Occupant restraint device

Abstract

To quickly restrain an occupant in the event of emergency and in response to the request of an occupant, while suppressing discomfort feeling by unnecessary restraint.SOLUTION: An occupant restraint device for restraining an occupant sitting on a seat of a vehicle includes a seat belt unit for restraining an occupant by driving a motor and winding webbing, and a seat belt control part for controlling the seat belt unit according to a travel mode of the vehicle, wherein the seat belt control part controls the seat belt unit so as to restrain the occupant, when the travel mode of the vehicle is switched to a bad road mode suitable for traveling on a bad road or a sport mode suitable for sport travel.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to an occupant restraint device mounted on a vehicle.

Background Art

[0002] As one of the protection devices for restraining or protecting an occupant seated on a vehicle seat, an electric occupant restraint device (hereinafter, MSB: motor seat belt) that winds a webbing by a driving means such as a motor is known (Patent Document 1). In the MSB, for example, when the body of the occupant swings greatly and the seating posture is disturbed, such as when a forced braking like a pre-crash brake occurs, the occupant is quickly restrained by winding the webbing by the driving means. By such restraint, the seating posture of the occupant is corrected, and even in a situation where a collision cannot be avoided, the effects of an airbag device or the like are maximally exerted, and injuries to the occupant caused by an inappropriate posture are prevented.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, in the MSB, in order to prevent excessive or unnecessary restraint and the resulting discomfort of the occupant, when the detection value of an acceleration sensor or the like reaches a predetermined threshold value, that is, only when forced braking occurs, the above-described motor is controlled to restrain the occupant. On the other hand, during driving such as driving on a rough road such as an unpaved road or sports driving on a circuit or the like where the vehicle vibrates and the body of the occupant swings greatly, there may be a case where it is required to correct or stabilize the seating posture by the restraint of the MSB.

[0005] The present invention aims to address such a situation. That is, while suppressing the discomfort of the occupant, it aims to quickly restrain the occupant in case of an emergency and in response to the occupant's request, etc.

Means for Solving the Problem

[0006] In order to solve such problems, the occupant restraint device according to the present invention has the following configuration. That is, one aspect of the present invention is an occupant restraint device for restraining an occupant seated on a vehicle seat, comprising a seat belt unit that restrains the occupant by driving a motor to wind up a webbing, and a seat belt control unit that controls the seat belt unit according to the driving mode of the vehicle. The seat belt control unit controls the seat belt unit to restrain the occupant when the driving mode of the vehicle is switched to a rough road mode suitable for driving on rough roads or a sports mode suitable for sports driving. An occupant restraint device provided with such an occupant restraint device is provided.

Effects of the Invention

[0007] According to the occupant restraint device having such characteristics, it is possible to quickly restrain the occupant in case of an emergency and in response to the occupant's request while suppressing the discomfort caused by unnecessary restraint.

Brief Description of the Drawings

[0008]

Figure 1

Figure 2

Figure 3

Figure 4

Mode for Carrying Out the Invention

[0009] Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following description, the same reference numerals in different drawings indicate parts having the same function, and duplicate descriptions in each drawing are omitted as appropriate.

[0010] As shown in FIG. 1, the occupant restraint device 20 according to the present embodiment includes a seat belt unit 5 that restrains an occupant and a seat belt control ECU (seat belt control unit) 12 that controls the seat belt unit 5, and functions as a part of a vehicle control system 1 mounted on a vehicle 100, as shown in FIG. 1.

[0011] The vehicle control system 1 is mounted on the vehicle 100 and includes a plurality of sensors that acquire information indicating the driving state and surrounding environment of the vehicle 100, and a plurality of ECUs (Electronic Control Units) that control various electronic devices necessary for the driving of the vehicle 100. The plurality of sensors and the plurality of ECUs are communicably connected to each other by an in-vehicle network 3 such as CAN (Controller Area Network) or LIN (Local Interconnect Network) and a central gateway (CGW) 4 as a relay device.

[0012] In the vehicle control system 1, information (data) acquired by each sensor is output to the in-vehicle network 3, and each ECU controls the operation of each electronic device based on this information acquired from the in-vehicle network 3. Further, each ECU outputs information indicating the operation state of the electronic device to the in-vehicle network 3.

[0013] The plurality of sensors include a vehicle speed sensor 31 that detects the driving speed of the vehicle 100, a camera 32 that images a predetermined range in front including the road surface in the traveling direction of the vehicle 100, and an acceleration sensor 33 that detects the acceleration of the vehicle 100 in the front-rear direction, up-down direction, and left-right direction. The plurality of ECUs include a driving mode control ECU 11 and a seat belt control ECU 12. Note that, among the vehicle control system 1, illustrations and detailed descriptions of electronic devices, sensors, ECUs, etc. that do not participate in the operation of the occupant restraint device 20 are omitted.

[0014] Each ECU can be configured to include a processor such as a CPU (Central Processing Unit) or MPU (Micro Processing Unit), an electric circuit, a volatile memory element such as a RAM (Random Access Memory) that temporarily processes data used by the CPU or MPU, and a non-volatile memory element such as a ROM (Read Only Memory) that stores programs executed by the CPU or MPU. Further, part or all of the operations executed by the ECU can also be realized by hardware such as an ASIC (application specific integrated circuit), an FPGA (field-programmable gate array), or a GPU (Graphics Processing Unit).

[0015] In the driving mode control ECU 11, a plurality of pre-programmed driving modes, such as a driving mode corresponding to the road surface condition and a driving mode for suppressing fuel consumption, are stored in a non-volatile memory element such as a ROM included in the driving mode control ECU 11. These plurality of driving modes include a normal mode suitable for driving on a general road surface, a rough road mode suitable for driving on rough roads (including so-called off-road such as unpaved roads and wasteland), and a sports mode suitable for sports driving.

[0016] In each driving mode, the engine, driving motor, transmission, etc. are programmed to be controlled according to each driving mode, and the driving mode control ECU 11 outputs a control signal to each ECU so that the vehicle 100 travels according to the set driving mode.

[0017] When an input operation indicating a switching instruction for the driving mode is performed in the driving mode control ECU 11, the driving mode is switched according to the input operation. Further, the driving mode control ECU 11 can also be set to automatically switch the driving mode while driving according to the driving environment that changes during driving. Further, in the driving mode control ECU 11, permission or non - permission of such automatic switching of the driving mode can be preset according to an input operation by an occupant or the like.

[0018] When automatic switching of the driving mode is permitted, the driving mode control ECU 11 acquires the vehicle speed of the vehicle 100 and the state of the road surface in the traveling direction of the vehicle 100 from the vehicle speed sensor 31, the camera 32, the acceleration sensor 33, etc. via the in - vehicle network 3 at a predetermined cycle, and automatically switches the driving mode when these satisfy predetermined conditions.

[0019] The driving mode control ECU 11 stores, in the aforementioned ROM, as conditions for automatic switching of the driving mode, for example, conditions for switching to the rough road mode, conditions for temporary stop in the rough road mode, conditions for rough road mode stop (switching to another driving mode), etc. The driving mode control ECU 11 performs automatic switching of the driving mode during driving when these conditions are satisfied.

[0020] As an example, as a condition for switching to the rough road mode, it is determined that the vehicle speed V of the vehicle 100 is equal to or less than a predetermined second speed V2 and the road on which the vehicle 100 is traveling is a rough road. As a condition for temporary stop in the rough road mode, it is determined that the vehicle speed V has become faster than a predetermined first speed V1. Further, as a condition for rough road mode stop (switching to another driving mode), it is determined that the time during which the state where the vehicle speed V is equal to or less than the first speed V1 but no rough road is detected continues is equal to or longer than a first continuous time LT1, or the time during which the temporary stop in the rough road mode continues is equal to or longer than a second continuous time LT2.

[0021] Therefore, when the automatic switching of the driving mode is permitted, the driving mode control ECU 11 monitors the vehicle speed and the road surface condition during driving. When the vehicle speed V of the vehicle 100 is equal to or lower than a predetermined second speed V2 and a rough road is detected, the driving mode control ECU 11 automatically switches from the currently set driving mode to the rough road mode.

[0022] On the other hand, after the driving mode control ECU 11 has switched to the rough road mode, if it is detected that the vehicle speed V is higher than the first speed V1, the rough road mode is suspended, that is, the switching to another driving mode is temporarily performed. When the duration for which the suspension of the rough road mode continues is the second duration LT2 or when the duration for which no rough road is detected continues is the first duration LT1, the rough road mode is automatically stopped, that is, the switching to another driving mode is performed. Here, the first speed V1 is preferably higher than the second speed V2. An example of the automatic switching process of the driving mode by the driving mode control ECU 11 will be described later.

[0023] As shown in FIG. 2, the seat belt control ECU 12 is connected to the seat belt unit 5 and functions as an occupant restraint device 20 together with the seat belt unit 5. The seat belt unit 5 includes a motor 51 that rotates a spool around which a webbing is wound, and drives the motor 51 in accordance with a control signal from the seat belt control ECU 12 to wind up the webbing, thereby restraining an occupant seated on the seat of the vehicle 100.

[0024] In the vehicle 100, when the acceleration measured by the acceleration sensor 33 exceeds a threshold value, for example, a collision is predicted by an ECU included in an ADAS (Advanced Driver-Assistance Systems) that supports the driving of the vehicle 100, and a collision prediction signal is output. When the seat belt control ECU 12 receives the collision prediction signal, the seat belt control ECU 12 drives the motor 51 to wind up the webbing to restrain the occupant.

[0025] On the other hand, even when a collision is not predicted, that is, when the seat belt control ECU 12 does not receive a collision prediction signal, there may be cases where the occupant desires restraint according to the driving state of the vehicle 100. In such cases, the seat belt control ECU 12 controls the seat belt unit 5 according to the occupant's request to restrain the occupant.

[0026] The seat belt control ECU 12 includes a CPU 201, a ROM 202, and a RAM 203, and the CPU 201 executes various processes based on the programs stored in the ROM 202. In the present embodiment, the CPU 201 reads the programs stored in the ROM 202 into a memory such as the RAM 203 and executes them, thereby functioning as a road surface state detection unit 211, a driving mode detection unit 212, a restraint availability setting unit 213, and a motor drive control unit 214 shown in FIG. 2. Hereinafter, the road surface state detection unit 211, the driving mode detection unit 212, the restraint availability setting unit 213, and the motor drive control unit 214 will be described.

[0027] The road surface state detection unit 211 detects the state of the road surface in the traveling direction of the vehicle 100. The road surface state detection unit 211 can detect the state of the road surface based on, for example, an image in front of the vehicle 100 captured by the camera 32. Also, the state of the road surface can be grasped based on the acceleration in the vertical direction of the vehicle input to the vehicle 100 detected by the acceleration sensor 33. In addition, the road surface state detection unit 211 may detect the road surface state from information regarding the external environment of the vehicle 100 grasped by various sensors such as a radar included in an ADAS (Advanced Driver-Assistance Systems) that supports the driving of the vehicle 100.

[0028] The driving mode detection unit 212 detects the driving mode set by the driving mode control ECU 11 and the stop (switching) and temporary stop (temporary switching) of the set driving mode. Specifically, the driving mode detection unit 212 acquires information regarding the set driving mode and transitions such as the stop (switching) and temporary stop (temporary switching) of the driving mode from the driving mode control ECU 11 via the in-vehicle network 3.

[0029] The restraint permission setting unit 213 sets the permission or non - permission of restraint by the seat belt unit 5 during traveling in the rough road mode or the sports mode according to the input operation by the occupant.

[0030] The motor drive control unit 214 controls the seat belt unit 5 according to the traveling mode of the vehicle 100. For example, when the traveling mode of the vehicle 100 is switched to the rough road mode or the sports mode, that is, when the traveling mode detection unit 212 detects that the traveling mode is switched to the rough road mode or the sports mode, the motor drive control unit 214 drives the motor 51 to wind up the webbing and restrain the occupant.

[0031] At this time, when the automatic switching of the traveling mode is permitted in the traveling mode control ECU 11 and the restraint by the seat belt unit 5 is permitted in the restraint permission setting unit 213, the motor drive control unit 214 drives the motor 51 along with the switching to the rough road mode or the sports mode to wind up the webbing and restrain the occupant.

[0032] On the other hand, even when the automatic switching of the traveling mode is permitted in the traveling mode control ECU 11, if the restraint by the seat belt unit 5 is not permitted in the restraint permission setting unit 213, the motor drive control unit 214 does not drive the motor 51 even when detecting the switching to the rough road mode or the sports mode and does not restrain the occupant.

[0033] Note that even when the occupant switches to the rough road mode or the sports mode by his / her own input operation, the restraint or non - restraint by the seat belt unit 5 is determined according to the permission or non - permission of restraint in the restraint permission setting unit 213.

[0034] That is, regardless of whether the driving mode is automatically switched or manually switched, when the restraint by the seat belt unit 5 is permitted in the restraint permission setting unit 213, the motor 51 is driven along with the switch to the rough road mode or the sports mode to restrain the occupant with the webbing. On the other hand, when the restraint by the seat belt unit 5 is not permitted in the restraint permission setting unit 213, even if the detection of the switch to the rough road mode or the sports mode is made, the motor 51 is not driven and the occupant is not restrained.

[0035] Further, when the rough road mode or the sports mode is paused or stopped, that is, when switched from the rough road mode or the sports mode to another driving mode, the motor drive control unit 214 determines the timing to release the restraint of the occupant by the seat belt unit 5 based on the road surface condition, and releases the restraint of the occupant based on the determined timing.

[0036] Hereinafter, with reference to FIGS. 3 and 4, the automatic switching process of the driving mode by the driving mode control ECU 11 and the restraint process by the seat belt control ECU 12 accompanying the automatic switching of the driving mode will be described.

[0037] First, the automatic switching process of the driving mode by the driving mode control ECU 11 will be described according to the flowchart of FIG. 3. In FIG. 3, as an example, the automatic switching process from the normal mode to the rough road mode will be described. When the automatic switching of the driving mode is permitted (YES in step S11), the driving mode control ECU 11 performs the automatic switching process of the driving mode according to the subsequent steps. When the automatic switching of the driving mode is not permitted (NO in step S11), the automatic switching is not performed.

[0038] When the automatic switching of the driving mode is permitted (YES in step S11), the driving mode control ECU 11 acquires the vehicle speed V of the vehicle 100 and the road surface condition in the traveling direction of the vehicle 100 at a predetermined cycle during traveling (step S12). In the next step, in the normal mode, when the switching to the rough road mode has not been performed, it is monitored whether the vehicle speed V of the vehicle 100 is less than or equal to the second speed V2 (step S13), and whether the traveling road of the vehicle 100 is a rough road (step S14).

[0039] When the vehicle speed V is not less than or equal to the second speed V2 (NO in step S13), or when no rough road is detected (NO in step S14), the driving mode control ECU 11 continues to monitor the vehicle speed V and the road surface condition without performing the switching of the driving mode (repeating steps S12 to S14).

[0040] On the other hand, when the vehicle speed V is less than or equal to the second speed V2 (YES in step S13) and a rough road is detected (YES in step S14), the driving mode control ECU 11 switches the driving mode of the vehicle 100 to the rough road mode (step S15).

[0041] Even after the driving mode is switched to the rough road mode by the driving mode control ECU 11, the acquisition of the vehicle speed V of the vehicle 100 and the road surface condition in the traveling direction of the vehicle 100 is continued, and it is monitored whether the vehicle speed V becomes less than or equal to the first speed V1 (step S16). When the vehicle speed V is less than or equal to the first speed V1 (YES in step 16), the driving mode control ECU 11 continues the rough road mode (step S17). When the vehicle speed V is higher than the first speed V1 (NO in step S16), the rough road mode is temporarily stopped (step S21).

[0042] While the rough road mode is continuing (step S17), if the vehicle speed V is less than or equal to the first speed V1 and a rough road is detected during running in the rough road mode (YES in step S18), the running mode control ECU 11 returns to step S16 and repeats the above process. On the other hand, if the vehicle speed V is less than or equal to the first speed V1 and no rough road is detected during running in the rough road mode (NO in step S18), the duration of the state where no rough road is detected (rough road undetected time) is monitored (step S19). If the rough road undetected time is greater than or equal to the first duration LT1 (YES in step S19), the rough road mode is stopped (step S20), that is, it is switched to the normal mode.

[0043] On the other hand, when the rough road mode is temporarily stopped (step S21), the running mode control ECU 11 monitors whether the vehicle speed V is less than or equal to the second speed V2 (step S22). If the vehicle speed V is less than or equal to the second speed V2 (YES in step S22), the rough road mode is restarted (step S23). If the vehicle speed V is higher than the second speed V2 (NO in step S23), the duration of the state where the vehicle speed V is higher than the second speed V2 (temporary stop duration) is monitored (step S24). If the temporary stop duration is greater than or equal to the second duration LT2 (YES in step S24), the rough road mode is stopped (step S20), that is, it is switched to the normal mode.

[0044] In the above example, the automatic switching process from the normal mode to the rough road mode has been described. However, also in the automatic switching process from the normal mode to the sports mode, the automatic switching conditions can be stored in the ROM of the running mode control ECU 11, and the automatic switching process can be performed according to these conditions.

[0045] Subsequently, the occupant restraint process by the seat belt control ECU 12 will be described according to the flowchart of FIG. 4. In FIG. 4, as an example, the restraint process associated with the automatic switching to the rough road mode will be described. When the automatic switching of the driving mode is permitted in the driving mode control ECU 11 (YES in step S31), the seat belt control ECU 12 performs an occupant restraint process according to the automatic switching of the driving mode in the subsequent steps. When the automatic switching of the driving mode is not permitted (NO in step S31), the seat belt control ECU 12 does not perform the occupant restraint process.

[0046] Further, when the permission of restraint by the seat belt unit 5 during traveling in the rough road mode or the sports mode is set in the restraint permission setting unit 213 (YES in step S32), the seat belt control ECU 12 performs an occupant restraint process according to the subsequent processes. When the permission of restraint is not set (NO in step S32), the seat belt control ECU 12 does not perform the occupant restraint process.

[0047] When the automatic switching of the driving mode is permitted in the driving mode control ECU 11 (YES in step S31) and the restraint by the seat belt unit 5 is permitted (YES in step S32), the seat belt control ECU 12 monitors whether the switching to the rough road mode is detected by the driving mode detection unit 212 (step S33).

[0048] When the driving mode detection unit 212 detects the switching to the rough road mode (including the turn-on and restart of the rough road mode) (YES in step S33), the motor drive control unit 214 drives the motor 51 of the seat belt unit 5 to wind up the webbing to restrain the occupant (step S34). Thereby, the vehicle 100 can be in a state where the occupant is restrained during traveling in the rough road mode.

[0049] During traveling in the rough road mode, the driving mode detection unit 212 monitors whether a stop signal related to the temporary stop or stop (off) of the rough road mode is received from the driving mode control ECU 11 (step S35). When the stop signal is received (YES in step S35), the timer provided in the seat belt control ECU 12 starts measuring the traveling time DT in the temporarily stopped or stopped state, that is, the traveling time DT in another driving mode (step S36).

[0050] While the seat belt control ECU 12 measures the running time DT while the rough road mode is paused or stopped, the road surface condition detection unit 211 monitors whether a rough road is detected (step S37). Then, it monitors whether the running time DT in a state where no rough road is detected (NO in step S37) is equal to or greater than a predetermined first running time DT1 (step S38), or whether the running time DT in a state where a rough road is detected (YES in step S37) is equal to or greater than a predetermined second running time DT (step S41).

[0051] During the measurement of the running time DT, it monitors the turning on or restarting of the rough road mode (step S42). If the rough road mode is not turned on or restarted (NO in step S42) and the running time DT in a state where no rough road is detected is equal to or greater than the predetermined first running time DT1 (YES in step S38), the restraint is released (step S39), and the measurement of the running time DT by the timer is stopped (step S40). By doing so, it is possible to prevent the continuous restraint of the occupant for a long time when no rough road is detected. Therefore, the first running time DT1 is preferably set to a time that reduces the discomfort of the occupant.

[0052] On the other hand, during the measurement of the running time DT and during the monitoring of the turning on or restarting of the rough road mode (step S42), if the rough road mode is not turned on or restarted (NO in step S42) and a rough road is detected (YES in step S37), when the running time DT is equal to or greater than the predetermined second running time DT2 (YES in step S41), the restraint is released (step S39), and the measurement of the running time DT by the timer is stopped (step S40).

[0053] Thus, when the rough road mode is suspended or stopped and a rough road is detected, the seat belt control ECU 12 monitors the activation or restart of the rough road mode until the second travel time DT2 elapses. When a rough road is detected, it is assumed that the road is rough enough to require the activation or restart of the rough road mode. On the other hand, for example, even if a rough road is partially caused by rain or the like, it is also assumed that there is no need to restrain the occupant. Therefore, by monitoring the activation or restart of the rough road mode while continuing to restrain the occupant until the second travel time DT2 elapses, it is possible to accurately determine whether the road is rough enough to require the activation or restart of the rough road mode. Therefore, it is preferable to set the second travel time DT2 to be longer than the first travel time DT1.

[0054] During the measurement of the travel time DT and during the monitoring of the activation or restart of the rough road mode (step S42), when the rough road mode is activated or restarted (YES in step S42), the timer reset the measurement (step S43), returns to step S35, and repeats the above process.

[0055] In the above description, as an example, the restraint process associated with the automatic switching to the rough road mode has been described. However, the restraint process associated with the automatic switching to the sports mode is also processed in the same manner as the restraint process associated with the automatic switching to the rough road mode described above.

[0056] In the occupant restraint device 20 according to the present embodiment configured as described above, when a collision is predicted for the vehicle 100, the seat belt control ECU 12 drives the motor 51 of the seat belt unit 5 to wind up the webbing to restrain the occupant.

[0057] Even when no conflict is predicted, for example, during driving when the vehicle occupants' bodies are jolted and their seating postures are disrupted due to a rough road mode or a sports mode, the occupant restraint device 20 performs restraint only when permission for restraint is given in response to the occupants' requests, that is, by an input operation by the occupants. In particular, in the occupant restraint device 20, when automatic switching of the driving mode of the vehicle 100 is permitted, restraint of the occupants is performed in conjunction with switching to the rough road mode or the sports mode.

[0058] As described above, according to the present embodiment, when there is no input operation by the occupants and restraint is not permitted, unnecessary restraint is not performed without performing restraint of the occupants corresponding to the driving mode, and discomfort is not given to the occupants. On the other hand, in an emergency such as when a collision is predicted, or when restraint is permitted by an input operation by the occupants, the occupants can be restrained quickly. That is, according to the present embodiment described above, the occupants can be quickly restrained in an emergency and in response to the occupants' requests while suppressing the discomfort of the occupants.

[0059] The embodiments of the present invention have been described in detail with reference to the drawings, but the specific configuration is not limited to these embodiments, and design changes and the like within the scope not departing from the gist of the present invention are also included in the present invention. Also, the above-described embodiments can be combined by diverting each other's technologies as long as there are no particular contradictions or problems in their purposes and configurations.

Description of Reference Numerals

[0060] 1: Vehicle control system, 3: In-vehicle network, 5: Seat belt unit 11: Driving mode control ECU, 12: Seat belt control ECU 20: Occupant restraint device, 31: Vehicle speed sensor, 32: Camera, 33: Acceleration sensor 51: Motor, 100: Vehicle, 211: Road surface state detection unit, 212: Driving mode detection unit 213: Restraint permission setting unit, 214: Motor drive control unit, T: Driving time, V: Vehicle speed

Claims

1. An occupant restraint device for restraining an occupant seated on a vehicle seat, comprising: a seat belt unit that restrains the occupant by driving a motor to wind a webbing; and a seat belt control unit that controls the seat belt unit according to a driving mode of the vehicle. The seat belt control unit: controls the seat belt unit to restrain the occupant when the driving mode of the vehicle is switched to a rough road mode suitable for driving on rough roads or a sports mode suitable for sports driving.

2. The seat belt control unit: can set permission or non - permission of restraint by the seat belt unit in the rough road mode or the sports mode, and controls the seat belt unit to restrain the occupant when restraint by the seat belt unit in the rough road mode or the sports mode is permitted and the vehicle is switched to the rough road mode or the sports mode. The occupant restraint device according to Claim 1.

3. The seat belt control unit: detects a road surface condition in the traveling direction of the vehicle, and determines a timing for releasing the restraint of the occupant by the seat belt unit based on the detected road surface condition when the vehicle is switched from the rough road mode or the sports mode to another driving mode. The occupant restraint device according to Claim 1 or Claim 2.

4. The seat belt control unit: after the vehicle is switched from the rough road mode or the sports mode to another driving mode, releases the restraint of the occupant by the seat belt unit after the elapse of a first driving time when the road surface condition is a rough road, and releases the restraint of the occupant by the seat belt unit after the elapse of a second driving time longer than the first driving time when the road surface condition is not a rough road. The occupant restraint device according to Claim 3.

5. Regarding the driving mode of the vehicle, it is possible to set whether to permit automatic switching to the rough road mode or the sports mode when the vehicle speed of the vehicle and the road surface condition in the traveling direction of the vehicle satisfy predetermined conditions. The occupant restraint device according to claim 2, wherein the seat belt control unit controls the seat belt unit to restrain an occupant in conjunction with a change in the driving mode when automatic switching to the rough road mode or the sports mode is permitted and restraint by the seat belt unit during driving in the rough road mode or the sports mode is permitted.

Images