Fatigue evaluation device and vehicle comprising same

Abstract

A fatigue assessment device (10) is provided with: a sensor (3) for detecting the movement of any one of the right leg, left leg, right arm, left arm, and neck of a seated person seated on a seat; and a fatigue evaluation unit (5a) that evaluates the fatigue state of the seated person on the basis of the detection results detected by the sensor (3).

Description

Technical Field

[0001] This invention relates to a fatigue assessment device for evaluating the fatigue state of a person sitting in a chair. Background Technology

[0002] As such a device, there is a known device for assessing the fatigue state of a person sitting in a vehicle seat (for example, see Patent Document 1). In the device described in Patent Document 1, a first sensor and a second sensor are arranged at a predetermined distance in the front-back direction of the seat cushion to detect the pressure from the person's thigh to the knee. If the detection results indicate that an action causing the lower body to move forward and backward is detected, it is determined that the person's fatigue is increasing.

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 2004-168224 Summary of the Invention

[0006] The problem that the invention aims to solve

[0007] However, the movement of the lower body moving forward and backward is mostly a conscious action when the person sitting down feels tired and sits up again. In the device described in Patent Document 1, it is difficult to assess the fatigue state of the person sitting down in advance.

[0008] Technical means to solve the problem

[0009] One aspect of the fatigue assessment device of the present invention includes: a sensor for detecting movements of any one of the right leg, left leg, right arm, left arm, and neck of a person sitting in a chair; and a fatigue assessment unit for assessing the fatigue state of the person based on the detection results detected by the sensor. By detecting movements of the legs and other parts that are more prone to movement and unconscious movements while sitting compared to the torso, unconscious movements of the person can be preferably detected, thereby allowing for earlier assessment of the person's fatigue state.

[0010] The seat is mounted on a vehicle where the occupant operates the vehicle using either their right or left leg, and sensors detect the movement of the other leg. This allows for the detection of the occupant's unconscious movements without being affected by actions accompanying the driving operation.

[0011] Sensors detect movements of the right and left legs, and the fatigue assessment unit evaluates fatigue levels based on the larger of the movements detected by the sensors. In this case, the fatigue level of the occupant can be accurately assessed based on the movements of the dominant leg, which is more mobile and prone to unconscious movements than the supporting leg.

[0012] The fatigue assessment unit calculates the change in the center of gravity position of at least one of the seat's fore-aft and width directions based on the detection results obtained by sensors, and assesses the fatigue state based on the calculated change. By detecting the movement of the legs and other parts that move around the torso as the change in the center of gravity position of at least one of the seat's fore-aft and width directions, it is preferable to detect the unconscious movements of the occupant.

[0013] The center of gravity position is the coordinate value of at least one of the front-to-back and width directions. By determining the center of gravity position as the coordinate value of at least one of the front-to-back and width directions of the seat, the calculation process of the center of gravity position and its variation can be simplified and the computational load can be reduced.

[0014] The sensor is a pressure sensor installed on the seat surface that is in contact with any one of the following: the right leg, left leg, right arm, left arm, or neck. The fatigue assessment unit evaluates the fatigue state based on the detection results detected by the sensor within a range on the seat surface that is away from the sitter's torso. By setting the sensor's detection range to a range away from the sitter's torso, it is preferable to detect movements of the legs, etc., which are more likely to move while seated than the torso and are more likely to produce unconscious movements by the sitter.

[0015] The sensor is a pressure sensor and is positioned on the seat surface further away from the center, away from the occupant's buttocks. By setting the sensor's detection range away from the operating leg or buttocks, unconscious movements of the occupant can be detected without being affected by actions accompanying driving.

[0016] The fatigue assessment department calculates the variation at a predetermined period and then smooths the calculated variation to obtain an assessment value. Based on this assessment value, the fatigue state is evaluated. In the smoothing process, the current assessment value is calculated as the sum of the current variation and the previous assessment value multiplied by a predetermined weighting coefficient. By smoothing the variation, a suitable assessment value representing a gradually changing fatigue state can be calculated, thereby allowing for a proper assessment of the fatigue state of the person sitting in the seat.

[0017] The fatigue assessment department normalizes the current assessment value based on its ranking within a specified dataset, converting it to a value between 0 and 1. The fatigue state is then assessed based on this normalized assessment value. This allows for a more accurate assessment of the fatigue level of the person sitting in the seat.

[0018] The specified data set comprises all assessment values ​​calculated for the same individual. In this case, it is more appropriate to assess the individual's fatigue level.

[0019] The fatigue assessment department uses a logistic regression model to evaluate fatigue levels. This model uses whether the occupant is fatigued as the target variable and values ​​calculated based on sensor readings as explanatory variables. In this case, the fatigue probability obtained from the logistic regression model allows for a more accurate assessment of the occupant's fatigue level.

[0020] The sensor detects the movement of the left leg. By detecting the movement of the left leg, which is more prone to movement and unconscious actions while seated compared to the torso, the unconscious actions of the seated person can be preferably detected, thereby allowing for early assessment of the seated person's fatigue status.

[0021] Another embodiment of the present invention includes a vehicle with a fatigue assessment device. In this case, the fatigue state of the occupant, who is sitting in the seat, can be assessed earlier.

[0022] The effects of the invention

[0023] According to the present invention, the fatigue state of the seated person can be assessed in advance. Attached Figure Description

[0024] [ Figure 1 [Image 1] is a diagram showing an example of a seat to which an embodiment of the fatigue assessment device of the present invention is applied.

[0025] [ Figure 2 [ ] is a block diagram illustrating an example of the overall structure of a fatigue assessment device according to an embodiment of the present invention.

[0026] [ Figure 3 [ is used for explanation] Figure 1 The diagram shows the detection range of the surface pressure sensor.

[0027] [ Figure 4 ] is used to explain the composition Figure 1 A diagram showing the configuration of the pressure-sensing element in a surface pressure sensor.

[0028] [ Figure 5 ] is to show based on Figure 1 A figure showing an example of the change in the center of gravity position calculated from the detection results of the surface pressure sensor.

[0029] [ Figure 6 ] is used to explain the use of Figure 5 A graph of the weights for smoothing out the variation.

[0030] [ Figure 7 ] is to show through Figure 2 A flowchart of an example of the processing performed by the controller.

[0031] [ Figure 8 [ ] is a side view illustrating a schematic structure of a vehicle seat according to another embodiment of the present invention.

[0032] [ Figure 9 [ ] is a diagram illustrating the main part of a vehicle seat according to another embodiment of the present invention, and is an example showing a cutout provided at the front end of the seat cushion of the rear seat in order to support the lower surface near the rear end of the leg rest.

[0033] [ Figure 10 [ ] is a diagram illustrating the main part of a vehicle seat according to another embodiment of the present invention, and is a diagram showing an example of a lower surface near the rear end of the leg rest portion supported by the front end of the seat cushion of the rear seat.

[0034] [ Figure 11 [ ] is a diagram illustrating the main part of a vehicle seat according to another embodiment of the present invention, and is an example showing an example in which the seating position of the rear seat is set higher.

[0035] [ Figure 12 [Illustration 1] is a diagram illustrating the main part of a vehicle seat according to another embodiment of the present invention, and is an example illustrating a situation where the passenger's legs cannot reach the support surface of the leg rest.

[0036] [ Figure 13 [ ] is a diagram illustrating the main part of a vehicle seat according to another embodiment of the present invention, and is also a diagram illustrating another example of a situation where the passenger's legs cannot reach the support surface of the leg rest.

[0037] [ Figure 14 [ ] is a diagram illustrating the main part of a vehicle seat according to another embodiment of the present invention, and is an example illustrating that the leg rest is used as a seating part.

[0038] [ Figure 15 [ ] is a diagram illustrating the main parts of a vehicle seat according to another embodiment of the present invention, and also illustrating an example of using the leg rest as a seating area and the seat cushion as a table or shelf.

[0039] [ Figure 16[Illustration 1] is a diagram illustrating the main parts of a vehicle seat according to another embodiment of the present invention, and also an example illustrating the use of built-in lighting in the headrest when the leg rest is used as a seat and the seat cushion is used as a table or shelf.

[0040] [ Figure 17 [Illustration 1] is a diagram illustrating the main part of a vehicle seat according to another embodiment of the present invention, and also an illustration of the use of replaceable and different types of leg rests in suitable positions. Detailed Implementation

[0041] Fatigue assessment device

[0042] The following is for reference Figures 1 to 7 An embodiment of the present invention will be described below. The fatigue assessment device of this embodiment assesses fatigue levels, including fatigue or decreased concentration, in individuals who are seated and maintain a fixed posture for an extended period. For example, it assesses fatigue levels in individuals who are drivers of vehicles, passengers restrained by seatbelts, workers performing specific tasks such as work or play, or those undergoing medical examinations or treatment. Hereinafter, an example of assessing fatigue levels in individuals who are drivers of vehicles with automatic transmissions (AT) will be specifically described.

[0043] Figure 1 This is a diagram showing an example of a seat 1 to which the fatigue assessment device according to an embodiment of the present invention is applied, and showing the driver's seat, i.e., seat 1, mounted in the driver's seat of a vehicle 2 which is an AT car. Figure 1 As shown, seat 1 includes: a seat cushion 1a that supports the buttocks of the person sitting in the seat as a driver, a seat back 1b that supports the lower back and back, and a headrest 1c that supports the head. Hereinafter, with the person sitting in seat 1 as a reference, the front-back direction, left-right direction, and up-down direction are defined as shown in the figure, and the structure of each part is explained according to this definition.

[0044] The seat cushion 1a extends in both the front-to-back and left-to-right directions, and is roughly rectangular in shape when viewed from above. The seat back 1b and headrest 1c extend in both the vertical and horizontal directions, and are roughly rectangular in shape when viewed from the front. Alternatively, it can be said that the upper part of the seat back 1b and headrest 1c corresponds to the rear, the lower part to the front, and the vertical direction to the front-to-back direction. The upper surface of the seat cushion 1a, the front surface of the seat back 1b, and the front surface of the headrest 1c constitute the seating surface. A surface pressure sensor 3 is installed on the seat cushion 1a to detect the load acting on the seating surface (body pressure and seat pressure acting on the body surface of the seated person). The body movements of the seated person can be detected based on the detection results detected by the surface pressure sensor 3.

[0045] Inside the vehicle 2, operating pedals (accelerator pedal and brake pedal) 3 for driving operations are provided in front of the seat 1. The driver operates the vehicle 2 by using the operating pedals 4 with their right foot. In this case, the right leg (operating leg) for driving operations moves according to the driving operation of the right foot, while the left leg (non-operating leg) for not driving operations is almost inactive.

[0046] If a person sitting in seat 1 maintains a certain sitting posture for a long time, body pressure will concentrate on the seat surface, gradually leading to fatigue or decreased concentration. When a person feels fatigued or their concentration has decreased, they tend to consciously change their posture, such as by sitting up straight again. However, even before they consciously feel fatigued or their concentration has decreased, they tend to unconsciously move parts of their body that are in contact with the seat surface to alleviate the concentration of body pressure (in other words, they produce unconscious movements). Therefore, in this embodiment, a fatigue assessment device is configured such that the fatigue state of the person can be assessed earlier by detecting these unconscious movements.

[0047] Figure 2 This is a block diagram illustrating an example of the overall structure of a fatigue assessment apparatus (hereinafter, apparatus) 10 according to an embodiment of the present invention. Figure 2 As shown, the device 10 includes: Figure 1 The system includes a surface pressure sensor 3 and a controller 5, wherein the controller 5 functions as a fatigue assessment unit 5a that evaluates the fatigue state of the seated person based on the detection results detected by the surface pressure sensor 3. The surface pressure sensor 3 is connected to the controller 5, and the detection results detected by the surface pressure sensor 3 are input to the controller 5.

[0048] The controller 5 is configured as a computer, including a processor such as a central processing unit (CPU), memory such as random access memory (RAM) and read-only memory (ROM), and other peripheral circuits, for example... Figure 1 The controller 5 is located inside the seat 1. The controller 5 may also be located outside the seat 1. The controller 5 detects the body movements of the occupant who is sitting in the seat 1 and performing driving operations of the vehicle 2, especially the movements of the non-operating leg, based on the detection results detected by the surface pressure sensor 3.

[0049] Figure 3 This is a diagram illustrating the detection range of the surface pressure sensor 3, showing the seating surface of the seat cushion 1a as seen from above. (As shown...) Figure 1 as well as Figure 3As shown, in the seating surface of the seat cushion 1a, the rear area AR1 mainly contacts the buttocks of the occupant and bears the load from the buttocks, the right front area AR2 mainly contacts the operating leg and bears the load from the operating leg, and the left front area AR3 mainly contacts the non-operating leg and bears the load from the non-operating leg.

[0050] The rear region AR1 is the area contacted by the buttocks, which are part of the occupant's torso. The right front region AR2 and the left front region AR3 are areas further forward than the rear region AR1, i.e., further away from the occupant's torso (buttocks). Furthermore, the right front region AR2 is the area of ​​the seat 1 closer to the operating leg than the center, and the left front region AR3 is the area of ​​the seat 1 closer to the non-operating leg than the center. A surface pressure sensor 3 is located in the left front region AR3, enabling the detection of non-operating leg movements based on load from the non-operating leg.

[0051] Compared to the torso, the legs, arms, and neck are more prone to movement while seated, making them susceptible to unconscious movements by the occupant. By setting the detection range of the face pressure sensor 3 to a distance away from the occupant's torso, these unconscious movements can be preferably detected. Furthermore, by setting the detection range of the face pressure sensor 3 to a distance away from the operating leg or hip, unconscious movements can be accurately detected without being affected by movements accompanying driving operations. That is, by individually detecting the movements of the right leg, left leg, right arm, left arm, and neck (e.g., the non-operating leg) that are prone to unconscious movements, and by independently evaluating the movements of each part, the occupant's fatigue level can be accurately assessed.

[0052] Figure 4 This diagram illustrates the configuration of the pressure-sensing elements that constitute the surface pressure sensor 3. (See diagram for example.) Figure 4 As shown, the surface pressure sensor 3 has multiple (e.g., M×N) sensors (M, N: arbitrary natural numbers, in...). Figure 4 In the example, M=N=8) pressure-sensing elements are used to detect the pressure distribution in the left front region AR3. For each pressure-sensing element, the coordinate value i in the width direction (left-right direction) of seat 1 is assigned sequentially from right to left as 0, 1, ..., M-2, M-1 (in Figure 4 In the example, the coordinates j are 0, 1, ..., 7, representing the depth direction (front-back direction) coordinates of seat 1. Starting from the front, they are sequentially assigned 0, 1, ..., N-2, N-1 (in...). Figure 4 In the example, the values ​​are 0, 1, ..., 7). The pressure distribution P detected by the multiple pressure-sensing elements of the surface pressure sensor 3 is... ij Input is given at a specified period T1 (e.g., 0.1 seconds). Figure 2Controller 5.

[0053] The fatigue assessment unit 5a (controller 5) calculates the change σ of at least one of the fore-aft and width directions of the seat 1, such as the center of gravity position G in the width direction, based on the detection results detected by the surface pressure sensor 3, and assesses the fatigue state of the occupant based on the calculated change σ. More specifically, firstly, based on the pressure distribution P detected by the surface pressure sensor 3 at a predetermined period T1... ij The center of gravity position G, which is the coordinate value i in the width direction of seat 1, is calculated using the following formula (i). By determining the center of gravity position G as the coordinate value i in at least one of the front-back direction and the width direction of seat 1, the calculation process of the center of gravity position G and the change σ can be simplified and the computational load can be reduced.

[0054] [Number 1]

[0055] ···(i)

[0056] Unconscious movements of the occupant, generated by the legs, arms, and neck moving around the torso, are primarily manifested as movements in the width direction of the seat 1. By individually detecting the width-direction movements of the right leg, left leg, right arm, left arm, and neck (e.g., the non-operating leg), unconscious movements of the occupant can be accurately detected without being affected by torso movements. Furthermore, by detecting the movement of the non-operating leg as a change σ in the center of gravity position G in the width direction of the seat 1, unconscious movements of the occupant can be preferably detected. Additionally, by detecting the pressure distribution P... ij The detection cycle and the calculation cycle of the center of gravity position G (i.e., the specified cycle T1) are set short enough to detect instantaneous and subtle movements, thereby accurately detecting the unconscious movements of the seated person.

[0057] Next, the fatigue assessment unit 5a, based on the center of gravity position G calculated according to a predetermined period T1, calculates the average center of gravity position Ga in the current period (predetermined period T2) using the following formula (ii) over a predetermined period T2 (e.g., 60 seconds). Then, using the following formula (iii), the standard deviation of the coordinate value i based on the average center of gravity position Ga in the current period is calculated as the variation σ of the center of gravity position G in the width direction of the seat 1. The variation σ of the center of gravity position G in the left front region AR3 is equivalent to the magnitude of the movement of the non-operating leg.

[0058] [Number 2]

[0059] ...(ii)

[0060] [Number 3]

[0061] ···(iii)

[0062] Figure 5 This is a diagram illustrating an example of the variation σ in the center of gravity position G calculated based on the detection results from the surface pressure sensor 3. (See diagram for example.) Figure 5 As shown, since the variation σ calculated according to the prescribed period T2 represents the magnitude of the movement of the non-operating leg in each period, it changes discontinuously over time. The fatigue assessment unit 5a smooths this variation σ and calculates an assessment value X representing the fatigue state that gradually changes over time. More specifically, as shown in equation (iv) below, the variation σ is used to... n The previous evaluation value X after multiplying by the specified weighting coefficient k (0 < k < 1) n-1 The assessed value X is calculated as a sum. n By smoothing the variable σ, a suitable assessment value X representing the gradually changing fatigue state can be obtained, which can be used to properly assess the fatigue state of the seated person.

[0063] [Number 4]

[0064] ...(iv)

[0065] Figure 6 This is a graph used to illustrate the weights used in the smoothing process, showing the variation σ calculated by multiplying by a specified period T2. m And the weight k corresponding to the time delay (nm) n-m As shown in equation (iv) and Figure 6 As shown, the evaluation value X for this (nth) time is... n The change σ is calculated as follows: up to the current time (the m-th time (m=1, 2, ..., n-2, n-1, n)). m Multiplied by a weight k that decays as the time delay (nm) increases. n-m And accumulate these products k n-mσ m Therefore, an assessment value X representing the fatigue state that gradually changes over time can be calculated.

[0066] The fatigue assessment department 5a also uses the current assessment value X from the specified data set. n The ranking will be used to determine the evaluation value X. n Normalization treatment of percentage rank values ​​α that are normalized to 0 or less and less than 1 (when the current evaluation value X) n(The minimum value is "0", and the maximum value is "1"). The defined data set is, for example, all assessment values ​​X calculated for the same person, such as all assessment values ​​X calculated after sitting on seat 1 based on the detection results of the surface pressure sensor 3. When the individual person can be identified, all assessment values ​​X calculated when the same person previously sat on seat 1 are set as the defined data set. By considering the past assessment values ​​X of the same person, a suitable percentage level value α representing the individual person's fatigue state can be calculated.

[0067] The fatigue assessment unit 5a uses a pre-stored formula in the memory of the controller 5 to calculate the current assessment value X. n The percentage rank value α corresponds to the fatigue probability. The defined judgment formula uses whether the occupant of seat 1 is fatigued (fatigued or not fatigued) or whether their concentration has decreased (decreased or not decreased) as the target variable, and the normalized evaluation value X (percentage rank value α) as the explanatory variable, pre-created using a learned logistic regression model. Then, if the calculated fatigue probability is above a specified threshold (e.g., 0.5), it is judged as fatigued (or with decreased concentration), and if it is below the threshold, it is judged as not fatigued (or not with decreased concentration), thus assessing the occupant's fatigue state. This allows for a more accurate assessment of the occupant's fatigue state. By using the normalized evaluation value X (percentage rank value α), even if the occupant being assessed is different from the occupant at the time the judgment formula was created, a suitable fatigue probability can be calculated, thus allowing for a more appropriate assessment of the occupant's fatigue state.

[0068] Figure 7 This is a flowchart illustrating an example of a process performed by controller 5. The process shown in this flowchart begins, for example, when vehicle 2 is started and power is supplied to surface pressure sensor 3 and controller 5, and repeats at a predetermined period T1. Figure 7 As shown, in step S1, the pressure distribution P detected by the surface pressure sensor 3 is first obtained. ij Next, in step S2, based on the pressure distribution P obtained in step S1... ij The center of gravity G in the width direction of seat 1 is calculated. The center of gravity G calculated in step S2 is stored as a time series data with a specified period T1 in the memory of controller 5.

[0069] Next, in step S3, it is determined whether the specified period T2 has elapsed. If a positive determination is obtained in step S3, the process proceeds to step S4; otherwise, the current process ends. In step S4, based on the centroid position G of the specified period T1 stored in the memory, the average centroid position Ga and the change in centroid position G σ in the current period (specified period T2) are calculated. The change σ calculated in step S4 is stored as time series data for the specified period T2 in the memory of the controller 5.

[0070] Next, in step S5, the variation σ of the specified period T2 stored in the memory is smoothed to calculate the fatigue state evaluation value X in the current period (specified period T2). The evaluation value X calculated in step S5 is stored as time series data of the specified period T2 in the memory of the controller 5.

[0071] Next, in step S6, based on the order of all evaluation values ​​X stored in the memory, the current evaluation value X is normalized to calculate the percentage grade value α. The percentage grade value α calculated in step S6 is stored as time series data for a specified period T2 in the memory of the controller 5.

[0072] Next, in step S7, using a predetermined judgment formula pre-stored in the memory of controller 5, the fatigue probability corresponding to the percentage level value α calculated in step S6 is calculated. Next, in step S8, it is determined whether the fatigue probability calculated in step S7 is above a predetermined threshold (e.g., 0.5). If a positive determination is obtained in step S8, the process proceeds to step S9, where the fatigue state of the seated person is assessed as "fatigued" (or "decreased concentration"). If a negative determination is obtained in step S8, the process proceeds to step S10, where the fatigue state of the seated person is assessed as "no fatigue" (or "no decreased concentration").

[0073] Thus, by detecting the movement of the legs and other parts of the body, which are more prone to movement and unconscious actions while seated compared to the torso, as the change in the center of gravity position G (steps S1 to S4), the unconscious actions of the seated person can be preferably detected, thereby allowing for earlier assessment of the seated person's fatigue state. Furthermore, by smoothing the change in σ, a suitable assessment value X representing the gradually changing fatigue state can be calculated, thereby allowing for a more appropriate assessment of the seated person's fatigue state (step S5). Additionally, by normalizing the assessment value X based on past assessment values ​​X of the same seated person, a suitable percentage level value α representing the individual seated person's fatigue state can be calculated, thereby allowing for a more appropriate assessment of the seated person's fatigue state (step S6). Furthermore, by using a predetermined decision formula pre-stored in the memory of the controller 5, the fatigue probability corresponding to the assessment value X (percentage level value α) is calculated, and the fatigue state is assessed based on the calculated fatigue probability, thereby further improving the assessment accuracy (steps S7 to S10).

[0074] The assessment results of the seated person's fatigue status can be output and utilized in various forms. For example, when fatigue or decreased concentration is assessed, verbal guidance can be provided. By assessing and informing the seated person about their fatigue status before they consciously experience fatigue or decreased concentration, they can be encouraged to take timely measures such as resting. Specific suggestions, such as appropriate rest times, can also be given.

[0075] When fatigue or decreased concentration is assessed, devices located on or around seat 1 (e.g., inside the vehicle 2) can be activated to alleviate the occupant's fatigue or restore concentration. Such devices include, for example, massage devices installed on seat 1, ventilation devices, aromatherapy spray devices installed on or around seat 1, audio equipment, air exchange devices installed around seat 1, and air conditioning devices. When operating the devices based on the fatigue assessment results, it is preferable to provide suitable switches that allow the user (occupant or someone nearby) to enable or disable the operation of each device. The switch operation for enabling or disabling the operation of each device is preferably received when controller 5 is activated (at the start of the fatigue assessment) and also after the devices are operated based on the fatigue assessment results.

[0076] It can also output as follows Figure 5 The assessed value X (or the change σ of the center of gravity position G, or the percentage ranking value α of the assessed value X) of the time series shown can be confirmed by the seated person or those around them. For example, it can also be sent to vehicle 2 and displayed on the in-vehicle display, or sent to the seated person's own smartphone or wearable device, allowing the seated person to manage it themselves. In this case, the seated person can utilize the assessment results of their fatigue status as one of their vital signs.

[0077] According to embodiments of the present invention, the following effects can be achieved.

[0078] (1) The device 10 includes: a surface pressure sensor 3 for detecting the movement of the left leg (non-operating leg) of the occupant sitting on the seat 1; and a fatigue assessment unit 5a for assessing the fatigue state of the occupant based on the detection results detected by the surface pressure sensor 3. Figures 1-3 By detecting movements of the legs and other parts of the body that are more prone to movement and unconscious actions while seated compared to the torso, unconscious actions of the seated person can be preferably detected, thereby allowing for early assessment of the seated person's fatigue status.

[0079] (2) Seat 1 is the driver's seat of vehicle 2, which is an AT vehicle, where the occupant operates the vehicle by using their right leg (operating leg). The surface pressure sensor 3 detects the movement of the occupant's left leg (non-operating leg) as the driver of vehicle 2. Figure 1 , Figure 3 Therefore, unconscious movements of the occupant can be detected without being affected by the actions accompanying the driving operation.

[0080] (3) The fatigue assessment unit 5a calculates the change σ of the center of gravity position G of at least one of the front-back direction and the width direction (left-right direction) of the seat 1 based on the detection results detected by the surface pressure sensor 3, and assesses the fatigue state of the occupant based on the calculated change σ. Figures 3-5 By detecting the movement of the legs, etc., which move around the torso as a center, as the change σ of the center of gravity position G in at least one of the front-back direction and the width direction of the seat 1, the unconscious movements of the seated person can preferably be detected.

[0081] (4) The center of gravity position G is the coordinate value i of at least one of the fore-aft direction and the width direction of seat 1. Figure 4 By determining the center of gravity position G as the coordinate value i of at least one of the fore-and-aft direction and the width direction of seat 1, the calculation process of the center of gravity position G and the change σ can be simplified and the computational load reduced.

[0082] (5) The surface pressure sensor 3 is installed on the seating surface of the seat 1 (seat cushion 1a) that is in contact with the non-operating side leg. The fatigue assessment unit 5a assesses the fatigue state of the occupant based on the detection results detected by the surface pressure sensor 3 in the area of ​​the seating surface away from the occupant's torso (buttocks). Figure 1 , Figure 3 , Figure 4 Additionally, the surface pressure sensor 3 is located on the side of the seat surface of the seat 1 that is further from the center than the non-operating leg and away from the occupant's buttocks. Figure 1 , Figure 3 , Figure 4 By setting the detection range of the face pressure sensor 3 to a range far from the occupant's torso, it is preferable to detect movements of the legs and other parts of the body that are more prone to movement while seated and to generate unconscious movements of the occupant compared to the torso. Furthermore, by setting the detection range of the face pressure sensor 3 to a range far from the operating side leg or buttocks, unconscious movements of the occupant can be detected without being affected by movements accompanying driving operations.

[0083] (6) The fatigue assessment unit 5a calculates the change σ of the center of gravity position G at a specified period T2 (e.g., 60 seconds), and calculates the assessment value X by smoothing the calculated change σ, and assesses the fatigue state of the seated person based on the calculated assessment value X. Figure 5 , Figure 7 Step S5). In the smoothing process, the change σ is used as the current value. n The previous evaluation value X after being multiplied by the prescribed weighting coefficient k n-1 Calculate the evaluation value X in the form of the sum of the terms. n ( Figure 6 By smoothing the variation σ, a suitable assessment value X representing the gradually changing fatigue state can be calculated, thereby allowing for a proper assessment of the fatigue state of the seated person.

[0084] (7) The fatigue assessment department 5a uses the current assessment value X from the specified data set. n The ranking will be used to determine the evaluation value X. n The percentage rank values ​​α, which are normalized to be between 0 and 1, are used as the evaluation value X for this assessment. n The percentage rank value α is used to assess the fatigue level of seated individuals. Figure 7 Step S6). The specified data set is, for example, all assessment values ​​X calculated for the same individual. In this case, a suitable percentage rank value α representing the individual's fatigue level can be calculated, thereby allowing for a more appropriate assessment of the individual's fatigue level.

[0085] (8) The fatigue assessment unit 5a uses a logistic regression model to assess the fatigue state of the seated person. The logistic regression model uses whether the seated person is fatigued (or whether their concentration has decreased) as the target variable and the percentage grade value α calculated based on the detection results detected by the surface pressure sensor 3 as the explanatory variable. Figure 7 (Steps S7 to S10). In this case, the fatigue state of the seated person can be more accurately assessed based on the fatigue probability obtained from the logistic regression model.

[0086] In the described embodiment, utilizing Figure 1The example described is the application of device 10 to the driver's seat, i.e., seat 1, of vehicle 2, which is an AT vehicle. However, the seats to which the fatigue assessment device can be applied are not limited to this type of seat. For example, it can be applied to passenger seats in vehicles, seats in other modes of transportation, work seats other than those used in vehicles (e.g., office chairs or gaming chairs), medical seats, and other types of seats where the occupant maintains a certain sitting posture for a long time. Furthermore, compared to tasks requiring concentration, such as driving, the change in the center of gravity position G is greater when performing slow tasks such as simply sitting in seat 1, making fatigue or decreased concentration more likely.

[0087] In the described embodiment, utilizing Figure 1 Examples include a surface pressure sensor 3 installed on the driver's seat 1 of vehicle 2 (an AT vehicle) to detect the movement of the driver's left leg (non-operational leg) when driving with the right leg (operational leg). However, sensors that detect the movement of any one of the occupant's right leg, left leg, right arm, left arm, or neck while seated are not limited to this type of sensor. That is, any sensor that detects the movement of the leg, arm, or neck that is in contact with the seat surface of seat 1 and produces an unconscious movement centered on the occupant's torso, and that is not engaged in driving or specific work, or that is almost inactive without being examined or treated, is acceptable.

[0088] In the described embodiment, an example of calculating the change σ of the center of gravity position G in the width direction of the seat 1 was given. However, the change in the center of gravity position can be calculated as the change in the center of gravity position in at least one of the front-back direction and the width direction of the seat. The change σ of the center of gravity position G in the front-back direction of the seat 1 can also be calculated. That is, when seated in the seat 1, the position of the legs, arms, and neck is restricted to a certain extent due to the shape of the seat 1, making it difficult to move forward and backward. However, depending on the structure of the seat 1 and its surroundings, or the physique of the person sitting there, sometimes each part can move easily in the front-back direction.

[0089] In the described embodiment, an example of assessing the fatigue state of a seated person based on the detection results of the movement of the left leg in the seat width direction is given. However, the fatigue state of a seated person can also be assessed based on the movement of the right leg in the seat width direction and the movement of the left leg in the seat front-back direction.

[0090] The sensor can detect movements from any of the following body parts: right leg, left leg, right arm, left arm, or neck. This can also be user-defined and switched appropriately based on the analysis results. For example, it can switch based on the ease with which each person's body movements reflect their fatigue level. The sensor can detect a single body part (right leg, left leg, right arm, left arm, or neck) or multiple body parts. Even when multiple body parts are detected, the fatigue level of the person is assessed based on the movements of each body part, and these assessments are performed independently. For example, even when detecting movements of both the right and left legs, the fatigue level is assessed based on the movements of the right leg and the left leg, respectively, with each assessment being independent of the others.

[0091] When assessing the fatigue state of the occupant of a vehicle 2 that can switch between manual and automatic driving, the assessment can be switched between manual driving mode and automatic driving mode, based on the movement of the non-operating leg, and automatic driving mode and based on the movement of the right and left legs. When assessing the fatigue state of the occupant of a vehicle 2 with a reconfigurable seating arrangement, the location of motion detection can be switched according to the seating arrangement. That is, for the driver's seat occupant, in manual driving mode, it is determined that they are performing a driving operation requiring concentration, and in automatic driving mode, it is determined that they are performing a slow operation simply while seated on seat 1. Furthermore, based on the seating arrangement, it can be determined which part of the body is most likely to produce unconscious movements of the occupant—the right leg, left leg, right arm, left arm, or neck—and which direction is most likely to produce unconscious movements—either the fore-aft or width direction of seat 1—and the location and direction of motion detection can be switched accordingly.

[0092] The sensor can be any sensor that detects unconscious movements of the occupant, primarily aimed at alleviating concentrated body pressure, and is not limited to pressure sensors. For example, it could be a vibration sensor installed on the seat 1, or a sensor that uses a camera installed outside the seat 1 to capture the movements of various parts and detect the movements through image processing.

[0093] In the described embodiment, Figure 1 The example shown is a seat 1 with a seat cushion 1a, a seat back 1b, and a headrest 1c, but the seat may also have a footrest to support the occupant's legs or an armrest to support the arm. It may also be a seat with only a seat cushion 1a and a seat back 1b, or a seat with only a seat cushion 1a.

[0094] In the described embodiment, utilizing Figure 3 Examples have been described where the surface pressure sensor 3 is only installed in the left front region AR3, and only the movement of the left leg, which is the non-operational leg, is detected. However, the sensor can also detect the movement of the right leg (load P acting on the right front region AR2) and the movement of the left leg (load P acting on the left front region AR3). In this case, the fatigue assessment unit 5a can also assess the fatigue state of the occupant based on the larger movement of the right leg and the left leg detected by the surface pressure sensor 3. That is, when there are multiple parts of the legs, arms, and neck that move around the occupant's torso and produce unconscious movements, and which are in contact with the seating surface of the seat 1 but are almost inactive without driving or specific work, or without being examined or treated, the magnitude of the movement of each part is detected, and the occupant's fatigue state is assessed based on the movement of the part with the larger detected movement. For example, surface pressure sensors 3 are installed in the right front region AR2 and the left front region AR3 of seat 1 (seat cushion 1a), which serves as a seat for occupants. These sensors detect the magnitude of the movements of the left and right legs, respectively, and assess the occupant's fatigue level based on the larger movement of the leg. In this case, the occupant's fatigue level can be accurately assessed based on the movement of the dominant leg, which is more mobile and prone to unconscious movements than the supporting leg.

[0095] In the described embodiment, an example of calculating the fatigue probability using a decision formula is illustrated. This decision formula is created using a learned logistic regression model with the fatigue status of the occupant of seat 1 as the target variable and the percentage rank value α of the assessment value X as the explanatory variable. However, instead of the logistic regression model, a decision formula created using other regression models such as a support vector machine can be used to calculate the fatigue probability.

[0096] In the described embodiment, utilizing Figure 7 The examples illustrate how fatigue or decreased concentration can be assessed by calculating the fatigue probability (step S7) and comparing it with a single threshold, thereby determining whether fatigue or concentration has decreased. However, fatigue assessment using a fatigue assessment device is not limited to this. For example, the degree of fatigue (e.g., three stages: mild, moderate, and severe) can be determined by comparing the calculated fatigue probability with multiple thresholds, thus assessing the fatigue state of the seated person. Furthermore, fatigue can be assessed by comparing the change σ of the center of gravity position G calculated in step S4 with a predetermined threshold, by comparing the smoothed assessment value X calculated in step S5 with a predetermined threshold, or by comparing the normalized assessment value X (percentage grade value α) calculated in step S6 with a predetermined threshold.

[0097] In the described embodiment, specific values ​​are illustrated for the prescribed period T1 for calculating the center of gravity position G by acquiring the sensor value of the surface pressure sensor 3, and the prescribed period T2 for calculating, smoothing, normalizing, calculating the fatigue probability, and assessing the fatigue state of the center of gravity position G. However, these are merely examples and are not limited to the illustrated values. The period for each process can be set to a fixed value, can be set by the user, or can be appropriately reset based on the analysis results. For example, it can also be set according to the ease of physical movement in relation to the fatigue state of each seated person.

[0098] [Vehicle Seats]

[0099] Next, refer to Figures 8 to 17 Another embodiment of the present invention will now be described. The vehicle seat of this embodiment is a vehicle seat to which the fatigue assessment device described above can be applied, but it can also be used without applying the fatigue assessment device.

[0100] A technique exists where the portion supporting the lumbar spine of the passenger in the front seat is removed from the front seat and installed behind the seat back, thereby supporting the calves of the passenger in the rear seat from below. This allows the rear passenger to stretch their legs and maintain a comfortable posture. The portion supporting the calves, specifically the area below the knees, is sometimes referred to as an ottoman.

[0101] However, when the rear end of the footrest installed on the back of the front seat is lower than the front end of the seat cushion of the rear seat where the passenger using the footrest sits, the length of the portion from near the rear end of the footrest to the front end of the seat cushion of the rear seat that cannot support the lower part of the knee becomes longer, thus failing to stably support the passenger's legs.

[0102] Therefore, in this embodiment, the vehicle seat is configured as follows to provide a vehicle seat that can stably support the knees of the passenger.

[0103] The vehicle seat according to embodiments of the present invention includes a footstool (leg rest) for supporting the legs of a passenger seated in the seat assembly, and can be applied to various types of seats. Hereinafter, an example of its application in a vehicle seat will be described as an example of a vehicle seat including a footstool.

[0104] Figure 8This is a side view of a vehicle seat including a footstool according to an embodiment of the present invention. Furthermore, for convenience, the left-right direction in the figure will be defined as the horizontal direction, and the up-down direction as the vertical direction, and the parts will be described accordingly. Figure 8 The horizontal, vertical, and orthogonal directions to the paper are respectively aligned with the longitudinal, vertical, and width directions of the vehicle equipped with vehicle seats (front seat 100, rear seat 200). For reference later... Figures 9-17 The same applies.

[0105] like Figure 8 As shown, the vehicle seats include a front seat 100 for the front passenger P1 and a rear seat 200 for the rear passenger P2. The front seat 100 and the rear seat 200 are fixed to a pair of left and right tracks R, which are slidable in the front-rear direction and are fixed to the vehicle body below the two seats 100 and 200 and spaced apart in the width direction of the two seats 100 and 200. In a vehicle with two rows of seats, the front seat 100 can be used as the front row seat and the rear seat 200 as the rear row seat. In a passenger car with three rows of seats, the front seat 100 can be used as the front row seat and the rear seat 200 as the middle seat in the second row, or the front seat 100 can be used as the middle seat and the rear seat 200 as the third row seat. In addition, in vehicles with three or more rows of seats, such as buses, any seat other than the last row of the vehicle can be designated as the front seat 100, and the seat behind this seat can be designated as the rear seat 200.

[0106] The front seat 100 has a seat cushion 104 that supports the thighs of the front passenger P1, and a seat back 102 that is rotatably (reclining) relative to the seat cushion 104 and supports the back of the front passenger P1. In addition, if the front seat 100 is a bucket seat type, the reclining function can be omitted, and the seat back 102 can be erected at the rear of the seat cushion 104.

[0107] The lower part of the seat cushion 104 includes a seat height adjustment mechanism 130 that can adjust the height of the front seat 100 according to the body size of the front passenger P1. Additionally, an armrest 120 is provided on the front seat 100. An operating section 122 is provided on the upper surface of the armrest 120, i.e., the portion where the front passenger P1 places their forearm, for setting various functions of the front seat 100, such as seat height / position, seat heater, seat ventilation, and massage functions.

[0108] A leg rest 106, serving as a footstool, is provided on the rear side (rear side) of the seat back 102. In use, the leg rest 106 functions as a footstool supporting the knees of the rear passenger P2. For example, the leg rest 106 is rotatably mounted on a pivot 110 provided on the seat back 102 and is stored in a recess 103 formed on the back of the seat back 102 when not in use. An air cell 108 may also be provided within the leg rest 106. The air cell 108 forms a fluid bag that expands by pressurizing fluid, such as air, using a pump and introducing it into the air cell 108, and contracts by expelling air. By inflating and contracting the air cell 108, the height adjustment function or massage function of the support surface 105 constituting the upper surface of the leg rest 106 in use can be achieved.

[0109] The rear seat 200 includes a seat cushion 204 that supports the thighs of the rear passenger P2, and a seat back 202 that is rotatably (reclining) relative to the seat cushion 204 and supports the back of the rear passenger P2. Similar to the description of the front seat 100, if the rear seat 200 is a bucket seat type, the reclining function can be omitted, and the seat back 202 can be erected at the rear of the seat cushion 204. The same applies to rear seats that do not have a reclining function.

[0110] The lower part of the seat cushion 204 includes a seat height adjustment mechanism 230 that can adjust the height of the rear seat 200 according to the physique of the rear passenger P2. Additionally, an armrest 220 is provided on the side of the seat back 202 via a rotation axis 224 extending in the width direction of the vehicle. An operating section 222 is provided on the upper surface of the armrest 220, i.e., the portion where the rear passenger P2 places their forearm, allowing for the setting of various functions of the rear seat 200, such as seat height / position, and settings for seat heating, seat ventilation, and massage functions.

[0111] The armrest 220 is configured to rotate freely about the rotation axis 224. It can be configured such that the angular position (tilt) of the armrest 220 relative to the seat back 202 can be electrically changed, for example, by operating the operating part 222. Alternatively, it can be configured to include a mechanism that locks the armrest 220 in rotation about the rotation axis 224, allowing the tilt of the armrest 220 to be adjusted by raising or lowering the front side of the armrest 220 while operating an unlocking operating member included on the armrest 220.

[0112] The armrest 220 is configured to rotate to a stowed position in a direction where its upper surface 226, the support surface for the rear passenger P2's forearm to rest on in the use state, faces downwards towards the front of the vehicle. That is, it can rotate in the opposite direction to the upward-folding position, so that the armrest 220 is rotated to a stowed position where the upper surface 226 of the armrest 220 is approximately parallel to the seating surface 203 of the seat back 202. Therefore, even when the seat back 202 is reclined to a near-horizontal position, the upper surface 226 of the armrest 220 continues to face the rear passenger P2, thus maintaining a comfortable posture and good operability when operating the control unit 222. Furthermore, even when the armrest 220 is lowered to the stowed position, the rear passenger P2 can easily operate the control unit 222.

[0113] The seat cushion 204 is rotatably connected to the seat height adjustment mechanism 230 via a rotating shaft 242 located near its rear end. A seat cushion angle adjustment mechanism 240 is connected near the front end of the seat cushion 204. The seat cushion angle adjustment mechanism 240 is a mechanism that uses a direct-acting cylinder unit or a linkage mechanism to raise and lower the front end of the seat cushion 204. By rotating the seat cushion 204 around the rotating shaft 242 as the center of rotation, the inclination of the seating surface 206 relative to the horizontal plane is adjusted, thereby adjusting the seat cushion angle for the rear passenger.

[0114] In the vehicle seat of the aforementioned structure, if the leg rest 106 housed in the recess 103 is pulled out and rotates around the pivot 110 along... Figure 8 When rotated clockwise, the leg support 106 is positioned in the use position by a rotation stop near the rotation shaft 110. Figure 8 The state shown is the usage state of the leg support 106. In the usage state, the support surface 105 provided on the upper surface portion of the leg support 106 is located at the highest position of the support surface 105 on the rear end 107 side of the leg support 106.

[0115] When not in use, the leg rest 106 can be folded upward about the rotation axis 110 and stored in the recess 103 of the seat back 102, opposite to the aforementioned configuration. Alternatively, the leg rest 106 can be configured to be pluggable relative to the rear surface of the seat back 102. In this case, the leg rest 106 is configured such that when the protrusion for insertion provided on the front side of the leg rest 106 is inserted into the socket formed on the rear surface of the seat back 102, the leg rest 106 is in the aforementioned use state.

[0116] In the stated usage state, such as Figure 8 As shown, ideally, the leg rest 106 abuts against the seat cushion 204 of the rear seat 200. Figure 8In the example shown, the rear end 107 of the leg rest 106 abuts against the front end 205 of the seat cushion 204.

[0117] Figure 9 , Figure 10 This is a side view showing a modified example of a vehicle seat according to an embodiment of the present invention; details are omitted. Figure 8 The illustration shows the front passenger P1 and the rear passenger P2. Figure 9 , Figure 10 In the middle, to and Figure 1 The vehicles shown are labeled with the same symbols for the same components as the seats, and their descriptions are omitted.

[0118] Regarding the aforementioned contact portion, as Figure 9 As shown, the cutout portion 205A can also be used to support the lower surface 109 of the leg support portion 106 near the rear end 107 and abut against the front end of the seat cushion 204. The cutout portion 205A is formed of a material with higher rigidity than the seat cushion 204, such as resin or steel.

[0119] Or, such as Figure 10 As shown, the rear end 107 of the lower surface 109 of the leg rest 106 can also be supported near the front end 205 of the seat cushion 204 of the rear seat 200. If the rear end 107 of the leg rest 106 is supported near the front end of the seat cushion 204 of the rear seat 200 by any of the methods described above, the rigidity of the leg rest 106 can be increased when using the leg rest 106. In addition, since it is not necessary to increase the rigidity of the leg rest 106, the thickness of the leg rest 106 can also be reduced. As a result, the front seat 100 can also be reduced in thickness because the space of the recess 103 can be minimized. Furthermore, the following situation can be prevented: when the rear passenger P2 places his / her knees below the knees LL on the leg rest 106, the torque generated around the rotation axis 110 causes the seat back 102 of the front seat 100 to deform toward the rear of the vehicle body, causing the front passenger P1 to feel uncomfortable.

[0120] In reference Figures 8-10 In any of the described cases, when the leg rest 106 is in use, the area near the center of the support surface 105 along the front-rear direction of the seat is located higher than the front end 205 of the seating surface 206 of the rear seat 200.

[0121] Reference Figure 9The relationship between the inclination of the support surface 105 of the leg rest 106 and the angular position of the seating surface 206 of the rear seat 200 will be explained. As described above, in the use state of the leg rest 106, the support surface 105 provided on the upper surface portion of the leg rest 106 is located at the highest position of the support surface 105 on the rear end 107 side of the leg rest 106. At this time, the support surface 105 is inclined in a manner that increases in height towards the rear of the seat with reference to the horizontal plane. The inclination of the support surface 105 at this time is as follows: Figure 9 The angle θa shown is the inclination angle of the support surface.

[0122] Using the seat cushion angle adjustment mechanism 240, the seat surface 206 can be tilted downwards towards the rear of the seat, with the horizontal plane as the reference. The tilt angle of the seat surface 206 at this time is as follows: Figure 9 The seat surface tilt angle θb is shown. In an embodiment of the present invention, the seat cushion angle adjustment mechanism 240 is configured to set the seat surface tilt angle θb to be larger than the support surface tilt angle θa. By setting the angle in this way, the rear passenger P2 sitting on the rear seat 200 can obtain a more relaxed sitting posture.

[0123] Regarding another example where, when the leg support 106 is in use, the support surface 105 provided on the upper surface portion of the leg support 106 is located at the highest position among the support surfaces 105 on the rear end 107 side of the leg support 106, see [reference]. Figure 9 The following explanation is provided. A protrusion 112 may also be provided on the rear end 107 side of the support surface 105. For example, even when the tilt angle θa of the support surface is close to 0°, by providing the protrusion 112 on the rear end 107 side of the support surface 105, the knees of the rear passenger P2 seated on the rear seat 200 can be supported, thereby maintaining the comfort of the rear passenger P2.

[0124] Figure 11 This is a side view illustrating a modified example of a vehicle seat according to an embodiment of the present invention. Figure 11 In the middle, to and Figure 8 The vehicles shown are labeled with the same symbols for the same components as the seats, and their descriptions are omitted.

[0125] exist Figure 11 The seats in the vehicles shown will be referenced Figure 9 The seat cushion angle is set to approximately horizontal, and the seat height 204 is adjusted high using the seat height adjustment mechanism 230. This ensures a clear view forward, even for a smaller rear passenger (P2), helping to reduce motion sickness. Figure 11The illustrated implementation can be applied to a one-box car or minivan with three rows of seats. Alternatively, the first seat 100 can be configured as the middle seat and the second seat 200 as the third row of seats.

[0126] Figure 12 This is a side view illustrating another variation of a vehicle seat according to an embodiment of the present invention. Figure 12 In the middle, to and Figure 8 The vehicles shown are labeled with the same symbols for the same components as the seats, and their descriptions are omitted.

[0127] exist Figure 12 In the illustrated vehicle seat, a footrest cover 114 is rotatably mounted on the rear end 107 of the leg rest portion 106 about a pivot 116. When not in use, the footrest cover 114 can be folded into a recess formed near the rear end 107 of the leg rest portion 106. When the distance between the front seat 100 and the rear seat 200 (seat pitch) is wide and the leg rest portion 106 does not abut against the seat cushion 204 of the rear seat 200, and when the rear passenger P2 sitting in the rear seat 200 is small and the lower part of the rear passenger P2's knees LL cannot reach the leg rest portion 106, the footrest cover 114 can be unfolded to support the toes of the rear passenger P2.

[0128] In Figure 12 The illustrated implementation can be applied to a three-row sedan or minivan type vehicle, where the first seat 100 can be set as the middle seat and the second seat 200 as the third row of seats.

[0129] Figure 13 This is a side view illustrating yet another variation of the vehicle seat according to an embodiment of the present invention. Figure 13 In the middle, to and Figure 8 The vehicles shown are labeled with the same symbols for the same components as the seats, and their descriptions are omitted.

[0130] exist Figure 13In the illustrated vehicle seat, an extension support mechanism 117 is rotatably supported on the back side of the seat back 102 of the front seat 100 about a rotation axis 110. A support portion 119 is provided on the opposite side of the side supported by the axis of the extension support mechanism 117. A leg rest portion 106 is mounted on the support portion 119 relative to the extension support mechanism 117 in a manner that allows it to slide along the extending direction of the extension support mechanism 117. When the distance between the front seat 100 and the rear seat 200 (seat pitch) is wide and the leg rest portion 106 does not abut against the seat cushion 204 of the rear seat 200, and when the rear passenger P2 sitting on the rear seat 200 is small and the lower part of the rear passenger P2's knees LL cannot reach the leg rest portion 106, the leg rest portion 106, which is housed in the recess 103, can be flipped up and pulled out toward the rear seat 200. By pulling out the leg rest 106 toward the rear seat 200 as described above, the lower part of the knees LL of the rear passenger P2 can be placed on the leg rest 106. When the leg rest 106 is pulled out in this way, it is ideal that the rear end 107 of the leg rest 106 can also abut against the front end 205 of the seat cushion 204.

[0131] In Figure 13 The illustrated embodiment is applied to a single-box or minivan type vehicle with three rows of seats. Alternatively, the first seat 100 can be set as the middle seat and the second seat 200 as the third row of seats.

[0132] Figure 14 This is a side view showing another variation of the vehicle seat according to an embodiment of the present invention, and illustrating the utilization form in which the leg rest 106 is used as a seating portion. Figure 14 In the middle, to and Figure 8 The vehicles shown are labeled with the same symbols for the same components as the seats, and their descriptions are omitted. Figure 14 An example is shown where the vehicle seating includes a third row of seats 300 in addition to the front seats 100 and the rear seats 200. The third row of seats 300, like the rear seats 200, includes a seat height adjustment mechanism 330, a seat cushion 304, a seat back 302, and armrests 320. Furthermore, this third row of seats 300 is not essential in this embodiment and may be omitted.

[0133] Figure 14The illustrated usage configuration is, for example, conceived of relaxing or working inside the vehicle while traveling to a destination. Passenger P can pull up the leg rest 106 of the front seat 100 from the recess 103 of the seat back 102 and sit on the support surface 105. At this time, by adjusting the height of the seat cushion 204 using the seat height adjustment mechanism 230, the seat cushion 204 can be used as a footrest. In this case, when the leg rest 106 is in use, the area near the center of the support surface 105 along the fore-and-aft direction is also located higher than the front end 205 of the seating surface 206 of the rear seat 200. Alternatively, the seat distance between the front seat 100 and the rear seat 200 can be reduced so that the rear end 107 of the leg rest 106 abuts against the front end 205 of the seat cushion 204.

[0134] Figure 15 This is a side view showing another variation of the vehicle seat according to an embodiment of the present invention, and is compared with reference to... Figure 14 The description also illustrates a diagram showing the leg rest 106 used as a seating area. Figure 15 In the middle, to and Figure 8 as well as Figure 14 The vehicles shown are labeled with the same symbols for components with identical seats, and their descriptions are omitted. Figure 15 Nakaya and Figure 14 Similarly, an example is shown where the vehicle seats include a third row of seats 300 in addition to the front seats 100 and the rear seats 200. However, this third row of seats 300 is not necessary in this embodiment and may not be present.

[0135] by Figure 14 The vehicle seats shown Figure 15 The explanation will focus on the differences in the seats of the vehicles shown. The leg rest 106 of the front seat 100 is used as a seating area, which is different from... Figure 14 The structures shown are the same, but the difference is that... Figure 15 In the structure shown, the seat cushion 204 of the rear seat 200 is used as a table or shelf instead of a footstool. The seat height adjustment mechanism 230A is configured to allow for a height adjustment ratio of... Figures 8 to 14 The seat height adjustment mechanism 230 shown is large. For example, the seat height adjustment mechanism 230 can also be constructed by overlapping multiple segments of a multi-section linkage mechanism, such as a four-section parallel linkage mechanism, or by using a scissor lifting mechanism, etc.

[0136] Figure 15 The image shows the state after the airbag 108 built into the leg rest 106 has been inflated. By adjusting the degree of inflation of the airbag 108, the seating comfort when using the leg rest 106 as a seat can be improved.

[0137] The armrest 220 can also be configured to be easily detached and reattached to the side of the seat back 202. For example, the armrest 220 can be fixed to the rotating shaft 224 with screws, or a bayonet-type connection structure can be provided on both the rotating shaft 224 and the armrest 220. Alternatively, the end of the rotating shaft 224 can be formed into a polygonal shaft shape, or a portion of a round shaft can be cut into a flat D-cut shape, and a hole with a complementary shape to the shaft can be provided on the side of the armrest 220 for fitting. By making the armrest 220 easily detachable and reattached, any of a variety of pre-prepared armrests can be installed. For example, such as Figure 15 As shown, when the seat cushion 204 is positioned high, the installation of a large armrest 220A can prevent items placed on the seat cushion 204 from becoming unstable.

[0138] Figure 16 This is a side view showing yet another variation of the vehicle seat according to an embodiment of the present invention, and is compared with reference to... Figure 14 , Figure 15 The description also illustrates a diagram showing the leg rest 106 used as a seating area. Figure 16 In the middle, to and Figure 8 , Figure 14 as well as Figure 15 The vehicles shown are labeled with the same symbols for components with identical seats, and their descriptions are omitted. Figure 16 Nakaya and Figure 14 , Figure 15 Similarly, an example is shown where the vehicle seats include a third row of seats 300 in addition to the front seats 100 and the rear seats 200. However, this third row of seats 300 is not necessary in this embodiment and may not be present.

[0139] exist Figure 16 In the example shown, the seat cushion 204 can be configured to tilt downwards toward the front of the vehicle via the seat cushion angle adjustment mechanism 240, and the seat cushion 204 can be moved in the fore-and-aft direction. In the illustrated example, it moves toward the front of the vehicle, i.e., the side of the passenger P seated on the leg rest 106. Furthermore, an armrest 220B with a lighting device such as a reading light can be installed as needed. With the configuration described above, in the mode where the leg rest 106 is used as a seat, the seat cushion 204 can be used like a table, and by using the armrest 220B with the lighting device, one can comfortably read or operate electronic devices such as personal computers even in darker environments.

[0140] Figure 17 This diagram illustrates an example of a footstool device, specifically the leg rest 106, that can be interchanged between multiple different seats. Figure 17 In the middle, to and Figure 8The same components are labeled with the same symbols and their descriptions are omitted.

[0141] Near the front end of the seat cushion 104 of the front seat 100, there is a rotating shaft 101 that allows for the detachable mounting of a leg rest 106A and extends in the width direction of the vehicle. The leg rest 106A mounted on the rotating shaft 101 is configured to be adjustable in tilt angle relative to the horizontal plane in the fore-and-aft direction of the vehicle.

[0142] A leg rest 106B is detachably mounted on the back side of the seat back 102 of the front seat 100. Similarly, a leg rest 106C is detachably mounted on the back side of the seat back 202 of the rear seat 200. The leg rests 106A, 106B, and 106C are all interchangeable in shape, allowing users to customize the arrangement of these three leg rests, or even include... Figure 17 Any of the other leg supports not shown in the diagram may be installed in any location described herein.

[0143] In the leg support portion 106A, leg support portion 106B, leg support portion 106C or Figure 17 Other leg rests, not shown, can be combined and have various functions built-in. For example, leg rest 106A, in addition to the built-in airbag 108, can also have a built-in heater or ventilation function. Leg rest 106B, in addition to the built-in airbag 108, can also have a built-in sensor. As a sensor, a seating sensor, pressure sensor, biosensor, etc., can be incorporated. Leg rest 106C, in addition to the built-in airbag and sensor, can also have a built-in speaker or occupant protection device, such as an airbag. Alternatively, a vibration generator can be built-in instead of an airbag to provide a massage function. The described functions are just one example; various functions can be incorporated individually or in combination in each leg rest. Users can install leg rests with their preferred functions on their favorite seats. Alternatively, leg rests may not have any built-in functions, or the material or color of the leg rest surface can be changed, allowing users to coordinate with the interior of their vehicle according to their preferences. By making each leg rest detachable, the ease of cleaning can also be improved.

[0144] According to the embodiments of the present invention, the following effects can be achieved.

[0145] (1) A vehicle seat includes a first seat 100 and a second seat 200 disposed behind the first seat 100. The first seat 100 has a first seat cushion 104 and a first seat back 102 erected from the rear end of the first seat cushion 104. The second seat 200 has a second seat cushion 204 and a second seat back 202 erected from the rear end of the second seat cushion 204. The first seat back 102 has a leg rest 106, which, in use, protrudes rearward and has a support surface 105 for supporting the lower knee portion LL of the rear passenger P2 seated in the second seat 200. The vehicle seat also includes a support portion, which is designed to support the lower knee portion LL of the rear passenger P2 seated in the second seat 200. Figure 8 In the usage state shown, the leg rest 106 is positioned above the front end 205 of the seating surface 206 of the second seat cushion 204, supporting the leg rest 106 in such a way that it is located higher than the front end 205 of the seating surface 206 of the second seat cushion 204. As a support, a stop may also be provided on the rotation axis 110 so that when the leg rest 106 is pulled out to the angled position of the usage state, it stops at said angle. Alternatively, as shown in reference... Figure 9 or Figure 10 The leg rest 106 can also be supported near the front end of the seat cushion 204.

[0146] According to the vehicle seat, the support surface of the leg rest is close to the front end of the second seat cushion, which can stably support the occupant's legs, thereby maintaining a relaxed state for a long time.

[0147] (2) In the vehicle seat, when the leg rest 106 is in use, the second seat cushion 204 abuts against the leg rest 106. In this way, a continuous support surface for supporting the lower part LL of the knee can be ensured by the second seat cushion 204 and the leg rest 106 abutting against it.

[0148] (3) In the vehicle seat, when the leg rest 106 is in use, the rear end 107 of the leg rest 106 abuts against the front end 205 of the seating surface 206 of the second seat cushion 204. This reduces the area of ​​overlap between the leg rest 106 and the second seat cushion 204 in the vertical direction, making it easier to ensure the front-rear length of the surface supporting the lower knee portion LL. Furthermore, the support surface 105 used to support the lower knee portion LL can become a smoother, more continuous support surface.

[0149] (4) In the vehicle seat, when the leg rest 106 is in use, the lower surface 109 of the rear end 107 of the leg rest 106 is supported by the second seat cushion 204. In this way, the rear end 107 of the leg rest 106 can be supported by the second seat cushion 204, thereby reducing the rigidity required for the leg rest 106. Therefore, the leg rest 106 can be made thinner, and the large size of the first seat back 102 can be suppressed.

[0150] (5) In the vehicle seat, when the leg rest 106 is in use, the area near the center of the support surface 105 in the front-rear direction of the seat is located higher than the front end 205 of the seating surface 206 of the second seat cushion 204. As a result, since the position of the lower knee portion LL can be raised, blood stagnation in the lower knee portion LL can be suppressed.

[0151] (6) In the vehicle seat, the support portion preferably supports the leg rest 106 in such a way that the rear end of the leg rest 106 is at the highest position in the support surface 105 when in use. In this way, by making the rear end of the leg rest 106 the highest in the support surface, it is easier to support the knees and improve comfort.

[0152] (7) In the vehicle seat, the second seat cushion 204 is configured to rotate about an axis 242 extending in the width direction of the seat, and also includes a cushion angle adjustment mechanism 240 for adjusting the tilt angle of the second seat cushion 204 in the fore-and-aft direction of the seat. Furthermore, when the leg rest 106 is in use, with the horizontal plane as a reference, the tilt angle θb of the second seat cushion 204 towards the rear of the seat can be set larger than the tilt angle θa of the support surface 105 towards the rear of the seat. This allows the occupant to achieve a more relaxed sitting posture.

[0153] (8) The vehicle seat also includes a second seat height adjustment mechanism 230A that adjusts the height of the second seat cushion 204. The second seat height adjustment mechanism 230A is configured such that, when the leg rest 106 is used as a seat, the height of the second seat cushion 204 can be set higher than the support surface 105 of the leg rest 106 in use. In this way, the second seat cushion 204 can be used as a table or shelf, increasing convenience.

[0154] (9) In the vehicle seat, the second seat back 202 is provided with an armrest mounting part of any one of a variety of armrests 220 and 220A that can be detachably installed. Thus, an armrest 220 or armrest 220A suitable for a set height of the second seat cushion can be installed.

[0155] (10) The vehicle seat is configured to accommodate an armrest 220A with a shape such that, when the height of the second seat cushion 204 is set higher than the support surface 105 when the leg rest 106 is in use, it can prevent the passenger or the items placed on the second seat 200 from being in an unstable state. In this way, the armrest can be used to stabilize the items placed on it.

[0156] (11) In the vehicle seat, the upper surface 226 of the armrest 220 has a forearm support surface 226 that supports the forearm of a passenger sitting in the second seat, and an operating part 222 provided on the forearm support surface 226 and operable by the passenger. The armrest 220 can be angled such that the forearm support surface 226 is inclined forward and backward in the front-to-back direction of the seat, and is configured to be rotated to a stowed position in a direction that further increases the forward-to-back inclination angle. In this way, even when the armrest is rotated to the stowed position, the hand can easily reach the operating part, thus improving operability.

[0157] Summary of usage Figures 8 to 17 The structure of the seat in the vehicle described is as follows.

[0158] A vehicle seat includes a first seat and a second seat disposed behind the first seat. The first seat has a first seat cushion and a first seat back extending from the rear end of the first seat cushion. The second seat has a second seat cushion and a second seat back extending from the rear end of the second seat cushion. The first seat back has a leg rest that, in use, protrudes rearward and provides a support surface for supporting the lower knees of a passenger seated in the second seat. The vehicle seat also includes a support portion that supports the leg rest in use such that, in use, the leg rest is located above the front end of the seating surface of the second seat cushion.

[0159] In the stated usage state, the second seat cushion abuts against the leg rest.

[0160] In the usage state, the rear end of the leg rest abuts against the front end of the seating surface of the second seat cushion.

[0161] Alternatively, in the stated usage state, the lower surface of the rear end of the leg rest is supported by the second seat cushion.

[0162] In the usage state, the area near the center of the support surface along the front-rear direction of the seat is located at a position higher than the front end of the seating surface of the second seat cushion.

[0163] The support portion supports the leg support in such a way that the rear end of the leg support is at the highest position in the support surface when in use.

[0164] The second seat cushion is configured to rotate about an axis extending in the width direction of the seat, and also includes a seat cushion angle adjustment mechanism for adjusting the tilt angle of the second seat cushion in the fore-aft direction. The vehicle seat is configured such that, in use, with a horizontal plane as a reference, the tilt angle of the second seat cushion towards the rear of the seat can be set to be larger than the tilt angle of the supporting surface towards the rear of the seat.

[0165] The vehicle seat also includes a second seat height adjustment mechanism that allows adjustment of the height of the second seat cushion. This mechanism is configured such that, in a mode where the leg rest is used as a seating area, the height of the second seat cushion can be set higher than the support surface in its active position.

[0166] In a vehicle seat, a handrail mounting part is provided on the back of the second seat, which can be detachably installed on any of a variety of handrails.

[0167] The vehicle seat is configured to be equipped with armrests of the shape that, when the height of the second seat cushion is set higher than the support surface in the use state, can prevent the passenger or the goods placed on the second seat from being in an unstable state.

[0168] The upper surface of the armrest has a forearm support surface that supports the forearm of a occupant seated in the second seat, and an operating part disposed on the forearm support surface and operable by the occupant. The armrest is configured to be angle-adjustable such that the forearm support surface is tilted forward and backward in the fore-and-aft direction of the seat.

[0169] In the described embodiment, the case of it being incorporated into a vehicle as a seat for transportation is illustrated, but it can also be used as a seat for vehicles other than vehicles, such as seats for aircraft and other means of transportation.

[0170] The above description is merely an example, and the present invention is not limited to the described embodiments and variations as long as it does not impair the characteristics of the invention. One or more of the described embodiments and variations can be combined arbitrarily, and variations can also be combined with each other.

[0171] Explanation of icon numbers

[0172] 1: Seat

[0173] 1a: Seat cushion

[0174] 1b: Seat backrest

[0175] 1c: Headrest

[0176] 2: Vehicles

[0177] 3: Surface pressure sensor

[0178] 4: Operation pedal

[0179] 5: Controller

[0180] 5a: Fatigue Assessment Department

[0181] 10: Fatigue assessment device

[0182] 100: Front Seat

[0183] 102: Seat backrest

[0184] 103: concave part

[0185] 104: Seat cushion

[0186] 105: Support surface

[0187] 106: Leg support section

[0188] 107: Rear end

[0189] 108: Airbag

[0190] 109: Lower surface

[0191] 110: Rotating shaft

[0192] 112: Protrusion

[0193] 120: Handrail

[0194] 122: Operations Department

[0195] 130: Seat height adjustment mechanism

[0196] 200: Rear Seats

[0197] 202: Seat backrest

[0198] 204: Seat cushion

[0199] 205: Front end

[0200] 205A: Incision site

[0201] 206: Seating surface

[0202] 220: Handrail

[0203] 222: Operations Department

[0204] 224: Rotating shaft

[0205] 226: Upper surface

[0206] 230: Seat height adjustment mechanism

[0207] 230A: Seat height adjustment mechanism

[0208] 240: Seat cushion angle adjustment mechanism

[0209] 242: Rotation shaft

[0210] LL: Below the knee

[0211] P1: Front passenger

[0212] P2: Rear passenger

Claims

1. A fatigue assessment device, characterized in that, include: Sensors detect movements of any part of the occupant's right leg, left leg, right arm, left arm, and neck while seated in the chair. as well as The fatigue assessment unit assesses the fatigue state of the seated person based on the detection results obtained by the sensors.

2. The fatigue assessment device according to claim 1, characterized in that, The seat is mounted on a vehicle in which the occupant operates the vehicle using either their right or left leg. The sensor detects the movement of the right leg and the other of the left leg.

3. The fatigue assessment device according to claim 1, characterized in that, The sensor detects the movement of the right leg and the movement of the left leg. The fatigue assessment unit assesses the fatigue state based on the larger of the movements of the right leg and the left leg detected by the sensor.

4. The fatigue assessment device according to any one of claims 1 to 3, characterized in that, The fatigue assessment unit calculates the change in the center of gravity position of at least one of the front-to-back direction and the width direction of the seat based on the detection results detected by the sensor, and assesses the fatigue state based on the calculated change.

5. The fatigue assessment device according to claim 4, characterized in that, The center of gravity position is the coordinate value of at least one of the front-back direction and the width direction.

6. The fatigue assessment device according to any one of claims 1 to 3, characterized in that, The sensor is a pressure sensor disposed on the seat surface of the seat that is in contact with any one of the right leg, the left leg, the right arm, the left arm, and the neck. The fatigue assessment unit evaluates the fatigue state based on the detection results detected by the sensors within a range of the seating surface away from the occupant's torso.

7. The fatigue assessment device according to claim 2, characterized in that, The sensor is a pressure sensor and is located on the side of the seat surface that is closer to the other person than the center and away from the seated person's buttocks.

8. The fatigue assessment device according to claim 5, characterized in that, The fatigue assessment unit calculates the variation at a predetermined period, and calculates an assessment value by smoothing the calculated variation. Based on the calculated assessment value, the fatigue state is assessed. In the smoothing process, the current evaluation value is calculated as the sum of the current change and the previous evaluation value multiplied by a predetermined weighting coefficient.

9. The fatigue assessment device according to claim 8, characterized in that, The fatigue assessment unit performs a normalization process based on the ranking of the current assessment value in the specified data group, normalizing the current assessment value to a value greater than 0 and less than 1, and assesses the fatigue state based on the current assessment value after normalization.

10. The fatigue assessment device according to claim 9, characterized in that, The specified data set is all the evaluation values ​​calculated for the same person seated.

11. The fatigue assessment device according to any one of claims 1 to 3, characterized in that, The fatigue assessment unit uses a logistic regression model to assess the fatigue state. The logistic regression model uses whether the occupant is fatigued as the target variable and the value calculated based on the detection results detected by the sensor as the explanatory variable.

12. The fatigue assessment device according to claim 1, characterized in that, The sensor detects the movement of the left leg.

13. A vehicle, characterized in that, Includes the fatigue assessment device as described in any one of claims 1 to 3.

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