Rider protection aid

Abstract

This invention relates to a passenger protection assist device. The passenger protection assist device includes: a seat mounted on a vehicle and allowing a passenger to sit facing the rear of the vehicle; a head detection sensor capable of detecting the relative position of the passenger's head with respect to the headrest of the seat; and a control unit that determines, based on the detection result of the head detection sensor, whether to perform at least one of the following actions: providing attention reminders to the passenger, setting a speed limit, and changing the reclining angle.

Description

Technical Field

[0001] This invention relates to a passenger protection auxiliary device. Background Technology

[0002] Japanese Patent Application Publication No. 2018-135038 discloses a device that, when a passenger is seated facing forward, switches the seat to a predetermined rear-impact protection state in the event of a predicted rear-end collision. Specifically, in the device described in Japanese Patent Application Publication No. 2018-135038, the front surface of the headrest protrudes forward of the vehicle in the event of a predicted rear-end collision.

[0003] The device described in Japanese Patent Application Publication No. 2018-135038 can protect the occupant from a rear-end collision when the occupant is seated facing forward. On the other hand, in the event of a frontal collision when the occupant is seated facing backward, since the vehicle is traveling in the direction of travel, the collision load is more likely to be greater than that in a rear-end collision. Therefore, the occupant's head may pass over the headrest, requiring countermeasures. Summary of the Invention

[0004] The purpose of this invention is to provide an occupant protection aid that can improve the collision protection performance of rear-facing occupants.

[0005] The occupant protection assist device of Scheme 1 includes: a seat mounted on a vehicle and allowing an occupant to sit facing the rear of the vehicle; a head detection sensor capable of detecting the relative position of the occupant's head relative to the headrest of the seat; and a control unit that determines, based on the detection result of the head detection sensor, whether to perform at least one of the following: providing attention reminders to the occupant, setting a speed limit, and changing the reclining angle.

[0006] In the occupant protection assist device of Scheme 1, the vehicle seat allows the occupant to sit facing the rear of the vehicle. Furthermore, a head detection sensor is configured to detect the relative position of the occupant's head relative to the headrest of the seat. The control unit determines, based on the detection results from the head detection sensor, whether to perform at least one of the following: issuing a attention warning to the occupant, setting a speed limit, or changing the reclining angle. Thus, for example, if the relative position of the occupant's head relative to the headrest is relatively high, i.e., the difference between the headrest and the occupant's head is relatively small, the control unit determines that an attention warning to the occupant should be issued, and the occupant is alerted accordingly.

[0007] Furthermore, for example, if the occupant's head is positioned relatively high relative to the headrest, the control unit determines that a speed limit setting should be implemented, and a speed limit should be set on the vehicle to suppress collisions at high speeds. Moreover, for example, if the occupant's head is positioned relatively high relative to the headrest, the control unit determines that a reclining angle should be changed, and the seat back should be rotated towards an upright position, thereby making it less likely for the occupant's head to pass over the headrest in a frontal collision.

[0008] Regarding the occupant protection assist device of Scheme 2, in Scheme 1, the control unit determines whether to perform at least one of the following actions based on the reclining angle of the seat and the detection results of the head detection sensor: to provide attention reminders to the occupant, to set a speed limit, and to change the reclining angle.

[0009] In the occupant protection assist device of Scheme 2, when the occupant is in a comfortable reclining position with a large angle and when the relative position of the occupant's head relative to the headrest is relatively high, countermeasures against forward collisions are executed. Therefore, compared to a configuration that determines whether to execute countermeasures against forward collisions solely based on the relative position of the occupant's head relative to the headrest, unnecessary execution of countermeasures against forward collisions can be suppressed, thereby ensuring occupant comfort.

[0010] Regarding the occupant protection assist device in Scheme 3, in Scheme 1, the control unit determines whether to perform at least one of the following actions based on the vehicle's speed and the detection results of the head detection sensor: alerting the occupant, setting a speed limit, and changing the reclining angle.

[0011] In the occupant protection assist device of Scheme 3, countermeasures against forward collisions are implemented when the vehicle speed is high and the relative position of the occupant's head relative to the headrest is relatively high. Therefore, compared to a configuration that determines whether to implement countermeasures against forward collisions solely based on the relative position of the occupant's head relative to the headrest, unnecessary implementation of countermeasures against forward collisions can be suppressed, thereby ensuring occupant comfort.

[0012] Regarding the occupant protection assist device in Scheme 4, in Scheme 3, the control unit changes the threshold for judgment based on the presence or absence of the oncoming lane.

[0013] In the occupant protection assist device of Scheme 4, the threshold for determining whether countermeasures against a forward collision are needed is changed based on the presence or absence of an oncoming lane. Here, the probability of a forward collision increases when an oncoming lane is present compared to when there is no oncoming lane. Furthermore, the collision load input during a collision with an oncoming vehicle is more likely to be greater than the collision load input during a collision with a preceding vehicle in the same lane. Therefore, by increasing the threshold for determining whether a forward collision is needed when an oncoming lane is present, it is easier to implement countermeasures against a forward collision, thereby improving occupant protection performance.

[0014] Regarding the occupant protection assist device of Scheme 5, in any of Schemes 1 to 4, if the control unit determines that it is necessary to remind the occupant of attention based on the detection result of the head detection sensor, it reminds the occupant of attention through sound from a speaker mounted in the vehicle.

[0015] In the occupant protection assist device of Option 5, an audio alert is output from a speaker to the occupant, indicating that the countermeasures against a forward collision are insufficient. This prompts the occupant to change their seat position, etc.

[0016] Regarding the occupant protection assist device of Scheme 6, in any of Schemes 1 to 4, if the control unit determines that a speed limit setting is required based on the detection result of the head detection sensor, it sets an upper limit value for the vehicle speed.

[0017] In the occupant protection assist device of Scheme 6, by setting an upper limit value for vehicle speed, it is possible to suppress the vehicle from traveling in the speed range where the collision load input to the vehicle increases during a frontal collision.

[0018] Regarding the occupant protection assist device of Scheme 7, in any of Schemes 1 to 4, if the control unit determines that a change in the reclining angle is required based on the detection result of the head detection sensor, it controls the seat to rotate the seat back towards the upright direction.

[0019] In the occupant protection assist device of Option 7, by rotating the seat back towards the upright direction, it can prevent the occupant from sliding up the seat back during a frontal collision when the occupant moves forward due to inertia.

[0020] Regarding the occupant protection assist device of Scheme 8, in any of Schemes 1 to 4, the head detection sensor is configured to include a camera that captures images of the occupant from the rear side of the vehicle.

[0021] In the occupant protection assist device of Scheme 8, a camera is used to photograph the occupant from the rear side of the vehicle. Therefore, compared with the configuration of photographing from other directions by camera, the relative position of the occupant's head with respect to the headrest can be detected with high precision.

[0022] Regarding the occupant protection assistive device of Scheme 9, in Scheme 8, the headrest is woven with a pattern using a material with high infrared reflectivity, and the camera is an infrared camera.

[0023] In the occupant protection assist device of Scheme 9, an infrared camera is used to detect the pattern woven into the headrest, thereby enabling high-precision detection of the relative position of the occupant's head with respect to the headrest, even at night.

[0024] As described above, the occupant protection assist device of the present invention can improve the collision protection performance for rearward-facing occupants. Attached Figure Description

[0025] Hereinafter, with reference to the accompanying drawings, the features, advantages, and technical and industrial significance of exemplary embodiments of the present invention will be described, wherein the same reference numerals denote the same elements, wherein:

[0026] Figure 1 This is a schematic side view of a vehicle equipped with the occupant protection assist device, viewed from the vehicle width direction.

[0027] Figure 2 This is a block diagram showing the hardware configuration of the control unit in the implementation method.

[0028] Figure 3 This is a block diagram illustrating the functional configuration of the occupant protection auxiliary device in the embodiment.

[0029] Figure 4 This is a graph representing image data obtained by capturing images of the seat in the embodiment using an infrared camera, showing an example of detecting the relative position of the head.

[0030] Figure 5 This shows another example of detecting the relative position of the head.

[0031] Figure 6 This shows yet another example of detecting the relative position of the head.

[0032] Figure 7 This is a diagram showing the threshold for determining the relative position of the head with respect to the headrest and the angle of inclination.

[0033] Figure 8 This is a flowchart illustrating an example of the passenger protection auxiliary processing procedure in an implementation method.

[0034] Figure 9 This is a diagram representing image data obtained by capturing images of the seat in the modified example using an infrared camera. Detailed Implementation

[0035] The occupant protection auxiliary device 10 of the embodiment will be described with reference to the accompanying drawings.

[0036] like Figure 1 As shown, the occupant protection assist device 10 of this embodiment is mounted on a vehicle V and is configured to include a seat 12, a head detection sensor 18, and a control unit 19. It should be noted that, as an example, the vehicle V of this embodiment is configured to perform autonomous driving. That is, it is configured to control the acceleration, deceleration, and steering of the vehicle V when the occupant P is not driving.

[0037] In this embodiment, the seat 12 is configured to include a front seat 12A located at the front of the vehicle and a rear seat 12B located at the rear of the vehicle. Furthermore, the front seat 12A is configured to change its orientation, allowing the passenger P to sit facing the rear of the vehicle, thus creating a face-to-face situation between the passenger P in the front seat 12A and the passenger P in the rear seat 12B.

[0038] The front seats 12A and the rear seats 12B are respectively configured to include: a seat cushion 15 that can support the hips and thighs of the passenger P from below; a seat back 16 that can support the back of the passenger P; and a headrest 17 that can support the head of the passenger P.

[0039] Here, the seat back 16 is configured to rotate relative to the seat cushion 15 in the vehicle's fore-and-aft direction, and is configured to tilt the seat back 16 at an angle greater than when driving. It should be noted that, in the following description, the tilt angle is the angle of inclination when the seat back 16 is in a vertical position and set to 0 degrees.

[0040] Furthermore, in this embodiment, the seat back 16 and headrest 17 are woven with a pattern using a material with high infrared reflectivity. For example... Figure 4 As shown, the seat back 16 and headrest 17 of this embodiment are woven with a material with high infrared reflectivity, and are therefore configured to reflect light when photographed by an infrared camera.

[0041] The head detection sensor 18 is located in the roof of the passenger compartment of vehicle V. The head detection sensor 18 is configured to include a front infrared camera 18A and a rear infrared camera 18B.

[0042] An infrared camera 18A is installed in the roof at the rear of the vehicle, facing the front seat 12A. The infrared camera 18A then captures images of the occupant P seated in the front seat 12A.

[0043] An infrared camera 18B for the rear seats is installed in the roof at the front of the vehicle, facing the rear seats 12B. The infrared camera 18B then captures images of the passenger P seated in the rear seats 12B.

[0044] In this embodiment, a control unit 19 is installed in the vehicle V.

[0045] (Hardware configuration of the occupant protection assist device 10)

[0046] Figure 2 This is a block diagram showing the hardware configuration of the control unit 19. (As shown...) Figure 2 As shown, the control unit 19 is configured to include a CPU (Central Processing Unit) 20, a ROM (Read Only Memory) 22, a RAM (Random Access Memory) 24, a storage device 26, a communication I / F (communication interface) 28, and an input / output I / F (input / output interface) 30. All components are connected to each other via a bus 32 in a manner enabling communication.

[0047] CPU 20 is the central processing unit, which executes various programs or controls various components. Specifically, CPU 20 reads programs from ROM 22 or storage device 26 and uses RAM 24 as the working area to execute the programs. CPU 20 performs control and various arithmetic operations on the aforementioned components according to the programs recorded in ROM 22 or storage device 26.

[0048] ROM 22 stores various programs and data. RAM 24 serves as a temporary storage area for programs or data. Storage device 26 is composed of HDD (Hard Disk Drive) or SSD (Solid State Drive) and stores various programs and data, including the operating system. In this embodiment, ROM 22 or storage device 26 stores programs and data for various processes.

[0049] Communication I / F28 is the interface used by the control unit 19 to communicate with devices such as servers (not shown), for example, using standards such as CAN (Controller Area Network), Ethernet (registered trademark), LTE (Long Term Evolution), FDDI (Fiber Distributed Data Interface), and Wi-Fi (registered trademark).

[0050] The front infrared camera 18A, the rear infrared camera 18B, the front seat 12A, the rear seat 12B, the speaker 34, the peripheral sensor 36, and the autonomous driving ECU (Electronic Control Unit) 38 are electrically connected to the input / output I / F 30.

[0051] The control unit 19 acquires images captured by the front-row infrared camera 18A via the input / output I / F 30. Additionally, the control unit 19 acquires images captured by the rear-row infrared camera 18B via the input / output I / F 30.

[0052] The control unit 19 is configured to obtain the reclining angle of the front seat 12A via the input / output I / F30. In addition, the front seat 12A is equipped with an electric recliner (not shown), which is operated by the control unit 19, thereby being configured to change the reclining angle of the front seat 12A.

[0053] The control unit 19 is configured to obtain the reclining angle of the rear seat 12B via the input / output I / F30. In addition, the rear seat 12B is equipped with an electric adjuster (not shown), which is operated by the control unit 19, thereby being configured to change the reclining angle of the rear seat 12B.

[0054] The speaker 34 is located inside the carriage and is configured to output sound to the passenger P, based on a signal from the control unit 19.

[0055] The peripheral sensor 36 consists of a group of sensors located around the vehicle V to detect the conditions around the vehicle V.

[0056] The autonomous driving ECU 38 is connected to a throttle actuator that changes the throttle opening of vehicle V, a brake actuator that changes the braking force of vehicle V, and a steering actuator that changes the steering amount of vehicle V, to perform autonomous driving processing that enables vehicle V to drive automatically.

[0057] (Functional configuration of the occupant protection assist device 10)

[0058] The occupant protection assist device 10 uses the aforementioned hardware resources to implement various functions. (See reference...) Figure 3 The functional configuration of the occupant protection auxiliary device 10 is explained.

[0059] like Figure 3 As shown, the occupant protection assist device 10 is configured to include a head position acquisition unit 42, a reclining angle acquisition unit 44, an oncoming lane information acquisition unit 46, a attention reminder unit 48, a speed limit setting unit 50, and a reclining angle control unit 52 as its functional configuration. It should be noted that each functional configuration is implemented by the CPU 20 reading and executing a program stored in the ROM 22 or the storage device 26.

[0060] The head position acquisition unit 42 acquires the relative position of the occupant P's head with respect to the headrest 17 of the seat 12. Specifically, the head position acquisition unit 42 acquires the relative position of the occupant P's head in the front seat 12A based on image information captured by the front infrared camera 18A. Furthermore, the head position acquisition unit 42 acquires the relative position of the occupant P's head in the rear seat 12B based on image information captured by the rear infrared camera 18B.

[0061] Here, refer to Figure 4 An example of a method for obtaining the head position of occupant P, who is seated in the front seat 12A, will be illustrated. Figure 4 As shown, in the image captured by the infrared camera 18A in the front row, the occupant P, with low infrared reflectivity, appears dark, while the seat back 16 and headrest 17 appear bright. Therefore, by performing image processing, the upper end of the headrest 17 and the upper end of the occupant P's head HE can be detected, and the head position acquisition unit 42 acquires the height difference H1 between the upper end of the headrest 17 and the head HE as the relative position of the head HE. Therefore, the higher the relative position of the occupant P's head HE relative to the headrest 17, the smaller the relative position of the head HE acquired by the head position acquisition unit 42.

[0062] It should be noted that it is not limited to Figure 4 The example shown can also be used to obtain the relative position of the head HE using other methods. For example, it can also be done through... Figure 5 and Figure 6 The method shown is used to obtain the relative position of the head HE.

[0063] exist Figure 5 In the method shown, the head position acquisition unit 42 calculates the relative position of the head HE based on the height difference H1 between the upper end of the headrest 17 and the head HE, and the height difference H2 between the upper end of the headrest 17 and the shoulder. Figure 5In this method, even when the position of the head HE cannot be accurately detected, the difference H2 can be considered to infer the height of the head HE.

[0064] exist Figure 6 In the method shown, the head position acquisition unit 42 acquires the difference H3 between the upper end of the headrest 17 and the eye level of the occupant P as the relative position of the head HE. The eye level can be determined by detecting the positions of both eyes, with the height of the midpoint as the eye level. It should be noted that the eyes of the occupant P can be detected using an infrared camera 18A in the front row, but... Figure 6 For ease of explanation, the eyes are not shown in the illustration.

[0065] Figure 3 The reclining angle acquisition unit 44 acquires the reclining angle of the seat 12. Specifically, the reclining angle acquisition unit 44 acquires the reclining angle of the front seat 12A via a signal from the adjuster of the front seat 12A. Furthermore, the reclining angle acquisition unit 44 acquires the reclining angle of the rear seat 12B via a signal from the adjuster of the rear seat 12B.

[0066] The oncoming lane information acquisition unit 46 acquires information about oncoming lanes adjacent to the driving lane of vehicle V. Specifically, the oncoming lane information acquisition unit 46 acquires information about oncoming lanes adjacent to the driving lane based on signals from the surrounding sensors 36 and information stored in the navigation system. It should be noted that the oncoming lanes mentioned here only include lanes adjacent to the driving lane. Therefore, if there is an oncoming lane separated by a central divider, the oncoming lane information acquisition unit 46 determines that there is no oncoming lane adjacent to the driving lane.

[0067] If, based on the relative position H1 of the head HE obtained by the head position acquisition unit 42, it is determined that attentional reminders need to be given to the passenger P, the attentional reminder unit 48 provides an auditory reminder to the passenger P via a speaker 34 mounted on the vehicle V. Alternatively, the attentional reminder unit 48 may also provide attentional reminders to the passenger P by displaying a message on a monitor (not shown) mounted on the vehicle V.

[0068] Here, as an example, the attention reminder unit 48 of this embodiment provides attention reminders based on the reclining angle of the seat 12 and the relative position H1 of the head HE obtained by the head position acquisition unit 42. Specifically, when the relative position H1 of the head HE is greater than... Figure 7 When the threshold L1 shown is small, the attention reminder unit 48 will remind the passenger P to pay attention.

[0069] That is, when the reclining angle is below a predetermined angle θ, a warning is issued to the occupant P if the relative position of the head (HE) is smaller than that of the head (HA). Furthermore, when the reclining angle exceeds the predetermined angle θ, a warning is issued to the occupant P if the relative position of the head (HE) is smaller than a threshold L1 that has changed according to the reclining angle. The predetermined angle θ is, for example, set to 30°. When the reclining angle exceeds 30°, the likelihood of the head (HE) passing over the headrest 17 during the inertial movement of the occupant P due to a frontal collision increases. Therefore, the threshold for the warning is increased so that a warning is issued even when the relative position of the head (HE) is relatively large.

[0070] When it is determined that a speed limit setting for the vehicle V is required based on the relative position of the head HE obtained by the head position acquisition unit 42, the speed limit setting unit 50 sets an upper limit value for the vehicle speed. That is, the speed limit setting unit 50 reduces the upper limit speed during autonomous driving by setting a speed limit for the autonomous driving ECU 38.

[0071] Specifically, in the relative position of HE in the head, H1 is compared to... Figure 7 When the threshold L2 shown is small, the speed limiting setting unit 50 sets a speed limit. That is, when the reclining angle is θ or less, the speed limit is set when the relative position H1 of the head HE is smaller than HB. Furthermore, when the reclining angle exceeds θ, the speed limit is set when the relative position of the head HE is smaller than the threshold L2 that has changed according to the reclining angle.

[0072] If it is determined that the reclining angle of the seat 12 needs to be changed based on the relative position of the head HE obtained by the head position acquisition unit 42, the reclining angle control unit 52 controls the seat 12 to rotate the seat back 16 in the upright direction.

[0073] Specifically, when the relative position of the head (HE) is smaller than a predetermined threshold, the reclining angle control unit 52 rotates the seat back 16 in an upright direction. That is, in the case of the front seat 12A, when the relative position H1 of the head (HE) of the occupant P of the front seat 12A is smaller than a predetermined threshold, the reclining angle control unit 52 rotates the seat back 16 of the front seat 12A towards the rear of the vehicle.

[0074] (effect)

[0075] Next, the function of this embodiment will be explained.

[0076] (An example of occupant protection assistance)

[0077] Figure 8This is a flowchart illustrating an example of the occupant protection assistance process performed by the occupant protection assistance device 10. This occupant protection assistance process is executed by the CPU 20 reading the program from the ROM 22 or storage device 26 and expanding it in the RAM 24.

[0078] In step S102, CPU 20 obtains the relative position of the head HE of the occupant P who is seated in the front seat 12A. Specifically, CPU 20 obtains the relative position H1 of the head HE through the function of the head position acquisition unit 42.

[0079] In step S104, CPU 20 obtains the reclining angle of the front seat 12A. Specifically, CPU 20 obtains the reclining angle of the front seat 12A through the function of reclining angle acquisition unit 44.

[0080] In step S106, CPU20 determines whether a speed limit setting is required. Specifically, CPU20 changes the threshold value when the tilt angle is greater than θ and when the tilt angle is less than θ.

[0081] When the tilt angle is θ or less, and the relative position H1 of the CPU20 to the head HE is smaller than HB, it is determined that a speed limit setting is required. Conversely, when the relative position H1 of the CPU20 to the head HE is greater than HB, it is determined that a speed limit setting is not required.

[0082] On the other hand, when the tilt angle is larger than θ, CPU20 is based on Figure 7 The graph shown is used to calculate the threshold L2 corresponding to the tilt angle. If the relative position H1 of the head is smaller than this threshold L2, it is determined that a speed limit setting is required. Furthermore, if the relative position H1 of the head is greater than or equal to the predetermined threshold L2, the CPU20 determines that a speed limit setting is not required. Thus, when the tilt angle is less than or equal to θ, the threshold L2 is set to a fixed value HB; when the tilt angle is greater than θ, the threshold L2 varies according to the tilt angle.

[0083] If it is determined in step S106 that a speed limit setting is required, the CPU 20 proceeds to step S112, where the speed limit setting unit 50 sets the speed limit for the vehicle V. Then, the occupant protection assistance process ends.

[0084] If it is determined in step S106 that a speed limit setting is not required, the CPU 20 proceeds to step S108 to determine whether a change in the reclining angle is needed. In this embodiment, as an example, if the CPU 20 determines that a change in the reclining angle of the front seat 12A is needed when the relative position H1 of the head HE is smaller than HA and the reclining angle of the front seat 12A is larger than θ, then the CPU 20 determines that a change in the reclining angle of the front seat 12A is needed.

[0085] If it is determined in step S108 that a change in the reclining angle is required, the CPU 20 proceeds to step S114 to change the reclining angle of the front seat 12A. Specifically, the CPU 20 uses the function of the reclining angle control unit 52 to rotate the seat back 16 of the front seat 12A toward the rear of the vehicle, i.e., the upright side. In this embodiment, as an example, the reclining angle control unit 52 rotates the seat back 16 until the reclining angle becomes θ or less. Then, the occupant protection assistance process ends.

[0086] If it is determined in step S108 that no change in the reclining angle is needed, the CPU 20 proceeds to step S110 to determine whether a notice to the passenger P needs to be given. Specifically, the CPU 20 changes the threshold for determining whether the reclining angle is greater than θ and whether the reclining angle is less than θ.

[0087] When the tilt angle is less than θ, and the CPU 20's relative position H1 to the head HE is smaller than HA, it determines that a warning is needed. Conversely, when the CPU 20's relative position H1 to the head HE is greater than HA, it determines that a warning is not needed.

[0088] On the other hand, when the tilt angle is larger than θ, CPU20 is based on Figure 7 The graph shown is used to calculate the threshold L1 corresponding to the tilt angle. If the relative position H1 of the head is smaller than this threshold L1, it is determined that a attention warning is needed. Furthermore, if the relative position H1 of the head is greater than or equal to the predetermined threshold L1, the CPU20 determines that no attention warning is needed. Thus, when the tilt angle is less than θ, the threshold L1 is set to a fixed value HA; when the tilt angle is greater than θ, the threshold L1 varies according to the tilt angle.

[0089] If it is determined in step S110 that a attention reminder is needed, the CPU 20 proceeds to step S116, whereby the attention reminder unit 48 uses the speaker 34 and a monitor (not shown) to remind the occupant P of the attention. Then, the occupant protection assistance process ends.

[0090] If it is determined in step S110 that no attention reminder is needed, the CPU20 ends the occupant protection assistance process without issuing an attention reminder.

[0091] As described above, in the occupant protection assist device 10 of this embodiment, the front seat 12A mounted on the vehicle V allows the occupant P to sit facing the rear of the vehicle. Furthermore, it is designed so that the relative position H1 of the occupant P's head HE with respect to the headrest 17 of the front seat 12A can be detected by a front infrared camera 18A.

[0092] Then, the control unit 19 determines, based on the detection results from the front-row infrared camera 18A, whether to perform at least one of the following: issuing a attention reminder to the occupant P, setting a speed limit, or changing the reclining angle. Thus, for example, if the relative position of the occupant P's head HE with respect to the headrest 17 is smaller than a threshold L1, a attention reminder is issued to the occupant P.

[0093] Furthermore, when the relative position H1 of the occupant P's head HE is smaller than the threshold L2, a speed limit is set for the vehicle V to suppress collisions at high speeds. Moreover, the control unit 19 rotates the seat back 16 in an upright direction, thereby preventing the occupant P's head HE from easily passing over the headrest 17 during a forward collision.

[0094] Furthermore, in this embodiment, when a comfortable reclining posture with a large angle is achieved, and when the relative position H1 of the occupant P's head HE is relatively high, countermeasures against forward collisions are implemented. Therefore, compared to a configuration that determines whether to implement countermeasures against forward collisions solely based on the relative position H1 of the occupant P's head HE relative to the headrest 17, unnecessary implementation of countermeasures against forward collisions can be suppressed, thereby ensuring the comfort of the occupant P.

[0095] Furthermore, in this embodiment, the attention reminder unit 48 reminds the occupant P to pay attention by outputting sound from the speaker 34. This encourages the occupant P to change seat positions, etc.

[0096] Furthermore, in this embodiment, by limiting the speed setting unit 50 to set the upper limit of the vehicle speed according to the prescribed conditions, it is possible to suppress the vehicle V from traveling in the speed range where the collision load input to the vehicle V increases during a frontal collision.

[0097] Furthermore, in this embodiment, by rotating the seat back 16 in the upright direction according to the prescribed conditions by the reclining angle control unit 52, the occupant P can be prevented from sliding up the seat back 16 when the occupant P moves forward due to inertia during a frontal collision.

[0098] The occupant protection assist device 10 of the above embodiment has been described, but it can of course be implemented in various ways without departing from the spirit of the invention. For example, in the above embodiment, at least one of attention reminder, speed limit setting and reclining angle change is performed based on the relative position H1 of the head HE and the reclining angle, but it is not limited to this, and the threshold for judgment can be changed according to the vehicle speed and the presence or absence of the oncoming lane.

[0099] When the threshold for judgment is changed based on vehicle speed, for example, when the vehicle V is traveling at a speed of 20 km / h or less, attention alerts are only issued if the relative position H1 of the head HE is less than a predetermined threshold, regardless of the lean angle. In this case, the threshold is set to a value greater than HA.

[0100] When the vehicle V's speed exceeds 20 km / h, the determination of attention alerts and speed limits is based on a coefficient corresponding to the vehicle speed, calculated by multiplying the relative position H1 of the head (HE) by the coefficient corresponding to the vehicle speed. That is, the higher the vehicle V's speed, the larger the coefficient is set. Figure 7 The larger the thresholds L1 and L2 shown, the more likely attention alerts and speed limits can be applied, even when the relative position H1 of the head HE is larger than HA, if the speed of vehicle V increases. It should be noted that the speed of vehicle V can be sensed by a vehicle speed sensor (not shown) or similar device.

[0101] Alternatively, when an oncoming lane exists, thresholds L1 and L2 can be made larger than when no oncoming lane exists. The presence or absence of an oncoming lane is obtained through the function of the oncoming lane information acquisition unit 46.

[0102] Furthermore, it is also possible that, when an oncoming vehicle traveling in the opposite lane is detected by surrounding sensors 36, the relative speed obtained by adding the speed of vehicle V to the speed of the oncoming vehicle is used to... Figure 7 The thresholds L1 and L2 are shown to vary.

[0103] If the threshold is changed based on vehicle speed as described above, it can suppress the unnecessary execution of countermeasures against forward collisions at low vehicle speeds, thereby ensuring the comfort of passenger P.

[0104] Furthermore, by changing the threshold for determining whether countermeasures against a forward collision are needed based on the presence or absence of an oncoming lane, the protection performance of occupant P can be improved.

[0105] Furthermore, in this embodiment, a material with high infrared reflectivity is woven into the seat back 16 and headrest 17, but this is not a limitation. For example, other materials may also be used. Figure 9The structure of the modified example shown.

[0106] (Modified Example)

[0107] like Figure 9 As shown, in this modified example, the seat back 16 is not woven with a material that has high infrared reflectivity. Furthermore, the headrest 17 is woven with patterns 62A and 62B using a material with high infrared reflectivity.

[0108] Pattern 62A extends linearly along the width of the vehicle at the upper end of the headrest 17. Pattern 62B is located below pattern 62A and extends linearly along the width of the vehicle, similar to pattern 62A. Furthermore, patterns 62A and 62B are configured to reflect light when captured by an infrared camera.

[0109] In this modified example, the occupant protection assist device 10 acquires the relative position H1 of the occupant P's head via the head position acquisition unit 42. Furthermore, if the occupant P's head HE is positioned lower than the pattern 62B, no attention alert is given to the occupant P. Conversely, if the occupant P's head HE is positioned higher than the pattern 62B but lower than the pattern 62A, an attention alert is given to the occupant P via the attention alert unit 48. Moreover, if the occupant P's head HE is positioned higher than the pattern 62A, a speed limit is set.

[0110] Thus, in this variant, the relative position H1 of the head HE of the passenger P can be easily determined.

[0111] Furthermore, in the above-described embodiments and variations, a configuration is adopted to provide attention reminders to the passenger P sitting in the front seat 12A. However, in addition, it is also possible to provide attention reminders to the passenger P sitting in the rear seat 12B based on the relative position of their heads.

[0112] Furthermore, in the above-described embodiments and variations, the head position acquisition unit 42 acquires the relative position of the head HE of the occupant P in the front seat 12A based on image information captured by the front infrared camera 18A, but is not limited to this. For example, it may be equipped with a sensor capable of sensing the height of the head HE of the occupant P seated in the front seat 12A, and the relative position of the head HE may be acquired based on the sensed information obtained by the sensor.

[0113] Alternatively, the processing described in the above embodiment, which involves the program read and executed by the CPU 20, can be performed by various processors other than the CPU 20. Examples of processors in this case include dedicated circuits designed specifically for performing particular processes, such as PLDs (Programmable Logic Devices) with circuit configurations that can be changed after manufacturing, including FPGAs (Field-Programmable Gate Arrays), and ASICs (Application Specific Integrated Circuits). Furthermore, the above processing can be performed by one of these various processors, or by a combination of two or more processors of the same or different types; for example, it can be performed by multiple FPGAs or a combination of a CPU and an FPGA. More specifically, the hardware structure of these various processors is a circuit composed of circuit elements such as semiconductor components.

[0114] Furthermore, while the above embodiment employs a configuration that stores various types of data in the storage device 26, it is not limited to this. For example, non-transitory recording media such as CDs (Compact Disk), DVDs (Digital Versatile Disk), and USB (Universal Serial Bus) memory can also be used as storage units. In this case, various programs and data are stored on these recording media.

[0115] Furthermore, the processing flow described in the above embodiments is just an example. Unnecessary steps can be deleted, new steps can be added, or the processing order can be changed without departing from the main idea.

Claims

1. A passenger protection auxiliary device, comprising: A seat, mounted on a vehicle and allowing passengers to sit facing the rear of the vehicle; A head detection sensor can detect the relative position of the occupant's head with respect to the headrest of the seat; as well as The control unit determines, based on the detection results from the head detection sensor, whether to issue a attention reminder to the passenger, set a speed limit, or change the reclining angle. The control unit is configured to: If it is determined that a attention reminder needs to be given to the passenger based on the reclining angle of the seat and the relative position of the passenger's head relative to the headrest of the seat, the attention reminder unit is controlled to give the attention reminder to the passenger. The relative position of the passenger's head that triggers the attention reminder is determined based on the height difference between the upper end of the headrest and the height of the passenger's head. When a speed limit setting is determined to be necessary based on the relative position of the occupant's head relative to the headrest of the seat, the speed limit setting unit sets the speed limit. The relative position of the occupant's head that triggers the speed limit setting is determined based on the height difference between the top of the headrest and the occupant's eyes. If it is determined that a change in reclining angle is required based on the relative position of the occupant's head with respect to the headrest of the seat, the reclining angle control unit changes the reclining angle of the seat. The occupant's head that triggers the change in reclining angle is determined based on the height difference between the upper end of the headrest and the occupant's eyes.

2. The occupant protection auxiliary device according to claim 1, wherein, The control unit determines whether to issue a attention reminder to the passenger, set a speed limit, and change the reclining angle based on the vehicle's speed and the detection results of the head detection sensor.

3. The occupant protection auxiliary device according to claim 2, wherein, The control unit changes the threshold value for the determination based on whether the opposite lane is present or not.

4. The occupant protection auxiliary device according to any one of claims 1 to 3, wherein, When the control unit determines that it is necessary to remind the passenger to pay attention, it uses a speaker mounted in the vehicle to remind the passenger to pay attention via sound.

5. The occupant protection auxiliary device according to any one of claims 1 to 3, wherein, When the control unit determines that a speed limit setting is required, it sets an upper limit value for the vehicle speed.

6. The occupant protection auxiliary device according to any one of claims 1 to 3, wherein, When the control unit determines that a change in reclining angle is required, it controls the seat to rotate the seat back towards an upright position.

7. The occupant protection auxiliary device according to any one of claims 1 to 3, wherein, The head detection sensor is configured to include a camera that captures images of the occupants from the rear side of the vehicle.

8. The occupant protection auxiliary device according to claim 7, wherein, The headrest is made of a material with high infrared reflectivity woven with patterns. The camera in question is an infrared camera.

Images