Collision detection device

Abstract

To provide a collision detection device capable of determining the necessity of inspection of an air bag when receiving an impact to deform a body.SOLUTION: A collision detection device according to the present invention is a collision detection device mounted on a vehicle including an airbag, the collision detection device including a reading unit configured to read physical data that changes according to deformation of a body of the vehicle, a processing unit configured to perform band limitation processing on time-series physical data read by the reading unit, and a setting of a first threshold value serving as a reference for deployment of the airbag and a second threshold value serving as a reference for inspection of the airbag. And a determination unit configured to determine that inspection of the airbag is "necessary".SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a collision detection device. [Background technology]

[0002] Conventionally, one of the systems installed in vehicles is an airbag control system that deploys an airbag by determining the impact of a collision using an acceleration sensor, a collision sensor, etc. The impact of a side collision is detected by a sensor installed in the door and the airbag is deployed.

[0003] Patent Document 1 discloses a collision determination control that determines a collision based on the amount of pressure change per unit time inside a door panel. Patent Document 2 also discloses a technology that compares the measurement value of a first pressure sensor at a different position with the measurement value of another pressure sensor over a predetermined time period, and determines that the first pressure sensor has failed if the measurement value of the first pressure sensor differs from the measurement value of the other pressure sensors by a predetermined value or more. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2012-166619 [Patent Document 2] Special Publication No. 2005-520149 Summary of the Invention [Problem to be solved by the invention]

[0005] However, even if the impact is not strong enough to deploy the airbag, there is a problem in that once the body, such as the door, is plastically deformed, the airbag may not operate normally.

[0006] SUMMARY OF THE INVENTION An object of the present invention is to provide a collision detection device that can determine whether or not an airbag needs to be inspected when a vehicle receives an impact that deforms the body. [Means for solving the problem]

[0007] In order to achieve the above-mentioned object, the collision detection device of the present invention is a collision detection device mounted on a vehicle equipped with an airbag, and is characterized by having: a reading unit that reads physical data that changes in accordance with deformation of the vehicle body; a processing unit that performs band-limiting processing on the time-series physical data read by the reading unit; a judgment unit that sets a first threshold value that serves as a reference for deploying the airbag and a second threshold value that serves as a reference for inspecting the airbag, and that judges that inspection of the airbag is "required" on the condition that the value indicated by the physical data after band-limiting by the processing unit exceeds the second threshold value but does not reach the first threshold value. [Effects of the Invention]

[0008] According to the present invention, it is possible to determine whether or not an inspection of an airbag is required when an impact that deforms the body is received. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a diagram illustrating an example of a configuration of a collision detection device according to an embodiment. [Figure 2] FIG. 2 is a plan view of a vehicle showing an example of the arrangement of sensors in a collision detection device in the vehicle. [Figure 3] FIG. 3 is a diagram showing an example of the arrangement of sensors inside a door. [Figure 4] FIG. 4 is a diagram showing an example of output data indicating a deformation pattern of a door. [Figure 5] FIG. 5 is a diagram showing a modified example using a two-dimensional map. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, a collision detection device according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

[0011] <Embodiment> Depending on the vehicle, airbags are installed in the steering wheel (or near the steering wheel), dashboard, passenger seat, or door to protect the occupants. Airbags that protect occupants from side collisions with the doors are called side airbags or curtain airbags. Some vehicles also have airbags installed in the hood or bumper to protect pedestrians, and the type of airbag installed varies depending on the type of vehicle.

[0012] A system installed in a vehicle deploys airbags when a collision of a predetermined level is detected by collision sensors and acceleration sensors. In this system, an ECU (Electronic Control Unit) detects the collision and impact using collision sensors and acceleration sensors installed in solid parts of the vehicle, and outputs an ignition signal to a gas generator called an inflator. Airbags installed in various parts are inflated by the gas generated by ignition and deployed from their stored state into the vehicle interior.

[0013] The technology related to the collision detection device of the embodiment relates to a sensor that detects physical information that varies based on the deformation of the body, which is made of an elastically deformable material, unlike the rigid parts of the vehicle. For example, the door panel is made of an elastically deformable material, unlike the rigid frame. The door panel uses a pressure sensor that detects the pressure in the door interior (an example of physical information). The pressure sensor outputs pressure data (dP / P) proportional to dV / V, which indicates the relationship between the volume V of the door interior and the amount of change dV relative to the volume V. P is a reference air pressure (e.g., atmospheric pressure), and dP is the amount of pressure change from atmospheric pressure. If the door panel is hit and the impact is extremely small, it is determined to be below a predetermined level, no ignition signal is output to the gas generator, and the airbag remains stored, i.e., not deployed. However, if the door panel is plastically deformed by a force exceeding its elastic deformation during the collision, the airbag system may not operate normally thereafter. If plastic deformation occurs that changes the volume V, the output of the pressure sensor changes, and the airbag will not operate normally. Therefore, in this embodiment, a collision detection device that can uniformly determine whether or not inspection of airbags that remain undeployed is required will be described in detail using a vehicle equipped with side airbags as an example.

[0014] 1 is a diagram showing an example of the configuration of a collision detection device according to an embodiment, which shows an ECU 10, a sensor 20, and a display device 30.

[0015] The ECU 10 includes a microcomputer (microcontroller unit) and determines whether or not an airbag inspection is required.

[0016] A microcomputer includes, for example, a CPU (Central Processing Unit), a non-volatile memory such as a flash memory, and a volatile memory such as a DRAM (Dynamic Random Access Memory).

[0017] The sensor 20 is a sensor that outputs to the ECU 10 physical information that varies based on the deformation of the body.

[0018] The display device 30 is a display device that displays the result of the determination as to whether or not the airbag needs to be inspected. The display device 30 may display the result of the determination as to whether or not the airbag needs to be inspected by lighting an indicator such as an LED, or may display the result of the determination as to whether or not the airbag needs to be inspected as an image using a display such as a liquid crystal display. Furthermore, the display device 30 may be a meter display provided on the front panel of the vehicle. The meter display displays a speedometer, indicator lights, warning lights, etc. as images, and is set to display the result of the determination as to whether or not the inspection needs to be performed using warning lights.

[0019] The ECU 10 has, as means for determining whether or not an airbag inspection is required, a data reading unit 11, a data processing unit 12, and a threshold determination unit 13. The data reading unit 11, the data processing unit 12, and the threshold determination unit 13 may be realized as software modules by storing corresponding programs in a memory and having a microcomputer execute the programs, or may be realized by providing dedicated hardware, or may be designed by combining software and hardware.

[0020] The data reader 11 reads the physical data via the sensor 20 .

[0021] The data processing unit 12 processes the physical data read by the data reading unit 11 in time series, and performs preprocessing for determining whether or not the airbag needs to be inspected.

[0022] In the configuration shown in this embodiment, the data processing unit 12 performs band limiting processing on the time-series physical data using, for example, a digital filter, and outputs the band-limited physical data to a subsequent stage. Note that the digital filter is an example of a filter. Of course, an analog filter may also be used as the filter.

[0023] In this embodiment, as an example, band limitation is performed using a low-pass filter. A low-pass filter with an appropriate cutoff frequency is used to emphasize the physical data when plastic deformation occurs and the physical data when no plastic deformation occurs. In a later stage, the physical data when plastic deformation occurs and the physical data when no plastic deformation occurs are distinguished using a threshold value.

[0024] The difference between the maximum values ​​of the physical data when plastic deformation occurs and when not plastic deformation occurs varies depending on the cutoff frequency of the low-pass filter used. In the explanation of Fig. 4 described later, a case where multiple low-pass filters with different cutoff frequencies are provided and each low-pass filter is selectively used will be shown.

[0025] The threshold determination unit 13 determines whether or not the airbag needs to be inspected based on a first threshold and a second threshold. Here, the first threshold is a condition that serves as a criterion for determining whether or not the airbag needs to be deployed. The second threshold is a condition that serves as a criterion for determining whether or not the airbag needs to be inspected.

[0026] When the result of the airbag inspection necessity determination is "necessary," the threshold determination unit 13 outputs information indicating that the airbag inspection is "necessary" to a predetermined output destination. The output destination is, for example, the display device 30 or a memory.

[0027] Next, an example of installing the sensor 20 on a vehicle door will be described with reference to Figures 2 and 3. The impact object 200 shown in Figures 2 and 3 will be described in detail later when explaining a side impact on a door, and here an example of installing the sensor 20 on a vehicle door will be described.

[0028] Fig. 2 is a plan view of a vehicle showing an example of the arrangement of sensors in a collision detection device in a vehicle. In the vehicle 100 shown in Fig. 2, dotted lines indicate the arrangement of a driver's seat 101, a passenger seat 102, a rear seat 103, a steering wheel 104, and the like in the vehicle cabin. Airbags are provided on the steering wheel 104 or near the steering wheel 104 (such as the dashboard in front of the front seats), in passenger seats (such as the driver's seat 101 or passenger seat 102), and in doors 105 and 106. When an ignition signal is output to a gas generator, the airbags are inflated by the generation of gas and deployed from a stored state into the vehicle cabin.

[0029] The ECU 10 is provided below the meter display. The sensor 20 is provided on each of the door 105 on the driver's seat 101 side and the door 106 on the passenger seat side. The sensor 20 and the ECU 10 are connected by a wiring 50. Note that although the ECU 10 is disposed below the meter display, the location is not limited to this. The location of the ECU 10 may be determined appropriately depending on the system configuration.

[0030] Fig. 3 is a diagram showing an example of the arrangement of the sensor 20 inside the door. For the purpose of explanation, Fig. 3 shows a schematic diagram of the configuration inside the door as seen from the front side of the vehicle 100. The sensor 20 is a pressure sensor that detects pressure, which is one piece of physical information that changes with the deformation of the door. The pressure sensor detects the pressure value in real time in the space 115 between the outer panel (corresponding to the outer surface) 111 and the inner panel (corresponding to the inner surface) 112 of the door 105 (hereinafter referred to as the door internal space).

[0031] In FIG. 3, the sensor 20 has a pressure sensing portion disposed on the door interior space 115 side, and a wiring 50 is connected from the sensor 20 to the ECU 10 through the space between the inner panel 112 and the interior lining 116.

[0032] A service hole 113 in the inner panel 112 is filled with a service cover 114, and the interior side of the inner panel 112 is covered with an interior lining 116. The upper part of the door 105 is a window 117, and the gap is sealed with a rubber member or the like.

[0033] When the door 105 (outer panel 111) is deformed, the volume of the door internal space 115 changes. At this time, the pressure value of the door internal space 115 also changes along with the change in volume.

[0034] The pressure sensor outputs pressure data (dP / P) proportional to dV / V, where dV is the amount of change relative to the volume V of the door internal space 115. Here, P is the reference air pressure, and as an example, is atmospheric pressure. dP is the amount of pressure change from atmospheric pressure. Therefore, the pressure data read in chronological order from the pressure sensor includes the deformation pattern when the door 105 deforms.

[0035] The ECU 10 applies appropriate band restriction to the pressure data read from the pressure sensor in chronological order to emphasize the deformation pattern of the door 105, and compares the pressure data indicating the deformation pattern of the door 105 with a set threshold value to determine whether or not the airbag needs to be deployed.

[0036] Although the door 105 on the driver's seat 101 side has been described as an example here, the door 106 on the passenger's seat 102 side also has a configuration corresponding to the door 105 on the driver's seat 101 side. The description of the door 106 on the passenger's seat 102 side will be omitted as it would be a repetition of the description of the door 105 on the driver's seat 101 side.

[0037] In addition, for ease of understanding, an example in which one pressure sensor is provided on the door is shown here, but the number of pressure sensors provided on the door is not limited to one. Multiple pressure sensors may be provided in predetermined locations throughout each of the doors 105 and 106.

[0038] Next, the relationship between the selection of an appropriate filter and the result of the determination of whether or not the airbag needs to be inspected will be described.

[0039] Data showing the deformation pattern of the door 105 is output with the difference in maximum values ​​between those that cause plastic deformation and those that do not, appropriately emphasized by passing the pressure data read in chronological order from the pressure sensor through an appropriate filter.

[0040] Fig. 4 is a diagram showing an example of output data indicating a deformation pattern of the door 105. Fig. 4(a) is an example of output when a first low-pass filter (corresponding to a low-pass filter with a cutoff frequency of low frequencies) is used, and Fig. 4(b) is an example of output when a second low-pass filter (corresponding to a low-pass filter with a cutoff frequency of high frequencies) having a higher cutoff frequency than the first low-pass filter is used. In Fig. 4, the vertical axis represents pressure (dP / P) and the horizontal axis represents elapsed time.

[0041] Output data S1 shown in FIG. 4(a) is an example of output data output from the filter when the door receives an impact classified as Category 1. Output data S2 is an example of output data output from the filter when the door receives an impact classified as Category 2. Output data S3 is an example of output data output from the filter when the door receives an impact classified as Category 3.

[0042] Note that if the impact to the door does not fall into categories 1 to 3, it has reached the first threshold value Th1 and is a collision that satisfies the conditions for deploying an airbag. Output data for collisions that satisfy the conditions for deploying an airbag is not shown in the figure.

[0043] 4(a), the output data S1, the output data S2, and the output data S3 are shown on the same time axis for the sake of explanation. Depending on the type of impact, output data corresponding to either the output data S1, the output data S2, or the output data S3 is output.

[0044] Category 1 is a side collision (collision with the entire surface of the door 105) caused by another vehicle that occurs at an extremely low speed and does not affect the occupants. Although plastic deformation of the door 105 occurs, the airbag is not deployed because the impact level does not meet the conditions.

[0045] Classifications 2 and 3 are both localized collisions caused by a ball or other impacting object 200 on a portion of the entire surface of the door 105. Classification 2 is a collision at a high speed that causes plastic deformation of the door 105, while Classification 3 is a collision at a low speed that does not cause plastic deformation of the door 105. Note that the impact level does not meet the conditions, so the airbag is not deployed.

[0046] As an example of output from categories 2 and 3, a local collision experiment was conducted using a basketball as the collision object 200 against the door 105. In this experiment, when the basketball collided with the door 105 at a low speed, the door 105 elastically deformed and returned to its original state. On the other hand, when the collision speed was gradually increased, the door 105 exceeded its elastic deformation and began to deform plastically at a certain speed.

[0047] From these results, localized collisions with the door 105 (fast speed) were classified as category 2, and localized collisions with the door 105 (slow speed) were classified as category 3.

[0048] The deformation pattern of the door 105 varies depending on the type of colliding object 200 that collided with it from the side, the impact area (full or localized), the speed of the colliding object 200, etc. The pressure in the door internal space 115 varies based on the deformation pattern, so the frequency distribution varies depending on the type of impact. Furthermore, even when the door 105 is closed tightly, data showing a predetermined frequency distribution (corresponding to category 3) is output. Therefore, as described below, an appropriate filter is used so that the subsequent threshold determination unit 13 can make a threshold determination between impacts that cause plastic deformation and impacts that do not cause plastic deformation.

[0049] The first threshold value Th1 and the second threshold value Th2 shown in (a) of Fig. 4 are set in the subsequent threshold value determination unit 13. The first threshold value Th1 is a condition that serves as a criterion for determining whether the airbag should be deployed, and the second threshold value Th2 is a condition that serves as a criterion for determining whether the airbag needs to be inspected.

[0050] As shown in (a) of Figure 4, when the first low-pass filter is used, in the case of an impact corresponding to category 1, output data S1 is output and exceeds the second threshold value Th2. In addition, in the case of an impact corresponding to category 3, the output is output data S3 and does not reach the second threshold value Th2.

[0051] When the first low-pass filter is used, the second threshold value Th2 is set between the maximum values ​​of Class 1 and Class 3, so the judgment results for Class 1 and Class 3 are clearly separated by the second threshold value Th2. Therefore, when the impact corresponds to Class 1, it is determined that the airbag needs to be inspected, and when the impact corresponds to Class 3, it is determined that the airbag needs to be inspected.

[0052] On the other hand, when an impact of Category 2 occurs, it becomes difficult to distinguish Category 2 from Category 3 by using the second threshold value Th2 from the output of the first low-pass filter and obtain a different determination result. In other words, when the first low-pass filter is used for an impact corresponding to Category 2, the determination result will be the same as that of Category 3, and in the case of an impact that causes plastic deformation, the airbag inspection requirement will be determined to be "no" rather than "required."

[0053] When the second low-pass filter is selected, the output from the filter is in the relationship shown in Fig. 4(b). The first threshold value Th1 and the second threshold value Th2 shown in Fig. 4(b) are threshold values ​​corresponding to the first threshold value Th1 and the second threshold value Th2 shown in Fig. 4(a), respectively.

[0054] The second low-pass filter has a high cutoff frequency, and therefore outputs data in which the magnitude relationship between the output data S1 and the output data S2 shown in FIG. 4(a) is reversed.

[0055] As shown in the output results in FIG. 4(b), when the second low-pass filter is used, in the case of an impact corresponding to category 2, output data S2 is output and exceeds the second threshold value Th2, as shown in FIG. 4(b). On the other hand, in the case of an impact corresponding to category 3, the second threshold value Th2 is not reached, as shown in output data S3. In this way, by using the second low-pass filter, it is possible to correctly determine whether or not an airbag inspection is required for an impact corresponding to category 2.

[0056] The threshold determination unit 13 determines whether or not the airbag needs to be inspected if the output data from the low-pass filter exceeds the second threshold Th2 but does not reach the first threshold Th1, and determines whether or not the airbag needs to be inspected if the output data does not exceed the second threshold Th1. The output examples of the output data S1, S2, and S3 are just examples, and each may show a maximum value not in the primary wave but in a secondary wave or tertiary wave with a slight delay. Therefore, the threshold determination is made based on the output values ​​up to a certain time after the impact.

[0057] If the output data reaches the first threshold value, the airbag changes from the stored state to the deployed state, so the process may end without outputting the result of the determination as to whether or not the airbag needs to be inspected.

[0058] As described above, when the second low-pass filter is used, even if an impact corresponding to Category 1 occurs, the output data S1 does not reach the second threshold value Th2, but the data S1 in the result output from the first low-pass filter exceeds the second threshold value Th2. Therefore, when the first low-pass filter and the second low-pass filter are used together, if the output of either low-pass filter indicates that an airbag inspection is required, then a final determination that an airbag inspection is required may be made.

[0059] Here, the operation of two filters has been described using classifications 1 to 3 as an example. The number of filters is not limited to two filters having different band limiting ranges. The number of filters may be set appropriately depending on the number of classifications to be determined as those in which plastic deformation occurs.

[0060] In this way, multiple filters with different band-limiting ranges are provided in the data processing unit 12, and band-limiting processing is performed in parallel, and threshold determination is performed from the output results of each filter in the threshold determination unit 13. The threshold determination unit 13 may also input output data from each filter provided in the data processing unit 12 in parallel and perform threshold determination in parallel. By performing band-limiting processing in parallel, it becomes possible to determine that an impact of a classification that could not be determined as causing plastic deformation from the output of one filter will cause plastic deformation from the output of another filter.

[0061] Furthermore, ECU 10 may be applied as an ECU (referred to as the first ECU) that makes a comprehensive judgment based on the outputs of the acceleration sensor and collision sensor mounted on the vehicle and deploys an airbag, or may be provided as an ECU (referred to as the second ECU) that makes a judgment on whether to deploy or not deploy an airbag for each body part such as a door of the vehicle and outputs the judgment result to the first ECU, or may be provided as an ECU (referred to as the third ECU) that is separate from these ECUs and is dedicated to determining whether or not an airbag inspection is required.

[0062] For example, the first ECU is an ECU that comprehensively determines whether an airbag should be deployed or not and outputs an ignition electrical signal to a gas generator of the airbag. The sensor 20 may also function as a collision sensor. The second ECU is an ECU that determines whether an airbag should be deployed or not using the sensor 20 provided in the door of the vehicle and outputs the determination result to the first ECU. The sensor 20 may also function as a collision sensor for a side collision. The third ECU is a dedicated ECU that determines whether an airbag needs to be inspected using the sensor 20 provided in the door of the vehicle. The sensor 20 may also function as a collision sensor for a side collision, or may be provided separately from the collision sensor for a side collision.

[0063] Furthermore, the ECU 10 may be configured to be communicatively connected to other ECUs using a CAN (Controller Area Network) communication protocol or the like.

[0064] So far, the explanation has focused on doors. The body is made up of doors, bumpers, exterior panels, etc., in contrast to the frame, which is the rigid skeletal part of the vehicle. Since the body is made of an elastically deformable material, it is of course possible to apply the present invention to parts other than doors that are configured to deploy airbags. The same applies to the various modified examples described below. For example, bumpers equipped with airbags to protect pedestrians and the like are also included in the scope of application.

[0065] (Effects of the embodiment) As described above, the airbag system installed in a vehicle outputs an ignition signal to the gas generator when the impact of a collision detected by a sensor satisfies the conditions for airbag deployment, which causes the airbag to inflate and deploy from its stored state due to the generation of gas.

[0066] On the other hand, if the impact detected by the sensor does not meet the conditions for airbag deployment, the airbag will remain stored and not deployed. If the impact is caused by a strong collision and the body, such as the door, is plastically deformed at the time, the airbag system may not operate normally afterwards. For example, the sensor of a plastically deformed door may not output the value required for normal operation.

[0067] Even if the body has been deformed by an impact to the extent that it has undergone plastic deformation, because the standards for judgment vary from person to person, some people may not notice it and continue to use the vehicle as if it were in normal operation. Also, in the case of visible dents in the body, the body may be returned to its original state without being inspected.

[0068] However, the collision detection device of this embodiment can determine whether an airbag that remains undeployed needs to be inspected based on the first threshold value and the second threshold value each time an impact occurs. Furthermore, in the collision detection device of this embodiment, the result of the determination of whether an airbag needs to be inspected is output to an output destination such as the display device 30 or a memory, making it possible to confirm the result from recorded information in the display device 30 or a memory. Therefore, it is possible to uniformly confirm whether an airbag needs to be inspected from an output destination such as the display device 30 or a memory without relying on human judgment. Similarly, even if a ball or the like hits the vehicle body when the driver is absent and plastic deformation of the body goes unnoticed, the result can be confirmed from an output destination such as the display device 30 or a memory.

[0069] In the case of the display device 30, for example, the driver can visually check whether the airbag needs to be inspected from the lighting status of the indicator, so after confirming that the indicator is lit, the driver can immediately take the vehicle to a service center.

[0070] The memory to which the information is output is a non-volatile memory within the ECU 10 or an external memory, and when it is determined that an airbag inspection is required, the information that an airbag inspection is required is recorded by writing a code for the airbag inspection (such as a fault code) or by changing the airbag inspection flag from off to on. Whether an airbag inspection is required can be confirmed by reading the code or inspection flag from the memory during vehicle maintenance.

[0071] Because the acceleration sensor is installed in a sturdy part of the vehicle, it is unlikely to malfunction in an impact that does not deploy the airbag. However, collision sensors in the body may not function properly, so repairs and replacements can be made during maintenance based on the results of the airbag inspection requirement determination.

[0072] (First Modification of the Embodiment) When the output data reaches the first threshold, the airbag is deployed at that point, regardless of the result of the airbag inspection necessity determination. Therefore, the determination of whether the airbag needs to be inspected is not limited to being performed in real time based on the physical data, but may be performed later. For this reason, it is also possible to generate a two-dimensional map and perform threshold determination.

[0073] Fig. 5 is a diagram showing a modified example using a two-dimensional map. The two-dimensional map shown in Fig. 5 is created by plotting the pressure data value d / dP output from the second low-pass filter (a low-pass filter with a cutoff frequency of a high frequency) on the vertical axis and the pressure data value d / dP output from the first low-pass filter (a low-pass filter with a cutoff frequency of a low frequency) on the horizontal axis. The output data output from the first low-pass filter and the second low-pass filter based on the impact is plotted on the two-dimensional map.

[0074] In Figure 5, the two-dimensional map is divided into three regions. The first region is the "airbag deployment region." The second region is the "door deformation detection region." The third region is the "nothing region." Multiple output data D1, D2-1, D2-2, and D3 are shown superimposed on the two-dimensional map for the purpose of explanation.

[0075] The "airbag deployment area" is an area where the impact level is equal to or greater than the level at which the airbag is deployed. The "door deformation detection area" is an area where the airbag is not deployed, but where the plastic deformation of the door means that the airbag needs to be inspected. The "no action area" is an area where the impact level is equal to or greater than the level at which the airbag is not deployed, and where the airbag does not need to be inspected.

[0076] Depending on the type of impact, one of the output data D1, D2-1, D2-2, and D3 is used for the judgment. The output data D1 is output data corresponding to category 1. The output data D2 (D2-1, D2-2) is output data corresponding to category 2. The output data D3 is output data corresponding to category 3.

[0077] The output data D1 is, for example, output data resulting from a high-speed vehicle collision. The output data D2-1 is, for example, output data resulting from a very low-speed vehicle collision. The output data D2-2 is, for example, output data resulting from a ball collision (high-speed collision). The output data D3 is, for example, output data resulting from a ball collision (low-speed collision) or a door being slammed shut.

[0078] When a two-dimensional map is used, if output data D2 is detected that exceeds the "do nothing area" but does not reach the "airbag deployment area", the necessity of airbag inspection is determined to be "necessary." In this case, the value on the boundary between the "door deformation detection area" and the "airbag deployment area" is the first threshold value, and the value on the boundary between the "do nothing area" and the "door deformation detection area" is the second threshold value.

[0079] (Modification 2 of the embodiment) The collision detection device of this embodiment may determine whether or not the airbag needs to be inspected based not only on the output information of the sensor 20 but also on a comprehensive determination of the output information of other sensors.

[0080] For example, by combining this with side sensors (such as acceleration sensors mounted on the B-pillar) that are used to determine the deployment of other airbags, the accuracy of detecting collisions that cause plastic deformation of the body can be improved.

[0081] Furthermore, by also using images obtained from a side camera that is not used for airbag deployment in a combined manner, the accuracy of detecting collisions that cause plastic deformation of the body is improved. The side camera captures an image of the colliding object 200 immediately before it hits the door from the side, and the type of colliding object 200 can be image-recognized from the side camera image, and the speed of the colliding object 200 can be calculated from consecutive images. In this case, the accuracy of detecting collisions that cause plastic deformation of the body is further improved by selecting an appropriate filter from filters provided for each type of colliding object 200 based on the image recognition results, the calculated speed, etc.

[0082] (Third Modification of the Embodiment) Furthermore, when the ECU 10 determines that an inspection is required in the airbag inspection necessity determination, the ECU 10 may not only notify the driver of the inspection but also prohibit the deployment of the airbag itself. By prohibiting the deployment of the airbag itself, it is possible to prevent the deployment of the airbag due to a malfunction in advance.

[0083] (Fourth Modification of the Embodiment) Furthermore, in this embodiment, the configuration of the collision detection device that determines whether or not an airbag needs to be inspected has been described, but the configuration of the collision detection device may also be applied to passenger restraint devices other than airbags.

[0084] In addition, various design modifications can be made to the above-described configuration within the scope of the claims. [Explanation of symbols]

[0085] 10 ECU 11 Data reading unit 12 Data processing section 13 Threshold judgment unit 20 Sensor (pressure sensor) 30 Display device 100 vehicles Doors 105 and 106 111 Outer panel (equivalent to outer surface) 112 Inner panel (corresponding to the inner surface) 115 Door interior space 200 Collision object

Claims

1. A collision detection device mounted on a vehicle equipped with an airbag, a reading unit that reads physical data that changes in response to deformation of the vehicle body; a processing unit that performs band limiting processing on the time-series physical data read by the reading unit; a determination unit that has a first threshold value that is a reference for deploying the airbag and a second threshold value that is a reference for inspecting the airbag, and determines that inspection of the airbag is "necessary" on the condition that the value indicated by the physical data after being band-limited by the processing unit exceeds the second threshold value but does not reach the first threshold value; A collision detection device comprising:

2. the processing unit performs the band limiting process using a low-pass filter having a cutoff frequency of a high frequency or a low-pass filter having a cutoff frequency of a low frequency.

2. The collision detection device according to claim 1.

Images