Occupant protection system

Abstract

An occupant protection system that protects an occupant (70) in a vehicle (1) by means of a protective device (10, 50) provided in the vehicle (1), the occupant protection system comprising: a gas generator (122, 63) which includes an igniter (121) which is ignited by an ignition signal and generates gas as a result of the activation of the igniter (121), the gas generator (122, 63) is configured to actuate the protective device (10, 50) with the gas generated by the gas generator (122, 63); a prediction unit (106) configured to predict a collision between the vehicle (1) and an obstacle present around the vehicle (1); and a control unit (103) configured to control the supply of the ignition signal to the igniter (121) based on a prediction result by the prediction unit (106), The protective device (10, 50) is configured to be actuated by a pressure exerted on a predetermined space (62) with gas generated by the gas generator (122, 63) and directed into the predetermined space (62) in the protective device (10, 50), and the control unit (103) includes, an actuation control unit (105) configured to actuate the gas generator (122, 63) at an actuation time (T20, T20', T120, T120') that is earlier than a collision time (T30) predicted by the prediction unit (106) based on pressure data relating to a pressure transition of the gas in the predetermined space (62) when the ignition signal is supplied to the igniter (121), characterized in that the control unit (103) includes, a calculation unit (104) configured to calculate a protective pressure (P11, P12, P13, P14) exerted on the occupant (70) by the protective device (10, 50) to protect the occupant (70), and to calculate a protective time (T40, T140) at which the protective pressure (P11, P12, P13, P14) is exerted on the occupant (70), and the actuation control unit (105) is configured to actuate the gas generator (122, 63) at an actuation time (T20, T20', T120, T120') in such a way that the protective pressure (P11, P12, P13, P14) is applied by the protective device (10, 50) at the protection time (T40, T140) based on pressure data relating to a pressure transition of the gas in the predetermined space (62) when the ignition signal is supplied to the igniter (121).

Description

[0001] The present invention relates to an occupant protection system that protects an occupant in a vehicle according to the preamble of independent patent claim 1. Such an occupant protection system is known from the document DE 10 2013 003 667 A1.

[0002] It is known to use protective devices such as various airbags to protect occupants from impact in vehicles. For example, various types of airbag devices are widely used, such as a frontal impact airbag that inflates from a steering wheel, dashboard, or the like toward the front of an occupant; a knee protection airbag (a knee bag) that inflates at the lower part of a steering column; a side impact airbag that inflates from the seat side toward the occupant's side; and a curtain airbag that inflates along the side door windows. In addition to airbags, seat belt devices are also known that increase the tension of the seat belt so that the occupant is held in an appropriate position on the seat when a collision is detected.

[0003] To protect the occupant from impact by the protection device, an appropriate protection pressure must be applied to the occupant according to the protection mode of the protection device. If the protection pressure deviates from a predetermined pressure range, the occupant may not be adequately protected or an excessive impact may be applied to the occupant. For example, in the gas generator described in Patent Document 1, two igniters are provided, the ignition timing of which is adjusted after the impact is detected, and the pressure inside the airbag is adjusted by the generated gas, thereby adjusting the protection pressure with which the airbag applies to the occupant. In the technology disclosed in Patent Document 2, the pressure inside the airbag is similarly adjusted by controlling the actuation of two gas generators after the impact is detected. Citation listPatent document Patent document 1: JP 3 965 050 B2 Patent Document 2: JP 2013-256227 A Patent Document 3: JP 2009-520628 A

[0004] To protect a vehicle occupant from impact with a protective device, it is necessary to restrain the occupant with an appropriate protective pressure. According to a known technique, when a collision occurs between a vehicle and an obstacle, the actuation of two igniters contained in one or two gas generators is controlled. With such a configuration, the generation of gas to deploy the airbag occurs only after a certain period of time after the impact is detected, so the airbag may not necessarily act on the occupant with an appropriate pressure (contact). Therefore, since the gas generated by the two igniters and the like combine to exert pressure on the occupant through the airbag, the applicable pressure range is limited.

[0005] Furthermore, the configuration requiring two detonators or similar devices makes the protection device mechanically complex or tends to increase in size. Therefore, it is difficult to provide a protection device that is also suitable from a cost perspective.

[0006] In view of the problems described above, an object of the present disclosure is to provide an occupant protection system that can apply an appropriate protective pressure to an occupant when the occupant is protected from impact in a vehicle by a protective device.

[0007] This object is achieved according to the invention by an occupant protection system having the features of independent patent claim 1. Preferred developments are set out in the subclaims.

[0008] According to the present disclosure, the gas generator is actuated at a time prior to the predicted collision time, so that the protective pressure exerted on the occupant by the actuation of the protective device and its timing become appropriate for the occupant in a case where a collision between the vehicle and an obstacle is predicted. By performing such actuation control of the gas generator, an appropriate pressure can be exerted on the occupant by the protective device at an appropriate time, even if the number of gas generators is one.

[0009] Specifically, the present disclosure is an occupant protection system that protects an occupant in a vehicle by a protection device provided in the vehicle. The occupant protection system includes: a gas generator having an igniter that is ignited by an ignition signal and generates gas due to the actuation of the ignition of the igniter. The gas generator is configured to actuate the protection device with the gas generated by the gas generator. A prediction unit configured to predict a collision between the vehicle and an obstacle present around the vehicle. A control unit configured to control the supply of the ignition signal to the igniter based on a prediction result by the prediction unit.Then, the protection device is configured to be actuated by a pressure exerted on a predetermined space with gas generated by the gas generator and supplied into the predetermined space in the protection device.The control unit includes a calculation unit configured to calculate a protection pressure exerted by the protection device on the occupant to protect the occupant and to calculate a protection time at which the protection pressure is exerted on the occupant, and an actuation control unit configured to actuate the gas generator at an actuation time earlier than a collision time predicted by the prediction unit such that the protection pressure is exerted at the protection time by the protection device based on pressure data related to the pressure transition of the gas in the predetermined space when the ignition signal is supplied to the igniter.

[0010] The occupant protection system of the present disclosure is a system that protects an occupant in a vehicle through a protection device. The protection device is not limited to a specific configuration but is configured such that the protection device is actuated by the pressure of the gas applied to a predetermined space, and the gas generated by the gas generator is supplied to the predetermined space provided in or contained in the protection device. Examples of the protection device include an airbag device that is supplied with the gas generated by the gas generator and inflated to a predetermined inflation level, and a seatbelt device that restrains the occupant to the seat by using the gas generated by the gas generator to pull the seatbelt.By transferring gas pressure in a predetermined space to an occupant, such protection devices can protect the occupant from an impact during the collision between the vehicle and the obstacle.

[0011] Here, the occupant protection system includes a prediction unit. Using known techniques, the prediction unit can predict a collision between the vehicle and an obstacle, for example, a collision time at which a collision with an obstacle will occur, whether a collision with the obstacle can be avoided, and the like. For example, the prediction unit can perform collision prediction based on a relative distance, a relative speed, and the like between the vehicle and a surrounding obstacle, which are detected using a camera that detects the traveling direction of the vehicle, LIDAR technology that uses short-wavelength electromagnetic waves such as near-infrared waves, and the like.In the occupant protection system described above, the control unit controls the supply of an ignition signal to the igniter to actuate the protection device based on the prediction result by the prediction unit.

[0012] The control unit includes a calculation unit and an actuation control unit to control the supply of the ignition signal to the igniter. The calculation unit calculates the protective pressure exerted on the occupant by the protective device for occupant protection, i.e., the pressure exerted on the occupant by the gas generated by the gas generator, and the time at which the protective pressure is exerted on the occupant. In order to achieve occupant protection through the protective device, it is important that pressure is exerted on the occupant at a suitable time for protection, which protects the occupant appropriately without causing harm. This protective pressure and the time at which the protective pressure is exerted can vary depending on the type of occupant protection provided by the protective device.In addition, the protection pressure and the protection time can be adjusted depending on physical parameters related to the movement of the occupant at the time of impact, for example parameters related to the inertial forces acting in the direction of travel (vehicle speed, occupant weight, etc.) as well as the distance to and arrangement of devices in the vehicle with which the occupant's body may come into contact.

[0013] Using pressure data related to the pre-stored pressure transition of the gas in the predetermined space, the actuation control unit delivers an ignition signal to the igniter to actuate the gas generator at an actuation time prior to the collision time, so that the protection device performs occupant protection at a protective pressure calculated by the calculation unit and at the protective time. In other words, based on the pre-assumed pressure transition in the predetermined space with the gas generated by the gas generator, the actuation control unit determines an appropriate actuation time of the igniter and delivers the ignition signal at the actuation time.In such a configuration, by adjusting the actuation timing of an igniter just before and after a time before the collision time, a desired protective pressure can be applied to the occupant at a desired protection time, whereby it is possible to apply an appropriate pressure to the occupant via the protection device with a simple method.

[0014] Here, in the occupant protection system described above, the pressure data may include data relating to a peak time at which the gas pressure in the predetermined space reaches a peak value after the ignition signal is delivered to the igniter, as well as a pressure transition in the predetermined space at and after the peak time, and in particular, a pressure drop. That is, by including at least this data, the actuation time for actuating the gas generator can be appropriately determined.

[0015] In the above-described occupant protection system, the pressure data may be formed as data related to a pressure transition of the gas in the predetermined space, in a manner corresponding to the temperature of the gas generator. Then, the actuation control unit can trigger the gas generator at the actuation timing based on the temperature of the gas generator. According to such a configuration, even if the temperature around the gas generator fluctuates, the actuation timing is appropriately determined in accordance with the ambient temperature, and the gas generator is actuated. Since the gas generation characteristic of the gas generator depends on the ambient temperature, the occupant can be appropriately protected by activating the gas generator based on the ambient temperature in this way.

[0016] In the occupant protection system described above, the calculation unit can calculate the protection pressure based on the occupant's weight. The inertial force acting on the occupant at the time of impact is greatly influenced by the occupant's weight. Therefore, to achieve adequate occupant protection, it is preferable to determine the protection pressure taking the occupant's weight into account.

[0017] Here, in the occupant protection system described above, various configurations of devices can be used as the protection device, and the control of the gas generator can be performed by the control unit depending on the device configuration. Examples of the configurations are given below. As a first configuration, the protection device may be an airbag device that is supplied with gas generated by the gas generator and inflated into a predetermined inflation shape. In this case, the predetermined space is an inflation space in the airbag device, and the pressure data relates to a pressure transition of the gas in the inflation space.The calculation unit may calculate the protection pressure acting on the occupant when the airbag device is inflated to the predetermined inflation shape and comes into contact with the occupant, and the protection timing for the contact of the airbag device with the occupant, and the actuation control unit may actuate the gas generator at the actuation timing based on the protection timing and the pressure data.

[0018] With such a device configuration, the control unit controls the actuation of the gas generator so that the protective pressure is applied at the time of contact between the airbag device, which is inflated by supplying gas into a predetermined space of the airbag device, and the occupant at a time suitable to protect the occupant from the impact at the time of a collision. This enables safe and reliable protection of the occupant by deploying the airbag device with a simple procedure.

[0019] In a configuration using an airbag device, the actuation control unit can further trigger the gas generator at the actuation time depending on the vehicle's traveling speed. The higher the vehicle's traveling speed, the shorter the time (hereinafter referred to as "contact reaching time") until the occupant comes into contact with the deployed airbag device after the impact. By determining the actuation time while taking the contact reaching time into account, better occupant protection can be achieved.

[0020] Next, in a second configuration, the protection device may be a seatbelt device that restrains an occupant to a seat, wherein the gas generated by the gas generator is supplied to pull a seatbelt. In this case, the predetermined space may be a pressure space in which pressure is applied with the gas to cause the seatbelt to exert a restraining force on the occupant, and the pressure data may be data related to a pressure transition of the gas in the pressure space. The calculation unit may calculate the protection pressure exerted on the occupant when the seatbelt restrains the occupant by applying pressure to the seat with the gas, and the protection timing for the seatbelt to restrain the occupant, and the actuation control unit may actuate the gas generator at the actuation timing based on the protection timing and the pressure data.

[0021] In such a device configuration, gas is introduced into a predetermined space of the seat belt device, thereby exerting pressure on the seat belt to move the seat belt to restrain the occupant. The control unit then controls the operation of the gas generator so that, when the occupant is restrained to the seat by the seat belt, the protective pressure acts on the occupant at a time suitable to protect the occupant from the impact at the time of a collision. This enables safe and reliable protection of the occupant by the seat belt device with a simple method. It should be noted that, in one example of the seat belt device, the predetermined space may be a pressure space for pressurizing a piston slidably connected to an end portion of the seat belt with gas to displace the piston.

[0022] The occupant protection system described above may be further configured to protect the occupant with an airbag device that is inflated to a predetermined inflation shape. The occupant protection system may further include a second gas generator containing a second igniter that is ignited by a second ignition signal and configured to generate gas upon actuation of the second igniter and deploy the airbag device via a pressure exerted on an inflation space. The gas generated by the second gas generator is directed into the inflation space of the airbag device. In such a case, the control unit controls the supply of the ignition signal to the igniter and the second ignition signal to the second igniter based on the prediction result from the prediction unit. The calculation unit may further calculate a second protection pressure exerted on the occupant.When the airbag device is inflated to the predetermined inflation shape and comes into contact with the occupant, the actuation control unit calculates a second protection time for the airbag device to come into contact with the occupant. The actuation control unit can actuate the gas generator at the actuation time based on the pressure data in such a way that the protection pressure is exerted on the occupant by the seat belt at the protection time after the collision time and before the second protection time. The actuation control unit can further actuate the second gas generator at a second actuation time based on second pressure data relating to a pressure transition of gas in the inflation space when the second ignition signal is supplied to the second igniter in such a way that the airbag device and the occupant come into contact with each other at the second protection time to exert the second protection pressure on the occupant.

[0023] That is, as the occupant protection system, the protection devices include both the seat belt device and the airbag device. In such a configuration, the control unit controls the operation of both the seat belt device and the airbag device. More specifically, the control unit controls the operation of the gas generator and a second gas generator so that the pressure (protection pressure and second protection pressure) from each device acts on the occupant at a time (protection time and second protection time) appropriate for the occupant protection by each device. This enables safe and reliable protection of the occupant by the seat belt device and the airbag device through a simple process.

[0024] It should be noted that in the above-described occupant protection system, the initial actuation timing and the second actuation timing are both before the collision time, and the initial actuation timing may be earlier than the second actuation timing. As a result, the occupant can enjoy the protection of the airbag device while being properly restrained to the seat by the seatbelt device, thereby providing a technique that contributes to ensuring occupant safety. Advantageous effects of the invention

[0025] According to the present disclosure, an appropriate pressure can be applied to an occupant by a simpler method when the occupant in a vehicle is protected from the impact by a protection device. Brief description of the drawings Fig. 1 is a first view showing the condition of an occupant on board a vehicle. Fig. 2 is a view showing a functional block for an occupant protection system installed in a vehicle. Fig. 3 is a second view showing the condition of an occupant on board a vehicle. Fig. 4 is a third view showing the condition of an occupant on board a vehicle. Fig. 5 is a first view showing a transition of gas pressure in an airbag of an airbag device. Fig. 6 is a flowchart relating to the actuation control of an occupant protection squib executed in the occupant protection system. Fig. Fig. 7 is a view for explaining a determination process of a timing at which an igniter of an airbag device in the Fig. 6 shown actuation control is operated. Fig. 8 is a second view showing a transition of gas pressure in the airbag of the airbag device. Fig. 9 is a view showing a schematic configuration of the seat belt device. Fig. 10 is a view for explaining a method of determining the timing at which an igniter of an airbag device and an igniter of a seatbelt device are triggered. Description of the embodiments

[0026] Below, aspects of an occupant protection system according to an embodiment will be described with reference to the drawings. It should be noted that each of the configurations, combinations thereof, and the like in each embodiment is an example, and various configuration additions, omissions, substitutions, and other changes can be made as appropriate without departing from the spirit of the present invention. The present disclosure is not limited by the embodiments and is limited only by the claims. First embodiment

[0027] An occupant protection system according to a first embodiment is described. Fig. 1 shows a state of an occupant 70 who is on board a vehicle 1 and driving a vehicle 1. Fig. Figure 2 is a functional block diagram for the actuation control of an airbag device 10, which is implemented in a control device 100 in the vehicle 1 as an occupant protection system. The airbag device 10 corresponds to the protection device in the present application.

[0028] As in Fig. 1, the occupant 70 drives the vehicle 1 in a state in which he is seated on a seat 40. The seat 40 is configured such that a backrest 42 can be reclined against a seat cushion 41 on which the occupant sits. A headrest 43 is connected to the backrest 42. In the state shown in Fig. As shown in Fig. 1, the occupant 70 steers the vehicle 1 via a steering wheel 2 in a state where the driver's head is placed on the headrest 43 and most of the driver's body is placed on the seatback 42 and the seat cushion 41. A seat belt device 50 is provided to ensure the safety of the occupant 70 in the event of an accident while the occupant 70 is driving the vehicle 1. The seat belt device 50 is configured as a three-point belt including a shoulder belt 52 and a lap belt 53. A metal tongue 54 through which these belts are passed is connected to a buckle 51, thereby restraining the body of the occupant 70 while driving relative to the seat 40.

[0029] In the vehicle 1, the airbag device 10 is arranged inside the steering wheel 2 for the safety of the occupants 70. The airbag device 10 has a gas generator 122 including an igniter 121 and is configured so that gas generated by combustion of a gas generating agent in the gas generator 122 is supplied to deploy an airbag 123 (see Fig. 3). That is, the interior of the airbag 123 corresponds to the specified space in the present application. For the gas generating agent, for example, a single-perforated cylindrical agent composed of guanidine nitrate (41 wt%), basic copper nitrate (49 wt%), and a binder or additive can be used. For the gas generator 122, a known hybrid type using a pressurized gas and a gas generating agent in combination, or a known storage type using only a pressurized gas, can also be used.

[0030] Before the airbag device 10 is deployed, that is, when there is no need to protect the occupant on the seat 40, the entire airbag device 10 is housed in the steering wheel 2 in a state in which the airbag 123 is folded. Then, when a collision between the vehicle 1 and an obstacle is predicted or when a collision occurs, an ignition signal is supplied to the igniter 121 of the airbag device 10 to protect the occupant 70 from the impact of the collision, and gas generated by the gas generator 122 is supplied to the interior of the airbag 123 to deploy the airbag 123 (state of Fig. 3). Thereafter, the body of the occupant 70, which is thrown in the direction of travel of the vehicle 1, is received by the deployed airbag 123 (state of Fig. 4). At this time, the airbag 123 is preferably inflated to a level that prevents the body of the occupant 70 from moving further forward and that no excessive pressure is exerted on the body at the time of contact.

[0031] It should be noted that the airbag 123 is provided with a vent hole to release the gas introduced into the interior over time. Therefore, the pressure inside the airbag 123 changes when gas is supplied from the gas generator 122, as shown in Fig. 5. The horizontal axis in Fig. 5 represents time, and the vertical axis represents the pressure inside the airbag 123. Then, time T1 is the time at which an ignition signal is supplied to the igniter 121. When an ignition signal is supplied to the igniter 121, the gas generating agent inside the gas generator 122 begins to burn with combustion product generated by the igniter 121. The gas thus generated easily deploys the airbag 123, and this pressure ruptures the airbag module and causes the airbag to be released (inflated) outward from the accommodation space of the steering wheel 2. Therefore, the internal pressure of the airbag 123 drops shortly after its temporary rise (transition of the Fig. 5). On the other hand, the combustion of the gas generating agent continues, and the internal pressure of the airbag 123 begins to rise again at time T2 due to the generated gas, and then the internal pressure reaches a peak value at time T3. The peak pressure at this time is P1. Thereafter, the internal pressure of the airbag 123 gradually decreases due to the correlation between the supply flow rate of the gas from the gas generator 122, the outlet flow rate of the gas from the vent hole provided in the airbag 123, and the cooling of the gas in the airbag 123 (transition of line L2 into Fig. 5). In view of such a pressure transition, the protection of the occupant 70 by the airbag device 10 is preferably carried out.

[0032] Details of the control for protecting the occupant by the occupant protection system described above will now be described with reference to Fig. 2 described. Fig. 2 is a functional block diagram for the actuation control of the airbag device 10 implemented in the control device 100 in the vehicle 1 as an occupant protection system. The control device 100 includes, for example, a microcomputer, and each function is implemented by causing a central processing unit (CPU) (not shown) to execute a program stored in a memory device (ROM) or the like (not shown).

[0033] Fig. 2 also shows a vehicle information request unit 130 and a sensor 140 provided in the vehicle 1. The vehicle information request unit 130 is a device for acquiring information about the driving state of the vehicle, such as the speed and current position of the vehicle 1, and is typically configured to include a speed sensor and a GPS receiver. The information requested by the vehicle information request unit 130 is transmitted to the control device 100 and used for control related to the driving of the vehicle 1, for example, for displaying the route in a vehicle navigation device, for protection control for protecting the occupants 70 when the vehicle 1 is traveling, and the like.Sensor 140 is a device for performing measurements to acquire information required for protective control, including information about structures (obstacles) in the vehicle's surroundings, and is typically configured to include a stereo camera, a visible light camera, a laser scanner, LIDAR, radar, and the like. The information acquired by sensor 140 is also transmitted to control device 100.

[0034] The functional units of the control device 100 are described below. The control device 100 includes a request unit 101, a state acquisition unit 102, a control unit 103, a prediction unit 106, and a storage unit 107. First, the request unit 101 is a functional unit for acquiring environmental information related to the traveling vehicle 1 or the surroundings of the vehicle 1. The environmental information is information related to a collision between the vehicle 1 and an obstacle in its surroundings, and examples include information related to the traveling and steering of the vehicle 1, relative position information of the obstacle with respect to the vehicle 1, relative speed information, information related to the distance between the vehicle 1 and the obstacle, and the like.The request unit 101 obtains the environmental information regarding the situation surrounding the vehicle 1 using the data obtained from the vehicle information request unit 130 and the sensor 140. Next, the state acquisition unit 102 is a functional unit that acquires information about the state of the occupant 70 in the vehicle 1, such as information about the weight of the occupant 70 and information about the relative position of the occupant 70 sitting on the seat 40 with respect to the structure (specifically, the steering wheel 2) in the vehicle 1. Specifically, the state acquisition unit 102 acquires the weight of the occupant 70 through a weight sensor provided in the seat 40 and acquires a distance between the occupant 70 and the steering wheel 2 through a camera provided in the vehicle 1.

[0035] Next, the control unit 103 is a functional unit that controls the supply of the ignition signal to the igniter 121 included in the airbag device 10 based on the prediction result of the prediction unit 106 described below. In other words, in a case where it is determined that the airbag device 10 needs to be deployed to protect the occupant 70 as a result of the prediction by the prediction unit 106, the control unit 103 achieves deployment by supplying an ignition signal to the igniter 121. To activate the igniter 121, the control unit 103 includes a calculation unit 104 and an actuation control unit 105.More specifically, the calculation unit 104 is a functional unit that calculates a protective pressure suitable for protecting the occupant 70 when the airbag 123 of the airbag device 10 is inflated, as well as a protective timing at which the protective pressure is applied. The actuation control unit 105 is a functional unit that supplies an ignition signal to the igniter 121 and actuates the gas generator 122 so that the occupant 70 can be protected by the airbag device 10 with the protective pressure and protection timing calculated by the calculation unit 104. At this time, the actuation control unit 105 controls the actuation of the gas generator 122 based on the assumed pressure transition data in the airbag 123 while the gas generator 122 is under actuation. The assumed pressure transition data are stored in the storage unit 107 described below.Details of the actuation control will be described later.

[0036] The prediction unit 106 is a functional unit that predicts a collision between the vehicle 1 and an obstacle. Specifically, the possibility of a collision is predicted based on the speed information of the vehicle 1, the separation distance between the obstacle and the vehicle 1, and the like, which serve as environmental information obtained from the request unit 101. For example, it can be predicted that the shorter the time to collision calculated from the vehicle speed and the separation distance, the higher the probability of a collision. When the time is less than a reference value, the "occurrence of a collision" is predicted. In this case, the prediction unit 106 also predicts and outputs the time (collision time) at which the collision occurs.The storage unit 107 is a functional unit which stores the assumed pressure transition data stored in . Fig. 5, and stores other assumed data in the airbag 123 when the gas generator 122 is in operation. It should be noted that during the pressure transition shown in Fig. 5, the pressure transition (i.e., the protective pressure required to restrain the occupant 70) actually associated with the deployment of the airbag 123 is indicated by line L2. Accordingly, the storage unit 107 only needs to store at least the pressure transition L2, the peak time T3 at which the peak pressure P1 is reached, and the data related to the pressure transition at and after the peak time T3.

[0037] The actuation control of the airbag device 10 is now carried out using Fig. 6. This operation control is repeatedly performed by the control device 100 at predetermined intervals. First, in S101, information about the weight of the occupant 70 and the separation distance between the occupant 70 and the steering wheel 2 are acquired from the state acquisition unit 102 as information about the state of the occupant 70 in the vehicle 1. The former refers to the inertial force generated when the vehicle 1 collides with an obstacle, and the latter refers to the contact reaching time between the occupant 70 and the steering wheel 2 when a collision occurs. Next, in S102, the surrounding information is obtained from the request unit 101. As described above, the surrounding information is travel information of the vehicle 1 and information related to the collision between the vehicle 1 and the obstacle around the vehicle.

[0038] Then, in S103, the prediction unit 106 determines whether or not there is a possibility of collision between the vehicle 1 and an obstacle. It should be noted that the possibility of collision in the present embodiment refers to a situation in which a collision with an obstacle is difficult to avoid even by the steering of the occupant 70. For example, if the time to collision calculated from the speed and separation distance of the vehicle 1 is shorter than a predetermined threshold, it is determined that there is a possibility of collision, and an affirmative determination is made in S103. At this time, the collision time, which corresponds to the time to collision, is also output from the prediction unit 106.The process proceeds to S104 if an affirmative determination is made in S103, while the actuation control is terminated if a negative determination is made.

[0039] Next, in S104, the protection pressure is calculated by the calculation unit 104. As in Fig. As shown in Figure 4, the protection pressure is an appropriate pressure that the occupant 70 receives from the deployed airbag 123 when the airbag device 10 protects the occupant 70 from the impact at the time of collision. That is, if the pressure absorbed by the airbag 123 is too high, an excessive impact will be applied to the occupant 70, which is undesirable from the perspective of occupant protection. If the pressure absorbed by the airbag 123 is too low, it becomes difficult to properly support the occupant 70, who is thrown in the traveling direction of the vehicle 1 due to the inertial force at the time of impact, which is also undesirable from the perspective of occupant protection. Therefore, the calculation unit 104 calculates an appropriate protection pressure from the perspective of occupant protection based on the inertial force that can be applied.The heavier the weight of the occupant 70 and the higher the speed of the vehicle 1, the greater the inertial force becomes, and therefore the calculation unit 104 calculates the protective pressure based on at least one of these parameters. Specifically, the calculation unit 104 calculates the protective pressure, and the heavier the weight of the occupant 70, the greater the protective pressure becomes.

[0040] Subsequently, in S105, the calculation unit 104 calculates the protection time. The protection time is a time suitable for the airbag device 10 to protect the occupant 70, that is, the time at which the inflated airbag 123 is brought into contact with the occupant 70 to assist the occupant 70 moving with inertia. Therefore, the protection time is preferably calculated based on the contact time until the body of the occupant 70, which is moving with inertia due to the impact at the time of the collision, comes into contact with the steering wheel 2. For example, the protection time can be calculated based on the distance between the occupant 70 and the steering wheel 2 and the traveling speed of the vehicle 1, which are detected by the state detection unit 102.In a case where the protection time is defined with reference to the collision time (predicted by the prediction unit 106) (for example, in a case where the time after a predetermined time since the collision time is taken as the protection time), the calculation is performed, and the shorter the separation distance and the faster the traveling speed, the closer the protection time comes to the collision time.

[0041] Next, in S106, the actuation time is determined, at which the actuation control unit 105 delivers an ignition signal to the igniter 121 to trigger the gas generator 122. The process of determining the actuation time is described in Fig. 7. The Fig. The horizontal axis shown in Figure 7 is a time axis. On this time axis, time T10 is a time at which a collision is predicted by the prediction unit 106, that is, a time at which an affirmative determination is made in the process of S103. The collision time predicted at this time is represented by time T30, and the protection time calculated in S105 is represented as time T40, at which the airbag 123 comes into contact with the occupant 70. Then, the actuation time at which the gas generator 122 is actuated is represented as time T20 or T20'.

[0042] Here the upper part (a) of Fig. 7, that it is necessary to send an ignition signal to the igniter 121 and to actuate the gas generator 122 at the time T20, which is before the collision time T30, in order to deploy the airbag 123 at the time T40, which is the protection time, in contact with the occupant 70 (weighing 60 kg) with a protection pressure P11, using the Fig. 5. That is, if the occupant 70 weighs 60 kg, the inflator 122 must be actuated at time T20, which is before the collision time T30, in order to adequately protect the occupant 70. Note that the actuation mode of the inflator 122 shown in the upper part (a) has been determined in advance through a prior experiment or the like and is referred to as a "standard actuation mode." Then, it is assumed that the storage unit 107 stores information regarding this standard actuation mode, that is, information that the actuation timing of the inflator 122 is set to T20 in order to apply the protection pressure P11 to the occupant 70 at the protection time T40 after the collision time T30 (that is, the time after T40 - T30 since the collision time T3).

[0043] Here, in the current S106, when the occupant 70 has a body weight of less than 60 kg, the protection pressure P12 applied to the occupant 70 is calculated to be smaller than P11 (the above-described process of S104). In S105, the protection timing is calculated to be the same as in the standard actuation form. In this case, in order to apply the protection pressure P12 to the occupant 70 at the protection timing T40, the protection timing T40 must be reached at a time when the pressure in the airbag 123 is further reduced after a longer period of time has elapsed since the actuation of the gas generator 122. For this purpose, it is necessary to set the actuation time of the gas generator 122 earlier by ΔTA compared to the standard actuation form and to set the actuation time to T20' (see the lower part (b) of Fig. 7). ΔTA can be calculated in accordance with the protection pressure P12 based on pressure transition data stored in the storage unit 107. With respect to the actuation time T20 of the standard actuation form with the thus calculated ΔTA, the actuation time T20' is determined in S106. As can be seen from Fig. 7, this actuation time T20' is earlier than the collision time T30 predicted by the prediction unit 106.

[0044] If the actuation time T20' is determined in S106, then in S107 an ignition signal is delivered to the igniter 121 at the actuation time T20' to achieve the actuation of the gas generator 122. Thus, in the event of a collision of the vehicle 1 with an obstacle, appropriate occupant protection can be achieved by activating the gas generator 122 at an appropriate time before the collision.

[0045] It can be seen that in the form shown in the lower part (b) of Fig. 7, the traveling speed of the vehicle 1 is the same as the case corresponding to the standard actuation form, and therefore the protection timing is the same as the protection timing T40 of the case corresponding to the standard actuation form. When the traveling speed of the vehicle 1 is faster, the actual protection timing is closer to the collision time T30 than the protection timing T40 of the case corresponding to the standard actuation form, and the actuation timing T20' of the gas generator 122 is executed earlier, and thus the protection pressure P12 is applied to the occupant 70 at the protection time. Modified examples

[0046] Here, a modified example of assumed pressure transition data in the airbag 123 during operation of the gas generator 122 stored in the storage unit 107 is shown by Fig. 8. The Fig. The pressure transient data shown in Fig. 8 refer to three forms of pressure transients according to the temperature at which the gas generator 122 is placed. Note that in the present modified example, the pressure transient L1 when the airbag 123 comes out from inside the steering wheel 2 is omitted, and the pressure transient from and after time T2 is stored in the storage unit 107. Like the combustion characteristics, the gas generating agent in the gas generator 122 is sensitive to the ambient temperature (temperature of the gas generator 122). That is, the higher the ambient temperature becomes, the harder the gas generating agent burns. Therefore, the pressure transient data at room temperature, low temperature, and high temperature of the gas generator 122 are L20, L21, and L22, respectively. It can be seen that the pressure transition L20 at room temperature is identical to that in Fig. 5. The peak pressures of pressure transitions L20, L21, and L22 are P1, P2, and P3, respectively.

[0047] When such pressure transition data is stored in the storage unit 107, information about the standard actuation form is also stored in the storage unit 107 in a manner corresponding to each pressure transition. Fig. 6 is performed, when determining the actuation timing in S106, an appropriate pressure transition from L20 to L22 is selected based on the temperature of the gas generator 122 at that time, and the actuation timing at that time is determined in accordance with the corresponding standard actuation pattern. In this way, appropriate occupant protection can be achieved without affecting the temperature of the gas generator 122. Second embodiment

[0048] An occupant protection system according to the second embodiment is described with reference to Fig. 9 and Fig. 10 described. Fig. 9 is a view showing a schematic configuration of a pretensioner mechanism provided at the end portion of the shoulder belt 52 of the seatbelt device 50. In the present embodiment, the seatbelt device 50 corresponds to the protection device of the present application in addition to the airbag device 10 described above. The seatbelt device 50 in the present embodiment is provided with a gas generator 63, and the gas generator 63 includes an igniter for actuating the gas generator. Then, a metal casing 60 having a predetermined space 62 into which gas generated by the gas generator 63 is supplied is connected to the gas generator 63 at one end portion thereof. Note that the other end portion of the casing 60 communicates with an outside space via an opening portion.Then, a piston 61, which can slide in the predetermined space 62 within the housing 60, is arranged in a straight portion of the housing 60. The predetermined space 62 into which the generated gas is discharged is defined by the end portion of the piston 61, the gas generator 63, and the housing 60. Thus, the volume of the predetermined space 62 varies with the displacement of the piston 61.

[0049] It should be noted that although the pressure within the predetermined space 62 initially rises sharply when gas flows from the gas generator 63, the piston 61 slides with the pressure increase, and the volume of the predetermined space 62 increases, thus alleviating the internal pressure of the predetermined space 62. It should be noted that one end portion of a wire 65 is connected to one end portion of the piston 61. The wire 65 is wound in a state of contact with a rotary shaft 64 and a hook portion 66a provided on an anchor 66 at the end portion of the shoulder strap 52, and its other end is fixed with respect to the rotary shaft 64. Thus, when the piston 61 slides due to the pressure of the gas, the wire 65 is pulled, and the shoulder strap 52 is pulled in the same way. Since the shoulder belt 52 is at this time in a state in which it is hooked by the shoulder of the occupant 70 at the chest (see Fig. 1), the sliding of the piston 61 can push the occupant 70 over the shoulder belt 52 and restrain the body in the seat 40.

[0050] Such restraint of the body of the occupant 70 by the seat belt device 50 makes the posture of the occupant 70 with respect to the seat 40 generally constant and contributes to making the occupant protection by the airbag device 10 more effective. Therefore, in the present embodiment, in order to appropriately control the pressure on the occupant 70 by the seat belt device 50, the actuation control of the gas generator 63 provided on the seat belt device 50 is performed in the same manner as in the first embodiment described above.

[0051] The assumed pressure transition data in the predetermined space 62 within the housing 60 upon actuation of the gas generator 63 are also stored in the storage unit 107. The pressure transition is in Fig. 10 (A) and (B) are shown schematically. It can be seen that Fig. 10 (A) shows the pressure transition in the standard actuation form of the gas generator 63 of the seat belt device 50. The difference in the trend between the pressure transition corresponding to the seat belt device 50 and the pressure transition corresponding to the airbag device 10 is that the pressure increases immediately upon actuation of the gas generator 63 (i.e., there is no transition corresponding to the pressure transition L1 required for the airbag 123 to be inflated from the steering wheel 2).

[0052] Now, the operation control in the present embodiment will be mentioned. As described above, the protection device of the present embodiment includes the airbag device 10 and the seatbelt device 50. Since the operation control for the airbag device 10 is described above with reference to Fig. 6, a detailed description of the same (in particular details of determining the time ΔTA which is to be counted from the actuation time T20 of the gas generator 122 in the Fig. 10 is omitted. Regarding the seat belt device 50, in S104 of the operation control, an appropriate protective pressure exerted by the seat belt device 50 on the occupant 70 is calculated, that is, the pressure at which the body can be appropriately restrained in the seat 40 within a range in which no excessive impact is exerted on the occupant 70 is calculated. In this case, too, in view of restraining the body against the inertial force at the time of impact, the protective pressure on the seat belt device 50 can be calculated based on the weight of the occupant 70 and the like.

[0053] In S105, the protection timing for the application of the protective pressure to the occupant 70 by the seat belt device 50, that is, the timing at which the body is restrained to the seat 40 by the seat belt device 50, is calculated. The protection timing of the seat belt device 50 can be determined according to criteria such as a certain period of time from the collision time predicted by the prediction unit 106.

[0054] The determination (process in S106) of the actuation timing of the gas generator 63 of the seat belt device 50 based on the above-described protection pressure and protection timing in the seat belt device 50 is carried out using Fig. 10. It should be noted that the third part (a) and the fourth part (b) described in Fig. 10 are the same as the upper part (a) and the lower part (b) shown in Fig. 7. In the timeline of Fig. 10, the times T10, T20, T20', T30, and T40 are as described in the first embodiment. Furthermore, the above-described protection time in the seat belt device 50 is represented as time T140, at which the seat belt device 50 restrains the occupant 70 on the seat 40. Then, the actuation time at which the gas generator 63 is triggered is represented as time T120 or T120'.

[0055] Here the first part (A) of Fig. 10 is the standard actuation form for the seat belt device 50 and is determined in advance by a previous test or the like. As with the standard actuation form for the airbag device 10 (third part (a) of Fig. 10), the condition is described such that the weight of the occupant 70 is 60 kg, and in order to properly restrain the body of the occupant 70 on the seat 40 before the airbag 123 is fully inflated, it is necessary to send an ignition signal to the igniter of the gas generator 63 and trigger the gas generator 63 at a time T120 which is before the collision time T30. The time T120 is before the actuation time T20 in the airbag device 10. Then, it is assumed that the storage unit 107 stores information about this standard actuation form, that is, information that the actuation time of the gas generator 63 is set to T120 in order to apply the protection pressure P13 to the occupant 70 at the protection time T140 after the collision time T30 (that is, the time after T140 - T30 since the collision time T3).

[0056] As in the first embodiment, in the actual situation S106, when the occupant 70 has a body weight of less than 60 kg, the protective pressure exerted by the safety belt device 50 on the occupant 70 is calculated as P14, which is lower than P13. In the actual situation S105, the protection time in the safety belt device 50 is calculated as the same time as in the standard actuation form. In this case, in order to exert the protective pressure P14 on the occupant 70 at the protection time T140, the protection time T140 must be reached at a time at which the pressure in the predetermined space 62 is further reduced after a longer period of time has elapsed since the actuation of the gas generator 63 of the safety belt device 50. For this purpose, in comparison with the situation described in the first part (A) of Fig. 10, it is necessary to set the actuation time of the gas generator 63 by ΔTB earlier and to set the actuation time to T120' (see second part (B) of Fig. 10). ΔTB can be calculated in accordance with the protection pressure P14 based on the pressure transition data stored in the storage unit 107. With respect to the actuation time T120 of the standard actuation form, with the thus calculated ΔTB, the actuation time T120' of the gas generator 63 of the seat belt device 50 is determined. As shown in Fig. 10, this actuation time T120' is a time earlier than the collision time T30 predicted by the prediction unit 106 and a time earlier than the actual actuation time T20' of the gas generator 122 of the airbag device 10.

[0057] Then, when the actuation timing T120' is determined in S106 together with the actuation timing T20' for the airbag device 10, in S107, first, an ignition signal is delivered to the igniter of the gas generator 63 in the seatbelt device 50 at the actuation timing T120' to achieve the actuation of the gas generator 63, and then an ignition signal is delivered to the igniter 121 at the actuation timing T20' to achieve the actuation of the gas generator 122. Thus, when the vehicle 1 collides with an obstacle, appropriate occupant protection can be achieved by activating both the gas generator 63 and the gas generator 122 at an appropriate time before the collision.

[0058] It should be noted that in the first and second examples described above, the protection of the occupant 70 sitting on the driver's side seat 40 was described, but the present embodiment can also be applied to the protection of the occupant 70 sitting on the passenger's side seat, for example. In this case, the state detection unit 102 detects, as information related to the state of the occupant 70 in the vehicle 1, information related to the weight of the occupant 70 and the distance between the occupant 70 and the instrument panel or window glass. The former refers to the inertial force generated when the vehicle 1 collides with an obstacle, and the latter refers to the contact-reaching time between the occupant 70 and the instrument panel or window glass when a collision occurs.Furthermore, the present embodiment can also be applied to a protection system for an occupant on another seat (for example, the rear seat) of the vehicle. Other embodiments

[0059] In the first embodiment, a configuration is disclosed in which only the airbag device 10 is included as a protection device that protects the occupant 70. In the second embodiment, a configuration is disclosed in which the airbag device 10 and the seatbelt device 50 are included as protection devices. Apart from these configurations, a configuration in which only the seatbelt device 50 is included as a protection device or a configuration in which another device is included also falls within the scope of the disclosure of the present specification.Each protection device includes a gas generator for activating the protection device. The protective pressure exerted on the occupant 70 via the protection device using the generated gas, as well as the timing of the protection, can be sufficiently understood by a person skilled in the art based on the above disclosure of the present application. Each embodiment disclosed in the present specification can be combined with any of the features disclosed in the present specification. Reference symbol list 1 vehicle 2 steering wheel 10 Airbag device 40 seats 50 Safety belt device 60 housings 61 pistons 62 Predetermined Space 63 Gas Generator 70 inmates 100 control device 101 Requirement Unit 102 Condition Detection Unit 103 Control unit 104 Calculation unit 105 Actuation control unit 106 Forecast Unit 107 Storage Unit 121 detonators 122 Gas Generator 123 airbags 130 Vehicle Information Request Unit 140 sensors

Claims

[1] An occupant protection system that protects an occupant (70) in a vehicle (1) by a protection device (10, 50) provided in the vehicle (1), the occupant protection system comprising: a gas generator (122, 63) containing an igniter (121) which is ignited by an ignition signal and generates gas upon actuation of the ignition of the igniter (121), the gas generator (122, 63) being configured to actuate the protective device (10, 50) with the gas generated by the gas generator (122, 63); a prediction unit (106) configured to predict a collision between the vehicle (1) and an obstacle present around the vehicle (1); and a control unit (103) configured to control the supply of the ignition signal to the igniter (121) based on a prediction result by the prediction unit (106), the protective device (10, 50) is configured to be actuated by a pressure exerted on a predetermined space (62) with gas generated by the gas generator (122, 63) and directed into the predetermined space (62) in the protective device (10, 50), and the control unit (103) contains, an actuation control unit (105) configured to actuate the gas generator (122, 63) at an actuation time (T20, T20', T120, T120') earlier than a collision time (T30) predicted by the prediction unit (106) based on pressure data relating to a pressure transition of the gas in the predetermined space (62) when the ignition signal is supplied to the igniter (121), characterized by that the control unit (103) includes a calculation unit (104) configured to calculate a protection pressure (P11, P12, P13, P14) exerted on the occupant (70) by the protection device (10, 50) to protect the occupant (70), and to calculate a protection time (T40, T140) at which the protection pressure (P11, P12, P13, P14) is exerted on the occupant (70), and the actuation control unit (105) is configured to actuate the gas generator (122, 63) at an actuation time (T20, T20', T120, T120') in such a way that the protection pressure (P11, P12, P13, P14) is applied at the protection time (T40, T140) by the protection device (10, 50) on the basis of pressure data relating to a pressure transition of the gas in the predetermined space (62) when the ignition signal is supplied to the igniter (121). [2] The occupant protection system according to claim 1, characterized bythat the pressure data includes data relating to a peak time (T3) at which the pressure of the gas in the predetermined space (62) reaches a peak value (P1, P2, P3) after the ignition signal has been supplied to the igniter (121), and to the pressure transition in the predetermined space (62) to and after the peak time (T3). [3] The occupant protection system according to claim 1 or 2, characterized by , that the pressure data are formed as data relating to the pressure transition of the gas in the predetermined space (62) in a manner corresponding to a temperature of the gas generator (122, 63), and the actuation control unit (105) actuates the gas generator (122, 63) at the actuation time (T20, T20', T120, T120') based on the temperature of the gas generator (122, 63). [4] The occupant protection system according to one of claims 1 to 3, characterized bythat the calculation unit (104) calculates the protective pressure based on a weight of the occupant (70). [5] The occupant protection system according to one of claims 1 to 4, characterized by that the protective device is an airbag device (10) which is supplied with gas generated by the gas generator (122) and is inflated into a predetermined inflation shape, the predetermined space is an inflation space in the airbag device (10), the pressure data are related to the pressure transition of the gas in the inflation space, the calculation unit (104) calculates the protection pressure (P11, P12) exerted on the occupant (70) when the airbag device (10) is inflated to the predetermined inflation shape and comes into contact with the occupant (70), and calculates the protection time (T40) at which the airbag device (10) comes into contact with the occupant (70), and the actuation control unit (105) actuates the gas generator (122) at the actuation time (T20, T20') based on the protection time (T40) and the pressure data. [6] The occupant protection system according to claim 5, wherein the actuation control unit (105) further actuates the gas generator (122) at the actuation time (T20, T20') based on a traveling speed of the vehicle (1). [7] The occupant protection system according to one of claims 1 to 4, characterized by that the protection device is a seat belt device (50) which holds the occupant (70) to a seat by pulling a seat belt with the gas generated and supplied by the gas generator (63), the predetermined space (62) is a pressure space in which pressure is exerted with the gas to cause the seat belt to exert a restraining force on the occupant (70), the pressure data are assigned to a pressure transition of the gas in the pressure chamber, the calculation unit (104) calculates the protection pressure (P13, P14) exerted on the occupant (70) when the seat belt restrains the occupant (70) by exerting pressure with the gas to the seat, and calculates the protection timing (T140) for the seat belt to restrain the occupant (70), and the actuation control unit (105) actuates the gas generator (63) at the actuation timing (T120, T120') based on the protection timing (T140) and the pressure data. [8] The occupant protection system according to claim 7, characterized by : a second gas generator (122) including a second igniter (121) ignited by a second ignition signal and configured to generate gas upon actuation of the ignition of the second igniter (121) and to trigger an airbag device (10) via a pressure exerted on an inflation space with gas generated by the second gas generator (122) and supplied into the inflation space in the airbag device (10), wherein the occupant protection system is further configured to protect the occupant (70) with the airbag device (10) inflated in a predetermined inflation shape, the control unit controls the supply of the ignition signal to the igniter and the second ignition signal to the second igniter (121) on the basis of the prediction result from the prediction unit (106), the calculation unit (104) further calculates a second protection pressure (P11, P12) exerted on the occupant (70) when the airbag device (10) is inflated to the predetermined inflation shape and comes into contact with the occupant (70), and a second protection time (T40) at which the airbag device (10) comes into contact with the occupant (70), and the actuation control unit (105) actuates the gas generator (63) at the actuation time (T120, T120') on the basis of the pressure data in such a way that the protective pressure (P13, P14) is exerted on the occupant (70) by the seat belt at the protection time (T140) after the collision time (T30) and before the second protection time (T40), and further actuates the second gas generator (122) at a second actuation time (T20, T20') on the basis of second pressure data relating to a pressure transition of gas in the inflation space when the second ignition signal is supplied to the second igniter (121), in such a way that the airbag device (10) and the occupant come into contact with each other at the second protection time (T40) to initiate the second To exert protective pressure (P11, P12) on the occupant (70). [9] The occupant protection system according to claim 8, characterized bythat the actuation time (T120, T120') and the second actuation time (T20, T20') are both times before the collision time (T30) and the actuation time (T120, T120') is an earlier time than the second actuation time (T20, T20').

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