People-chair coupling relation adjusting method, device, equipment and medium

Abstract

The invention discloses a human-chair coupling relation adjusting method and device, electronic equipment and a medium, and the method comprises the steps: building a human body model and a chair model in the same space coordinate system, and symmetrically arranging a plurality of first key contact points at the target parts of the left and right sides of a human body; adjusting the model, obtaining an initial person-chair coupling relation when the simulation contact force at the first key contact point is not zero, and obtaining the simulation contact force at the target parts on the left and right sides of the human body; and identifying actual pressure distribution, determining positions of target parts on the left and right sides of the human body based on the maximum stress areas on the left and right sides and the pressure peak position, extracting a pressure distribution gradient value to obtain a stress range, and calculating actual contact force. Minimizing the difference between the simulated contact force and the actual contact force at the left and right target parts of the human body as a target, obtaining the offset and rotation amount of the center line of the seat through the positions of the left and right target parts of the human body, adjusting the offset, rotation amount and / or height of the center line of the seat, and iteratively optimizing the human-seat 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] 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;

[0009] 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;

[0010] 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;

[0011] 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.

[0012] In a second aspect, an embodiment of the present invention provides a system for adjusting a person-chair coupling relationship, the system comprising:

[0013] 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;

[0014] 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;

[0015] 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;

[0016] 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.

[0017] In a third aspect, an embodiment of the present invention provides an electronic device, comprising a memory and a processor, wherein 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 method for adjusting the human-chair coupling relationship.

[0018] In a fourth aspect, an embodiment of the present invention provides a computer-readable storage medium having a computer program stored thereon, wherein the program, when executed by a processor, implements the above-mentioned method for adjusting the human-chair coupling relationship.

[0019] In a fifth aspect, an embodiment of the present invention provides a computer program product, including a computer program / instruction, which implements the above-mentioned method for adjusting the human-chair coupling relationship when executed by a processor.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] The present invention provides a method for adjusting a coupling relationship between a person and a chair, wherein a plurality of first key contact points are symmetrically set at target parts on the left and right sides of a human body, and the simulated contact forces at the first key contact points are adjusted to be non-zero, thereby obtaining an initial coupling relationship between the person and the chair, 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 of the target parts on the left and right sides of the human body and the actual contact forces by analyzing the actual pressure distribution; 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, adjusting the spatial position parameters of the seat including the offset, the rotation amount and / or the height, thereby iteratively optimizing the coupling relationship between the person and the chair, so as to truly reflect the coupling relationship between the person and the chair when the sitting posture is not constrained. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings in the following description are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative labor.

[0023] Figure 1 A schematic diagram of a flow chart of a method for adjusting a person-chair coupling relationship provided by an embodiment of the present invention;

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

[0025] Figure 3 A schematic diagram of calculating the actual contact force 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 A schematic diagram of a person-chair coupling relationship adjustment system provided by an embodiment of the present invention;

[0027] Figure 5 A schematic diagram of an electronic device provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0028] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0029] It should be noted that, in the absence of conflict, the features in the following embodiments and implementations may be combined with each other.

[0030] Example 1

[0031] like Figure 1 As shown, in this example, the ischial tuberosity of the buttocks is used as the target part to illustrate 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, establishing 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 the head, back, buttocks, thighs, calves and feet, and each part is simplified into multiple rigid bodies of constant shape and size, and connected by hinges to form a multi-rigid body model. Furthermore, the human body model is required to be consistent with the height and weight of the experimenter.

[0034] The seat model is a rigid body model including the seat's geometric shape, structure, and size.

[0035] 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 chair model, and when the simulated contact forces at the first key contact points are not zero, obtain the initial human-chair coupling relationship. After obtaining the initial human-chair coupling relationship, perform simulation and calculate the simulated contact forces at the left and right target parts of the human body respectively.

[0036] Specifically, this example uses the ischial tuberosity of the buttocks as the target part to simulate the actual contact between the human buttocks and the seat surface; in this example, Figure 2 As shown, 7 groups of first key contact points are set symmetrically on the left and right sides of the ischial tuberosity of the buttocks and the back of the thigh muscles, with a total of 14 first key contact points.

[0037] Furthermore, the process of obtaining the initial human-chair coupling relationship includes:

[0038] 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;

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

[0040] Perform inverse dynamics analysis on the current human body model and seat model to calculate the simulated contact force at the first key contact point; 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 force at the first key contact point is not zero, and obtain the initial human-chair coupling relationship. In this embodiment, the simulated contact force at the first key contact point is not 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 critical contact point, in Newton; k represents the kth first critical contact point, K represents the number of first critical contact points, and in this example, K=14.

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

[0044] For example, a female experimenter with a height of 170 cm and a weight of 60.5 kg is used as an example to illustrate the initial human-chair coupling relationship. 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 (-1.450m, 0.450m, 0.050m), and the initial rotation angle is 0°. The origin of the seat is at the center of the seat surface, that is, the initial seat surface height is 45cm.

[0046] Among them, the first item in the bracket 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 adjusting the spatial position parameters of the seat model for the first time includes: setting the coordinates of the seat to (-1.850m, 0.450m, -0.130m) and the rotation angle to +7°, so that the seat model is located below the human body model and faces the same direction. At this time, the calculation results are F1 to F 14 The simulated contact forces are all 0. Therefore, the second adjustment is made by increasing the seat height by 1 cm, that is, the seat coordinates increase by 1 cm along the positive direction of the Y axis. At this time, F1 to F4 are still 0. Continue to make the third adjustment, increase by 1 cm along the Y axis. At this time, F1 to F2 are still 0. Continue to make the fourth adjustment, at this time, F1 to F 14 The simulated contact force is not 0. After adjusting the spatial position parameters of the seat model four times, the spatial coordinates of the seat are (-1.850m, 0.480m, -0.130m), the rotation angle is +7°, and the seat height is 48cm.

[0048] After initializing 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 the simulated contact forces at the left and right ischial tuberosities are obtained and They are 69.42N and 65.33N respectively.

[0049] Step S3, identifying the actual pressure distribution at the first key contact point; taking the left and right maximum force areas located 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; taking 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 taking 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.

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

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

[0052] Specifically, multiple 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-type thin film pressure sensor. These sensors are evenly distributed on the seat cushion, covering the contact area 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, the experimenter sits on a sitting posture collection chair equipped with a pressure sensor, and takes a standard upright sitting posture as an example. The upright sitting posture refers to a relatively common sitting posture, that is, a sitting posture with shoulders relaxed, feet flat on the ground, and back straight. Then, the pressure sensor is started to collect data for more than 5 seconds. During this period, the experimenter should keep the center of gravity of the experimenter's body between the two ischial tuberosities to reduce the changes in pressure distribution caused by body movement and tilt. During the data collection process, each pressure reading is sequentially arranged and stored with a timestamp as a label. This ensures the timing of the data and facilitates 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, which 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 sensor unit on the seat and generates a pressure value.

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

[0056]

[0057] Furthermore, the pressure distribution data is stored for further analysis and processing; after the data collection is completed, a preliminary check of the collected data is also included to check whether there are any abnormal values ​​or data missing caused by sensor failure to ensure the integrity and accuracy of the data.

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

[0059] Specifically, in this embodiment, the standard force range of the ischial tuberosity is first defined as an area of ​​4 cm×4 cm, that is, the initial window size w s is 3, indicating 3×3 units, and the sliding window algorithm is used to identify the area S where the target part on the left side of the human body is located. L , the area S where the target part on the right side of the human body is located R ; If the area where the left sciatic tuberosity of the human body is located S L 、The area where the right ischial tuberosity of the human body is located S R If they are not on the same horizontal line, the initial window size is gradually adjusted to w s =w s +1, until the area S where the ischial tuberosity on the left side of the human body is located L 、The area where the right ischial tuberosity of the human body is located S R Basically symmetrical.

[0060] Step S303, identifying the actual pressure distribution at the first key contact point, and obtaining the positions of the left pressure peak and the right pressure peak.

[0061] Specifically, since the pressure peak usually appears near the ischial tuberosity, but not necessarily at the center of the ischial tuberosity area, this example uses a dual-peak detection algorithm to detect the positions of the left and right pressure peaks, recorded as the position of the left pressure peak P L and the position of the pressure peak on the right side P R .

[0062] Step S304, determining whether the position of the left pressure peak and the position of 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;

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

[0064] If the position of 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 position of 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.

[0065] For example, 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 where the left ischial tuberosity of the human body is located. L and the area where the right ischial tuberosity is located S R ; Use the double peak detection algorithm to detect the actual pressure distribution at the first key contact point and obtain the position P of the left pressure peak. L and the position of the right pressure peak P R . Determine the position of the left pressure peak P L Is it in the area where the left ischial tuberosity of the human body is located? L In the figure, determine the position P of the peak pressure on the right side. R Is it in the area where the right ischial tuberosity of the human body is located? R If the pressure peak on the left is at position P L Located in the area where the ischial tuberosity on the left side of the human body is located S L , the current left pressure peak position P L As the left ischial tuberosity position P SL Otherwise, traverse the next left pressure peak until the area S located at the left sciatic tuberosity of the human body is found. L If the position of the right pressure peak is P R Located in the area where the ischial tuberosity on the right side of the human body is located S R , then the current right side pressure peak position P R As the right ischial tuberosity position P RL Otherwise, traverse the next right pressure peak until the area S located at the right ischial tuberosity of the human body is found. R The pressure peak on the right side of the

[0066] Step S4, extracting the gradient value of the actual pressure distribution, thereby obtaining the force range of the target parts on the left and right sides of the human body; respectively accumulating the pressure values ​​within the force range of the target parts on the left and right sides of the human body to obtain the actual contact force of the target parts on the left and right sides of the human body.

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

[0068] Step S401, extracting the gradient value of the actual pressure distribution.

[0069] In this embodiment, the pressure image features include the vertical gradient value G x (x, y) and the horizontal gradient value G y (x, y), and 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 recorded 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 recorded as . The horizontal direction x corresponds to the row of the pressure matrix, the vertical direction y corresponds to the column of the pressure matrix, and the first row and first column of the matrix is ​​the origin (0, 0).

[0070] Specifically, since the individual body shape will affect the pressure distribution image, the force range at the first key contact point may exceed the standard force range. Based on the characteristic that the pressure gradient of the target part changes the most, this embodiment treats each sensor unit as a pixel point and uses the HOG algorithm to detect the local gradient features of the pressure distribution image to obtain the gradient size G(x,y) and gradient direction θ of each sensor unit (x,y), as shown in the following expression:

[0071]

[0072]

[0073]

[0074]

[0075] Where I(x,y) is the pressure value at point (x,y), G x (x,y) and G y (x, y) represent the vertical gradient value and the horizontal gradient value respectively, where x represents the xth row of the matrix and y represents the yth column of the matrix.

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

[0077] The HOG parameters mean that the pressure matrix is ​​divided into 8×8 cell units, the image block is 1×1, and the gradient direction is divided into 9 units, each unit corresponds to 20°.

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

[0079] In this embodiment, a finite set To represent the area where the unilateral target part is located in the gradient image, the gradient information is first normalized, and then the overall gradient value of the first key contact point on one side is calculated, which can be expressed as:

[0080]

[0081] The first overall gradient value corresponding to the area where the target part on the left side of the human body is located is recorded 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 recorded as

[0082] Step S403, 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.

[0083] Specifically, Figure 3 As shown in the figure, the higher the overall gradient value, the more obvious the target part of the human body is in the gradient image, and the more concentrated the force range is; on the contrary, the lower the overall gradient value, the more difficult it is to distinguish the target part of the human body, and the corresponding force range is correspondingly larger, so a clarity threshold needs to be determined. According to the above local gradient characteristics, when the characteristics of the target part of the human body are obvious, the area S where the target part on the left side of the human body is located L , the area S where the target part on the right side of the human body is located R The corresponding side length is w s When the characteristics of the target part of the human body are difficult to distinguish, the force range of the target part on the left side of the human body and the target part on the right side of the human body increases by one unit in each direction, and the corresponding side length is (w s +2) square.

[0084] Therefore, in this embodiment, according to the actual situation, the clarity threshold w' is set 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] The gradient size and gradient direction are both 32×32 matrices, 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 ischial tuberosity on the left side corresponds to the cell in the second row and second column, and the position of the ischial tuberosity on the right side corresponds to the cell in the second row and third column. After normalizing the gradient information, the overall gradient value at the left ischial tuberosity is output. is 7.98, the right side is 7.45. According to the calculation formula, the corresponding ischial tuberosity force range w is 5. According to the individual ischial tuberosity force range, the actual contact force at the left and right ischial tuberosities is calculated. and They are 70.72N and 64.61N respectively.

[0096] Step S5, with the goal of minimizing the difference between the simulated contact force and the actual contact force, obtains 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, adjusts the offset, rotation and seat height of the seat centerline, and iteratively optimizes the human-chair coupling relationship.

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

[0098]

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

[0100] The offset of the seat centerline is set according to the midline coordinates 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, 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 expression is as follows:

[0101]

[0102] Where d1 represents the midline coordinate of the sensor array used to measure the actual pressure distribution at the first critical contact point, Indicates the column number where the target part on the left side of the human body is located. It indicates the column number where the target part on the right side of the human body is located, and d2 indicates the side length of the sensor array element.

[0103] Exemplarily, in this example, the pressure distribution data is recorded as a 32×32 pressure matrix, the first row and first column of the matrix is ​​the origin (0, 0), the row and column coordinate range is 0~31, then d1=15.5, the size of a sensor unit in the sensor array is 1.4732cm×1.4732cm, then d2=1.4732.

[0104] The rotation amount of the seat centerline is set according to the difference between the row number where the target part on the left side of the human body is located and the row number where the target part on the right side of the human body is located, and the difference between the column number where the target part on the left side of the human body is located and the column number where the target part on the right side of the human body is located;

[0105]

[0106] Where α represents the rotation of the seat centerline, Indicates the column number where the target part on the left side of the human body is located. Indicates the column number where the target part on the right side of the human body is located. Indicates the row number where the target part on the left side of the human body is located. Indicates the row number where the target part on the right side of the human body is located.

[0107] For example, a female experimenter with a height of 170 cm and a weight of 60.5 kg is used as an example to illustrate the adjustment of the human-chair coupling relationship. Specifically, it includes:

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

[0109] The optimization goal is 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. According to this optimization goal, 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 is calculated. They are 1.30N and 0.72N respectively.

[0110] Calculate the offset of the seat centerline It is -2.2cm, which means that the center of the ischial tuberosity is 2.2cm to the right of the center line of the seat. Therefore, the seat needs to be moved 2.2cm in the negative direction of the X-axis of the spatial coordinate. At the same time, the rotation amount α of the center line of the seat is calculated to be 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 target parts on the left and right sides of the human body are still 69.42N and 65.33N. 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 is determined. The minimum values ​​are 1.30N and 0.72N.

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

[0113] Example 2

[0114] In this example, the key part of the back of the human body is used as the target part to illustrate the execution process of a method for adjusting the coupling relationship between a person and a chair provided by the present invention, so as to solve the problem of optimizing the coupling relationship between a person and a chair. The method comprises the following steps:

[0115] Step S1, establishing 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, 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.

[0117] In this example, the back is taken as the target part, and three groups of contact points are symmetrically set on the left and right sides of the key parts of the back of the human body including the trapezius muscle and the outer side of the latissimus dorsi muscle, with a total of 6 first key contact points.

[0118] The process of obtaining the initial human-chair coupling relationship includes:

[0119] 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;

[0120] The seat is placed under the human body model, with the backrest located behind the human body, and the direction of the seat is set to be consistent with the direction of the human body;

[0121] Perform inverse dynamics analysis on the current human body model and seat model to calculate the simulated contact force at the first key contact point; 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 point are not zero, and then obtain the initial human-chair coupling relationship.

[0122] For example, a female experimenter with a height of 170 cm and a weight of 60.5 kg is used as an example to illustrate the initial human-chair coupling relationship. Specifically, it includes:

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

[0124] Among them, the first item in the bracket 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 (-1.850m, 0.480m, -0.130m), and the rotation angle is +7°. At this time, the simulated contact forces of F1 to F6 on the back are all calculated to be 0. Therefore, the first adjustment is made by adjusting the backrest forward by 1cm, that is, the seat coordinates increase by 1cm along the positive direction of the Z axis, and F1 to F6 are still 0. Continue the second adjustment, increase by 1cm along the Z axis, and F3 to F6 are still 0. Continue the third adjustment, increase by 1cm along the Z axis, and F5 to F6 are still 0. Continue the fourth adjustment, increase by 1cm along the Z axis, and the simulated contact forces of F1 to F6 are not 0. After adjusting the spatial position parameters of the seat model four times, the spatial coordinates of the seat are (-1.850m, 0.480m, -0.090m), and the rotation angle is +7°.

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

[0127] Step S3, identifying the actual pressure distribution at the first key contact point; taking the left and right maximum force areas located 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; taking 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 taking 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.

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

[0129] Step S4, extracting the gradient value of the actual pressure distribution, thereby obtaining the force range of the target parts on the left and right sides of the human body; respectively accumulating the pressure values ​​within the force range of the target parts on the left and right sides of the human body to obtain the actual contact force of the target parts on the left and right sides of the human body.

[0130] For example, a female subject with a height of 170 cm and a weight of 60.5 kg is used as an example to illustrate the calculation of the key back information data. Specifically, it includes:

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

[0132] The actual pressure distribution at the first key contact point is analyzed by the sliding window algorithm. After the sliding window is traversed twice, the window size is w. s When the value is 4, the area where the key back parts are basically symmetrical is found, and the position P of the key back parts on the left side of the human body is detected. SL = (10, 9), the key position of the right back of the human body is P RL is (10, 23).

[0133] The first item in the brackets is the number of rows corresponding to the key back position, and the second item is the number of columns corresponding to the key back position. The first row and first column of the matrix M corresponds 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, 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.

[0135] The gradient size and gradient direction are both 32×32 matrices, with a total of 4×4 cells. According to the HOG gradient image, the key parts of the back are generally clear. The key parts of the left back correspond to the cells in the first row and second column, and the key parts of the right back correspond to the cells in the first row and third column. Output the overall gradient value of the key parts of the left back. is 3.56, and the right is 3.35. According to the calculation formula, the corresponding force range w of the key back parts is 6. According to the force range of the key back parts of the individual, the actual contact force of the left and right key back parts is calculated. and They are 10.82N and 12.16N respectively.

[0136] Step S5 aims 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, obtains 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, adjusts the offset and rotation of the seat centerline and the seat height, and iteratively optimizes the human-chair coupling relationship.

[0137] For example, a female experimenter with a height of 170 cm and a weight of 60.5 kg is used as an example to illustrate the adjustment of the human-chair coupling relationship. Specifically, it includes:

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

[0139] The optimization goal is 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. According to this optimization goal, 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 is calculated. They are 0.39N and 0.92N respectively.

[0140] Calculate the offset of the seat centerline It is -0.7cm, which means that the center of the key part of the back is 0.7cm to the right of the center line of the seat. Therefore, the seat needs to be moved 0.7cm in the negative direction of the X-axis of the spatial coordinate. At the same time, the rotation amount α of the center line of the seat is calculated to be 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 10.82N and 12.16N, and 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 is determined. The minimum values ​​are 0.39N and 0.92N.

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

[0143] On the other hand, Figure 4 As shown, an embodiment of the present invention provides a system for adjusting a person-chair coupling relationship, the system comprising:

[0144] 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;

[0145] 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;

[0146] 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;

[0147] 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. 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 seat height of the seat centerline are adjusted to iteratively optimize the human-chair coupling relationship.

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

[0149] For the system embodiment, since it basically corresponds to the method embodiment, the relevant parts can refer to the partial description of the method embodiment. The system embodiment described above is only schematic, wherein the units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they may be located in one place, or they may be distributed on multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the present application. A person of ordinary skill in the art can understand and implement it without creative work.

[0150] Accordingly, the present application also provides an electronic device, comprising: 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 above-mentioned method for adjusting the human-chair coupling relationship. Figure 5 As shown, it is a hardware structure diagram of any device with data processing capability in which the method for adjusting the human-chair coupling relationship provided by the embodiment of the present invention is used, except Figure 5In addition to the processor, memory and network interface shown, any device with data processing capability in which the apparatus in the embodiment is located may also include other hardware, generally based on the actual functions of the device with data processing capability, which will not be described in detail.

[0151] Accordingly, the present application also provides a computer-readable storage medium on which computer instructions are stored, and when the instructions are executed by the processor, the method for adjusting the human-chair coupling relationship 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 aforementioned embodiments, such as a hard disk or a memory. The computer-readable storage medium can also be an external storage device, such as a plug-in hard disk, a smart memory card (Smart Media Card, SMC), an SD card, a flash card (Flash Card), etc. equipped on the device. Furthermore, the computer-readable storage medium can also include both an internal storage unit and an 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 data that has been output or is to be output.

[0152] The above embodiments are only used to illustrate the design ideas and features of the present invention, and their 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, any equivalent changes or modifications made based on the principles and design ideas 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.

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 direction of the seat to be consistent with the direction of the human body; 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 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.

5. 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.

6. 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.

7. A person-chair coupling relationship adjustment system, characterized in that: 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.

8. 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 6 above.

9. 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 6 is implemented.

10. 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 1-6 is implemented.

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