Human-chair coupling relationship adjustment method, device, equipment and medium

Abstract

The present invention discloses a method, device, electronic device and medium for adjusting the human-chair coupling relationship, including: establishing a human body model and a seat model in the same space coordinate system, and symmetrically arranging a plurality of first key contact points at the target parts on the left and right sides of the human body. Adjust the model. When the simulated contact forces at the first key contact points are all non-zero, obtain the initial human-chair coupling relationship, and acquire the simulated contact forces at the target parts on the left and right sides of the human body; identify the actual pressure distribution, determine the positions of the target parts on the left and right sides of the human body based on the maximum force-bearing areas and the pressure peak positions on the left and right sides, extract the pressure distribution gradient values to obtain the force-bearing range, and calculate the actual contact force. Taking the minimization of the difference between the simulated contact forces and the actual contact forces at the target parts on the left and right sides of the human body as the goal, obtain the offset and rotation amount of the seat center line through the positions of the target parts on the left and right sides of the human body, and adjust the offset amount, rotation amount and / or height of the seat center line to iteratively optimize the human-chair coupling relationship.

Description

Technical Field

[0001] The present invention belongs to the technical field of human factors engineering, and in particular relates to a method, device, electronic equipment and medium for adjusting a person-chair coupling relationship. Background Art

[0002] With the transformation of modern office mode, sitting for a long time has become the norm for many people's daily work. Office workers who maintain bad sitting posture for a long time are prone to musculoskeletal diseases. Therefore, it is of great significance to understand and improve sitting posture through biomechanical simulation modeling. In this context, the human-chair system model needs to reflect the real human-chair coupling relationship. Therefore, adjusting the human-chair coupling relationship in simulation modeling to a state that conforms to reality becomes the key to ensure the accuracy of biomechanical analysis.

[0003] The current method for adjusting the human-chair coupling relationship usually sets the human-chair contact point at the pressure peak or pressure center of the buttocks for the driving sitting posture. However, this method has some limitations: on the one hand, this method is only applicable to a single sitting posture constrained by the seat space to ensure that the contact point position is consistent with the pressure distribution. For other sitting postures, the position of the contact point needs to be adjusted according to the actual situation. Specifically, different sitting postures will cause changes in the pressure peak and pressure center positions, but once the position of the human-chair contact point is set in the model, it will not change with the change of pressure distribution. On the other hand, each person's body structure and sitting habits are different, and the existing method for adjusting the human-chair coupling relationship fails to fully consider these individual differences. Since the sitting posture of office workers is not constrained, their sitting posture and seating conditions are uncertain, which puts higher requirements on the method for adjusting the human-chair coupling relationship.

[0004] From an anatomical point of view, the contact points should be set at key parts of the human body such as the ischial tuberosity. On this basis, the force conditions of the contact points are determined according to the actual pressure distribution data, and the human-chair coupling relationship is optimized by narrowing the gap between the actual situation and the simulation situation, thereby avoiding biomechanical analysis errors caused by inaccurate human-chair coupling relationship. Therefore, how to improve the accuracy of the human-chair coupling relationship when the sitting posture is not constrained is one of the problems that need to be solved urgently. Summary of the invention

[0005] In view of the deficiencies in the prior art, embodiments of the present invention provide a method, device, electronic device and medium for adjusting a person-chair coupling relationship.

[0006] In a first aspect, an embodiment of the present invention provides a method for adjusting a person-chair coupling relationship, the method comprising:

[0007] Establish a human body model and a seat model in the same spatial coordinate system;

[0008] Symmetrically set a number of first key contact points at the target parts on the left and right sides of the human body; adjust the human body model and the seat model, and when the simulated contact forces at the first key contact points are all non-zero, obtain the initial human-seat coupling relationship; obtain the simulated contact forces at the target parts on the left and right sides of the human body;

[0009] Identify the actual pressure distribution at the first key contact points; respectively take the left and right maximum force areas on the same horizontal line as the areas where the left and right target parts of the human body are located; take the position where the left pressure peak is located within the area where the left target part of the human body is located as the position of the left target part of the human body, and take the position where the right pressure peak is located within the area where the right target part of the human body is located as the position of the right target part of the human body;

[0010] Extract the gradient values of the actual pressure distribution, so as to obtain the force ranges of the target parts on the left and right sides of the human body; respectively accumulate the pressure values within the force ranges of the target parts on the left and right sides of the human body to obtain the actual contact forces of the target parts on the left and right sides of the human body;

[0011] Aiming to minimize the difference between the simulated contact forces and the actual contact forces at the target parts on the left and right sides of the human body, obtain the offset and rotation amount of the seat center line through the positions of the target parts on the left and right sides of the human body, and adjust the offset and rotation amount of the seat center line and / or the seat height to iteratively optimize the human-seat coupling relationship.

[0012] In a second aspect, an embodiment of the present invention provides a human-seat coupling relationship adjustment system, and the system includes:

[0013] A human-seat coupling relationship initialization module, which is used to establish a human body model and a seat model in the same space coordinate system; symmetrically set a number of first key contact points at the target parts on the left and right sides of the human body; adjust the human body model and the seat model, and when the simulated contact forces at the first key contact points are all non-zero, obtain the initial human-seat coupling relationship; obtain the simulated contact forces at the target parts on the left and right sides of the human body;

[0014] A human body target part position recognition module, which is used to identify the actual pressure distribution at the first key contact points; respectively take the left and right maximum force areas on the same horizontal line as the areas where the left and right target parts of the human body are located; take the position where the left pressure peak is located within the area where the left target part of the human body is located as the position of the left target part of the human body, and take the position where the right pressure peak is located within the area where the right target part of the human body is located as the position of the right target part of the human body;

[0015] The human body target part actual contact force acquisition module is used to extract the gradient value of the actual pressure distribution, so as to obtain the force-bearing ranges of the target parts on the left and right sides of the human body; the pressure values within the force-bearing ranges of the target parts on the left and right sides of the human body are respectively accumulated to obtain the actual contact forces of the target parts on the left and right sides of the human body.

[0016] The human-chair coupling relationship optimization module aims to minimize the difference between the simulated contact forces and the actual contact forces at the target parts on the left and right sides of the human body, and obtains the offset and rotation amounts of the seat center line through the positions of the target parts on the left and right sides of the human body, and adjusts the offset and rotation amounts of the seat center line and / or the seat height to iteratively optimize the human-chair coupling relationship.

[0017] In a third aspect, an embodiment of the present invention provides an electronic device, including a memory and a processor, and the memory is coupled to the processor; wherein, the memory is used to store program data, and the processor is used to execute the program data to implement the above-mentioned human-chair coupling relationship adjustment method.

[0018] In a fourth aspect, an embodiment of the present invention provides a computer-readable storage medium, on which a computer program is stored, and when the program is executed by a processor, the above-mentioned human-chair coupling relationship adjustment method is implemented.

[0019] In a fifth aspect, an embodiment of the present invention provides a computer program product, including a computer program / instructions, and when the computer program / instructions are executed by a processor, the above-mentioned human-chair coupling relationship adjustment method is implemented.

[0020] Compared with the prior art, the beneficial effects of the present invention are:

[0021] The present invention provides a human-chair coupling relationship adjustment method. By symmetrically arranging a number of first key contact points at the target parts on the left and right sides of the human body, adjusting the simulated contact forces at the first key contact points to be non-zero to obtain an initial human-chair coupling relationship, and obtaining the simulated contact forces at the target parts on the left and right sides of the human body; detecting the actual pressure distribution at the first key contact points, and determining the positions and actual contact forces of the target parts on the left and right sides of the human body through the analysis of the actual pressure distribution; aiming to minimize the difference between the simulated contact forces and the actual contact forces at the target parts on the left and right sides of the human body, adjusting the spatial position parameters of the seat including the offset, rotation amount and / or height, so as to iteratively optimize the human-chair coupling relationship to truly reflect the human-chair coupling relationship under the condition that the sitting posture is not restricted. Description of the Drawings

[0022] To more clearly illustrate the technical solutions in the embodiments of the present invention, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0023] Figure 1 It is a schematic flowchart of a method for adjusting the human-chair coupling relationship provided by an embodiment of the present invention;

[0024] Figure 2 It is a schematic diagram of setting the first key contact point provided by an embodiment of the present invention;

[0025] Figure 3 It is a schematic diagram of calculating the actual contact forces of the target parts on the left and right sides of the human body provided by an embodiment of the present invention;

[0026] Figure 4 It is a schematic diagram of a human-chair coupling relationship adjustment system provided by an embodiment of the present invention;

[0027] Figure 5 It is a schematic diagram of an electronic device provided by an embodiment of the present invention. Detailed implementation manners

[0028] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the drawings in the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, rather than all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention.

[0029] It should be noted that, without conflict, the features in the following embodiments and implementation manners can be combined with each other.

[0030] Embodiment 1

[0031] As Figure 1 shown, in this example, the ischial tuberosity of the buttocks is used as the target part to elaborate on the execution process of a method for adjusting the human-chair coupling relationship provided by the present invention to solve the problem of optimizing the human-chair coupling relationship. The method includes the following steps:

[0032] Step S1, establish a human body model and a seat model in the same spatial coordinate system.

[0033] Specifically, the human body model includes, but is not limited to, parts such as the head, back, buttocks, thighs, calves, and feet. Each part is simplified into multiple rigid bodies with unchanged shapes and sizes, and is connected in the form of hinges to form a multi-rigid body model. Further, the human body model is required to be consistent with the height, weight, etc. of the experimenter.

[0034] The seat model is a rigid body model including the seat geometry, structure, and dimensions.

[0035] Step S2, symmetrically set a number of first key contact points at the target parts on the left and right sides of the human body; adjust the human body model and the seat model. When the simulated contact forces at the first key contact points are all non-zero, obtain the initial human-seat coupling relationship. After obtaining the initial human-seat coupling relationship, perform simulation and calculate the simulated contact forces at the target parts on the left and right sides of the human body respectively.

[0036] Specifically, in this example, the ischial tuberosity of the buttocks is used as the target part to simulate the actual contact situation between the human buttocks and the seat surface; in this example, as Figure 2 shown, 7 groups of left and right symmetric first key contact points are set at the ischial tuberosity of the buttocks and the posterior side of the thigh muscles, a total of 14 first key contact points.

[0037] Further, the process of obtaining the initial human-seat coupling relationship includes:

[0038] Set the spatial position parameters of the seat. The spatial position parameters of the seat include the coordinates, height, and rotation angle of the seat;

[0039] Place the seat under the human body model and set the seat direction to be the same as the human body orientation;

[0040] Perform inverse dynamics analysis on the current human body model and seat model, and calculate the simulated contact forces at the first key contact points; if the simulated contact force at a certain first key contact point is zero, then adjust the spatial position parameters of the seat until the simulated contact forces at the first key contact points are all non-zero, and obtain the initial human-seat coupling relationship. In this embodiment, the simulated contact forces at the first key contact points are all non-zero, which can be expressed as:

[0041] F k ≠0, k = 1, 2, …, K

[0042] In the formula, F k represents the simulated contact force at the kth first key contact point, with the unit of Newton; k represents the kth first key contact point, and K represents the number of first key contact points. In this example, K = 14.

[0043] It should be noted that if the simulated contact force at a certain first key contact point is zero, the spatial position parameters of the seat model are adjusted for the next time; after adjusting the spatial position parameters of the seat model each time, the simulated contact force at the first key contact point is recalculated to check the effect of the adjustment. When the simulated contact forces at all the first key contact points are not zero, it indicates that the human body model and the seat model are in correct contact. Ensure that each first key contact point can generate a simulated contact force, and record the simulated contact force at each first key contact point.

[0044] Exemplarily, taking a female experimenter with a height of 170 cm and a weight of 60.5 kg as an example, the initial human-seat coupling relationship is described. Specifically, it includes:

[0045] In this embodiment, the origin of the spatial coordinate system is (0, 0, 0), the initial coordinates of the seat are (-1.450 m, 0.450 m, 0.050 m), and the initial rotation angle is 0°. Among them, the origin of the seat is at the center of the seat surface, that is, the initial seat surface height is 45 cm.

[0046] Among them, the first item in the parentheses is the X-axis coordinate, the second item is the Y-axis coordinate, and the third item is the Z-axis coordinate. The positive direction of the X-axis corresponds to the left side of the human body, the positive direction of the Z-axis corresponds to the front side of the human body, and the positive direction of the Y-axis corresponds to the upper side of the human body.

[0047] The process of performing the first adjustment of the spatial position parameters of the seat model includes: setting the coordinates of the seat to (-1.850 m, 0.450 m, -0.130 m) and the rotation angle to +7°, so that the seat model is located below the human body model and has the same orientation. At this time, the calculated simulated contact forces from F 1 to F 14 are all 0. Therefore, the second adjustment is carried out in units of increasing the seat surface height by 1 cm, that is, the seat coordinates are increased by 1 cm along the positive direction of the Y-axis. At this time, the simulated contact forces from F 1 to F 4 are still 0. Continue to perform the third adjustment, increasing by 1 cm along the Y-axis direction. At this time, the simulated contact forces from F 1 to F 2 are still 0. Continue to perform the fourth adjustment. At this time, the simulated contact forces from F 1 to F 14 are all not 0. After adjusting the spatial position parameters of the seat model four times, the spatial coordinates of the seat are (-1.850 m, 0.480 m, -0.130 m), the rotation angle is +7°, and the seat surface height is 48 cm.

[0048] After initializing the human-seat coupling relationship, calculate the simulated contact forces at the target parts on the left and right sides of the human body , and obtain the simulated contact forces at the left and right ischial tuberosities and They are 69.42 N and 65.33 N respectively.

[0049] Step S3: Identify the actual pressure distribution at the first key contact point; take the left and right maximum stress regions on the same horizontal line as the regions where the left and right target body parts of the human body are located respectively; take the position where the left pressure peak is located within the region where the left target body part of the human body is located as the position of the left target body part of the human body, and take the position where the right pressure peak is located within the region where the right target body part of the human body is located as the position of the right target body part of the human body.

[0050] Specifically, step S3 includes the following sub-steps:

[0051] Step S301: Measure the actual pressure distribution at the first key contact point through a sensor array.

[0052] Specifically, a plurality of independent sensing units are arranged in an array on the seat, and each sensing unit can independently measure the pressure value at its location. In this embodiment, the pressure sensor is a 32×32 array thin-film pressure sensor. These sensors are evenly distributed on the seat cushion, covering the contact areas between the left and right target parts and the seat, and can accurately collect the pressure distribution data of the contact surface between the experimenter and the seat.

[0053] Furthermore, taking the standard upright sitting posture as an example, the experimenter sits on the sitting posture acquisition seat equipped with pressure sensors. The upright sitting posture refers to a relatively common sitting posture, that is, a sitting posture with relaxed shoulders, feet flat on the ground, and back straight. Then, start the pressure sensors and perform data acquisition for more than 5 seconds. During this period, the experimenter should keep the body center of gravity of the experimenter falling between the two ischial tuberosities to reduce the pressure distribution changes caused by body movement and tilt. During the data acquisition process, each pressure reading is sequentially arranged and stored with a timestamp as a label. This can ensure the timeliness of the data and facilitate the one-to-one correspondence between the actual contact force and the simulated contact force.

[0054] In this embodiment, the pressure distribution data corresponding to each timestamp is recorded as a 32×32 pressure matrix, and this matrix contains the collection of pressure values collected by the entire sensor array. This matrix represents the pressure distribution on the seat, where each matrix element corresponds to a sensing unit on the seat and generates a pressure value.

[0055] Since the pressure values recorded by the sensors are usually numerical values represented by the digital range of the sensors (such as integers in the range of 0 - 255), it is necessary to convert these range values into actual contact forces through corresponding force conversion formulas, with the unit being Newton (N). In this embodiment, the size of one sensing unit is 1.4732 cm × 1.4732 cm, and the digital range of 255 represents 34.47 kPa. Therefore, the calculation formula for the unit contact force Force of each sensing unit is:

[0056]

[0057] Furthermore, the pressure distribution data is stored for further analysis and processing; after the data acquisition is completed, it also includes a preliminary check of the collected data to check for outliers or data missing due to sensor failures, so as to ensure the integrity and accuracy of the data.

[0058] Step S302, identify the actual pressure distribution at the first key contact point, and take the left and right maximum force - bearing areas on the same horizontal line as the areas where the left - hand target part of the human body and the right - hand target part of the human body are located respectively.

[0059] Specifically, in this embodiment, first, the standard force - bearing range of the ischial tuberosity is defined as a region of 4 cm × 4 cm, that is, the initial window size w s is 3, representing 3×3 units. The sliding window algorithm is used to identify the area S L where the left - hand target part of the human body is located and the area S R where the right - hand target part of the human body is located; if the area S L where the left - hand ischial tuberosity of the human body is located and the area S R where the right - hand ischial tuberosity of the human body is located are not on the same horizontal line, then the initial window size is gradually adjusted to w s =w s +1 until the area S L where the left - hand ischial tuberosity of the human body is located and the area S R where the right - hand ischial tuberosity of the human body is located are basically symmetric.

[0060] Step S303, identify the actual pressure distribution at the first key contact point, and obtain the positions where the left - hand pressure peak and the right - hand pressure peak are located.

[0061] Specifically, since the pressure peak usually appears near the ischial tuberosity, but not necessarily at the center position of the area where the ischial tuberosity is located; therefore, in this example, the double - peak detection algorithm is used to detect the positions where the left - hand and right - hand pressure peaks are located, denoted as the position P L where the left - hand pressure peak is located and the position P R where the right - hand pressure peak is located.

[0062] Step S304: Determine whether the position where the left pressure peak is located and the position where the right pressure peak is located are in the area of the left target part of the human body and the area of the right target part of the human body;

[0063] If the position where the left pressure peak is located is within the area of the left target part of the human body, then take the current position where the left pressure peak is located as the position of the left target part of the human body; if the position where the right pressure peak is located is within the area of the right target part of the human body, then take the current position where the right pressure peak is located as the position of the right target part of the human body;

[0064] If the position where the left pressure peak is located is not within the area of the left target part of the human body, then traverse the next left pressure peak until a left pressure peak located within the area of the left target part of the human body is found; if the position where the right pressure peak is located is not within the area of the right target part of the human body, then traverse the next right pressure peak until a right pressure peak located within the area of the right target part of the human body is found.

[0065] Exemplarily, in this example, the actual pressure distribution at the first key contact point is analyzed by the sliding window algorithm to obtain the area S of the left ischial tuberosity of the human body L and the area S of the right ischial tuberosity of the human body R ; The double-peak detection algorithm is used to detect the actual pressure distribution at the first key contact point to obtain the position P where the left pressure peak is located L and the position P where the right pressure peak is located R . Determine whether the position P where the left pressure peak is located L is within the area S of the left ischial tuberosity of the human body L , and determine whether the position P where the right pressure peak is located R is within the area S of the right ischial tuberosity of the human body R . If the position P where the left pressure peak is located L is within the area S of the left ischial tuberosity of the human body L , then take the current position P where the left pressure peak is located L as the position P of the left ischial tuberosity SL ; otherwise, traverse the next left pressure peak until a left pressure peak located within the area S of the left ischial tuberosity of the human body is found. If the position P where the right pressure peak is located L is within the area S of the right ischial tuberosity of the human body R , then take the current position P where the right pressure peak is located R as the position P of the right ischial tuberosity R ; otherwise, traverse the next right pressure peak until a right pressure peak located within the area S of the right ischial tuberosity of the human body is found. RL ; Otherwise, traverse the next right pressure peak until a right pressure peak located within the area S of the right ischial tuberosity of the human body is found.R The right pressure peak value inside.

[0066] Step S4: Extract the gradient value of the actual pressure distribution to obtain the force-bearing ranges of the target parts on the left and right sides of the human body; respectively accumulate the pressure values within the force-bearing ranges of the target parts on the left and right sides of the human body to obtain the actual contact forces of the target parts on the left and right sides of the human body.

[0067] Specifically, the step S4 includes the following sub-steps:

[0068] Step S401: Extract the gradient value of the actual pressure distribution.

[0069] In this embodiment, the pressure image feature includes the vertical direction gradient value G x (x, y) and the horizontal direction gradient value G y (x, y), as well as the gradient direction θ. The first overall gradient value corresponding to the area where the target part on the left side of the human body is located is denoted as , and the second overall gradient value corresponding to the area where the target part on the right side of the human body is located is denoted as . Among them, the horizontal direction x corresponds to the rows of the pressure matrix, the vertical direction y corresponds to the columns of the pressure matrix, and the first row and the first column of the matrix are the origin (0, 0).

[0070] Specifically, since the personal body shape will affect the pressure distribution image, the force-bearing range at the first key contact point may exceed the standard force-bearing range. According to the characteristic that the change of the pressure gradient at the target part is the largest, in this embodiment, each sensing unit is regarded as a pixel point, and the HOG algorithm is used to detect the local gradient feature of the pressure distribution image, and the gradient magnitude G(x, y) and the gradient direction θ of each sensing unit (x, y) are obtained. The expressions are as follows:

[0071]

[0072]

[0073]

[0074]

[0075] In the formula, I(x, y) is the pressure value at the point (x, y), G x (x, y) and G y (x, y) respectively represent the vertical direction gradient value and the horizontal direction gradient value. Among them, x represents the x-th row of the matrix, and y represents the y-th column of the matrix.

[0076] According to the characteristics of the 32×32 pressure matrix, set the HOG parameters Cell=(32×32), Block=(1×1), and orientations=9. The obtained HOG gradient image can well describe the edge sharpness of the target part.

[0077] Among them, the meanings of the HOG parameters are as follows: divide the pressure matrix into 8×8 cell units, 1×1 block images, divide the gradient direction into 9 units, and each unit corresponds to 20°.

[0078] Step S402, accumulate the gradient values in the area where the left target part of the human body is located and the area where the right target part of the human body is located, to obtain the first overall gradient value corresponding to the area where the left target part of the human body is located, and the second overall gradient value corresponding to the area where the right target part of the human body is located.

[0079] In this embodiment, use the finite set to represent the area where the unilateral target part is located in the gradient image. First, perform normalization processing on the gradient information, and then calculate the overall gradient value of the unilateral first key contact point, which can be expressed as:

[0080]

[0081] Denote the first overall gradient value corresponding to the area where the left target part of the human body is located as , and denote the second overall gradient value corresponding to the area where the right target part of the human body is located as

[0082] Step S403, set the sharpness threshold, and obtain the force ranges of the left and right target parts of the human body according to the first overall gradient value, the second overall gradient value, and the sharpness threshold.

[0083] Specifically, as Figure 3 shown, the higher the overall gradient value, the more obvious the human target part is shown in the gradient image, and the more concentrated the force range is; on the contrary, the lower the overall gradient value indicates that the human target part is more difficult to distinguish, and the corresponding force range increases accordingly. It is necessary to determine a sharpness threshold. According to the above local gradient characteristics, when the characteristics of the human target part are obvious, the area S L where the left target part of the human body is located and the area S R where the right target part of the human body is located correspond to a square with a side length of w s ; when the characteristics of the human target part are difficult to distinguish, the force ranges of the left and right target parts of the human body increase by one unit in each direction, corresponding to a square with a side length of (w s +2).

[0084] Therefore, according to the actual situation, this embodiment sets the clarity threshold w' to 10, and the corresponding expression of the force range w of the target part of the human body is as follows:

[0085]

[0086] Wherein, in this example, w'=10.

[0087] Step S404, respectively accumulating the pressure values ​​within the force range of the target parts on the left side and the right side of the human body to obtain the actual contact forces of the target parts on the left side and the right side of the human body.

[0088]

[0089] Among them, the finite set W represents the force range of the unilateral target part in the gradient image, F(x, y) is the pressure value of each sensing unit (x, y), and Force is the unit contact force of each unit.

[0090] For example, a female subject with a height of 170 cm and a weight of 60.5 kg is taken as an example to illustrate the calculation of ischial tuberosity information data. Specifically, it includes:

[0091] Taking the actual pressure distribution data of the human-chair contact surface collected by the pressure sensor at the first time as an example, the actual pressure distribution data is a 32×32 matrix M.

[0092] Among them, in the ischial tuberosity position recognition stage, after sliding the window twice, the window size is w s When the value is 4, the basically symmetrical ischial tuberosity area is found, and the left ischial tuberosity position P is detected. SL is (8, 12), the right ischial tuberosity position P RL is (8, 22).

[0093] The first item in the brackets is the row number corresponding to the ischial tuberosity position, and the second item is the column number corresponding to the ischial tuberosity position. The first row and first column of the matrix M corresponds to the upper left corner of the actual pressure distribution data.

[0094] In the ischial tuberosity force range identification stage, according to the characteristics of the 32×32 pressure matrix, the HOG parameters Cell=(8×8), Block=(1×1), orientations=9 are applied to obtain the gradient size, gradient direction, and HOG gradient image of each pressure point.

[0095] Among them, both the gradient magnitude and the gradient direction are matrices of 32×32, with a total of 4×4 Cells. According to the HOG gradient image, the clarity of the ischial tuberosity is average. The position of the left ischial tuberosity corresponds to the Cell in the second row and the second column, and the position of the right ischial tuberosity corresponds to the Cell in the second row and the third column. After normalizing the gradient information, the overall gradient value at the left ischial tuberosity is output is 7.98, and the right one is 7.45. According to the above calculation formula, the corresponding force range w of the ischial tuberosity is 5. According to the force range of the individual's ischial tuberosity, the actual contact forces at the left and right ischial tuberosities are calculated and are 70.72N and 64.61N respectively.

[0096] Step S5: Aiming to minimize the difference between the simulated contact force and the actual contact force, obtain the offset and rotation amount of the seat center line through the positions of the left and right target parts of the human body, and adjust the offset, rotation amount of the seat center line and the seat height to iteratively optimize the human-seat coupling relationship.

[0097] Minimize the difference between the simulated contact force and the actual contact force, and the expression is as follows:

[0098]

[0099] In the formula, represents the difference between the simulated contact force and the actual contact force at the unilateral target position, represents the simulated contact force at the unilateral target position, represents the actual contact force at the unilateral target position.

[0100] According to the center line coordinates of the sensor array for measuring the actual pressure distribution at the first key contact point, the side length of the sensor element, and the mean of the column numbers where the left target part of the human body is located and the column numbers where the right target part of the human body is located, set the offset of the seat center line; the expression is as follows:

[0101]

[0102] In the formula, d 1 represents the center line coordinates of the sensor array for measuring the actual pressure distribution at the first key contact point, represents the column number where the left target part of the human body is located, represents the column number where the right target part of the human body is located, d 2 represents the side length of the sensor element.

[0103] Exemplarily, in this example, the pressure distribution data is recorded as a 32×32 pressure matrix. The first row and the first column of the matrix are the origin (0, 0), and the row and column coordinate ranges are 0 to 31. Then d 1 = 15.5. The size of a sensing unit in the sensor array is 1.4732 cm × 1.4732 cm. Then d 2 = 1.4732.

[0104] Set the rotation amount of the seat center line according to the difference between the row numbers where the left and right target parts of the human body are located, and the difference between the column numbers where the left and right target parts of the human body are located.

[0105]

[0106] In the formula, α represents the rotation amount of the seat center line. represents the column number where the left target part of the human body is located. represents the column number where the right target part of the human body is located. represents the row number where the left target part of the human body is located. represents the row number where the right target part of the human body is located.

[0107] Exemplarily, taking a female experimenter with a height of 170 cm and a weight of 60.5 kg as an example, the adjustment of the human-seat coupling relationship is described. Specifically, it includes:

[0108] The current position P of the left ischial tuberosity SL is (8, 12). The current position P of the right ischial tuberosity RL is (8, 22). The actual contact force at the left ischial tuberosity position is 70.72 N, the actual contact force at the right ischial tuberosity position is 64.61 N, the simulated contact force at the left ischial tuberosity position is 69.42 N, and the simulated contact force at the right ischial tuberosity position is 65.33 N.

[0109] Taking the minimization of the difference between the simulated contact force and the actual contact force at the left and right target parts of the human body as the optimization goal, according to this optimization goal, the differences between the simulated contact force and the actual contact force at the left and right target parts of the human body are calculated to be 1.30 N and 0.72 N respectively.

[0110] The offset amount of the seat center line is calculated to be -2.2 cm, indicating that the center of the human ischial tuberosity is 2.2 cm to the right of the seat center line. Therefore, the seat needs to move 2.2 cm in the negative X-axis direction of the spatial coordinate; at the same time, the calculated rotation amount α of the seat center line is 0°, so there is no need to adjust the rotation angle.

[0111] Based on this, after updating the spatial position parameters of the seat, the simulated contact forces at the left and right target parts of the human body are still 69.42 N and 65.33 N, and the differences between the simulated contact forces and the actual contact forces at the left and right target parts of the human body are determined. The minimum values are 1.30 N and 0.72 N.

[0112] Finally, the spatial coordinates of the seat are determined to be (-1.872 m, 0.480 m, -0.130 m), and the rotation angle is +7°. The adjustment of the human-seat coupling relationship is completed. At this time, the simulated contact forces at the left and right target parts of the human body are closest to the actual contact forces.

[0113] Embodiment 2

[0114] In this example, the execution process of a method for adjusting the human-seat coupling relationship provided by the present invention is described with the key parts of the human back as the target parts to solve the problem of optimizing the human-seat coupling relationship. The method includes the following steps:

[0115] Step S1, establish a human body model and a seat model in the same spatial coordinate system.

[0116] Step S2, symmetrically set a number of first key contact points at the left and right target parts of the human body; adjust the human body model and the seat model. When the simulated contact forces at the first key contact points are all non-zero, obtain the initial human-seat coupling relationship; obtain the simulated contact forces at the left and right target parts of the human body.

[0117] In this example, taking the back as the target part, three groups of contact points are symmetrically set on the left and right at the key parts of the human back including the trapezius muscle and the lateral latissimus dorsi muscle, for a total of 6 first key contact points.

[0118] Among them, the process of obtaining the initial human-seat coupling relationship includes:

[0119] Set the spatial position parameters of the seat, and the spatial position parameters of the seat include the coordinates, height, and rotation angle of the seat;

[0120] Place the seat under the human body model, with the backrest behind the human body, and set the seat direction to be the same as the human body orientation;

[0121] Perform inverse dynamics analysis on the current human body model and seat model, and calculate the simulated contact forces at the first key contact points; if the simulated contact force at a certain first key contact point is zero, adjust the spatial position parameters of the seat until the simulated contact forces at the first key contact points are all non-zero, and obtain the initial human-seat coupling relationship.

[0122] Exemplarily, taking a female experimenter with a height of 170 cm and a weight of 60.5 kg as an example, the initial human-chair coupling relationship is described as follows:

[0123] The origin of the space coordinate system is (0, 0, 0), the initial coordinates of the seat are (-1.450 m, 0.450 m, 0.050 m), and the initial rotation angle is 0°. Among them, the origin of the seat is at the center of the seat surface, that is, the initial seat surface height is 45 cm.

[0124] Among them, the first item in the parentheses is the X-axis coordinate, the second item is the Y-axis coordinate, and the third item is the Z-axis coordinate. The positive direction of the X-axis corresponds to the left side of the human body, the positive direction of the Z-axis corresponds to the front side of the human body, and the positive direction of the Y-axis corresponds to the upper side of the human body.

[0125] The initial spatial coordinates of the seat are (-1.850 m, 0.480 m, -0.130 m), and the rotation angle is +7°. At this time, the simulated contact forces of F 1 to F 6 are all 0. Therefore, the first adjustment is made with a 1 cm forward adjustment of the backrest, that is, the seat coordinates increase by 1 cm along the positive direction of the Z-axis. At this time, F 1 to F 6 are still 0. Continue the second adjustment, increasing by 1 cm along the Z-axis direction. At this time, F 3 to F 6 are still 0. Continue the third adjustment, increasing by 1 cm along the Z-axis direction. At this time, F 5 to F 6 are still 0. Continue the fourth adjustment, increasing by 1 cm along the Z-axis direction. At this time, the simulated contact forces of F 1 to F 6 are not all 0. After four adjustments of the spatial position parameters of the seat model, the spatial coordinates of the seat are (-1.850 m, 0.480 m, -0.090 m), and the rotation angle is +7°.

[0126] After completing the initialization of the human-chair coupling relationship, calculate the simulated contact forces at the target parts on the left and right sides of the human body , and obtain the simulated contact forces at the key parts on the left and right sides of the back and which are 10.43 N and 11.24 N respectively.

[0127] Step S3: Identify the actual pressure distribution at the first key contact point; take the left and right maximum stress regions on the same horizontal line as the regions where the left and right target body parts of the human body are located respectively; take the position where the left pressure peak is located within the region where the left target body part of the human body is located as the position of the left target body part of the human body, and take the position where the right pressure peak is located within the region where the right target body part of the human body is located as the position of the right target body part of the human body.

[0128] Further, in this example, the pressure sensor is a 32×32 array thin-film pressure sensor. These sensors are evenly distributed on the backrest of the seat, covering the contact area between the key back parts and the seat, and can accurately collect the pressure distribution data of the contact surface between the experimenter and the seat.

[0129] Step S4: Extract the gradient values of the actual pressure distribution to obtain the force-bearing ranges of the left and right target body parts of the human body; respectively accumulate the pressure values within the force-bearing ranges of the left and right target body parts of the human body to obtain the actual contact forces of the left and right target body parts of the human body.

[0130] Exemplarily, taking a female experimenter with a height of 170 cm and a weight of 60.5 kg as an example, the calculation of the key back part information data is described. Specifically, it includes:

[0131] Specifically, a 32×32 array thin-film pressure sensor is arranged on the backrest of the seat to collect the actual pressure distribution data of the human-seat contact surface, and the actual pressure distribution is a 32×32 matrix M.

[0132] Analyze the actual pressure distribution at the first key contact point through the sliding window algorithm. After traversing the sliding window twice, when the window size w s is 4, the region where the key back part is located with basic symmetry is found, and the position P SL of the left key back part of the human body is detected as (10, 9), and the position P RL of the right key back part of the human body is (10, 23).

[0133] Among them, the first item in the brackets is the row number corresponding to the position of the key back part, and the second item is the column number corresponding to the position of the key back part. The first row and first column of the matrix M correspond to the upper left corner of the actual pressure distribution data.

[0134] In the ischial tuberosity range recognition model stage, according to the characteristics of the 32×32 pressure matrix, applying the HOG parameters Cell = (8×8), Block = (1×1), orientations = 9, the gradient magnitude, gradient direction, and HOG gradient image of each pressure point are obtained.

[0135] Among them, both the gradient magnitude and the gradient direction are matrices of 32×32, and there are 4×4 cells in total. According to the HOG gradient image, the clarity of the key parts of the back is average. The position of the key part on the left back corresponds to the cell in the second column of the first row, and the position of the key part on the right back corresponds to the cell in the third column of the first row. Output the overall gradient value at the key part on the left back is 3.56, and that on the right is 3.35. According to the above calculation formula, the corresponding force range w of the key parts of the back is 6. According to the force range of the key parts of the back of the individual, calculate the actual contact forces of the key parts on the left and right backs and are 10.82N and 12.16N respectively.

[0136] Step S5: Aiming to minimize the difference between the simulated contact force and the actual contact force at the target parts on the left and right sides of the human body, obtain the offset and rotation amount of the seat center line through the positions of the target parts on the left and right sides of the human body, and adjust the offset, rotation amount, and seat height of the seat center line to iteratively optimize the human-seat coupling relationship.

[0137] Exemplarily, taking a female experimenter with a height of 170 cm and a weight of 60.5 kg as an example, illustrate the adjustment of the human-seat coupling relationship. Specifically include:

[0138] The current position P SL of the key part on the left back is (10, 9), and the current position P RL of the key part on the right back is (10, 23). The actual contact force at the position of the key part on the left back is 10.43N, the actual contact force at the position of the key part on the right back is 11.24N, the simulated contact force at the position of the key part on the left back is 10.82N, and the simulated contact force at the position of the key part on the right back is 12.16N.

[0139] Aiming to minimize the difference between the simulated contact force and the actual contact force at the target parts on the left and right sides of the human body as the optimization goal, according to this optimization goal, calculate the differences between the simulated contact force and the actual contact force at the target parts on the left and right sides of the human body are 0.39N and 0.92N respectively.

[0140] Calculate the offset of the seat center line is -0.7 cm, indicating that the center of the key part of the human back is 0.7 cm to the right of the seat center line. Therefore, the seat needs to move 0.7 cm in the negative X-axis direction of the space coordinate; at the same time, calculate that the rotation amount α of the seat center line is 0°, so there is no need to adjust the rotation angle.

[0141] Based on this, after updating the spatial position parameters of the seat, the simulated contact forces at the target parts on the left and right sides of the human body are still 10.82 N and 12.16 N, and the differences between the simulated contact forces and the actual contact forces at the target parts on the left and right sides of the human body are determined. The minimum values are 0.39 N and 0.92 N.

[0142] Finally, the spatial coordinates of the seat are determined to be (-1.857 m, 0.480 m, -0.090 m), and the rotation angle is +7°. The adjustment of the human-seat coupling relationship is completed. At this time, the simulated contact forces at the target parts on the left and right sides of the human body are closest to the actual contact forces.

[0143] On the other hand, as Figure 4 shown, an embodiment of the present invention provides a human-seat coupling relationship adjustment system, and the system includes:

[0144] A human-seat coupling relationship initialization module, configured to establish a human body model and a seat model in the same spatial coordinate system; symmetrically set a plurality of first key contact points at the target parts on the left and right sides of the human body; adjust the human body model and the seat model, and when the simulated contact forces at the first key contact points are all non-zero, obtain the initial human-seat coupling relationship; obtain the simulated contact forces at the target parts on the left and right sides of the human body;

[0145] A human body target part position recognition module, configured to recognize the actual pressure distribution at the first key contact points; respectively use the left and right maximum force regions on the same horizontal line as the regions where the target parts on the left and right sides of the human body are located; use the position where the left pressure peak is located within the region where the target part on the left side of the human body is located as the position of the target part on the left side of the human body, and use the position where the right pressure peak is located within the region where the target part on the right side of the human body is located as the position of the target part on the right side of the human body;

[0146] A human body target part actual contact force acquisition module, configured to extract the gradient values of the actual pressure distribution, so as to obtain the force ranges of the target parts on the left and right sides of the human body; respectively accumulate the pressure values within the force ranges of the target parts on the left and right sides of the human body to obtain the actual contact forces of the target parts on the left and right sides of the human body;

[0147] A human-seat coupling relationship optimization module, configured to aim at minimizing the differences between the simulated contact forces and the actual contact forces at the target parts on the left and right sides of the human body, and obtain the offset amount and rotation amount of the seat center line through the positions of the target parts on the left and right sides of the human body, and adjust the offset amount, rotation amount and height of the seat center line to iteratively optimize the human-seat coupling relationship.

[0148] Regarding the system in the above embodiments, the specific manner in which each module performs operations has been described in detail in the embodiments related to the method, and will not be elaborated here.

[0149] For the system embodiments, since they basically correspond to the method embodiments, the relevant parts can be referred to the descriptions in the method embodiments. The system embodiments described above are merely illustrative. The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed to multiple network units. Some or all of the modules can be selected according to actual needs to achieve the purpose of the solution of this application. Those of ordinary skill in the art can understand and implement it without creative efforts.

[0150] Correspondingly, this application also provides an electronic device, including: one or more processors; a memory for storing one or more programs; when the one or more programs are executed by the one or more processors, the one or more processors implement the human-chair coupling relationship adjustment method as described above. As Figure 5 shown, it is a hardware structure diagram of any device with data processing capabilities where the human-chair coupling relationship adjustment method provided by the embodiment of the present invention is located. In addition to Figure 5 the processors, memory, and network interfaces shown, any device with data processing capabilities where the device in the embodiment is located usually also includes other hardware according to the actual functions of the device with data processing capabilities, which will not be elaborated here.

[0151] Correspondingly, this application also provides a computer-readable storage medium, on which computer instructions are stored, and when the instructions are executed by a processor, the human-chair coupling relationship adjustment method as described above is implemented. The computer-readable storage medium can be an internal storage unit of any device with data processing capabilities described in any of the foregoing embodiments, such as a hard disk or memory. The computer-readable storage medium can also be an external storage device, such as a plug-in hard disk, a smart media card (SMC), an SD card, a flash card, etc. equipped on the device. Further, the computer-readable storage medium can also include both the internal storage unit and the external storage device of any device with data processing capabilities. The computer-readable storage medium is used to store the computer program and other programs and data required by any device with data processing capabilities, and can also be used to temporarily store the data that has been output or will be output.

[0152] The above embodiments are only used to illustrate the design concept and characteristics of the present invention, and the purpose is to enable those skilled in the art to understand the content of the present invention and implement it accordingly. The protection scope of the present invention is not limited to the above embodiments. Therefore, all equivalent changes or modifications made according to the principles and design concepts disclosed by the present invention are within the protection scope of the present invention.

Claims

1. A method for adjusting a person-chair coupling relationship, characterized in that: The method comprises: Establish a human body model and a seat model in the same spatial coordinate system; A plurality of first key contact points are symmetrically set at the left and right target parts of the human body; the human body model and the seat model are adjusted, and when the simulated contact forces at the first key contact points are not zero, an initial human-chair coupling relationship is obtained; and the simulated contact forces at the left and right target parts of the human body are obtained; Identify the actual pressure distribution at the first key contact point; take the left and right maximum force areas on the same horizontal line as the area where the left target part of the human body is located and the area where the right target part of the human body is located, respectively; take the position of the left pressure peak in the area where the left target part of the human body is located as the position of the left target part of the human body, and take the position of the right pressure peak in the area where the right target part of the human body is located as the position of the right target part of the human body; Extract the gradient value of the actual pressure distribution to obtain the force range of the target parts on the left and right sides of the human body; accumulate the pressure values ​​within the force range of the target parts on the left and right sides of the human body respectively to obtain the actual contact force of the target parts on the left and right sides of the human body; With the goal of minimizing the difference between the simulated contact force and the actual contact force at the target parts on the left and right sides of the human body, the offset and rotation of the seat centerline are obtained through the positions of the target parts on the left and right sides of the human body, and the offset, rotation and / or seat height of the seat centerline are adjusted to iteratively optimize the human-chair coupling relationship; The process of obtaining the position of the target part on the left side of the human body and the position of the target part on the right side of the human body includes: Identify the actual pressure distribution at the first key contact point, and use the maximum force areas on the left and right sides of the same horizontal line as the areas where the target parts on the left side of the human body are located and the areas where the target parts on the right side of the human body are located, respectively; Identify the actual pressure distribution at the first key contact point, and obtain the left pressure peak and the right pressure peak; Determine whether the left pressure peak and the right pressure peak are located in the area where the left target part of the human body is located and the area where the right target part of the human body is located; If the left pressure peak is located in the area where the left target part of the human body is located, the position of the current left pressure peak is used as the position of the left target part of the human body; if the right pressure peak is located in the area where the left target part of the human body is located, the position of the current right pressure peak is used as the position of the right target part of the human body; If the left pressure peak is not located in the area where the left target part of the human body is located, the next left pressure peak is traversed until the left pressure peak is found in the area where the left target part of the human body is located; if the right pressure peak is not located in the area where the right target part of the human body is located, the next right pressure peak is traversed until the right pressure peak is found in the area where the right target part of the human body is located.

2. A method for adjusting a person-chair coupling relationship according to claim 1, characterized in that: The human body model is a multi-rigid body model formed by simplifying the human body into multiple rigid bodies of constant shape and size, and connecting them in the form of hinges; The seat model is a rigid body model including the seat's geometric shape, structure, and size.

3. The method for adjusting the human-chair coupling relationship according to claim 1, characterized in that: The process of obtaining the initial human-chair coupling relationship includes: Setting the spatial position parameters of the seat, wherein the spatial position parameters of the seat include the coordinates, height, and rotation angle of the seat; Place the seat under the human body model and set the seat direction to be consistent with the human body orientation; The simulated contact force at the first key contact point is calculated; if there is a first key contact point where the simulated contact force is zero, the spatial position parameters of the seat are adjusted until the simulated contact forces at the first key contact points are not zero, thereby obtaining an initial human-chair coupling relationship.

4. The method for adjusting the human-chair coupling relationship according to claim 1, characterized in that: The process of obtaining the actual contact force of the target parts on the left and right sides of the human body includes: Extract the gradient value of the actual pressure distribution; Accumulate the gradient values ​​in the area where the target part on the left side of the human body is located and the area where the target part on the right side of the human body is located to obtain a first overall gradient value corresponding to the area where the target part on the left side of the human body is located and a second overall gradient value corresponding to the area where the target part on the right side of the human body is located; Setting a clarity threshold, and obtaining the force range of the target parts on the left side and the right side of the human body according to the first overall gradient value, the second overall gradient value and the clarity threshold; The pressure values ​​within the force range of the target parts on the left and right sides of the human body are accumulated respectively to obtain the actual contact forces of the target parts on the left and right sides of the human body.

5. The method for adjusting the human-chair coupling relationship according to claim 1, characterized in that: The process of obtaining the offset and rotation of the seat centerline through the left and right target parts of the human body includes: The offset of the center line of the seat is set according to the center line coordinate of the sensor array used to measure the actual pressure distribution at the first key contact point, the side length of the sensor array element, and the average of the number of columns where the target part on the left side of the human body is located and the number of columns where the target part on the right side of the human body is located; The rotation amount of the seat centerline is set according to the difference between the row number where the left target part of the human body is located and the row number where the right target part of the human body is located, and the difference between the column number where the left target part of the human body is located and the column number where the right target part of the human body is located.

6. A person-chair coupling relationship adjustment system, characterized in that: The system is used to implement the method for adjusting the human-chair coupling relationship according to any one of claims 1 to 5, and the system comprises: The human-chair coupling relationship initialization module is used to establish a human body model and a chair model in the same spatial coordinate system; symmetrically set a number of first key contact points at the left and right target parts of the human body; adjust the human body model and the chair model, and when the simulated contact forces at the first key contact points are not zero, obtain the initial human-chair coupling relationship; obtain the simulated contact forces at the left and right target parts of the human body; The human body target part position recognition module is used to recognize the actual pressure distribution at the first key contact point; the left and right maximum force areas located on the same horizontal line are respectively used as the area where the left target part of the human body is located and the area where the right target part of the human body is located; the position of the left pressure peak in the area where the left target part of the human body is located is used as the position of the left target part of the human body, and the position of the right pressure peak in the area where the right target part of the human body is located is used as the position of the right target part of the human body; The actual contact force acquisition module of the target part of the human body is used to extract the gradient value of the actual pressure distribution, so as to obtain the force range of the target part on the left side and the right side of the human body; the pressure values ​​within the force range of the target part on the left side and the right side of the human body are accumulated respectively to obtain the actual contact force of the target part on the left side and the right side of the human body; The human-chair coupling relationship optimization module is used to minimize the difference between the simulated contact force and the actual contact force at the target parts on the left and right sides of the human body, obtain the offset and rotation of the seat centerline through the positions of the target parts on the left and right sides of the human body, adjust the offset, rotation and / or seat height of the seat centerline to iteratively optimize the human-chair coupling relationship.

7. An electronic device comprising a memory and a processor, characterized in that: The memory is coupled to the processor; wherein the memory is used to store program data, and the processor is used to execute the program data to implement the method for adjusting the human-chair coupling relationship as described in any one of claims 1 to 5 above.

8. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the program is executed by a processor, the method for adjusting the human-chair coupling relationship as described in any one of claims 1 to 5 is implemented.

9. A computer program product comprising a computer program / instructions, characterized in that When the computer program / instruction is executed by a processor, the method for adjusting the human-chair coupling relationship described in any one of claims 1-5 is implemented.

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