The communication module 34 of the gait data analysis and storage device 3 is electrically connected to a host computer.

[0041] In actual operation, the measured person walks in the gait measurement space 11 with the support of the mobile platform 1, and the image acquisition device 2 acquires the measured person's footsteps image through a digital camera, and the information is processed in sequence by the image processing module 31, the gait solution module 32, the gait data storage module 33 and the communication module 34 in the gait data analysis and storage device 3; wherein the image processing module 31 identifies the position of the visual markers 4 of the measured person's feet; the gait solution module 32 calculates and obtains gait information including step length, step width, step speed, left and right foot speeds, acceleration, foot deflection angle, the switching time of the two feet between the swinging foot (swinging foot) and the supporting foot (standing foot) state, the swinging phase time period of the swinging foot, the supporting phase time period of the supporting foot, the walking movement time and the walking distance of the walker, and the gait information obtained by the solution is stored through the gait data storage module 33, and the gait information is sent to the mobile terminal (such as: host computer, etc.) through the communication module 34 for real-time display and monitoring of the gait. The gait measurement system has a simple structure, low cost, and is easy to use. It measures multiple gait parameters with high measurement accuracy. It is not limited by the venue and can be used in different occasions. At the same time, the measurement data can be output in real time to provide real-time feedback to the measured person, and the measurement records can be saved in real time to provide data analysts with rich and accurate gait information. It is particularly suitable for users with lower limb disabilities.

[0042] In this embodiment, the mobile platform 1 includes a front guardrail 12, a left support frame 13 and a right support frame 14, the left support frame 13 and the right support frame 14 are respectively connected to the two ends of the front guardrail 12, the front guardrail 12, the left support frame 13 and the right support frame 14 are enclosed to form a gait measurement space 11, the image acquisition device 2 is installed on the front guardrail 12, and the digital camera of the image acquisition device 2 is tilted toward the gait measurement space 11; this structural setting is convenient for the person being measured to hold the top of the left support frame 13 and the top of the right support frame 14 with both hands respectively (manual operation) to walk, the mobile platform 1 is always in front of the person being measured and surrounds the person being measured, and the feet of the person being measured walk in the gait measurement space 11, so that the camera of the image acquisition device 2 is convenient to capture the gait information of the feet of the person being measured, which is beneficial to improve the accuracy of gait measurement.

[0043] In this embodiment, the mobile platform 1 can also be a platform that can move automatically, such as a walking vehicle or a mobile robot, to assist the person being measured in walking, which is beneficial for gait measurement of the person being measured and improves the measurement accuracy of gait measurement.

[0044] Specifically, the image acquisition device 2 can be powered independently or by a battery inside the gait data analysis and storage device 3; the information transmission between the image acquisition device 2 and the gait data analysis and storage device 3 is not limited to a wired electrical connection; the number of the visual markers 4 is two, and the two visual markers 4 are respectively fixed on the left and right insteps of the measured person.

[0045] When the image acquisition device 2 and the gait data analysis and storage device 3 are of split structures, the image acquisition device 2 is electrically connected to the gait data analysis and storage device 3 via a cable, and the image acquisition device 2 is installed in the middle position of the front guardrail 12 so that the shooting range of the image acquisition device 2 covers the gait measurement space 11, and the gait data analysis and storage device 3 is installed on the left support frame 13 or the right support frame 14; preferably, the image acquisition device 2 is installed on the front guardrail 12 via auxiliary tools such as a camera fixture or a tripod, which is convenient for installing the image acquisition device 2 on the one hand, and for adjusting the angle and position of the image acquisition device 2 on the other hand.

[0046] The gait measurement system of the present invention can provide parameter information including step length, step width, step speed, left and right foot speeds, acceleration, foot deflection angle, the switching time of the swinging foot and supporting foot states of both feet, the swing phase time period and the support phase time period.

[0047] Embodiment 2.

[0048] The difference between this embodiment and the first embodiment is that: when the image acquisition device 2 and the gait data analysis and storage device 3 are of an integrated structure, the gait measurement system based on the mobile platform also includes a shell, and the image acquisition device 2 and the gait data analysis and storage device 3 are both installed in the shell to form an integrated structure. The shell is installed on the mobile platform 1, and the image acquisition device 2 is electrically connected to the gait data analysis and storage device 3. The shell is installed on the front guardrail 12 via auxiliary tools such as a camera fixture or a tripod, which is convenient for installing the image acquisition device 2 on the one hand, and for adjusting the angle and position of the image acquisition device 2 on the other hand.

[0049] The remaining structures of this embodiment are the same as those of the first embodiment and will not be described in detail here.

[0050] Embodiment three.

[0051] like Figures 1 to 5 As shown, the present invention also provides a gait measurement method, including the above-mentioned gait measurement system based on a mobile platform, and the steps include the following:

[0052] 1) According to the appearance of the feet of the person being measured, the visual markers 4 are fixed at appropriate positions on the feet of the person being measured, and the feet with the visual markers 4 fixed thereon walk in the gait measurement space 11;

[0053] 2) When the measured person's foot surface is deformed, the measured person fixes the visual marker 4 at a suitable position on the deformed surface and records the coordinates (x an ,y an ), the coordinates of the visual marker 4 of the left foot and the coordinates of the visual marker 4 of the right foot are: (x anL ,y anL ), (x anR ,y anR ), and the angle θ between the line connecting the position point of the visual marker 4 fixed on the instep and the center point of the heel contour and the line connecting the tip point of the middle toe and the center point of the heel contour an , the angles of the visual marker 4 of the left foot and the visual marker 4 of the right foot are: θ anL ,θ anR When the measured person's foot is normal, the center position of the visual marker 4 is fixed at the position of the projection center of the soles of both feet on the ground plane, and the line connecting the position point of the visual marker 4 fixed on the foot surface and the center point of the heel contour is parallel to the line connecting the tip of the middle toe and the center point of the heel contour. At this time: x anL =x anR =0,y anL =y anR =0,θ anL =θ anR = 0, the above position coordinates are expressed in the coordinate system of the left foot and the right foot respectively; where x anL is the x-coordinate of the visual marker 4 fixed to the left foot, y anL is the y coordinate of the visual marker 4 fixed to the left foot, θ anL is the installation angle of the left foot visual marker 4, x anR is the x coordinate of the visual marker 4 fixed on the right foot, y anR is the y coordinate of the visual marker 4 fixed on the right foot, θ anR is the installation angle of the right foot visual marker 4;

[0054] 3) The image acquisition device 2 is fixed at the center of the mobile platform 1, and the height h of the image acquisition device 2 is adjusted. tu and pitch angle θ tu , the shooting range of the image acquisition device 2 covers the gait measurement space 11, so as to obtain the entire field of view of the single-step movable range of the feet of the measured person;

[0055] 4) The measured person performs any walking action to measure gait. The mobile platform 1 moves along with the walking action of the measured person under manual operation or automatic control of the measured person and the measurement implementer. The output end of the image acquisition device 2 is connected to the input end of the gait data analysis and storage device 3. During the walking process of the measured person, the image acquisition device 2 shoots and collects images of the walking action pictures of the measured person's feet, and sends the walking action image information of the measured person to the image processing module 31 of the gait data analysis and storage device 3.

[0056] 5) The image processing module 31 of the gait data analysis storage device 3 processes the collected image data of the feet of the measured person when walking, so as to perform image processing on each frame of the walking action picture collected by the image acquisition device 2, identify the visual mark 4, and determine the coordinate position of the visual mark 4 in the image. According to the color and shape characteristics of the selected visual mark 4, the position coordinates and angle information of the visual mark 4 in the image coordinate system at time t are identified. The information of the visual mark 4 of the left foot is recorded as: The information of visual marker 4 of the right foot is recorded as:

[0057] 6) The gait analysis module 32 of the gait data analysis storage device 3 performs coordinate transformation, obtains the position and angle information of the feet of the measured person through coordinate transformation, transforms the position coordinates of the visual mark 4 in the image into the physical coordinate information of the plane coordinate system of the feet on the ground plane, and calculates the position coordinates of the visual mark 4 in the image according to the height h of the image acquisition device 2. tu and pitch angle θ tu and the coordinates and angles of visual marker 4 [x an ,y an ,θ an ], the position coordinates and angle information of the visual marker 4 fixed to the feet in the image: Transform to the plane physical coordinate system fixed on the plane where the feet of the person being measured are located, and obtain the actual physical space position information of the feet:

[0058] 7) The gait calculation module 32 of the gait data analysis storage device 3 calculates the position information of both feet: Perform differential operation to obtain the movement speed information of both feet: The swing foot and the supporting foot are identified by the speed threshold method, and the swing phase of both feet at the start time is determined: T baiL (t), T baiR (t) The support phase of both feet at the start: T zhiL (t), T zhiR (t), where: T baiL (t), TbaiR (t) are the start time of the swing phase of the left foot and the start time of the swing phase of the right foot, T zhiL (t), T zhiR (t) are the starting time of the stance phase of the left foot and the starting time of the stance phase of the right foot, respectively;

[0059] 8) The gait calculation module 32 of the gait data analysis and storage device 3 calculates the gait information of each foot in the swing phase period, compares the position changes of the two feet in the previous and next image frames, determines the state switching moment of the swing foot and the supporting foot of the two feet, the time period of the swing phase and the time period of the supporting phase, and calculates the step length, step width, step speed, acceleration of the swing foot and foot deflection angle according to the measurement results;

[0060] 9) The gait calculation module 32 of the gait data analysis and storage device 3 integrates the step length at the end of the swing phase of each foot, calculates the walking distance of the measured person, and updates the gait data according to the total walking measurement time;

[0061] 10) With the start time of walking as the starting point, the gait information output by the gait solution module 32 is sent to the gait data storage module 33 of the gait data analysis storage device 3 in real time in chronological order, and the gait data storage module 33 records and stores the measured gait data in real time;

[0062] 11) The communication module 34 of the gait data analysis and storage device 3 sends the real-time measurement data to the mobile terminal, and the real-time gait data is displayed and the historical data is managed through the mobile terminal.

[0063] In this embodiment, in step 1), the visual marker 4 has information providing direction, and there are two visual markers 4. The two visual markers 4 are respectively fixed at the center position of the projection plane where the soles of the feet of the person being measured are located or at a position close to the center position of the projection plane.

[0064] In this embodiment, the gait measurement system based on the mobile platform also includes a shell, and the image acquisition device 2 and the gait data analysis and storage device 3 are both installed in the shell to form an integrated structure. The shell is installed on the mobile platform 1, and the image acquisition device 2 is electrically connected to the gait data analysis and storage device 3.

[0065] In this embodiment, the gait data analysis and storage device 3 can be fixed at any position of the mobile platform 1, and the image acquisition device 2 is electrically connected to the gait data analysis and storage device 3 via a cable.

[0066] In this embodiment, in step 6), the image-physical coordinate transformation unit in the gait solution module 32 is based on the height h of the image acquisition device 2. tu and pitch angle θtu And the coordinates and angles of visual marker 4: [x an ,y an ,θ an ], according to the position coordinates and angle information of the visual marker 4 in the image coordinate system: Calculate the position information of the measured person's feet in the ground plane coordinate system:

[0067] In this embodiment, in step 7), the speed information of the movement of the two feet is calculated by a differential algorithm based on the position information of the two feet and the sampling time obtained by real-time measurement, and the position information of the movement of the two feet is analyzed and judged by the speed threshold method to determine the state of the swinging foot and the supporting foot, as well as the starting time of the swinging phase and the supporting phase.

[0068] In this embodiment, in step 8), based on the starting time of the swing phase and the support phase as the time node, the position information of the swing foot in the swing phase and its changes are selected, and the step length, left and right foot stride length, step width and foot deflection angle information are calculated, wherein the step length is the longitudinal movement distance of the swing foot, the left and right foot stride length is the longitudinal movement distance of each foot in a complete cycle of the support phase and the swing phase, the step width is the lateral distance between the two feet at the moment of switching between the swing phase and the support phase, and the foot deflection angle is the angle between the center line passing through the sole of one side and the forward direction. The position information of the swing foot is subjected to second-order differentiation to obtain the angular velocity information of the swing foot in the swing phase, and the step length, left and right foot stride length, step width and foot deflection angle information are all calculated with reference to the position information of the supporting foot to obtain the relative position of the swing foot and the supporting foot.

[0069] In this embodiment, in step 9), the position information of the feet of the person being measured is recorded and the time information of the sampling of the position information of the feet is used. The position information of the identified supporting foot is used as a reference point, and the total walking distance and total time are calculated by an integration algorithm, and then the average walking speed is calculated;

[0070] In step 10), the gait data storage module 33 records and saves the calculated gait information and the original information of the image acquisition device 2 in real time;

[0071] In step 11), the communication module 34 is a wireless communication module, and the mobile terminal is a host computer. Real-time measurement data is sent to the host computer by wireless communication. The measurer monitors the real-time gait information of the person being measured through the host computer, and can also trace back the historical data of gait measurement and manage the result report of gait measurement.

[0072] The gait measurement method of this gait measurement system is low-cost, easy to use, measures multiple gait parameters, has high measurement accuracy, is not limited by the venue, and can be used in different occasions. At the same time, the measurement data can be output in real time to provide real-time feedback to the measured person, and the measurement records can be saved in real time to provide data analysts with rich and accurate gait information, which is particularly suitable for users with lower limb disabilities.

[0073] Of course, the fixed position of the visual marker 4 can be adjusted according to the physiological structure of the foot of the person being measured, and the position and direction of the visual marker 4 measured by the measurement system of the present invention are used as initial values. During the measurement process, the position and direction of the visual marker 4 obtained by gait measurement are subtracted from the initial values ​​to eliminate installation errors and achieve accurate measurement of gait.

[0074] Specifically, the image processing module 31, the gait solving module 32, the gait data storage module 33 and the communication module 34 all belong to the prior art and are not described in detail here.

[0075] The gait calculation module 32 may also adopt an embedded Linux system or an embedded Android system.

[0076] All technical features in this embodiment can be freely combined according to actual needs.

[0077] The above embodiments are preferred implementation schemes of the present invention. In addition, the present invention may also be implemented in other ways. Any obvious replacement without departing from the concept of the present technical solution is within the protection scope of the present invention.

Claims

1. A gait measurement method, characterized in that: The gait measurement system based on the mobile platform includes an image acquisition device, a mobile platform for supporting a measured person to walk, a gait data analysis and storage device electrically connected to an output end of the image acquisition device, and visual markers fixed to the left and right feet of the measured person to identify and locate the left and right feet, the mobile platform is provided with a gait measurement space, a camera of the image acquisition device photographs the left and right feet of the measured person in the gait measurement space, the gait data analysis and storage device is used to perform gait analysis on the image acquired by the image acquisition device, the gait data analysis and storage device and the image acquisition device are both installed on the mobile platform, the gait data analysis and storage device includes an image processing module electrically connected to the image acquisition device, a gait solution module electrically connected to the image processing module, a gait data storage module electrically connected to the gait solution module, and a communication module electrically connected to the gait data storage module; The steps include the following: 1) Fix the visual markers on the feet of the person being measured, and walk in the gait measurement space with the feet fixed with the visual markers; 2) When the measured person's foot is deformed, the measured person fixes the visual mark at the appropriate position of the deformed surface and records the coordinates of the position of the visual mark fixed on the foot surface relative to the projection center of the soles of the feet on the ground plane. , the coordinates of the visual marker of the left foot and the coordinates of the visual marker of the right foot are: , , and the angle between the line between the point where the visual marker is fixed on the instep and the center point of the heel contour and the line between the tip of the middle toe and the center point of the heel contour , the angles of the visual markers for the left foot and the right foot are: , ; When the measured person's foot is not deformed, the center position of the visual mark is fixed at the position of the projection center of the soles of both feet on the ground plane, and the line connecting the position point of the visual mark fixed on the foot and the center point of the heel contour is parallel to the line connecting the tip of the middle toe and the center point of the heel contour. At this time: , , , the above position coordinates are expressed in the coordinate system of the left foot and the right foot respectively; 3) The image acquisition device is fixed at the center of the mobile platform and the height of the image acquisition device is adjusted. and pitch angle , the shooting range of the image acquisition device covers the gait measurement space to obtain the entire field of view of the movable range of the feet of the person being measured; 4) The output end of the image acquisition device is connected to the input end of the gait data analysis and storage device, and the walking motion image information of the measured person is sent to the image processing module of the gait data analysis and storage device; 5) The image processing module of the gait data analysis storage device processes the collected image data of the feet of the measured person when walking, and identifies the feet in the gait data according to the color and shape characteristics of the selected visual markers. At this moment, the position coordinates and angle information of the visual marker in the image coordinate system, the information of the visual marker of the left foot is recorded as: , the visual mark information of the right foot is recorded as: ; 6) The gait analysis module of the gait data analysis and storage device performs coordinate transformation, transforms the position coordinates of the visual markers in the image into the physical coordinate information of the plane coordinate system of the two feet on the ground plane, and converts the position coordinates of the visual markers in the image into the physical coordinate information of the plane coordinate system of the two feet on the ground plane according to the height of the image acquisition device. and pitch angle and the coordinates and angles of the visual markers , the position coordinates and angle information of the visual markers fixed to the feet in the image: , Transform to the plane physical coordinate system fixed on the plane where the feet of the person being measured are located, and obtain the actual physical space position information of the feet: , ; 7) The gait calculation module of the gait data analysis and storage device calculates the position information of both feet: , Perform differential operation to obtain the movement speed information of both feet: , , identify the swing foot and the supporting foot through the speed threshold method, and determine the swing phase of both feet at the beginning: , , the support phase of both feet at the beginning: , ; 8) The gait calculation module of the gait data analysis and storage device calculates the gait information of each foot in the swing phase cycle, and calculates the step length, step width, step speed, acceleration of the swing foot and foot deflection angle according to the measurement results; 9) The gait calculation module of the gait data analysis and storage device integrates the step length at the end of the swing phase of each foot, calculates the walking distance of the measured person, and updates the gait data according to the total walking measurement time; 10) The gait data storage module of the gait data analysis and storage device records and stores the gait data obtained by measurement in real time; 11) The communication module of the gait data analysis and storage device sends the real-time measurement data to the mobile terminal, and the real-time gait data is displayed and the historical data is managed through the mobile terminal.

2. A gait measurement method according to claim 1, characterized in that: In step 1), the visual marker has information providing direction, and there are two visual markers, which are respectively fixed at the center of the projection plane where the soles of the feet of the person being measured are located or at a position close to the center of the projection plane.

3. A gait measurement method according to claim 1, characterized in that: The gait measurement system based on the mobile platform also includes a shell, the image acquisition device and the gait data analysis and storage device are both installed in the shell to form an integrated structure, the shell is installed on the mobile platform, and the image acquisition device is electrically connected to the gait data analysis and storage device.

4. A gait measurement method according to claim 1, characterized in that: The image acquisition device is electrically connected to the gait data analysis and storage device via a cable.

5. A gait measurement method according to claim 1, characterized in that: In step 6), the image-physical coordinate transformation unit in the gait solution module transforms the image into physical coordinates according to the height of the image acquisition device. and pitch angle And the coordinates and angles of the visual markers: , based on the position coordinates and angle information of the visual marker in the image coordinate system: , , calculate the position information of the measured person's feet in the ground plane coordinate system: , .

6. A gait measurement method according to claim 1, characterized in that: In step 7), the speed information of the movement of the two feet is calculated by a differential algorithm based on the real-time measured position information of the two feet and the sampling time, and the position information of the movement of the two feet is analyzed and judged by the speed threshold method to determine the state of the swing foot and the supporting foot, as well as the starting time of the swing phase and the supporting phase.

7. A gait measurement method according to claim 1, characterized in that: In step 8), based on the starting time of the swing phase and the support phase as the time node, the position information and its change of the swing foot in the swing phase are selected, and the step length, left and right foot stride length, step width and foot deviation angle information are calculated, wherein the step length is the longitudinal movement distance of the swing foot, the left and right foot stride length is the longitudinal movement distance of each foot in a complete cycle of the support phase and the swing phase, the step width is the lateral distance between the two feet at the moment of switching between the swing phase and the support phase, and the foot deviation angle is the angle between the center line passing through the sole of one side and the forward direction. The position information of the swing foot is subjected to second-order differentiation to obtain the angular velocity information of the swing foot in the swing phase to obtain the relative position of the swing foot and the support foot.

8. A gait measurement method according to claim 1, characterized in that: In step 9), the position information of the feet of the person being measured is recorded and the time information of the sampling of the position information of the feet is used. The position information of the identified supporting foot is used as a reference point, and the total walking distance and total time are calculated by an integration algorithm, and then the average walking speed is calculated; In step 10), the gait data storage module records and saves the calculated gait information and the original information of the image acquisition device in real time; In step 11), the communication module is a wireless communication module, and the mobile terminal is a host computer. Real-time measurement data is sent to the host computer by wireless communication. The measurer monitors the real-time gait information of the measured person through the host computer, and can also trace back the historical data of gait measurement and manage the result report of gait measurement.

9. A gait measurement method according to claim 1, characterized in that: The mobile platform includes a front guardrail, a left support frame and a right support frame, wherein the left support frame and the right support frame are respectively connected to the two ends of the front guardrail, and the front guardrail, the left support frame and the right support frame enclose a gait measurement space. The image acquisition device is installed on the front guardrail, and the camera of the image acquisition device is tilted toward the gait measurement space.

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