JP7740187B2 - Vehicle collision detection device - Google Patents

Description

The present invention relates to a vehicle collision detection device.

Patent Document 1 discloses that the magnitude of vertical acceleration and the shape of the waveform can be used to distinguish between low-speed collisions and rough road conditions, and to distinguish between types of collisions such as pole collisions and underride collisions.

Specifically, in Patent Document 1, when a frontal collision occurs, if the acceleration detected by the front and rear G sensors is moderate and not large enough to exceed the threshold value for a low-speed head-on collision, and if the acceleration detected by the vertical G sensors rises to the positive side and exceeds a first threshold value, then turns negative and exceeds a second threshold value, it is determined that an impact has occurred due to driving on an extremely rough road. If the acceleration detected by the vertical G sensors rises to the negative side without rising to the positive side and exceeds the second threshold value, it is determined that an impact has occurred due to a frontal pole collision or an underride collision.

Japanese Patent Application Laid-Open No. 2020-138636

A system is being considered that can determine whether or not there is damage to a vehicle in advance from vehicle data, in order to prevent damage from being overlooked when a used car is appraised or when a customer returns a rental car.

However, when assessing damage from vehicle data such as vehicle behavior, there is a risk that damage to the vehicle's underside may not be detected if cases in which the vehicle's underside collides with a step due to driving over a step are simply judged as having been caused by the vehicle simply going over a step.

The present invention was developed in consideration of the above, and aims to provide a vehicle collision detection device that can detect the possibility of damage to the underside of a vehicle due to a collision.

The vehicle collision determination device of the first aspect comprises an acquisition unit that acquires the detection results of a detection unit that detects vertical acceleration generated in the vehicle and a vehicle speed detection unit that detects the vehicle speed, and a determination unit that determines that a collision has occurred with the underside of the vehicle if, from the acquisition results of the acquisition unit, vertical acceleration equal to or greater than a predetermined first threshold is detected within a predicted time corresponding to between the front wheels and rear wheels calculated based on the vehicle speed at the time the vehicle goes over a step, the determination unit determines that the step has been gone over if it detects the vertical acceleration equal to or greater than a predetermined second threshold, and the predicted time is a first time calculated by dividing the wheelbase of the vehicle by the vehicle speed at the time it is determined that the step has been gone over .

According to the first aspect, the acquisition unit acquires the detection results of the vertical acceleration and vehicle speed occurring in the vehicle.

The determination unit then determines, from the results acquired by the acquisition unit, that a collision has occurred with the underside of the vehicle if it detects vertical acceleration equal to or greater than a predetermined first threshold within a predicted time period corresponding to the distance between the front and rear wheels, calculated based on the vehicle speed at the time the vehicle went over the step. This makes it possible to determine whether the underside of the vehicle collided with the step when going over the step, thereby detecting the possibility of damage to the underside of the vehicle due to the collision.

In addition , the judgment unit judges that the step has been crossed when it detects the vertical acceleration equal to or greater than a predetermined second threshold, and the predicted time is a first time calculated by dividing the wheelbase of the vehicle by the vehicle speed at the time it is judged that the step has been crossed.

This makes it possible to detect whether the vehicle is going over a step based on the detection result of the vertical acceleration, and to determine whether a collision has occurred with the underside of the vehicle.

The vehicle collision judgment device of the second aspect comprises an acquisition unit that acquires the detection results of a detection unit that detects vertical acceleration generated in the vehicle and a vehicle speed detection unit that detects the vehicle speed, and a judgment unit that judges that a collision has occurred with the underside of the vehicle if vertical acceleration equal to or greater than a predetermined first threshold is detected from the acquisition results of the acquisition unit within a predicted time corresponding to between the front wheels and rear wheels calculated based on the vehicle speed at the time the vehicle goes over a step, wherein the acquisition unit further acquires the detection results of a step detection unit that is mounted on the vehicle and detects the step in front of the vehicle, and the predicted time is the time from when vertical acceleration occurs as the front wheels of the vehicle go over the step to when vertical acceleration occurs as the rear wheels go over the step, predicted from the distance to the step detected by the step detection unit and the vehicle speed at the time the step is detected .

According to the second aspect, by predicting the predicted time from when the front wheels climb over the step until when the rear wheels climb over the step, it is possible to determine whether the front and rear wheels will collide with the underside of the vehicle.

The vehicle collision determination device of the third aspect is the vehicle collision determination device of the first or second aspect, further comprising a transmission unit that transmits the collision history of the bottom of the vehicle to a server outside the vehicle when the determination unit determines that a collision has occurred on the bottom of the vehicle.

According to the third aspect, damage can be confirmed from the collision history transmitted to the server when a used car is appraised or when a rental car is returned.

As described above, the present invention provides a vehicle collision detection device that can detect the possibility of damage to the underside of a vehicle.

1 is a block diagram showing a schematic configuration of a vehicle including a vehicle collision determination device according to a first embodiment; FIG. 2 is a block diagram showing the configuration of a vehicle collision determination device and a part of a data server. FIG. 10 is a diagram showing an example of vertical acceleration waveforms when the front and rear wheels go over a step. FIG. 10 is a diagram showing an example of a vertical acceleration waveform when the underside of a vehicle is damaged. 4 is a flowchart showing an example of a flow of processing performed by the vehicle collision determination device according to the present embodiment. FIG. 10 is a block diagram showing a schematic configuration of a vehicle including a vehicle collision determination device according to a second embodiment. 10A and 10B are diagrams for explaining damage determination of the underside of a vehicle in the second embodiment; 4 is a flowchart showing an example of a flow of processing performed by the vehicle collision determination device according to the present embodiment. 10A and 10B are diagrams for explaining the difference between the first embodiment and the second embodiment in determining a collision with the underside of the vehicle.

An example of an embodiment of the present invention will now be described in detail with reference to the drawings. In this embodiment, a vehicle collision detection device that detects damage to the underside of a vehicle will be described.

(First embodiment)
FIG. 1 is a block diagram showing a schematic configuration of a vehicle including a vehicle collision determination device according to the first embodiment.

As shown in FIG. 1, a vehicle 10 is equipped with a vehicle collision determination device 12 according to this embodiment, a vertical G sensor 14 as an example of a detection unit, a vehicle speed sensor 16 as an example of a vehicle speed detection unit, a vehicle information recording unit 18, and an on-board communication device 20 as an example of a transmission unit.

The vehicle collision determination device 12 is connected to a vertical G sensor 14, a vehicle speed sensor 16, a vehicle information recording unit 18, and an on-board communication device 20.

The vertical G sensor 14 detects the vertical acceleration occurring in the vehicle 10 and outputs the detection result to the vehicle collision determination device 12.

The vehicle speed sensor 16 detects the speed of the vehicle 10 (hereinafter sometimes referred to as vehicle speed) and outputs the detection result to the vehicle collision determination device 12.

The vehicle information recording unit 18 records information such as the wheelbase of the vehicle 10, which the vehicle collision determination device 12 reads and uses when determining whether a collision has occurred with the underside of the vehicle.

The on-board communication equipment 20 connects the vehicle 10 to a data server 22 (an example of an external server) via wireless communication, and transmits the determination results of the vehicle collision determination device 12 to the data server 22.

Next, the configuration of the vehicle collision determination device 12 and the data server 22 will be described. Figure 2 is a block diagram showing a portion of the configuration of the vehicle collision determination device 12 and the data server 22. Note that the vehicle collision determination device 12 and the data server 22 have the general computer configuration shown in Figure 2, so the following description will focus on the configuration of the vehicle collision determination device 12 as a representative.

As shown in FIG. 2, the vehicle collision determination device 12 is composed of a general microcomputer including a CPU (Central Processing Unit) 12A, ROM (Read Only Memory) 12B, RAM (Random Access Memory) 12C, interface (I/F) 12D, and bus 12E. The CPU 12A functions as an example of an acquisition unit and a determination unit.

With the above configuration, the vehicle collision determination device 12 uses the CPU 12A to access ROM 12B and RAM 12C, and to control the sending and receiving of communication data via the communication I/F unit 12D. For example, the CPU 12A loads into RAM 12C and executes a vehicle collision determination program pre-stored in ROM 12B or storage (not shown), thereby determining a collision with the underside of the vehicle.

However, if an accident history is overlooked and an accurate appraisal is not made when appraising a used car, it could result in an inappropriate transaction for the user or a loss of credibility for the dealer. Therefore, a system is being considered that would prevent accident history from being overlooked when appraising a used car by detecting accidents using sensors mounted on the vehicle 10, such as an acceleration sensor, and recording the accident history for each vehicle 10 on a data server 22. Systems are also being considered that check for damage to rental cars and other vehicles 10 using data acquired in advance when the vehicle 10 is returned, and there is a growing need to utilize accident and damage data for the vehicle 10.

Furthermore, if the underside of the vehicle 10 is damaged when going over a step or speed bump, it is difficult to confirm the location of the damage, and there are concerns about the impact on parts related to driving, so it is important to detect a collision with the underside of the vehicle. However, because vertical acceleration is detected when the wheels go over a step, it is difficult to detect a collision with the underside of the vehicle based solely on the magnitude of vertical acceleration. A speed bump is a structure that raises part of the road to encourage the driver to slow down.

The vehicle collision determination device 12 according to this embodiment therefore determines a collision with the underside of the vehicle by utilizing the detection results of the vehicle's vertical acceleration to distinguish between a collision and rough road driving. However, in cases where the vehicle 10 damages the underside of the vehicle when going over a step, it is difficult to detect a collision with the underside of the vehicle using vertical acceleration alone. Therefore, the vehicle collision determination device 12 according to this embodiment detects damage to the underside of the vehicle from the relationship between the time when vertical acceleration occurs and the wheelbase.

Specifically, the CPU 12A loads into RAM 12C and executes the vehicle collision detection program stored in ROM 12B, thereby performing processing to determine whether a collision has occurred with the underside of the vehicle based on the detection results of the vertical G sensor 14 and the vehicle speed sensor 16.

The process for determining whether a collision with the underside of the vehicle has occurred determines whether or not a collision with the underside of the vehicle has occurred based on the timing of vertical acceleration. Specifically, as shown in FIG. 3, the time it takes for the rear wheels to cross the step is predicted based on the vertical acceleration generated when the front wheels cross the step, the vehicle speed at that time, and the length of the wheelbase of the vehicle 10. If vertical acceleration equal to or greater than a predetermined first threshold is not detected earlier than the predicted time, it is determined that there has been no collision with the underside of the vehicle. On the other hand, as shown in FIG. 4, if vertical acceleration equal to or greater than a predetermined threshold is detected earlier than the predicted time, it is determined that there has been a collision with the underside of the vehicle. If a collision with the underside of the vehicle is determined to have occurred, the determination result is transmitted to and recorded on the data server 22, which can be used for used car appraisals and damage detection for rental cars. In this embodiment, a step is determined to have occurred if vertical acceleration equal to or greater than a predetermined second threshold is detected. However, the first and second thresholds may be the same or different.

Next, we will explain the specific processing performed by the vehicle collision determination device 12 according to this embodiment, which is configured as described above. Figure 5 is a flowchart showing an example of the flow of processing performed by the vehicle collision determination device 12 according to this embodiment. Note that the processing in Figure 5 begins when, for example, an ignition switch (not shown) of the vehicle 10 is operated to turn on the power to the vehicle 10.

In step 100, the CPU 12A detects the vertical acceleration by obtaining the vertical acceleration detection result from the vertical G sensor 14, and proceeds to step 102. For example, the vertical acceleration when the front wheel goes over a step is detected. Note that the vertical acceleration detected in step 100 is not limited to the acceleration of the front wheel.

In step 102, the CPU 12A determines whether the vertical acceleration is greater than or equal to a predetermined threshold. If the determination is affirmative, the process proceeds to step 104; if the determination is negative, the process proceeds to step 112.

In step 104, the CPU 12A predicts the time T at which acceleration will occur at the rear wheels from the wheelbase and vehicle speed, and proceeds to step 106. That is, assuming that the vertical acceleration detected in step 100 is the front wheels, the detection result of the vehicle speed sensor 16 at the time the front wheels go over the step is obtained, and the wheelbase is divided by the obtained vehicle speed to calculate the time as the predicted time at which acceleration will occur at the rear wheels.

In step 106, the CPU 12A detects the vertical acceleration by obtaining the vertical acceleration detection result of the vertical G sensor 14, and proceeds to step 108. For example, the vertical acceleration of the rear wheels is detected. Note that the vertical acceleration detected in step 106 is not limited to the acceleration of the rear wheels.

In step 108, the CPU 12A determines whether acceleration equal to or greater than a predetermined threshold occurred within the predicted time T. If the determination is affirmative, the process proceeds to step 110; if the determination is negative, the process proceeds to step 112.

In step 110, the CPU 12A determines that a collision has occurred with the underside of the vehicle, transmits and records this information to the data server 22, and proceeds to step 112. The vertical acceleration at the time of the collision determination may be transmitted to the data server 22 along with the determination result as a collision history, allowing the degree of damage caused by the collision to be estimated from the vertical acceleration at the time of the collision.

In step 112, the CPU 12A determines whether to end the process. This determination is made, for example, by determining whether an ignition switch (not shown) has been turned off. If the determination is negative, the process returns to step 100 and the above-described process is repeated; if the determination is positive, the process ends.

In this way, in this embodiment, the time it will take for the rear wheels to go over the step is predicted from the vehicle speed and wheelbase length based on the acceleration when the front wheels go over the step, and if vertical acceleration equal to or greater than a predetermined threshold is detected within the predicted time, a collision with the underside of the vehicle is determined. This makes it possible to determine whether the underside of the vehicle has collided with the step when the vehicle 10 goes over the step, making it possible to detect possible damage to the underside of the vehicle.

Second Embodiment
Next, a vehicle collision determination device according to a second embodiment will be described. Fig. 6 is a block diagram showing a schematic configuration of a vehicle 10 including the vehicle collision determination device according to this embodiment. Note that the same components as those in Fig. 1 are assigned the same reference numerals, and detailed descriptions thereof will be omitted.

In the above embodiment, the vertical acceleration of the front wheels is detected solely from the detection results of the vertical G sensor 14, but since there is no guarantee that the vertical acceleration detected in step 100 of Figure 5 is the vertical acceleration of the front wheels, there is a possibility that a collision with the underside of the vehicle may be erroneously determined.

In this embodiment, as shown in Figure 6, a step detection unit 17 is provided to detect steps.

The step detection unit 17 may, for example, use various radars to detect steps and other targets ahead of the vehicle 10, as shown in the upper part of Figure 7, or may detect steps and other targets from images captured by a camera.

In this embodiment, the step detection unit 17 detects a step and determines whether or not a collision has occurred with the underside of the vehicle. Specifically, the time at which vertical acceleration occurs as the front and rear wheels climb over the step is predicted from the distance to the step detected by the step detection unit 17 and the vehicle speed at that time. Then, as shown in the lower part of Figure 7, if vertical acceleration equal to or greater than a predetermined threshold is detected between the time at which the front wheels climb over the step and the time at which the rear wheels climb over the step, it is determined that the underside of the vehicle has been damaged.

Next, specific processing performed by the vehicle collision determination device 12 according to this embodiment will be described. Figure 8 is a flowchart showing an example of the flow of processing performed by the vehicle collision determination device 12 according to this embodiment. Note that the processing in Figure 8 begins when, for example, an ignition switch (not shown) of the vehicle 10 is operated to turn on the power to the vehicle 10. Furthermore, the same processes as those in Figure 5 will be described using the same reference numerals.

In step 101, the CPU 12A obtains the step detection result from the step detection unit 17 and proceeds to step 103.

In step 103, the CPU 12A determines whether a step has been detected. If the determination is affirmative, the process proceeds to step 105; if the determination is negative, the process proceeds to step 112.

In step 105, the CPU 12A calculates the damage possibility time T' from the step detection time and vehicle speed, and then proceeds to step 107. That is, the CPU 12A derives the distance to the detected step from the detection result of the step detection unit 17, and obtains the detection result of the vehicle speed sensor 16 at the time the step was detected. Then, from the distance to the step detected by the step detection unit 17 and the vehicle speed at the time the step was detected, the CPU 12A calculates the damage possibility time T' as the time from the time when vertical acceleration occurs as the front wheels climb over the step to the time when vertical acceleration occurs as the rear wheels climb over the step.

In step 107, the vertical acceleration is detected by obtaining the vertical acceleration detection results of the vertical G sensor 14, and the process proceeds to step 109.

In step 109, the CPU 12A determines whether acceleration equal to or greater than the threshold value has occurred within time T'. This determination is made by determining whether vertical acceleration equal to or greater than the predetermined threshold value has been detected within the damage potential time T' between the predicted times at which acceleration occurs for the front and rear wheels, as shown in the lower part of Figure 7. If the determination is affirmative, the process proceeds to step 110; if the determination is negative, the process proceeds to step 112.

In step 110, the CPU 12A determines that a collision has occurred with the underside of the vehicle, transmits and records this information to the data server 22, and proceeds to step 112. The vertical acceleration at the time of the collision determination may be transmitted to the data server 22 along with the determination result as a collision history, allowing the degree of damage caused by the collision to be estimated from the vertical acceleration at the time of the collision.

In step 112, the CPU 12A determines whether to end the process. This determination is made, for example, by determining whether an ignition switch (not shown) has been turned off. If the determination is negative, the process returns to step 100 and the above-described process is repeated; if the determination is positive, the process ends.

In the first embodiment, if vertical acceleration above the threshold is not generated when the front and rear wheels go over a step, it may not be possible to determine whether the underside of the vehicle has been damaged. For example, if the vehicle speed is low when going over a step, the vertical acceleration generated by the front and rear wheels will also be small. If the vehicle height is low and there is a step or speed bump that could damage the underside of the vehicle, the detected vertical acceleration waveform will be like the one shown in the upper part of Figure 9. In this case, in the first embodiment, which determines a collision with the underside of the vehicle from the vertical acceleration generated by the front and rear wheels, it is difficult to distinguish between a collision and a wheel run-on. For example, it is not possible to determine whether the threshold was exceeded by a front wheel run-on or a collision with the underside of the vehicle.

In contrast, in the second embodiment, the damage possibility time T', during which a collision with the underside of the vehicle is predicted, is predicted from the time the step is detected and the vehicle speed. Therefore, as shown in the lower part of Figure 9, if vertical acceleration exceeding a threshold occurs within the damage possibility time T', it can be correctly determined that a collision with the underside of the vehicle has occurred.

In the above embodiment, an example was described in which vehicle speed was detected using the vehicle speed sensor 16. However, instead of the vehicle speed sensor 16, an acceleration sensor that detects the acceleration in the longitudinal direction of the vehicle may be provided, and the vehicle speed may be derived from the detection results of the acceleration sensor.

In addition, while the processing performed by the vehicle collision determination device 12 in each of the above embodiments has been described as software processing performed by executing a program, this is not limited to this. For example, the processing may be performed by hardware such as a GPU (Graphics Processing Unit), ASIC (Application Specific Integrated Circuit), or FPGA (Field-Programmable Gate Array). Alternatively, the processing may be a combination of both software and hardware. Furthermore, if the processing is software, the program may be stored on various storage media and distributed.

Furthermore, the present invention is not limited to the above, and it goes without saying that various modifications and variations are possible within the scope of the present invention.

10 Vehicle 12 Vehicle collision determination device 12A CPU (acquisition unit and determination unit)
14 Up and down G sensor (detection part)
16 Vehicle speed sensor (vehicle speed detection unit)
17 Bump detection unit 18 Vehicle information recording unit 20 In-vehicle communication device (transmitter)
22 Data Server (Server)

Claims (3)

an acquisition unit that acquires the detection results of a detection unit that detects vertical acceleration occurring in the vehicle and a vehicle speed detection unit that detects the vehicle speed;
a determination unit that determines that a collision has occurred with the underside of the vehicle when a vertical acceleration equal to or greater than a predetermined first threshold is detected within a predicted time corresponding to a distance between a front wheel and a rear wheel, the predicted time being calculated based on the vehicle speed at the time the vehicle goes over the step, from the results acquired by the acquisition unit;
Equipped with
The determination unit determines that the step has been overcome when the vertical acceleration is detected to be equal to or greater than a predetermined second threshold value,
The vehicle collision determination device , wherein the predicted time is a first time calculated by dividing the wheelbase of the vehicle by the vehicle speed at the time when it is determined that the vehicle has gone over the step . an acquisition unit that acquires the detection results of a detection unit that detects vertical acceleration occurring in the vehicle and a vehicle speed detection unit that detects the vehicle speed;
a determination unit that determines that a collision has occurred with the underside of the vehicle when a vertical acceleration equal to or greater than a predetermined first threshold is detected within a predicted time corresponding to a distance between a front wheel and a rear wheel, the predicted time being calculated based on the vehicle speed at the time the vehicle goes over the step, from the results acquired by the acquisition unit;
Equipped with
the acquisition unit further acquires a detection result from a step detection unit mounted on the vehicle and configured to detect the step ahead of the vehicle;
A vehicle collision judgment device in which the predicted time is the time from when vertical acceleration occurs as the front wheels of the vehicle climb up the step to when vertical acceleration occurs as the rear wheels climb up the step, predicted from the distance to the step detected by the step detection unit and the vehicle speed at the time the step is detected . 3. The vehicle collision determination device according to claim 1 , further comprising a transmission unit that transmits a collision history of the vehicle bottom to a server external to the vehicle when the determination unit determines that a collision has occurred on the bottom of the vehicle.