seat

Abstract

To provide a seat which improves operability of steering operation without affecting seat performance during normal usage.SOLUTION: A seat 1 having a seating surface part 10 on which a waist part 110 and a thigh part 120 of an occupant 100 who performs steering operation of a vehicle are rested and a seat back part 20 which comes into contact with a back part 131 of the occupant is configured to comprise: rigidity changing parts 23, 24 which change rigidity of positions coming into contact with vicinities of the blade bones 132 of the occupant in the seat back part; a steering operation prediction part for predicting whether or not a steering operation will be performed; and a rigidity change control part 210 which, when it is predicted that a steering operation will be performed, makes the rigidity change part increase the rigidity before the steering operation starts.SELECTED DRAWING: Figure 6

Description

Technical Field

[0001] The present invention relates to a seat on which an occupant sits, for example, mounted on a vehicle or the like.

Background Art

[0002] As a technology related to the control of a vehicle seat, for example, in Patent Document 1, in order to appropriately hold the posture of an occupant, the weight of the occupant sitting on the seat, the gripping force of the occupant detected by a grip sensor, the load of the occupant detected by an armrest sensor, etc. Based on the occupant seating state and the lateral acceleration predicted based on the curvature of the road on which the vehicle is traveling and the vehicle speed, it is described that the shoulder support part that supports the upper arm from the side, the armrest, and the seat inclination part are controlled. In Patent Document 2, in order to improve the steering performance in a cramped posture where the upper body is close to the steering wheel, in the seat back of the driver's seat, at least the shoulder parts at the upper left and right of the support surface that supports the driver are each independently provided with seat back displacement means that can be displaced rearward of the vehicle, and a steering assist control that displaces at least the shoulder part on the steering direction side of the support surface rearward of the vehicle is described. In Patent Document 3, in order to measure the body pressure value of an occupant and adjust the way of supporting the pelvis and scapula so that the appropriate body pressure value is obtained for that person, a bottom support member that is pivotally supported on the seat cushion directly below the hip point and supports the thigh from below, a lower support member that is pivotally supported on the seat back at a position below the seat back and supports the pelvis from behind, an upper support member that is pivotally supported on the seat back at a position above the seat back and supports the scapula from behind, and a control device that controls a drive device that drives each support member are described. In Patent Document 4, in order to match the forward field of view recognized by an occupant with the physical driving state of the vehicle and improve the steering operation performance during turning, in a vehicle seat having a seat cushion and a seat back, when a turning driving state is detected by a steering angle sensor, the rigidity value of the seat surface of the outer part in the turning direction of the seat cushion is controlled to be higher than the rigidity value of the seat surface of the inner part in the turning direction. [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2019-209733 [Patent Document 2] Japanese Patent Publication No. 2007-331650 [Patent Document 3] Japanese Patent Publication No. 2019-137286 [Patent Document 4] Japanese Patent Publication No. 2020-50255 [Overview of the project] [Problems that the invention aims to solve]

[0004] To improve the ease of steering for the driver, it is necessary to suppress the movement of the upper body caused by the reaction force generated when steering. In order to stop upper body movement, increasing the support rigidity of the shoulder blades is considered effective. However, simply improving the rigidity of the seat back to increase the support rigidity of the shoulder blades raises concerns that it may negatively affect comfort during normal driving (seating comfort) and whiplash protection in the event of a rear-end collision. In view of the above-mentioned problems, the object of the present invention is to provide a seat that improves steering operability without affecting the seat performance during normal use. [Means for solving the problem]

[0005] To solve the above-mentioned problems, the present invention provides a seat having a seat surface on which the occupant's waist and thighs rest when operating the steering wheel of the vehicle, and a seat back that contacts the occupant's back, An elastic body disposed in the seat back portion; a pair of side members constituting the frame of the seat back portion and disposed along the left and right side edges of the seat back portion; a beam-shaped member provided between the pair of side members behind the elastic body and within a predetermined height range along the surface of the seat back portion from the seat surface portion, the beam-shaped member being a hard member with higher hardness than the elastic body; an actuator equipped with an electric motor, which transmits power generated by the electric motor to the hard member, thereby moving the hard member in the front-rear direction relative to the pair of side members; a lateral acceleration estimation unit that calculates the lateral acceleration generated in the vehicle when traveling in a lane located a predetermined distance ahead of the vehicle, based on information indicating the vehicle speed input from the vehicle's speed sensor and information indicating the shape of the lane ahead of the vehicle input from at least one of the vehicle's navigation system and an environment recognition unit that recognizes the surrounding environment of the vehicle; and based on the lateral acceleration, A steering operation prediction unit predicts whether or not the steering operation will be performed, and when it is predicted that the steering operation will be performed, The actuator is controlled to move the rigid member from the first position to a second position which is forward of the first position, and when the steering operation is not expected to occur, the actuator is controlled to move the rigid member to the first position. It is characterized by comprising a stiffness change control unit. According to this, by improving the rigidity of the area of ​​the seat back that contacts the occupant's shoulder blades using feedforward control in response to predicted steering inputs, the system can appropriately receive the reaction force of the occupant's steering input from the initial stage of steering, regardless of the time required for the rigidity change part to operate, thereby improving the operability of the steering input. Furthermore, by reducing rigidity during normal steering operations, comfort and whiplash protection in the event of a rear-end collision can be ensured. According to this, it is possible to accurately predict that steering operations will be performed before the occupants actually begin steering. According to this, a sufficient improvement in rigidity can be obtained when steering is performed with a simple configuration.

[0006] In the present invention, before The steering operation prediction unit is: The predetermined distance is determined such that the predetermined distance increases as the vehicle speed increases. It can be configured as follows.

[0007] In the present invention, before The steering operation prediction unit is: The predetermined distance is determined based on the value obtained by multiplying the time required for the actuator to move the rigid member from the first position to the second position by the vehicle speed. It can be configured as follows.

[0008] In the present invention, The steering operation prediction unit predicts that the steering operation will be performed if the lateral acceleration is greater than or equal to a predetermined value, predicts that the steering operation will not be performed if the lateral acceleration is less than the predetermined value, and predicts that the steering operation will be performed regardless of the value of the lateral acceleration if the vehicle's turn signal operation is detected. It can be configured as follows. According to this, it can be predicted that steering operations for right and left turns and lane changes will be performed appropriately with a simple configuration.

[0009] In the present invention, before The stiffness change control unit controls the lateral acceleration The larger the value, the further forward the second position is positioned. It can be configured as follows. According to this, when the occupant's upper body is affected not only by the reaction force of steering operation but also by the vehicle's lateral acceleration, improving rigidity in proportion to the lateral acceleration can improve the operability of steering operation even in areas where the lateral acceleration is large. [Effects of the Invention]

[0010] As described above, the present invention provides a seat that improves steering operability without affecting the seat performance during normal use. [Brief explanation of the drawing]

[0011] [Figure 1] It is a schematic side view of an embodiment of a seat to which the present invention is applied. [Figure 2] It is a view taken in the direction of the arrow of the II-II section of FIG. 1. [Figure 3] It is a schematic diagram showing a state of a frame of a seat back in the seat of the embodiment as viewed from the vehicle front side. [Figure 4] It is a schematic view taken in the direction of the arrow of the IV-IV section of FIG. 3. [Figure 5] It is a diagram showing the configuration of a system for controlling an actuator in the seat of the embodiment. [Figure 6] It is a flowchart showing control of an actuator in the seat of the embodiment.

MODE FOR CARRYING OUT THE INVENTION

[0012] Hereinafter, an embodiment of a seat to which the present invention is applied will be described. The seat of the embodiment is used, for example, as a seat for the front seat (driver's seat) of an automobile such as a passenger car, and is for an occupant 100 (driver) to sit on. FIG. 1 is a schematic side view of the seat of the embodiment. FIG. 2 is a view taken in the direction of the arrow of the II-II section of FIG. 1. In FIG. 2, the occupant 100 is not shown.

[0013] The seat 1 of the embodiment is configured to include a seat surface portion 10, a seat back 20, a headrest 30, and the like. The seat surface portion (seat cushion) 10 is a portion on which the waist 110 and the thigh portion 120 of the seated occupant 100 are placed. The seat back (backrest) 20 is a backrest-shaped portion arranged along the back 131 of the upper body 130 of the occupant 100. The seat back 20 is formed to extend upward from the vicinity of the rear end portion of the seat surface portion 10. The headrest 30 is provided to protrude upward from the upper end portion of the seat back 20, and is a portion that supports the rear portion of the head 140 of the occupant 100.

[0014] Furthermore, a steering wheel switch is provided in front of the occupant 100, which the occupant 100 uses their arm 150 to perform steering operations. When the occupant 100 steers using the steering wheel SW, the reaction force is input to press the seatback 20 backward through the shoulder blades 132 and back 131.

[0015] The seat back 20 is equipped with a cushion 21, a frame 22, a scapula support member 23, an actuator 24, and the like. The cushion portion 21 is formed from an elastic porous material such as urethane foam. The surface of the cushion portion 21 is covered with a sheet covering (not shown). As the seat surface, flexible, film-like materials such as woven fabrics, knitted fabrics, natural leather, and synthetic leather can be used.

[0016] The frame 22 is a frame-shaped structural member embedded inside the cushion section 21 and receiving loads from the occupants 100 via the cushion section 21. The frame 22 is made of a material that is harder than the cushion part 21, such as a metal material like steel or an aluminum alloy. Figure 3 is a schematic diagram showing the seatback frame as viewed from the front of the vehicle. Figure 4 is a schematic view of section IV-IV in Figure 3.

[0017] The frame 22 has an upper member 22a and side members 22b. The upper member 22a is a beam-like member that extends in the vehicle width direction (the shoulder width direction of the occupant 100). The upper member 22a is provided near the upper end of the seat back 20. The side members 22b extend downward from both the left and right ends of the upper member 22a. The side member 22b is positioned along the side edge of the seat back 20.

[0018] The scapula support member 23 is a beam-shaped member provided between the left and right side members 22b. The scapula support member 23 is a rigid member made of a material with higher hardness than the cushioning portion 21, such as a metal material like steel or an aluminum alloy. The scapula support member 23 is positioned so as to be behind the scapula 132 of the occupant 100 when the occupant 100, who has a standard build, is seated in the seat 1. The scapula support member 23 can be configured such that, for example, the height along the surface of the seat back 20 from the seat surface 10 covers a range of 455 ± 15 mm. The scapula support member 23 is positioned so as to overlap at least a portion of the scapula 132 when viewed from the front-to-back direction. The scapula support member 23 faces the back 131 of the occupant 100, with a portion of the cushion 21 in between.

[0019] The actuator 24 drives the scapula support member 23 in the forward and backward direction (to move closer to or further away from the upper body 130 of the occupant 100). The actuator 24 includes, for example, an electric motor, a reduction gear, and a mechanism for converting rotational motion into translational motion. The actuators 24 are provided between both ends of the scapula support member 23 and the left and right side members 22b, respectively. The scapula support member 23 and actuator 24 work together to function as a stiffness-changing section that changes the stiffness of the area of ​​the seat back 20 that comes into contact with the vicinity of the scapula 132.

[0020] To control the actuator 24 described above, the seat 1 of the embodiment has a control system 200 which will be described below. Figure 5 shows the configuration of the system that controls the actuator. The control system 200 includes an actuator control unit 210, an environment recognition unit 220, a navigation device 230, a vehicle speed sensor 240, a turn signal switch 250, and the like.

[0021] The actuator control unit 210 provides operating instructions to the actuator 24 and controls the anterior-posterior position of the scapula support member 23. The actuator control unit 210 is a steering operation prediction unit that predicts whether or not the occupant 100 will perform steering operations within a predetermined time from the present moment, and is also a stiffness change control unit that controls the actuator 24 to control the stiffness of the part of the seat back 20 that comes into contact with the vicinity of the scapula 132. Furthermore, the actuator control unit 210 also functions as a lateral acceleration estimation unit that estimates the lateral acceleration generated when the vehicle passes through a curved road. The functions and operation of the actuator control unit 210 will be explained in detail later.

[0022] The environmental recognition unit 220 recognizes the environment around the vehicle based on the output of sensors such as the stereo camera device 221. The stereo camera device 221 includes a pair of cameras positioned horizontally separated by a predetermined baseline length, with their imaging range facing forward of the vehicle, and an image processing device that applies known stereo image processing to the images captured by each camera. The environmental recognition unit 220 recognizes the lane shape of the road that is ahead of the vehicle and on which the vehicle is expected to travel, based on the output of the stereo camera device 221. The environmental recognition unit 220 estimates the radius of curvature of a curved road if there is a curved road ahead of the vehicle that the vehicle is expected to pass through within a predetermined time.

[0023] The navigation device 230 is comprised of a positioning device that determines the vehicle's position using, for example, GPS or the Quasi-Zenith Satellite System (QZSS), and a storage medium that stores map data. The navigation device 230 has the function of extracting curved roads ahead of the vehicle from map data based on the vehicle's position, direction of travel, and speed of travel, and providing information regarding the radius of curvature of these curved roads to the actuator control unit 210.

[0024] The actuator control unit 210, the environment recognition unit 220, and the navigation device 230 can be configured to include, for example, a microcomputer having an information processing unit such as a CPU, a storage unit such as RAM or ROM, an input / output interface, and a bus connecting these. The actuator control unit 210, the environment recognition unit 220, and the navigation device 230 are connected to each other in a way that allows communication, for example, via an in-vehicle LAN such as a CAN communication system, or directly.

[0025] The vehicle speed sensor 240 is a sensor that detects the vehicle's own speed. The vehicle speed sensor 240 is installed, for example, in the hub portion that rotatably supports the wheel, and outputs a vehicle speed signal (typically a pulse signal) corresponding to the rotational speed of the wheel. The actuator control unit 210 calculates the vehicle's travel speed based on the vehicle speed signal.

[0026] The turn signal switch 250 is an operating component (turn signal operation detection unit) that allows the occupant 100 to switch the turn signal lamp (not shown) on or off (flashing or off). The state of the turn signal switch 250 is transmitted to a relay (not shown) that supplies power to the turn signal lamp, as well as to the actuator control unit 210.

[0027] Next, the operation of the seat in this embodiment will be described. Figure 6 is a flowchart showing the control of the actuator in the seat of the embodiment. The following explains each step in order.

[0028] <Step S01: Determine whether the turn signal is activated or not> The actuator control unit 210 determines whether the turn signal is activated (whether the driver has turned on the turn signal) based on the output of the turn signal switch 250. If the turn signal is activated, proceed to step S04; otherwise, proceed to step S02.

[0029] <Step S02: Estimating the radius of curvature of the road ahead> The actuator control unit 210 estimates the radius of curvature r [m] of a curved road located at a predetermined distance x [m] ahead of the vehicle, based on the outputs of the environment recognition unit 220 and the navigation device 230. Here, if the vehicle speed is v [m / s] and the time required for the actuator 24 to move the scapula support member 23 from the rearmost end to the frontmost end in its range of motion (actuator 24 driving time) is t [s], then the predetermined distance x is given by the following equation 1. Predetermined distance x[m]=v[m / s]×t[s] (Formula 1) Then, proceed to step S03.

[0030] <Step S03: Prediction of lateral acceleration> The actuator control unit 210 calculates the lateral acceleration A generated in the vehicle when passing through a curved road whose radius of curvature was estimated in step S02. Lateral acceleration A [m / s 2 This can be calculated by dividing the square of the vehicle speed V [m / s] by the radius of curvature r [m]. The calculated lateral acceleration A is 2m 2 If the value is greater than or equal to / s, proceed to step S04; otherwise, proceed to step S05.

[0031] <Step S04: Improving the rigidity of the scapular region support> The actuator control unit 210 instructs the actuator 24 to move the scapula support member 23 forward from its normal position, which is the rear end of its range of motion. As a result, the elastic body of the cushion portion 21 interposed between the back 131 of the occupant 100 and the scapula support member 23 is compressed, improving the rigidity of the support of the scapula 132 by the seat back 20. Here, the actuator 24 may be configured to move the scapula support member 23 to the front end of its range of motion. Furthermore, the actuator 24 may be configured to increase the amount of forward movement of the scapula support member 23 from its normal position in accordance with the increase in the lateral acceleration A calculated in step S03. After that, the series of processes is terminated (return).

[0032] <Step S05: Restoration of scapular support rigidity> The actuator control unit 210 issues an instruction to the actuator 24 to hold the scapula support member 23 in its normal position (or return it to its normal position if it is in any other position). As a result, the support rigidity of the scapula 132 by the seat back 20 is reduced to the lower limit of the range that can be adjusted by the actuator 24. After that, the series of processes is terminated (return).

[0033] According to the embodiments described above, the following effects can be obtained. (1) In response to the predicted steering operation by the occupant 100, the rigidity of the part of the seat back 20 that contacts the vicinity of the occupant 100's scapula 132 is improved by feedforward control. This allows the reaction force of the steering operation by the occupant 100 to be appropriately received from the initial stage of steering, regardless of the time required for the actuator 24 to drive the scapula support member 23, thereby improving the operability of the steering operation. Furthermore, by reducing rigidity during normal steering operations, comfort and whiplash protection in the event of a rear-end collision can be ensured. (2) The stereo camera device 221 and the navigation device 230 recognize the lane shape in front of the vehicle, and the actuator control unit 210 predicts whether or not steering operations will be performed based on the lane shape, thereby enabling accurate prediction of whether steering operations will be performed before the occupant 100 starts steering operations. (3) By predicting that steering operations will be performed when the ON operation of the turn signal switch 250 is detected, it is possible to predict that steering operations for turning right or left or changing lanes will be performed appropriately with a simple configuration. (4) By moving the scapula support member 23 embedded in the cushion portion 21 of the seat back 20 in the front-rear direction, the support rigidity near the scapula 132 in the seat back 20 can be changed, thereby providing a sufficient rigidity improvement effect when steering is performed with a simple configuration. (5) By estimating the lateral acceleration acting on the vehicle after steering operation and increasing the amount of improvement in the support stiffness near the scapula 132 in accordance with the increase in lateral acceleration, the operability of steering operation can be improved even in regions of high lateral acceleration by improving stiffness in accordance with the lateral acceleration when the occupant's upper body is affected by the lateral acceleration of the vehicle in addition to the reaction force of steering operation.

[0034] (modified version) The present invention is not limited to the embodiments described above, and various modifications and changes are possible, all of which fall within the technical scope of the present invention. (1) The configuration of the seats, control system, vehicle, etc., is not limited to the embodiments described above and can be modified as appropriate. For example, the shape, structure, material, manufacturing method, arrangement, and quantity of each component that makes up the sheet can be changed as appropriate. Furthermore, the configuration of the control system may also be modified by adding other units and sensors to the configuration of the embodiment, or by omitting some units and sensors. (2) In this embodiment, the support rigidity of the scapula is changed by changing the position of the rigid member embedded in the cushion portion of the seat back, but the method of changing the support rigidity of the scapula is not limited to this and can be changed as appropriate. (3) In this embodiment, as an example, a stereo camera device and a navigation device are used to recognize the lane shape of the curved road in front of the vehicle and to estimate the radius of curvature. However, the method for recognizing the lane shape is not limited to this and can be changed as appropriate. For example, information regarding the lane shape may be obtained by vehicle-to-infrastructure communication. (4) In this embodiment, both control is performed to improve the support rigidity of the scapula in accordance with the prediction of steering operation based on the lane shape, and control is performed to improve the support rigidity of the scapula in accordance with the prediction of steering operation by operating the turn signal switch. However, it is also possible to configure the system to perform only one of these controls. (5) In this embodiment, the scapular support member is a single unit for both left and right sides, and the same control is performed regardless of the steering direction. However, instead, the scapular support members, which are separate for the left and right sides and provided in the regions near the left and right scapulae, may be controlled independently. For example, the support rigidity of the scapular part may be improved only on the outward side of the turn. Alternatively, the support rigidity of both the left and right scapular parts may be improved, but the improvement in rigidity on the outward side of the turn may be greater than on the inward side. [Explanation of Symbols]

[0035] 1 seat 10 seat surface 20 Seat back 21 Cushion part 22 Frame 22a Upper Member 22b Side member 23 Scapula support member 24 Actuators 100 crew members 110 waist 120 Thigh 130 Upper body 131 Back 132 Scapula 140 Head 150 Arms 200 Control System 210 Actuator Control Unit 220 Environmental recognition unit 221 Stereo camera device 230 Navigation system 240 Vehicle speed sensor 250 Turn signal switch

Claims

1. A seat having a seat surface on which the occupant's waist and thighs rest when operating the steering of the vehicle, and a seat back that contacts the occupant's back, An elastic body disposed in the seat back portion, The frame of the seat back portion comprises a pair of side members arranged along the left and right side edges of the seat back portion, A beam-shaped member is provided between the pair of side members, behind the elastic body and within a predetermined height range along the surface of the seat back portion from the seat surface portion, and is a hard member having a higher hardness than the elastic body, An actuator comprising an electric motor, which transmits the power generated by the electric motor to the rigid member, thereby moving the rigid member in the front-rear direction relative to the pair of side members, A lateral acceleration estimation unit calculates the lateral acceleration generated in the vehicle when traveling in a lane located a predetermined distance ahead of the vehicle, based on information indicating the vehicle speed input from the vehicle's speed sensor and information indicating the shape of the lane ahead of the vehicle input from at least one of the vehicle's navigation system and an environment recognition unit that recognizes the surrounding environment of the vehicle. A steering operation prediction unit predicts whether or not the steering operation will be performed based on the lateral acceleration, A rigidity change control unit controls the actuator to move the rigid member from the first position to a second position forward of the first position when the steering operation is expected to occur, and controls the actuator to move the rigid member to the first position when the steering operation is not expected to occur. A sheet characterized by having the following features.

2. The steering operation prediction unit determines the predetermined distance such that the predetermined distance increases as the vehicle speed increases. The sheet according to claim 1, characterized in that

3. The steering operation prediction unit determines the predetermined distance based on a value obtained by multiplying the time required for the actuator to move the rigid member from the first position to the second position by the vehicle speed. The sheet according to claim 2, characterized in that

4. The steering operation prediction unit predicts that the steering operation will be performed when the lateral acceleration is greater than or equal to a predetermined value, predicts that the steering operation will not be performed when the lateral acceleration is less than a predetermined value, and predicts that the steering operation will be performed regardless of the value of the lateral acceleration when the vehicle's turn signal operation is detected. A sheet according to any one of claims 1 to 3, characterized by the following:

5. The stiffness change control unit moves the second position further forward as the lateral acceleration increases. A sheet according to any one of claims 1 to 3, characterized by the following:

Images