A method for calculating human body dimensions based on seat body pressure and sitting posture

Abstract

The present invention discloses a method for calculating human body dimensions based on seat body pressure and sitting posture, which belongs to the field of industrial design technology, including partitioning of automobile seat cushions and backrests; sitting in driving posture; measuring and obtaining prediction variables; selecting prediction variables according to prediction targets; obtaining prediction coefficients according to prediction targets; and calculating predicted human body dimensions. The calculation method can realize real-time prediction of human body dimensions, ensuring intelligence and customization for different users; on the other hand, the method utilizes relatively more accurate, low-cost, simple and easy-to-use pressure sensing technology, which makes up for the shortcomings of visual sensing technology limited by technology itself, cost and product structure from another perspective.

Description

Technical Field

[0001] The invention belongs to the technical field of industrial design, and in particular relates to a method for calculating human body dimensions based on seat body pressure and sitting posture. Background Art

[0002] Human body size is one of the important basic characteristics of the human body. It directly determines the geometric space that the human body can occupy and the range of activities. It is the basic information for human-machine systems, human-machine interfaces or product designs. Human body size includes static human body size and dynamic human body size, both of which can be obtained through human body measurement. Among them, the static human body size is the structural size, which is often obtained by direct measurement or sampling a certain number of individuals from a group as samples for measurement and statistical analysis; the dynamic human body size is the functional size, including the size measured when the product user is in a working posture or a certain operating activity state. From the perspective of ergonomics and industrial design, in order to ensure that the product can meet the most basic usage needs of the user, industrial design products must be designed based on human body size.

[0003] Under the intelligentization, user-centered intelligent customized function design is becoming more and more important. The human body size required in product design is no longer satisfied with the human body size statistics within a certain percentage range, but requires the user's human body size. In automotive products, whether it is the overall layout or the driving space and environment, if timely and reasonable adjustments can be made to the occupants before the car is driven, the intelligence of the product and the user's driving experience can be greatly improved. To achieve this process, it is necessary to be able to obtain the user's human body size, and the data is input and processed before the control output. Therefore, whether the human body size is obtained accurately ultimately affects the control output and directly affects the product experience. It is very important to be able to accurately obtain the human body size.

[0004] There are two main methods for obtaining human body dimensions: the most widely used one is based on traditional measurements in advance, and then the measurement results are input into a controller with a memory storage function. When the user uses it, the previously stored human body dimension data is directly retrieved to perform corresponding control actions without manual operation; the other is real-time measurement based on sensing and recognition. Before the driver and passengers enter the vehicle or before the car drives, the human body dimensions of the driver and passengers are obtained in real time in advance through sensors. When obtaining, the visual sensor camera is first used to identify the human body contour and skeleton, and then the human body dimensions are obtained based on this.

[0005] The human dimensions obtained based on the traditional measurement method are often accurate, but because they need to be input in advance, the automatic control function cannot be realized in special use cases, such as when the user is temporarily changed or the original user's human dimensions have changed significantly. In essence, this method only memorizes the control variables that need to be repeatedly implemented. When control is required, the fixed control variables are directly input to call the control action, and the intelligence and customization are very limited.

[0006] Real-time measurement based on sensing and recognition is not restricted by users, and can measure the body size of each user, realizing intelligence and customization to the greatest extent. However, due to the limitations of the product itself and the conditions of use, there are still great limitations: First, the limitations of the sensing technology itself, there is a certain recognition error, and the visual sensing technology is greatly affected by light, and the effect is not ideal when the light conditions are poor, such as at night or in rainy and snowy weather; second, due to cost constraints, it is difficult to arrange a large number of high-precision sensors for the sensing technology for drivers and passengers, resulting in large errors in the acquisition of body size; third, due to structural limitations, the cockpit space is limited, and it is difficult to arrange sensors in good positions to achieve accurate acquisition of body size.

[0007] In summary, the current technology for obtaining the body dimensions of automobile drivers and passengers has the following main shortcomings: first, it cannot be obtained in real time, and intelligence and customization are very limited; second, the single sensing technology is limited by the technology itself, cost, and product structure, and the body dimensions are difficult to obtain reliably. Summary of the invention

[0008] In view of the above-mentioned defects existing in the prior art, the present invention provides a method for calculating human body dimensions based on seat body pressure and sitting posture, which avoids the limitations of visual sensing technology while ensuring intelligent and customized real-time acquisition of human body dimensions; and reasonably utilizes sensing technology while reasonably meeting the requirements of product structure, i.e., the overall layout of the automobile, to circumvent various technical limitations at the lowest possible cost, thereby achieving relatively accurate acquisition and prediction of human body dimensions.

[0009] The present invention is achieved through the following technical solutions:

[0010] A method for calculating human body dimensions based on seat body pressure and sitting posture comprises the following steps:

[0011] Step 1: Partition the car seat cushion and backrest;

[0012] Step 2: Sit down in driving position;

[0013] Step 3: Measure and obtain predictor variables;

[0014] Step 4: Select predictor variables based on the prediction target;

[0015] Step 5: Check the prediction coefficient according to the prediction target;

[0016] Step 6: Calculate the predicted human body size.

[0017] Furthermore, the car seat cushion zoning in the step one is specifically as follows: taking the projection of the seat point H on the cushion as the size reference point, the cushion is divided into six zones: A, B, C, D, E and F, wherein the upper boundaries of zone A, zone E and zone F are on the same straight line and are 80 mm away from the size reference point, zone B is located below zone A, and the lower boundaries of zone B, zone E and zone F are on the same straight line; the lower boundary of zone C and the upper boundary and right boundary of zone E are all on the same straight line, the lower boundary and left boundary of zone D are both on the same straight line with zone F, and the upper boundaries of zone C and zone D are 100 mm away from the size reference point; the total length of all zones is 450 mm; the width of zone A and zone B is 220 mm; the total width of all zones is 450 mm.

[0018] Furthermore, the backrest partition in the step one is specifically as follows: define the backrest partition as a rectangular G zone, take the projection of the seat point H on the backrest as the size reference point, the lower boundary of the rectangular G zone is 30mm away from the size reference point, the upper boundary of the rectangular G zone is 180mm away from the size reference point, and the width of the rectangular G zone is 220mm.

[0019] Furthermore, the driving posture of step 2 is specifically as follows:

[0020] Sit down in the normal preparatory driving posture, and adjust the seat until it is comfortable and familiar. After the seat position is adjusted, the left foot is naturally placed in a comfortable and familiar position in front, the right heel is on the floor and the sole of the foot is naturally placed on the accelerator pedal, the whole body is naturally relaxed and the hands are on the steering wheel. The posture at this time is the driving posture.

[0021] Furthermore, the measurement and acquisition of the prediction variables in step 3 include acquiring the body pressure parameters of each partition of the seat and acquiring the sitting posture definition parameters; the body pressure parameters are the contact pressure between the human body and each partition of the seat in the driving posture, and the unit is N / cm 2 ; The body pressure parameters include the maximum body pressure of each partition from A to G and the average body pressure of each partition from A to G, which are respectively recorded as Max A to Max G and Ave A to Ave G; The sitting posture parameters include the thigh angle, knee angle and hip point height, the units of the thigh angle and knee angle are in degrees, and the unit of the hip point height is mm;

[0022] The thigh angle is the angle between the thigh line and the horizontal plane passing through the hip point, the knee angle is the angle between the thigh line and the calf line, and the hip point height is the vertical distance between the hip point and the heel point.

[0023] Furthermore, the prediction variables are selected according to the prediction target in step 4, as follows:

[0024] The prediction targets include leg length (L leg )、Thigh length(L thigh ) and driving posture height (H sitting ) ; predictor variables x required for different prediction targets i Different from that, there are 6 predictors needed to predict leg length (x leg , i = 1 to 6), there are 7 predictive variables needed to predict thigh length (x thigh , i = 1 to 7), there are 7 predictive variables required to predict the driving posture seat height (x sitting , i = 1 to 7), select the corresponding prediction variables according to the prediction target; the specific meanings of the prediction variables required for each prediction target are shown in Table 1:

[0025] Table 1 Prediction variables required for each prediction target

[0026]

[0027] Furthermore, the prediction coefficient is obtained according to the prediction target in step 5, as follows:

[0028] Prediction coefficients β for different predictors when the prediction targets are different i Different prediction variables correspond to different prediction targets. Different prediction targets also have different prediction constant coefficients β. 0 ; Therefore, there are 7 prediction coefficients required to predict leg length (β leg , i = 0 ~ 6), there are 8 prediction coefficients required to predict thigh length (β thigh , i = 0 ~ 7), there are 8 coefficient variables required to predict the driving posture seat height (β sitting , i = 0 ~ 7), select the corresponding required prediction coefficient according to the prediction target; the specific meaning of the prediction coefficient value required for each prediction target is shown in Table 2;

[0029] Table 2 Prediction coefficients required for each prediction target

[0030]

[0031] Furthermore, the predicted human body size is obtained by calculation in step six, as follows:

[0032] According to different prediction targets, the determined prediction variable values ​​and the prediction coefficients are substituted into the corresponding prediction formula to calculate the predicted human body size, where leg length L leg , Thigh length L thigh And driving posture sitting height H sitting The unit of the prediction results is mm. The prediction formula is as follows:

[0033]

[0034]

[0035]

[0036] Compared with the prior art, the advantages of the present invention are as follows:

[0037] The human body size calculation method based on seat body pressure and sitting posture of the present invention can realize real-time prediction of human body size, ensuring intelligence and customization for different users; on the other hand, the method utilizes relatively more accurate and low-cost, simple and easy-to-use pressure sensing technology, which makes up for the shortcomings of visual sensing technology limited by technology itself, cost and product structure from another perspective;

[0038] In addition, the combined use of multiple sensing technologies can achieve multiple measurements of multiple measurement technologies to reduce errors and make the obtained human body dimensions more accurate. The goodness-of-fit determination coefficients of the regression prediction model for the three prediction targets - leg length, thigh length, and driving posture seat height are all around 0.8, and the statistical significance levels are all less than 0.001. After actual testing on 26 adults with driving experience, the prediction error of the prediction model for leg length is only 8.866mm, the prediction error of the prediction model for thigh length is only 7.284mm, and the prediction error of the prediction model for driving posture seat height is only 8.126mm. The prediction results obtained by this method are very close to the experimental results and are accurate and reliable. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following is a brief introduction to the drawings required for the specific embodiments or the description of the prior art. In all the drawings, similar elements or parts are generally identified by similar reference numerals. In the drawings, the elements or parts are not necessarily drawn according to the actual scale.

[0040] Figure 1 It is a flow chart of a method for calculating human body dimensions based on seat body pressure and sitting posture of the present invention;

[0041] Figure 2 This is a schematic diagram of the seat cushion body pressure partition and size;

[0042] Figure 3 It is a schematic diagram of the seat back body pressure division and dimensions;

[0043] Figure 4 Define key points for sitting posture and schematic diagram of sitting posture parameters;

[0044] In the picture: hip point 1, ankle joint point 2, heel point 3, knee joint point 4. DETAILED DESCRIPTION

[0045] In order to clearly and completely describe the technical solution and its specific working process of the present invention, the specific implementation methods of the present invention are as follows in conjunction with the accompanying drawings of the specification:

[0046] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0047] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0048] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0049] Example 1

[0050] There is a significant correlation between human body size and static body pressure, and the dynamic body pressure in the driving posture is also affected by the driving posture. Therefore, in theory, the driving posture combined with the dynamic body pressure in the driving posture can reversely predict the human body size of the driver and passenger at this time. After a large number of ergonomic experimental measurements and statistical analysis, it was found that there is a significant correlation between leg length, thigh length, driving posture seat height and body pressure in various areas of the seat and some key dimensions of the driving posture. Therefore, the pressure sensor and position sensor (or visual sensor, etc.) can be used in combination in the driving posture to obtain the seat body pressure and sitting posture parameters, so as to predict the leg length, thigh length, and driving posture seat height.

[0051] Based on this, correlation analysis and regression analysis were carried out on the prediction target and prediction variables. Mathematical modeling was carried out based on a large amount of actual test data and statistical methods, and a series of prediction coefficients were obtained. A calculation model of human body size based on seat body pressure and sitting posture was established, as well as a method to predict human body size based on seat body pressure and sitting posture.

[0052] like Figure 1 As shown, this embodiment provides a method for calculating human body dimensions based on seat body pressure and sitting posture, which specifically includes the following steps:

[0053] Step 1: Car seat cushion and back partition:

[0054] Press the seat cushion Figure 2 The seat cushion is divided into six zones according to the dimensions shown. The projection of the seat H point on the seat cushion is used as the dimension reference point (i.e. 1. Hip point in the figure), and the seat cushion is divided into six zones: A, B, C, D, E and F. Among them, the upper boundaries of zones A, E and F are on the same straight line and 80mm away from the dimension reference point. Zone B is located below zone A, and the lower boundaries of zones B, E and F are on the same straight line; the lower boundary of zone C is on the same straight line with the upper boundary and right boundary of zone E, the lower boundary and left boundary of zone D are on the same straight line with zone F, and the upper boundaries of zones C and D are 100mm away from the dimension reference point; the total length of all zones is 450mm; the width of zones A and B is 220mm; the total width of all zones is 450mm.

[0055] Press the seat back Figure 3 The backrest partition is defined as a rectangular G zone, with the projection of the seat point H on the backrest as the size reference point (i.e. 1. hip point in the figure), the lower boundary of the rectangular G zone is 30mm away from the size reference point, the upper boundary of the rectangular G zone is 180mm away from the size reference point, and the width of the rectangular G zone is 220mm.

[0056] Step 2: Driving posture:

[0057] Sit down in the normal pre-driving posture, and adjust the seat (including but not limited to the front and rear position, height, backrest angle, etc.) until you reach a comfortable and familiar state. After the seat position is adjusted, the left foot is naturally placed in the front comfortable and familiar position, the right heel is on the floor and the sole is naturally on the accelerator pedal, the whole body is naturally relaxed and the hands are on the steering wheel. The posture at this time is the driving posture.

[0058] Step 3: Measure and obtain predictor variables:

[0059] The predicted variables are measured and obtained when the occupant is in the driving posture. The predicted variables are divided into two categories: body pressure parameters and sitting posture parameters; among them, body pressure refers to the contact pressure between the human body and each partition of the seat in the driving posture, and the unit is N / cm 2 The body pressure parameters include the maximum body pressure of each partition from A to G (recorded as Max A to Max G) and the average body pressure of each partition from A to G (recorded as Ave A to Ave G). The sitting posture parameters include three, namely, the thigh angle ( Figure 4 Middle A57), knee angle ( Figure 4 A44) and hip point height ( Figure 4 H30), the units of thigh angle and knee angle are in degrees, and the unit of hip point height is mm. The key points and sitting posture parameters for definition are shown in the attached Figure 4 The definitions are shown in Table 3.

[0060] Table 3 Definition of key points of sitting posture definition and sitting posture parameters

[0061]

[0062] * Sitting posture parameters required in predictor variables

[0063] Step 4: Select predictor variables based on the prediction target:

[0064] This method can predict three human body dimensions: leg length (L leg )、Thigh length(L thigh ) and driving posture height (H sitting ). The predictor variables x required for different prediction targets i Different from that, there are 6 predictors needed to predict leg length (x leg , i = 1 to 6), there are 7 predictive variables needed to predict thigh length (x thigh , i = 1 to 7), there are 7 predictive variables required to predict the driving posture seat height (x sitting , i = 1 to 7), select the corresponding prediction variables according to the prediction target. The meaning of the prediction variables required for each prediction target is shown in Table 1.

[0065] Table 1 Prediction variables required for each prediction target

[0066]

[0067] Step 5: Obtain the prediction coefficient according to the prediction target:

[0068] Prediction coefficients β for different predictors when the prediction targets are different i Different from each other, and correspond one to one with different prediction variables for different prediction targets. In addition, different prediction targets also have different prediction constant coefficients β 0 ; Therefore, there are 7 prediction coefficients required to predict leg length (β leg , i = 0 ~ 6), there are 8 prediction coefficients required to predict thigh length (β thigh , i = 0 ~ 7), there are 8 coefficient variables required to predict the driving posture seat height (β sitting , i = 0 ~ 7), select the corresponding prediction coefficient according to the prediction target. The meaning of the prediction coefficient values ​​required for each prediction target is shown in Table 2.

[0069] Table 2 Prediction coefficients required for each prediction target

[0070]

[0071] Step 6: Calculate the predicted human body size:

[0072] According to different prediction targets, the determined prediction variable values ​​and the prediction coefficients are substituted into the corresponding prediction formula to calculate the predicted human body size, where the leg length L leg , Thigh length L thigh And driving posture sitting height H sitting The unit of the prediction results is mm. The prediction formula is as follows:

[0073]

[0074]

[0075]

[0076] After actual measurement and testing on 26 adults with driving experience, the prediction error of the prediction model for leg length was only 8.866mm, the prediction error of the prediction model for thigh length was only 7.284mm, and the prediction error of the prediction model for driving posture seat height was only 8.126mm. The prediction results obtained by this method are very close to the experimental results and are accurate and reliable.

[0077] Example 2

[0078] A certain control action currently requires the leg length of a driver as a parameter, so the driver's leg length needs to be predicted, as follows:

[0079] Step 1: Car seat cushion and back partition:

[0080] Press the seat cushion Figure 2 The seat cushion is divided into six zones according to the dimensions shown. The projection of the seat H point on the seat cushion is used as the dimension reference point (i.e. 1. hip point in the attached figure), and the seat cushion is divided into six zones: A, B, C, D, E and F. Among them, the upper boundaries of zones A, E and F are on the same straight line and 80mm away from the dimension reference point. Zone B is located below zone A, and the lower boundaries of zones B, E and F are on the same straight line; the lower boundary of zone C is on the same straight line as the upper boundary and right boundary of zone E, the lower boundary and left boundary of zone D are on the same straight line as zone F, and the upper boundaries of zones C and D are 100mm away from the dimension reference point; the total length of all zones is 450mm; the width of zones A and B is 220mm; the total width of all zones is 450mm.

[0081] Press the seat back Figure 3 The backrest partition is defined as a rectangular G zone, with the projection of the seat point H on the backrest as the size reference point (i.e. 1. hip point in the attached figure), the lower boundary of the rectangular G zone is 30mm away from the size reference point, the upper boundary of the rectangular G zone is 180mm away from the size reference point, and the width of the rectangular G zone is 220mm.

[0082] Step 2: Driving posture:

[0083] The driver takes the seat in the normal pre-driving posture and adjusts the seat (including but not limited to the front and rear position, height, backrest angle, etc.) until it reaches a comfortable and familiar state. After the seat position is adjusted, the left foot is naturally placed in the front comfortable and familiar position, the right heel is on the floor and the sole is naturally on the accelerator pedal, the whole body is naturally relaxed and the hands are on the steering wheel. The posture at this time is the driving posture.

[0084] Step 3: Measure and obtain predictor variables:

[0085] The predicted variables are measured and obtained when the driver is in the driving posture. The predicted variables are divided into two categories: body pressure parameters and sitting posture parameters; among them, body pressure refers to the contact pressure between the human body and each partition of the seat in the driving posture, and the unit is N / cm 2 The body pressure parameters include the maximum body pressure of each partition from A to G (recorded as Max A to Max G) and the average body pressure of each partition from A to G (recorded as Ave A to Ave G). The sitting posture parameters include three, namely, the thigh angle ( Figure 4 Middle A57), knee angle ( Figure 4 A44) and hip point height ( Figure 4 In H30), the units of thigh angle and knee angle are in degrees, and the unit of hip point height is mm.

[0086] Step 4: Select predictor variables based on the prediction target:

[0087] The prediction target is leg length (L leg ), 6 predictor variables are needed, namely: Max B, Max F, Ave E, Ave F, Ave G, A57. Extract the above predictor variable values ​​obtained in step 3, which are: Max B = 0.24N / cm 2 、Max F=0.66N / cm 2 , Ave E=0.057N / cm 2 、Ave F=0.125N / cm 2 , Ave G=0.142N / cm 2 ,A57=3.783°.

[0088] Step 5: Obtain the prediction coefficient according to the prediction target:

[0089] The prediction target is leg length (L leg ), we need to check and determine 7 prediction coefficients, which are: β 0 =789.277, β 1 =115.538,β 2 =55.297,β 3 =315.743, β 4 =-190.806, β 5 =-88.015, β 6 =0.590.

[0090] Step 6: Calculate the predicted human body size:

[0091] Substituting the determined prediction variable values ​​and the obtained prediction coefficients into the corresponding prediction formula, the predicted human body size can be calculated, where the leg length L leg The prediction formula is as follows:

[0092] Substituting the predicted variables and prediction coefficients into the calculation, we get:

[0093] L leg =789.277+115.538×0.24+55.297×0.66+315.743×0.057-190.806×0.125-88.015×0.142+0.590×3.783=837.383mm

[0094] Therefore, the predicted leg length of the driver is 837.383 mm.

[0095] The preferred embodiments of the present invention are described in detail above in conjunction with the accompanying drawings. However, the present invention is not limited to the specific details in the above embodiments. Within the technical concept of the present invention, a variety of simple modifications can be made to the technical solution of the present invention, and these simple modifications all belong to the protection scope of the present invention.

[0096] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present invention will not further describe various possible combinations.

[0097] In addition, various embodiments of the present invention may be arbitrarily combined, and as long as they do not violate the concept of the present invention, they should also be regarded as the contents disclosed by the present invention.

Claims

1. A method for calculating human body dimensions based on seat body pressure and sitting posture, characterized in that: The specific steps include: Step 1: Partition the car seat cushion and backrest; Step 2: Sit down in driving position; Step 3: Measure and obtain predictor variables; Step 4: Select predictor variables based on the prediction target; Step 5: Check the prediction coefficient according to the prediction target; Step 6: Calculate the predicted human body size; The car seat cushion zoning in step 1 is specifically as follows: taking the projection of the seat point H on the seat cushion as the size reference point, the seat cushion is divided into six areas A, B, C, D, E and F, wherein the upper boundaries of the A area, the E area and the F area are on the same straight line and 80 mm away from the size reference point, the B area is located below the A area, and the lower boundaries of the B area, the E area and the F area are on the same straight line; the lower boundary of the C area and the upper boundary and the right boundary of the E area are all on the same straight line, the lower boundary of the D area and the upper boundary of the F area, and the left boundary of the D area and the F area are all on the same straight line, and the upper boundaries of the C area and the D area are 100 mm away from the size reference point; the total length of all areas is 450 mm; the width of the A area and the B area is 220 mm; the total width of all areas is 450 mm; The backrest partition in step 1 is specifically as follows: define the backrest partition as a rectangular G zone, take the projection of the seat H point on the backrest as the size reference point, the lower boundary of the rectangular G zone is 30mm away from the size reference point, the upper boundary of the rectangular G zone is 180mm away from the size reference point, and the width of the rectangular G zone is 220mm; The driving posture of step 2 is as follows: Sit down in the normal pre-driving posture and adjust the seat until you feel comfortable and used to it. After the seat is adjusted, place your left foot naturally in a comfortable and used position in front of you, with your right heel on the floor and your sole on the accelerator pedal. Relax your whole body and hold the steering wheel. This is the driving posture. The measurement and acquisition of prediction variables in step 3 include acquiring body pressure parameters of each seat partition and acquiring sitting posture definition parameters; the body pressure parameters are the contact pressure between the human body and each seat partition in the driving posture, and the unit is N / cm 2 ; The body pressure parameters include the maximum body pressure of each partition from A to G and the average body pressure of each partition from A to G, which are respectively recorded as Max A to MaxG and Ave A to Ave G; The sitting posture definition parameters include the thigh angle A57, the knee angle A44 and the hip point height H30, the units of the thigh angle and the knee angle are in degrees, and the unit of the hip point height is mm; The thigh angle is the angle between the thigh line and the horizontal plane passing through the hip point, the knee angle is the angle between the thigh line and the calf line, and the hip point height is the vertical distance between the hip point and the heel point; The step 4 selects the prediction variables according to the prediction target, as follows: The prediction target includes leg length L leg , Thigh length L thigh And driving posture seat height H sitting ; Different prediction targets require different predictors. There are 6 predictors required to predict leg length, x legi , i = 1-6, there are 7 predictor variables needed to predict thigh length, x thighi , i = 1-7, there are 7 predictive variables required to predict the driving posture seat height, x sittingi , i = 1-7, select the corresponding prediction variables according to the prediction target; the specific meanings of the prediction variables required for each prediction target are shown in Table 1: Table 1 Prediction variables required for each prediction target The prediction coefficient is obtained according to the prediction target in step 5, as follows: The prediction coefficients of different predictive variables are different when the prediction targets are different, and they correspond to the different predictive variables when the prediction targets are different. Different prediction targets also have different prediction constant coefficients. Therefore, there are 7 prediction coefficients required to predict leg length, β legi , i = 0-6, there are 8 prediction coefficients required to predict thigh length, β thighi , i = 0-7, there are 8 coefficient variables required to predict the driving posture seat height, β sittingi , i = 0-7, select the corresponding prediction coefficient according to the prediction target; the specific prediction coefficient values ​​required for each prediction target are shown in Table 2; Table 2 Prediction coefficients required for each prediction target The calculation in step six obtains the predicted human body size, as follows: According to different prediction targets, the determined prediction variable values ​​and the prediction coefficients are substituted into the corresponding prediction formula to calculate the predicted human body size, where: Leg length L leg , Thigh length L thigh And driving posture sitting height H sitting The unit of the prediction results is mm, and the prediction formula is as follows:

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