Patent Application
20240399992
The present disclosure relates to a collision detection device, a collision detection method, and a collision detection program that detects a frontal collision of a vehicle.
An airbag ECU described in JP 2013-95219 A is equipped with a main sensor and a safing sensor, which are acceleration sensors, and a control unit. ECU stands for Electronic Control Unit. The control unit controls airbag deployment/de-deployment based on the detection results of the main sensor and the safing sensor. Specifically, the control unit prepares for airbag deployment when the detection result of the safing sensor exceeds the safe threshold, and when the detection result of the main sensor exceeds the main threshold, the control unit determines that the deployment conditions have been met and sends a deployment instruction to the airbag. The safe threshold is set to a value smaller than the main threshold.
A collision detection device is configured to detect a frontal collision of a vehicle.
According to one aspect of the present disclosure, the collision detection device includes:
According to another aspect of the present disclosure, a collision detection method for detecting a frontal collision of a vehicle includes the following process or procedure:
According to yet another aspect of the present disclosure, a collision detection program is a program to be executed by a collision detection device configured to detect a frontal collision of a vehicle, a process performed by the collision detection device includes:
The above features of the present disclosure will be made clearer by the following detailed description, given referring to the appended drawings. In the accompanying drawings:
After diligent study, the inventor found the following issues. For example, the configuration described in JP 2013-95219 A disposes a safing determination sensor in the airbag ECU, which leads to an increase in equipment cost. On the other hand, a system that uses a so-called front sensor located in the front of the vehicle as a safing determination sensor can also be considered. However, from the standpoint of robustness against sensor failure and disconnection in the event of a frontal collision, it would be preferable to install a safing determination sensor in the airbag ECU, as in the configuration described in JP 2013-95219 A. The present disclosure was made considering the circumstances and other factors exemplified above. In other words, the present disclosure provides, for example, a collision detection device with high robustness against failures in acceleration sensors for safing determination and excellent frontal collision detection performance, while suppressing the equipment cost from increasing.
A collision detection device is configured to detect a frontal collision of a vehicle.
According to one aspect of the present disclosure, the collision detection device includes a left-side sensor, which is an acceleration sensor installed on the left-side of a vehicle body and detects longitudinal acceleration and lateral acceleration, a right-side sensor, which is an acceleration sensor installed on the right-side of the vehicle body and detects the longitudinal acceleration and the lateral acceleration, a first acceleration acquisition unit which acquires the longitudinal acceleration output from the left-side sensor and the right-side sensor, a second acceleration acquisition unit which acquires the longitudinal acceleration output from a main sensor, which is an acceleration sensor different from the left-side sensor and the right-side sensor and which detects the longitudinal acceleration, and a frontal collision determination unit which determines an occurrence of the frontal collision based on a safing determination based on the longitudinal acceleration acquired at the first acceleration acquisition unit and a main determination based on the longitudinal acceleration acquired at the second acceleration acquisition unit.
According to another aspect of the present disclosure, a collision detection method for detecting a frontal collision of a vehicle includes the following process or procedure:
According to yet another aspect of the present disclosure, a collision detection program is a program to be executed by a collision detection device configured to detect a frontal collision of a vehicle, a process performed by the collision detection device includes a process of acquiring longitudinal acceleration output from a left-side sensor, which is an acceleration sensor installed on the left-side of a vehicle body and which detects the longitudinal acceleration and lateral acceleration and a right-side sensor, which is an acceleration sensor installed on the right-side of the vehicle body and detects the longitudinal acceleration and the lateral acceleration, a process of acquiring the longitudinal acceleration output from a main sensor, which is an acceleration sensor different from the left-side sensor and the right-side sensor and which detects the longitudinal acceleration, and a process of determining an occurrence of the frontal collision based on a safing determination based on the longitudinal acceleration acquired and a main determination based on the longitudinal acceleration acquired.
Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. It should be noted that various modifications applicable to an embodiment may hinder the understanding of the embodiment if they are inserted in the middle of a series of explanations about the embodiment. For this reason, modifications are described collectively after the description of the series of embodiments.
First, a schematic configuration of a vehicle 1 to which the embodiment is applied is described with reference to
The vehicle 1 is a so-called automobile, and has a box-shaped vehicle body 2. A front bumper 4 is attached to a front 3 of the vehicle body 2. A rear bumper 6 is attached to a rear 5 of the vehicle body 2. Side panels 8, such as door panels, are attached to sides 7 of the vehicle body 2.
The vehicle 1 is equipped with an in-vehicle system 10. The vehicle 1 equipped with the in-vehicle system 10 is hereinafter referred to as an own vehicle. The in-vehicle system 10 is configured to control an activation of an occupant protection devices 11 installed in the own vehicle. In other words, the in-vehicle system 10, which may also be referred to as an occupant protection system, is configured to protect the occupants of the own vehicle with the occupant protection device 11 in the event of a collision between the own vehicle and an object present outside the own vehicle.
In the present embodiment, the occupant protection device 11 is a protective device for a frontal collision, and is equipped with a driver's airbag and a front passenger's airbag. A term frontal collision refers to a collision in which the impact is applied to the vehicle body 2 from the front. Frontal collisions include a head-on collision, an offset frontal collision, and an oblique frontal collision. The head-on collision is a frontal collision with an overlap ratio of substantially 100%. The overlap ratio is a ratio of the vehicle width dimension of the collision area of the vehicle body 2 with an object to be collied to the vehicle width. The vehicle width is the vehicle width dimension of the vehicle body 2. The head-on collision can also be referred to as a full-wrap frontal collision. The offset frontal collision is a frontal collision with an overlap ratio less than a predetermined value (e.g., 90%). The oblique frontal collision is a frontal collision in which corners of the front 3 of the vehicle body 2 collide with an object to be collied having a longitudinal or shortitudinal direction that is inclined to the vehicle centerline LC in plan view. The oblique frontal collision is also referred to as an oblique collision or an oblique offset collision. A typical example of an oblique frontal collision is a collision with a relative angle of 15° and an overlap ratio of about 35%, which is equivalent to the test conditions for an oblique collision test specified by the NHTSA. NHTSA stands for National Highway Traffic Safety Administration. A frontal collision other than the head-on collision is referred to as an asymmetric collision. In other words, the asymmetric collision is a type of collision in which one of the left or right sides of the front 3 of the vehicle body 2 collides with an object, such as another vehicle.
Front sensors 12 are disposed at the front in the vehicle body 2. The front sensors 12 are attached to unshown body parts that support the front bumper 4 from inside the vehicle body 2. The front sensors 12 are disposed in pairs on the left and right. In other words, a left-front sensor 12L and a right-front sensor 12R are mounted on the vehicle body 2. The left-front sensor 12L and the right-front sensor 12R are symmetrically located across the vehicle centerline LC. The front sensor 12 is a so-called uniaxial sensor, and is configured to detect the longitudinal acceleration (i.e., acceleration in the X-axis direction) acting on the vehicle body 2 when a collision between the own vehicle and an object occurs, and to output the detection results.
Side sensors 13 are disposed on the left and right sides in the vehicle body 2. In other words, the side sensors 13 are located at both ends of the vehicle body 2 in the vehicle width direction and in the middle of the vehicle in the overall length direction (e.g., in the substantially center position). Specifically, a left-side sensor 13L and a right-side sensor 13R are mounted on the vehicle body 2. The left-side sensor 13L and the right-side sensor 13R are symmetrically located across the vehicle centerline LC. The side sensor 13 is a so-called biaxial sensor, and is configured to detect the lateral acceleration (i.e., Y-axis acceleration) and longitudinal acceleration acting on the vehicle body 2 when a collision between the own vehicle and an object occurs, and to output the detection results.
In addition to the occupant protection device 11, the front sensors 12, and the side sensors 13, the in-vehicle system 10 is equipped with a main sensor 14. The main sensor 14 is located on the vehicle centerline LC in plan view, while being accommodated inside the vehicle body 2. The main sensor 14 is a so-called uniaxial sensor, and is configured to detect the longitudinal acceleration acting on the vehicle body 2 when a collision occurs between the own vehicle and an object, and to output the detection results. The main sensor 14, which is a floor sensor, is built into an electronic control unit 15.
The electronic control unit 15 is configured as a so-called airbag ECU. In other words, in the present embodiment, the electronic control unit 15, which functions as a collision detection device, is configured to detect a frontal collision of the own vehicle and activate the occupant protection device 11 for a frontal collision based on the output of the front sensors 12, the side sensors 13, and the main sensor 14. Specifically, the electronic control unit 15 is configured as an in-vehicle microcomputer with a CPU, a ROM, a RAM, a non-volatile rewritable memory, etc., which are not shown. The non-volatile rewritable memory is a storage device that allows information to be rewritten while the power is on, but retains information in a non-rewritable manner while the power is off, and is, for example, a flash ROM. The ROM, the RAM, and the non-volatile rewritable memory are non-transitory tangible storage media. The electronic control unit 15 is configured to control the operation of the in-vehicle system 10 by reading and executing a control program stored in the ROM or the non-volatile rewritable memory.
As shown in
In more detail, as shown in
The safing determination logic 153b includes a left-side determination logic 153d, a right-side determination logic 153e, and an OR gate 153f. The left-side determination logic 153d is configured to turn on the left-side safing determination (i.e., outputs a logic value of 1) when the longitudinal acceleration output from the left-side sensor 13L and acquired by the first acceleration acquisition unit 151 exceeds a predetermined safing determination threshold value. On the other hand, the left-side determination logic 153d is configured to turn off the left-side safing determination (i.e., outputs the logic value 0) when the longitudinal acceleration acquired by the first acceleration acquisition unit 151 does not exceed the safing determination threshold value. The right-side determination logic 153e is configured to turn on the right-side safing determination (i.e., output a logic value of 1) when the longitudinal acceleration output from the right-side sensor 13R and acquired by the first acceleration acquisition unit 151 exceeds the predetermined safing determination threshold value. On the other hand, the right-side determination logic 153e is configured to turn off the left-side safing determination (i.e., outputs the logic value 0) when the longitudinal acceleration acquired by the first acceleration acquisition unit 151 does not exceed the safing determination threshold value. The OR gate 153f is configured to output the logical sum of the output of the left-side determination logic 153d and the output of the right-side determination logic 153e. In other words, the safing determination logic 153b is configured to turn on the safing determination (i.e., outputs the logic value 1) when at least one of the left-side or the right-side safing determination is satisfied. On the other hand, the safing determination logic 153b is configured to turn off the safing determination (i.e., outputs a logic value of 0) when neither the left-side or right-side safing determination is satisfied.
In addition, as shown in
Furthermore, the electronic control unit 15 includes an asymmetric collision determination unit 156 as a functional configuration realized by program execution on the in-vehicle microcomputer. The asymmetric collision determination unit 156 is configured to determine that the frontal collision is an asymmetric collision. The threshold setting unit 154 is configured to perform the sensitization process when the asymmetric collision determination unit 156 determines an asymmetric collision. In the present embodiment, the asymmetric collision determination unit 156 is capable of lateral collision determination, i.e., whether the asymmetric collision is a collision on the right or left-side of the own vehicle. The threshold setting unit 154 then executes the sensitization process when the asymmetric collision determination unit 156 determines an asymmetric collision has occurred and one of the failed sensors is a collision side sensor. The term collision side sensor shall be defined as follows. When the own vehicle is divided into two parts on the left and right by the vehicle centerline LC, one part is a first region and another is a second region. In a case of an asymmetrical collision with an object in the first region, the sensor that is present in the first region among the left-side sensor 13L and the right-side sensor 13R is the collision side sensor. On the other hand, of the left-side sensor 13L and the right-side sensor 13R, a sensor that is not the collision side sensor in the event of an asymmetric collision is referred to as the non-collision side sensor. As shown in
The following is an overview of the operation of the present embodiment, using as a specific example a case where the left front part of the own vehicle collides with another vehicle BV, as shown in
A possible configuration is to install a sensor for the safing determination in the airbag ECU or to use the front sensor 12 as a sensor for the safing determination. Contrasting the two, from the standpoint of robustness against sensor failure and disconnection in the event of a frontal collision, it would be preferable to install a safing determination sensor in the airbag ECU, as in the former configuration. However, in such a configuration, the safing determination sensor is installed in the airbag ECU, which leads to an increase in equipment cost. Therefore, it is required in recent years to have high robustness against disconnection e and sensor failure, while minimizing the increase in equipment cost as much as possible.
Therefore, the inventor discovered that the above-mentioned problems can be solved by using a biaxial sensor as a side sensor 13 and using the forward/r backward acceleration detected by such a biaxial sensor to perform a safing determination of the occurrence of a frontal collision.
It should be noted that if the collision speed, i.e., the relative speed between the own vehicle and the other vehicle BV, is small, the output at the non-collision side sensor may be small and not exceed the normal safing determination threshold value, as shown in
As described above, a phenomenon where the output of the non-collision side sensor becomes small occurs in asymmetric collisions. Therefore, when asymmetric collision is determined by the asymmetric collision determination unit 156 and the collision side sensor has failed, the present embodiment executes the sensitization process for the non-collision side sensor. Asymmetric collisions can be determined, for example, using the front sensors 12, collision detection sensors in the front bumper 4 for activating pedestrian protection devices, and ADAS system sensors (e.g., cameras). This allows more precise activation of the occupant protection device 11 for frontal collision.
To further improve the activation control of the occupant protection device 11 for frontal collision, the sensitization process by lowering the safing determination threshold value should be done to the minimum extent necessary. Therefore, in the present embodiment, sensitization processing is limited to sensor failure and asymmetric collision occurrence. Furthermore, in the present embodiment, when a predetermined time has elapsed after the sensitization process has been executed, the sensitization process is reset. The predetermined time is the time that is normally assumed to elapse between the main determination being made and the safing determination being made in the event of a frontal collision requiring activation of the occupant protection device 11 for the frontal collision. Specifically, the time point at which the predetermined time elapses is the time point corresponding to the ignition timing of the second stage squib. The elapse of the predetermined time can be done, for example, using an unshown timer in the electronic control unit 15.
First, in step 701, the electronic control unit 15 obtains sensor diagnosis information, that is, whether the left-side sensor 13L and the right-side sensor 13R are normal or faulty, and determines whether any sensor is faulty. If no failure occurs in any of the sensors (i.e., step 701=NO), the electronic control unit 15 performs step 702. At step 702, the electronic control unit 15 sets thresholds for the left-side determination logic 153d and the right-side determination logic 153e in the safing determination logic 153b to normal threshold values.
In contrast, if any sensor is faulty (i.e., step 701=YES), the electronic control unit 15 performs step 703. At step 703, the electronic control unit 15 determines whether a collision has occurred based on the output of the main sensor 14. The process of step 703 corresponds to the main determination. If the main determination fails (i.e., step 703=NO), the electronic control unit 15 performs step 704. At step 704, the electronic control unit 15 sets the safing determination threshold value corresponding to the non-faulty sensor in the left-side determination logic 153d and the right-side determination logic 153e in the safing determination logic 153b to the normal threshold value.
If the main determination is satisfied (i.e., step 703=YES), the electronic control unit 15 performs step 705. At step 705, the electronic control unit 15 determines whether the collision that is determined to have occurred due to the main determination being satisfied is an asymmetric collision. If it is not an asymmetric collision (i.e., step 705=NO), the electronic control unit 15 performs step 704. In contrast, if it is an asymmetric collision (i.e., step 705=YES), the electronic control unit 15 performs step 706. At step 706, the electronic control unit 15 determines whether the sensor that was determined to be faulty at step 701 is the collision side sensor. If the failed sensor is a non-collision side sensor (i.e., step 706=NO), the electronic control unit 15 performs step 704. In other words, if the sensor that has not failed is the collision side sensor rather than the non-collision side sensor, a good safing determination can be made even with the normal threshold value. For this reason, the electronic control unit 15 sets the normal threshold of the left-side determination logic 153d and the right-side determination logic 153e in the safing determination logic 153b to the normal threshold corresponding to the collision side sensor that has not failed. In contrast, if the failed sensor is the collision side sensor (i.e., step 706=YES), the electronic control unit 15 performs step 707. At step 707, the electronic control unit 15 performs the sensitization process. In other words, the electronic control unit 15 sets the safing determination threshold value corresponding to the non-collision side sensor that has not failed to a low threshold value in the left-side determination logic 153d and right-side determination logic 153e in the safing determination logic 153b.
After executing the sensitization process in step 707, in step 708, the electronic control unit 15 determines whether a predetermined time has elapsed since the sensitization process was executed. Before the predetermined time elapses (i.e., step 708=NO), the electronic control unit 15 maintains the low threshold setting state with the sensitization process. In contrast, if a predetermined time has elapsed (i.e., step 708=YES), the electronic control unit 15 resets the low threshold setting state by the sensitization process and sets the safing determination threshold value corresponding to the non-collision side sensor that has not failed to the normal threshold value (i.e., step 704).
The present disclosure is not limited to the above embodiments. Therefore, modifications can be made to the above embodiments as appropriate. Typical modifications are described below. In the following description of the modifications, differences from the above embodiment are mainly explained. In addition, in the above embodiments and the following modifications, parts that are identical or equal are given the same reference numerals. Therefore, in the description of the following modifications, the description in the above embodiment may be aided as appropriate for components that have the same reference numerals as those in the above embodiment, unless there is a technical inconsistency or a special additional explanation.
The present disclosure is not limited to the specific device configuration shown in the above embodiments. That is, for example, the applicable vehicle 1 is not limited to four-wheeled vehicles. Specifically, a vehicle 1 may be a three-wheeled vehicle, or a six- or eight-wheeled vehicle such as a cargo truck. The type of the vehicle 1 may be a car equipped only with an internal combustion engine, an electric or fuel cell vehicle without an internal combustion engine, or a so-called hybrid vehicle. The shape and structure of the vehicle body 2 is also not limited to a box shape, i.e., a rectangular shape in plan view.
The present disclosure may also be suitably applied to cases where occupant protection devices 11 other than for frontal collisions or pedestrian protection devices are installed.
As described in the above embodiment, the side sensors 13 can be used to detect a frontal collision and activate the occupant protection device 11 for a frontal collision. Therefore, the front sensors 12 can be omitted. However, from the viewpoint of earlier determination of typical frontal collisions and redundancy, the front sensors 12 and frontal collision determination using them can be provided in parallel with the collision determination using the side sensors 13 in the above embodiment. The same is true for the main sensor 14, which can be used together, although it can be omitted from the point of view of making the present disclosure at a minimum feasible. The safing determination may be made redundant by installing a safing determination sensor in the electronic control unit 15, which is the airbag ECU.
All or part of the electronic control unit 15 may be configured with digital circuits, e.g., ASICs or FPGAs, configured to allow operation as described above. ASIC stands for Application Specific Integrated Circuit. FPGA stands for Field Programmable Gate Array. In other words, the in-vehicle microcomputer portion and the digital circuit portion can coexist in the electronic control unit 15.
Thus, each of the above functional configurations and methods may be realized by a dedicated computer provided by configuring a processor and memory programmed to perform one or more functions embodied by the computer program. Alternatively, each of the above functional configurations and methods may be realized by a dedicated computer provided by configuring the processor with one or more dedicated hardware logic circuits. Alternatively, each of the above functional configurations and methods may be realized by one or more dedicated computers composed of a processor and memory programmed to perform one or more functions, in combination with a processor composed of one or more hardware logic circuits. In addition, the computer program may also be stored in a computer-readable non-transitory tangible storage media as instructions to be executed by a computer. In other words, each of the above functional configurations and methods can also be expressed as a computer program containing procedures for realizing the same, or as a non-transitory tangible storage media storing the program.
There could be cases where asymmetric collisions can be determined but not lateral collision determination, such as a configuration where asymmetric collisions are determined by the output of the main sensor 14. In this case, it is useful to make the non-failing sensor sensitive to the impact, whether on the collision side or not, so that the occupant protection device 11 can be deployed when a relatively large impact input is made against the vehicle body 2. Therefore, the threshold setting unit 154 may perform the sensitization process when the asymmetric collision determination unit 156 determines an asymmetric collision, regardless of whether the sensor that has not failed is the collision side sensor.
It goes without saying that the elements comprising the above embodiments are not necessarily essential, except when specifically stated as essential, or when clearly considered essential in principle, etc. Further, when numerical values of the number, amount, range, etc., of components are mentioned, the disclosure is not limited to those specific values, except when specifically stated as essential or when clearly limited in principle to a specific value. Similarly, when the shape, orientation, positional relationship, etc. of components, etc. are mentioned, the disclosure is not limited to such shape, orientation, positional relationship, etc., except when expressly stated as being particularly essential or when limited to a specific shape, orientation, positional relationship, etc. in principle.
Modifications are also not limited to the above examples. That is, parts of one embodiment and parts of another embodiment may be combined with each other. Further, a plurality of modifications may also be combined with each other. Furthermore, all or part of the above embodiments and all or part of the modifications may also be combined with each other.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2022-023041 | Feb 2022 | JP | national |
The present application is the U.S. bypass application of International Application No. PCT/JP2023/001178 filed on Jan. 17, 2023 which designated the U.S. and claims priority to Japanese Patent Application No. 2022-023041 filed on Feb. 17, 2022, the contents of both of which are incorporated herein by reference.
| Number | Date | Country | |
|---|---|---|---|
| Parent | PCT/JP2023/001178 | Jan 2023 | WO |
| Child | 18806548 | US |
