JP6428177B2 - Vehicle collision notification device - Google Patents

Description

  The present invention relates to a vehicle collision notification device that detects vehicle periphery information and notifies a vehicle driver based on the detected periphery information.

  Conventionally, for the purpose of preventing a collision when the vehicle is running, an object existing around the vehicle is detected, and when the detected object and the vehicle approach each other, a collision indicating that there is a risk of collision to the driver Techniques for alarming are known. By performing this collision warning, it is possible to prompt the driver to perform a collision avoidance operation and to prevent or reduce collision damage.

  However, since there are variations in reaction time with respect to the collision warning depending on the driver, the warning given at the same timing every time is not always an appropriate warning timing for the driver. Therefore, it is necessary to issue a collision warning at a timing that matches the driver's sense (for example, Patent Document 1).

  The vehicle collision warning device disclosed in Patent Literature 1 learns the TTC when the driver performs a deceleration operation on the preceding vehicle by averaging collision prediction times TTC (Time to collision) calculated in the past. Then, a value obtained by adding a general driver's brake operation response time to the average TTC is set as a TTC threshold, and an actual TTC falls below the TTC threshold, and an alarm is activated after a predetermined delay time elapses.

JP 2005-329811 A

  The technique described in Patent Document 1 described above determines whether or not a collision warning is to be performed by comparing a TTC threshold value obtained by adding a driver's brake operation response time with an actual TTC. However, it is not preferable to perform a collision warning determination based on such a TTC threshold.

  Originally, it is necessary to add the brake operation response time to the TTC threshold when the driver is not aware of the danger of a collision, that is, when the driver is not ready to step on the brake against a forward collision. For this reason, when the driver is lightly braking or waiting for a brake operation, the warning based on the collision alarm timing added to the brake operation response time is at an earlier timing than the timing when the driver feels a collision risk. There is a risk that the driver may feel uncomfortable.

  Further, when the driver depresses the accelerator deeply, the vehicle speed is high, so that it takes more time for the brake to work than when the brake is depressed from a state where the accelerator is depressed shallowly. In such a case, a warning based on a collision warning timing that is simply the addition of a general brake operation reaction time becomes a warning at a timing later than the timing at which the driver feels a collision risk, and does not match the driver's feeling. .

  The present invention has been made in view of the above problems, and by setting a criterion for determining whether or not there is a risk of collision of the host vehicle every predetermined time based on the acceleration / deceleration operation state of the driver. An object of the present invention is to provide a vehicle collision notification device capable of performing a collision notification at an appropriate timing for the driver.

The first invention made to solve the above-described problems is an object detection means for detecting an object around the vehicle (14), and a collision prediction time calculation for calculating a prediction time until the vehicle collides with the object. and means (S123), and deceleration operation detection means for detecting an acceleration or deceleration operation by the driver of the vehicle (10, 11, 12), is required for the collision avoidance between the object every predetermined time based on the acceleration or deceleration operation Based on the comparison between the threshold time setting means (S107, S108, S113, S114, S119, S120) and the predicted collision time and the threshold time, it is determined whether or not there is a collision risk with the object. A collision risk determination means (S124) that performs a collision risk determination means, a notification output means (16) that notifies the vehicle driver of the collision risk when it is determined that there is a collision risk, equipped with a, The value time setting means calculates a threshold time based on the accelerator depression amount and a threshold time based on the vehicle acceleration, and sets a longer threshold time among the threshold time based on the accelerator depression amount and the threshold time based on the vehicle acceleration. It is characterized in that it is a comparison target for collision prediction time .
The second invention made to solve the above-mentioned problems is an object detection means for detecting an object around the vehicle, (14), and a predicted collision time calculation for calculating a predicted time until the vehicle collides with the object. Necessary for avoiding a collision with an object every predetermined time based on the means (S122), the acceleration / deceleration operation detection means (10, 11, 12) for detecting the acceleration / deceleration operation of the vehicle driver, and the acceleration / deceleration operation. Based on the comparison between the threshold time setting means (S105, S106, S111, S112, S118, S119) and the estimated collision time and the threshold time, it is determined whether or not there is a collision risk with the object. A collision risk determination means (S123) that performs a collision risk determination means, and when the collision risk determination means determines that there is a collision risk, a notification output means (16) that notifies the driver of the vehicle of the collision risk; With The value time setting means calculates a threshold time based on the brake depression amount and a threshold time based on the vehicle deceleration, and of the threshold time based on the brake depression amount and the threshold time based on the vehicle deceleration, the longer threshold value Time is used as a comparison target of collision prediction time.

  According to this configuration, the threshold time serving as a determination criterion for determining whether or not there is a risk that the host vehicle will collide takes into account the driver's acceleration / deceleration operation state every predetermined time. If it is determined that there is a risk of collision between the detected object and the vehicle based on such a threshold time, the collision will occur at a timing at which collision avoidance is ensured even if the driver performs acceleration / deceleration operations. The danger can be notified. Therefore, according to the present invention, collision notification can be performed at an appropriate timing for the driver.

1 is a block diagram of a collision notification device 1 according to a first embodiment of the present invention. It is a flowchart of the collision notification control process performed by control ECU15 of the collision notification apparatus 1 in 1st Embodiment of this invention. FIG. 3 is a flowchart continued from FIG. 2. FIG. 4 is a continuation flowchart of FIG. 3. FIG. 5 is a flowchart continued from FIG. 4. It is a related figure of the amount of accelerator depression, and collision avoidance time (TTC threshold). FIG. 6 is a relationship diagram between a brake depression amount and a collision avoidance time (TTC threshold). It is the table | surface which put together the length of the collision avoidance time (TTC threshold value) and collision alerting | reporting timing in each acceleration / deceleration operation.

  Hereinafter, an embodiment embodying a collision notification device of the present invention will be described with reference to the drawings.

(First embodiment)
First, the configuration of the collision notification device 1 in the first embodiment will be described with reference to FIG. The collision notification device 1 according to the present embodiment notifies a vehicle driver of a collision with a front object and is mounted on the vehicle. FIG. 1 is a block diagram of the collision notification device 1. Hereinafter, the vehicle on which the collision notification device 1 is mounted is referred to as a host vehicle.

  As shown in FIG. 1, a collision notification device 1 includes an accelerator opening sensor 10, a brake stroke sensor 11, an acceleration sensor 12, a wheel speed sensor 13, a millimeter wave radar 14, a control ECU 15, and a notification output device. 16.

  The accelerator opening sensor 10 is disposed in the vicinity of an accelerator pedal (not shown) that is operated when the driver of the host vehicle depresses, and detects the amount of depression of the accelerator pedal. The accelerator opening sensor 10 is composed of an accelerator position sensor that can obtain an output voltage corresponding to the depression amount of the accelerator pedal. The accelerator opening sensor 10 detects the accelerator depression amount and outputs it to the control ECU 15.

  The brake stroke sensor 11 is disposed in the vicinity of a brake pedal (not shown) that is operated when the driver of the host vehicle depresses, and detects the depression amount of the brake pedal. The brake stroke sensor 11 is configured by a brake position sensor that can obtain an output voltage corresponding to the brake depression amount. The brake stroke sensor 11 detects the brake depression amount and outputs it to the control ECU 15.

  The acceleration sensor 12 is mounted in the vehicle interior of the vehicle, detects acceleration acting on the host vehicle, and outputs it to the control ECU 15. Here, the accelerator opening sensor 10, the brake stroke sensor 11, and the acceleration sensor 12 function as "acceleration / deceleration operation detecting means" in the claims.

  The wheel speed sensor 13 is a magnetoresistive element attached toward the wheel of the host vehicle, and calculates the vehicle speed of the host vehicle by detecting the rotational speed of the wheel. The wheel speed sensor 13 is connected to the control ECU, and outputs vehicle speed information to the control ECU 15.

  The millimeter-wave radar 14 transmits a millimeter-wave transmission wave in front of the host vehicle at regular intervals (for example, 50 ms), and detects an object based on a reflected wave that is reflected back from an object existing ahead. Do. The object detection range is in front of the host vehicle in the present embodiment, and a number of millimeter wave radars 14 capable of detecting the front of the host vehicle are installed at predetermined positions of the host vehicle. The millimeter wave radar 14 outputs radar detection information to the control ECU 15 based on the received reflected wave. Here, the millimeter wave radar 14 functions as “object detection means” in claims.

  The control ECU 15 is configured as a known microcomputer including a CPU, a ROM, a RAM, and the like. For example, the CPU executes a predetermined calculation process based on a control program or a map stored in the ROM. In the calculation process, various signals input to the control ECU 15 are used. The control ECU 15 outputs a notification command signal to the notification output device 16 based on the calculation result. The control ECU 15 functions as “collision prediction time calculation means”, “threshold time setting means”, and “collision risk determination means” in the claims.

  The notification output device 16 is a device that operates based on a notification command signal output from the control ECU 15 and notifies the driver of the vehicle of a collision. The notification output device 16 is at least one of a sound output device, a display device, and a brake actuator (not shown), and functions as “notification output means” in the claims. The notification output device 16 in this embodiment includes all of an audio output device, a display device, and a brake actuator.

  The sound output device is a sound device or a buzzer such as a speaker system in a vehicle cabin that performs auditory notification. Further, the display device includes a video display device such as a head-up display and a liquid crystal monitor for visual notification, a light-emitting display device that displays character information and the like by turning on and blinking light-emitting elements such as LEDs arranged in large numbers, and a warning lamp Etc. Further, a car navigation monitor having two functions of voice output and display, a navigation device using a speaker, or the like may be used.

  Further, the brake actuator is actuated by a braking command signal output from the control ECU 15 to decelerate the host vehicle. The brake actuator as the notification output device 16 in the present embodiment is for informing the driver that there is a risk of collision by slightly reducing the vehicle speed, and for prompting a collision avoidance operation. .

  A collision notification control process executed by the control ECU 15 of the present embodiment in the collision notification device 1 having such a configuration will be described with reference to FIGS. This collision notification control process is repeatedly executed at regular intervals (for example, 50 ms) from when the ignition key of the host vehicle is turned on to when it is turned off.

  First, FIG. 2 will be described. In S100, it is determined whether or not the brake flag has been initialized. The brake flag in the present embodiment indicates whether or not the brake pedal has been depressed before the previous cycle. A brake flag of 0 indicates that the brake pedal was not depressed in the previous cycle, and a brake flag of 1 indicates that the brake pedal was depressed before the previous cycle. Point to.

   If it is determined in S100 that the brake flag has not been initialized (S100: No), the brake flag is initialized (brake flag = 0) (S101), and the process proceeds to S102. The process of S101 is a process performed only once for the first time when the control ECU 15 is activated and the collision notification control process is executed. Therefore, once the processing of S101 is executed, the ignition key is turned off, and the processing of S101 is not executed until the ignition ECU is turned on again and the control ECU 15 is activated.

  If it is determined in S100 that the brake flag has been initialized (S100: Yes), the process proceeds to the next step S102.

  Subsequently, in S102, acceleration / deceleration operation information of the host vehicle is acquired. Here, the acceleration / deceleration operation information refers to the accelerator depression amount detected by the accelerator opening sensor 10, the brake depression amount detected by the brake stroke sensor 11, and the acceleration detected by the acceleration sensor 12.

  In S103, it is determined whether or not the driver is performing an acceleration operation. Whether or not the acceleration operation is being performed is determined by the control ECU 15 based on whether or not the accelerator pedal is depressed, that is, whether or not the accelerator depression amount detected by the accelerator opening sensor 10 is greater than zero. .

  If it is determined in S103 that the driver is performing an acceleration operation (S103: Yes), the brake flag is set to 0 (S104).

  Subsequently, in S105, a collision avoidance time based on the accelerator depression amount and a collision avoidance time based on the acceleration are calculated. The collision avoidance time based on the accelerator depression amount and the collision avoidance time based on the acceleration correspond to the “threshold time” in the claims.

  The collision avoidance time based on the accelerator depression amount is a time obtained by adding a collision avoidance time further required by the accelerator depression to a predetermined TTC that is a predicted time until the host vehicle collides with a forward object. The predetermined TTC is calculated based on the vehicle speed of the host vehicle detected by the wheel speed sensor 13, and corresponds to the “predetermined threshold time” in the claims.

  At this time, the collision avoidance time further required by the accelerator depression added to the predetermined TTC is longer as the accelerator depression amount is larger. Therefore, as shown in FIG. 6, the collision avoidance time based on the accelerator depression amount becomes longer as the accelerator depression amount becomes larger.

  On the other hand, the collision avoidance time based on the acceleration of the host vehicle is a time obtained by adding a collision avoidance time further required according to the magnitude of acceleration to a predetermined TTC that is a predicted time until the host vehicle collides with a forward object. That is. At this time, the collision avoidance time based on the acceleration added to the predetermined TTC becomes longer as the vehicle acceleration increases.

  Here, the relationship between the accelerator depression amount and the acceleration of the vehicle will be described. The relationship between the accelerator depression amount and the acceleration changes depending on the vehicle type, the state of the brake pad, the temperature, the vehicle speed, and the like. Even if the accelerator depression amount is the same, when the acceleration of the vehicle is small, the time until braking is effective, that is, the collision avoidance time is shortened. On the other hand, when the acceleration of the vehicle is large, the collision avoidance time until the brake is effective becomes long.

  Thus, even if the accelerator depression amount is the same, the collision avoidance time when the brake is depressed differs depending on the magnitude of acceleration. Therefore, when the determination in S103 is Yes, the collision avoidance time and acceleration based on the accelerator depression amount are determined. It is necessary to calculate the collision avoidance time based on the above.

  Subsequently, in S106, it is determined whether or not the collision avoidance time based on the accelerator depression amount is longer than the collision avoidance time based on the acceleration.

  If it is determined in S106 that the collision avoidance time based on the accelerator depression amount is longer (S106: Yes), the collision avoidance time based on the accelerator depression amount is set as a TTC threshold (S107), and the process proceeds to the next step S121. .

  If it is determined in S106 that the collision avoidance time based on the accelerator depression amount is shorter (S106: No), the collision avoidance time based on the acceleration is set as a TTC threshold (S108), and the process proceeds to the next step S121. .

  As described above, the longer one of the collision avoidance time based on the accelerator depression amount and the collision avoidance time based on the acceleration is employed. As a result, when a collision determination is made with respect to the preceding vehicle, a forward collision notification is performed with a margin for performing a collision avoidance operation corresponding to the notification at an appropriate timing that matches the driver's feeling. be able to.

  Here, the reason why the collision avoidance time is set longer than the predetermined TTC when the determination in S103 is Yes will be described. The fact that the accelerator pedal is depressed indicates that the driver's foot is at least placed on the accelerator pedal. It is highly likely that the driver is not aware of the presence of the vehicle ahead and is not ready to step on the brake pedal in preparation for a collision with the vehicle ahead. Therefore, when it is determined that there is a collision risk with respect to the preceding vehicle, it takes time for the driver to change from the accelerator pedal to the brake pedal before performing the deceleration operation. Generally, the switching time from the accelerator pedal to the brake pedal is about 1.2 seconds on average.

  Also, if the brake pedal force and stepping speed are constant, it takes more time for the brake to operate when the brake pedal is depressed from an accelerated state than when the brake pedal is depressed from an unaccelerated state. It takes. Furthermore, since the speed of a vehicle is so quick that the accelerator depression amount is large, the time until a brake works becomes long.

  According to this, when the driver is operating the accelerator pedal, it is not appropriate to set a predetermined TTC that does not take into account the time for switching and the time until the braking force is exerted. Therefore, in S107 or S108, the collision avoidance time is set longer than the predetermined TTC as shown in FIG. 6 in order to allow time for switching from the accelerator pedal to the brake pedal and the time from the acceleration state until the brake works. Set it.

  In addition, it has been described that the collision avoidance time based on the accelerator depression amount is set longer as the accelerator depression amount is larger. However, according to FIG. 6, the collision avoidance time in the period where the accelerator depression amount is somewhat small is set longer than the predetermined TTC. Has become constant. In general, as a mechanism for acceleration, there is often a play period so that the accelerator pedal is not accelerated by a slight depression of the accelerator pedal. According to this, since it is not necessary to reflect the accelerator depression amount in the collision avoidance time during a period when the accelerator depression amount is small to some extent, the collision avoidance time may be constant.

  On the other hand, if it is determined in S103 that the acceleration operation is not being performed (S103: No), it is determined in S109 whether or not the driver is performing a deceleration operation (see FIG. 3). Whether or not the deceleration operation is being performed is determined by the control ECU 15 based on whether or not the brake pedal is depressed, that is, whether or not the brake depression amount detected by the brake stroke sensor 11 is greater than zero.

  If it is determined in S109 that the driver is decelerating (S109: Yes), the brake flag is set to 1 (S110).

  Subsequently, in S111, a collision avoidance time based on the brake depression amount and a collision avoidance time based on the deceleration are calculated.

  The collision avoidance time based on the amount of brake depression is the time obtained by subtracting the collision avoidance time that is excessive due to the brake depression already performed from the predetermined TTC that is the predicted time until the host vehicle collides with the object ahead. is there.

  At this time, the collision avoidance time that becomes extra due to the depression of the brake subtracted from the predetermined TTC becomes longer as the brake depression amount increases. Therefore, as shown in FIG. 7, the collision avoidance time based on the brake depression amount becomes shorter as the brake depression amount becomes larger.

  On the other hand, the collision avoidance time based on the deceleration of the host vehicle is obtained by subtracting the extra collision avoidance time according to the magnitude of the deceleration from the predetermined TTC that is the predicted time until the host vehicle collides with a forward object. It's about time. At this time, the collision avoidance time based on the deceleration subtracted from the predetermined TTC becomes shorter as the vehicle deceleration is larger.

  Here, the relationship between the brake depression amount and the vehicle deceleration will be described. The relationship between the brake depression amount and the deceleration varies depending on the vehicle type, the state of the brake pad, the temperature, the vehicle speed, and the like, similar to the relationship between the accelerator depression amount and the vehicle acceleration. Even if the amount of brake depression is the same, when the vehicle deceleration is small, the time until the brake is applied, that is, the collision avoidance time becomes long. On the other hand, when the deceleration of the vehicle is large, the collision avoidance time until the brake is effective is shortened.

  Thus, even if the brake depression amount is the same, the collision avoidance time when the brake is further depressed differs depending on the magnitude of the deceleration. Therefore, when the determination in S109 is Yes, the collision avoidance time based on the deceleration is also It is necessary to calculate.

  Subsequently, in S112, it is determined whether or not the collision avoidance time based on the brake depression amount is longer than the collision avoidance time based on the deceleration.

  If it is determined in S112 that the collision avoidance time based on the brake depression amount is longer (S112: Yes), the collision avoidance time based on the brake depression amount is set as a TTC threshold (S113), and the process proceeds to the next step S121. .

  If it is determined in S112 that the collision avoidance time based on the brake depression amount is shorter (S112: No), the collision avoidance time based on the deceleration is set as a TTC threshold (S114), and the process proceeds to the next step S121. move on.

  In this way, the longer collision avoidance time is selected from the collision avoidance time based on the brake depression amount and the collision avoidance time based on the deceleration. As a result, when a collision determination is made with respect to the preceding vehicle, a forward collision notification is performed with a margin for performing a collision avoidance operation corresponding to the notification at an appropriate timing that matches the driver's feeling. be able to.

  Here, the reason why the collision avoidance time is set shorter than the predetermined TTC when the determination in S109 is Yes will be described. The fact that the brake pedal is depressed indicates that the driver's foot is at least placed on the brake pedal. That is, the driver is aware of the presence of the forward vehicle and is likely to be ready to step on the brake pedal in preparation for a collision with the forward vehicle. According to this, when it is determined that there is a collision risk with respect to the preceding vehicle, it is considered that the driver can step on the brake pedal immediately.

  Also, when the brake pedal depressing force and depressing speed are constant, the time it takes for the brake to operate more when the brake pedal is further depressed from the decelerated state than when the brake pedal is depressed from a non-decelerated state. Is not required. Furthermore, since the speed of the vehicle is slower as the brake depression amount is larger, the time until the brake is applied becomes shorter.

  Therefore, as shown in FIG. 7, in consideration of the fact that the time for switching from the accelerator pedal to the brake pedal is unnecessary and the time from the deceleration state until the brake works, the collision avoidance time is set to a predetermined TTC in S113 or S114. Shorter.

  Further, it has been described that the collision avoidance time based on the brake depression amount is set to be shorter as the brake depression amount is larger. However, according to FIG. 7, the collision avoidance time when the brake depression amount is somewhat small is set to be shorter than the predetermined TTC. Has become constant. Similar to the acceleration mechanism, in general, as a deceleration mechanism, a play period is often provided so that the brake pedal is not decelerated by a slight depression of the brake pedal. According to this, since it is not necessary to reflect the brake depression amount in the collision avoidance time during a period when the brake depression amount is small to some extent, the collision avoidance time may be constant.

  On the other hand, if it is determined in S109 that the deceleration operation is not being performed (S109: No), it is determined in S115 whether or not the brake pedal has been depressed just before (see FIG. 4). Whether or not the brake pedal has been depressed until just before is determined by the control ECU 15 based on whether or not the value of the brake flag is 1.

  If it is determined in S115 that the brake pedal has been depressed just before (S115: Yes), a timer is counted until a predetermined time elapses after the driver releases the brake pedal (S116), and the next S117 is performed. Proceed to the process.

  On the other hand, when it is determined in S115 that an operation other than the depression of the brake pedal has been performed immediately before (S115: No), the process proceeds to S118.

  In S117, it is determined whether or not a predetermined time has elapsed after the driver releases the brake pedal (hereinafter, after the brake pedal is released). Whether or not the predetermined time has elapsed after the release of the brake pedal is determined by the control ECU 15 based on whether or not the timer count value started counting in S116 is equal to or greater than the predetermined timer value. Here, for example, 1 second is set in advance as the predetermined timer value, and is appropriately set depending on the driving environment.

  In S117, when it is determined that a predetermined time has elapsed after the release of the brake pedal (S117: Yes), the process proceeds to the next S118. In S118, the timer is reset, and in S119, the collision avoidance time when acceleration / deceleration is not operated is set as a TTC threshold. Then, the process proceeds to the next step S121.

  In S119, the collision avoidance time during acceleration / deceleration non-operation is shorter than the collision avoidance time based on the accelerator depression amount and longer than the collision avoidance time based on the brake depression amount. In the present embodiment, the predetermined TTC is set as the collision avoidance time when the acceleration / deceleration is not operated.

  On the other hand, if it is determined in S117 that the predetermined time has not elapsed after the release of the brake pedal (S117: No), the collision avoidance time based on the brake depression amount is set as the TTC threshold (S120), and the next processing of S121 Proceed to

  Here, when the determination of S117 is No, the reason why the collision avoidance time based on the brake depression amount is set as the TTC threshold in S120 will be described. Usually, in S103 and S109, when the depression amount of the accelerator pedal and the brake pedal is 0, it is considered that the driver is not performing any acceleration / deceleration operation.

  However, as a decelerating operation, there is a case where the depressing operation is divided into several times without depressing the brake pedal at a stretch like the pumping brake. Thus, the driver may step on the brake pedal again immediately after the brake pedal is released. When the collision avoidance time during acceleration / deceleration non-operation is set as the TTC threshold in a situation where the driver's operation is assumed and the predetermined time has not elapsed, the following may be considered.

  The collision avoidance time when acceleration / deceleration is not operated is longer than the collision avoidance time based on the brake depression amount. Therefore, when the collision avoidance time during acceleration / deceleration non-operation is set as the TTC threshold, the collision notification is performed at an earlier timing than when the collision avoidance time based on the brake depression amount is set as the TTC threshold. As described above, when the collision notification is performed at an early timing, when performing a deceleration operation such as a pumping brake, the collision notification may be performed before the brake pedal is depressed again.

  Therefore, it is assumed that the driver has depressed the brake pedal until the predetermined time has elapsed, and the collision avoidance time based on the brake depression amount is set as the TTC threshold value in S120. At this time, since the brake pedal is not actually depressed, it is desirable to set the amount of depression of the brake pedal used when setting the TTC threshold as close to zero.

  For the reasons described above, if the determination in S115 is No, or if the determination in S117 is Yes, it can be determined that the driver has not performed an acceleration operation and a deceleration operation including a pumping brake. Therefore, in S119, the collision avoidance time when acceleration / deceleration is not operated is set as the TTC threshold value.

  Subsequently, in S121, information ahead of the host vehicle is acquired based on the radar detection information input from the millimeter wave radar 14 (see FIG. 5). And in S122, based on the front information acquired in S121, the vehicle (henceforth a forward vehicle) which exists ahead of the own vehicle is detected.

  Next, in S123, a predicted collision time (hereinafter, calculated TTC) that is a time until the host vehicle is predicted to collide with the preceding vehicle is calculated. Specifically, first, a relative speed and a relative distance with respect to the preceding vehicle are calculated. The relative distance to the vehicle ahead is calculated based on radar detection information input from the millimeter wave radar 14. The relative speed is calculated from the change over time of the relative distance. Then, TTC is calculated by dividing the relative distance by the relative speed.

  In S124, it is determined whether there is a risk of collision of the host vehicle with the preceding vehicle (hereinafter referred to as collision risk). This determination is made based on a comparison between the TTC calculated in S123 and the TTC threshold set in any of S107, S108, S113, S114, S119, or S120.

  If the calculated TTC is equal to or greater than the TTC threshold, it is determined that there is no danger of collision and it is not necessary to perform collision notification control. When the calculated TTC is less than the TTC threshold, it is determined that there is a collision risk and it is necessary to perform the collision notification control.

  If it is determined in S124 that there is no collision risk (S124: No), the process returns to the first S100.

  On the other hand, when it is determined that there is a collision risk in S124 (S124: Yes), a notification command signal is input to the notification output device 16 in S125, and a forward collision notification is given to the driver. Return to processing.

  As the forward collision notification in S125, for example, an alarm sound output by a sound output device mounted on the host vehicle and a warning display by a display device are first performed. Further, the brake actuator automatically applies a weak brake to slightly reduce the speed of the vehicle. Accordingly, it is possible to notify the driver that there is a possibility of collision with the preceding vehicle in an auditory, visual, and bodily sense and it is necessary to reduce the vehicle speed.

  As described above, according to the vehicle collision notification device 1 according to the present embodiment, the control ECU 15 determines whether there is a collision risk of the host vehicle based on the acceleration / deceleration operation state of the driver. The collision avoidance time serving as a reference is calculated, and a TTC threshold is set every predetermined time. Then, the calculated TTC is compared with the TTC threshold, and when the calculated TTC falls below the TTC threshold, a collision notification is given to the driver.

  As shown in FIG. 8, when the accelerator pedal is in the depressed state, it is longer than a predetermined TTC considering the time for switching from the accelerator pedal to the brake pedal and the time for exerting the braking force based on the accelerator depression amount. A TTC threshold value is set (S107, S108). Therefore, it is determined that there is a risk of collision at a timing earlier than usual, and a collision notification is performed. According to this, the timing at which the driver who performs the acceleration operation of the vehicle feels the danger of the collision coincides with the collision notification timing, so that the driver can perform the collision avoidance operation at an appropriate timing.

  In addition, when the brake pedal is in the depressed state, it is shorter than a predetermined TTC in consideration of the time for switching from the accelerator pedal to the brake pedal is unnecessary and the time for exerting the braking force based on the brake depression amount. A TTC threshold value is set (S113, S114). Therefore, it is determined that there is a risk of collision at a timing later than usual, and a collision notification is performed. According to this, since the timing at which the driver who performs the deceleration operation of the vehicle feels a collision risk coincides with the collision notification timing, the driver can perform the collision avoidance operation at an appropriate timing.

  If neither the brake pedal nor the accelerator pedal is depressed and a predetermined time has not elapsed since the release of the brake pedal, the collision avoidance time based on the brake depression amount is set as a TTC threshold (S120). For example, here, if the collision avoidance time when acceleration / deceleration is not operated is set to the TTC threshold value, a collision notification may be performed before the brake pedal is depressed again in a deceleration operation such as a pumping brake. It will be annoying.

  Therefore, when the predetermined time has not elapsed, the collision avoidance time based on the brake depression amount is set as the TTC threshold, so that the driver feels inconvenience that the collision notification is performed before the brake pedal is depressed again. Without making it happen, it is possible to notify the collision at an appropriate timing.

  As described above, the TTC threshold value based on the driver's acceleration / deceleration operation state is set every predetermined time, that is, the TTC threshold value, which is a criterion for determining whether there is a collision risk of the host vehicle, is updated one by one. The collision can be notified at an appropriate timing without giving the driver a sense of incongruity.

  In addition, this invention is not limited to this embodiment mentioned above, It can change in the range which does not deviate from the main point of this invention.

(Modification 1)
For example, in the first embodiment, an example in which an object existing in front of the host vehicle is detected by the millimeter wave radar 14 has been described, but the vehicle peripheral information may be acquired using a sensor such as a laser radar or an ultrasonic wave. Good. Moreover, it is good also as a structure which acquires vehicle periphery information using a camera, and specifically, an object is detected by image | photographing the road condition around a vehicle for every fixed time, and imaging the vehicle front. Furthermore, the front object may be detected with higher accuracy by using the sensor in combination or by using the camera and the sensor in a fused manner.

(Modification 2)
Moreover, in 1st Embodiment, although the accelerator opening degree sensor 10 and the brake stroke sensor 11 were provided as determination of the acceleration / deceleration operation state by a driver | operator, it is not restricted to this. For example, it may be determined whether or not the brake pedal is depressed based on an on signal or an off signal of a stop lamp switch that switches according to depression of the brake pedal.
Further, the acceleration / deceleration operation state may be determined by detecting the position of the foot by imaging the driver's foot using a camera mounted in the passenger compartment. As a result, it is detected whether the driver's foot is placed on the accelerator pedal or the like, and it is determined whether or not the accelerator pedal is depressed based on the detection result.

(Modification 3)
In the first embodiment, the collision avoidance time during non-operation of acceleration and deceleration is set to a predetermined TTC. However, the value is within the range satisfying the condition that it is shorter than the collision avoidance time based on the accelerator depression amount and longer than the collision avoidance time based on the brake depression amount, and is not limited to this. For example, a value close to the collision avoidance time based on the accelerator depressing amount may be set as the collision avoidance time when acceleration / deceleration is not operated in order to allow the driver a collision avoidance operation. Further, in a situation where neither the accelerator pedal nor the brake pedal is depressed, there is a possibility that deceleration due to engine braking has occurred. The deceleration due to the engine brake varies depending on the vehicle speed and the vehicle type. Therefore, the deceleration due to engine braking may be detected by the acceleration sensor 12, and the collision avoidance time based on the detected deceleration may be set as the collision avoidance time when acceleration / deceleration is not operated.

(Modification 4)
In the first embodiment, during the acceleration operation of the driver, the collision avoidance time based on the accelerator depression amount and the acceleration is compared, and the longer collision avoidance time is set as the TTC threshold. However, only one of the collision avoidance time based on the accelerator depression amount or the collision avoidance time based on the acceleration may be calculated and set as the TTC threshold. Similarly, in setting the TTC threshold value during the deceleration operation, either the collision avoidance time based on the brake depression amount or the collision avoidance time based on the deceleration may be calculated and set as the TTC threshold value.

(Modification 5)
In the first embodiment, the collision avoidance time based on each operation is calculated by increasing / decreasing the time based on the predetermined TTC based on the accelerator depression amount or the brake depression amount, and set as the TTC threshold value. However, the control ECU 15 may store in advance a map or the like indicating the relationship between the depression amount of the brake pedal and the collision avoidance time, and set the TTC threshold based on the map.

(Modification 6)
In the first embodiment, an example is shown in which the collision avoidance time based on the accelerator depression amount and the collision avoidance time based on the brake depression amount are calculated on the assumption that the depression force and the depression speed of the accelerator pedal and the brake pedal are constant. . However, the present invention is not limited to this, and it is also possible to sequentially reflect changes in pedal effort and changes in depression speed.

(Modification 7)
In the first embodiment, it is determined whether or not the driver is performing an acceleration operation (S103). When it is determined that the driver is not performing an acceleration operation, it is determined whether the driver is performing a deceleration operation (S109). showed that. However, it may be determined whether the driver is decelerating first, and if it is determined that the driver is not decelerating, it may be determined whether the driver is accelerating.

  For example, a driver who performs an acceleration operation and a deceleration operation with both feet may depress both an accelerator pedal and a brake pedal at the same time. According to this, the effect is different between the case where the acceleration operation is preferentially determined and processed and the case where the deceleration operation is preferentially determined and processed. When the acceleration operation is preferentially determined, the collision notification timing works on the safe side. In addition, when priority is given to the deceleration operation, it acts as an unnecessary operation prevention for the driver who is fine-adjusting with both feet.

  In this way, in consideration of the effect when each process is prioritized, the order of the process during the acceleration operation (S103 to 108) and the process during the deceleration operation (S109 to 114) may be switched. In any of the above modifications, the same effect as that of the first embodiment can be obtained.

DESCRIPTION OF SYMBOLS 1 Collision notification apparatus, 10 Accelerator opening sensor, 11 Brake stroke sensor, 12 Acceleration sensor, 13 Wheel speed sensor, 14 Millimeter wave radar, 15 Control ECU, 16 Notification output apparatus

Claims (8)

Object detection means for detecting an object around the vehicle; and (14);
Collision prediction time calculating means for the vehicle before Symbol object body to calculate a predicted time until the collision with (S122),
Acceleration / deceleration operation detecting means (10, 11, 12) for detecting the acceleration / deceleration operation of the driver of the vehicle;
A collision avoidance threshold time setting means for setting a threshold time required for (S105, S106, S111, S112 , S118, S119) with the previous SL was member every predetermined time based on the previous SL acceleration and deceleration operation,
Collides with the risk determination means (S123) determines whether there is a risk of collision with the previous SL product body based on a comparison between the threshold time and the collision prediction time,
A notification output means (16) for notifying the driver of the vehicle of the collision risk when the collision risk determination means determines that there is a collision risk;
Equipped with a,
The threshold time setting means calculates the threshold time based on the accelerator depression amount and the threshold time based on the acceleration of the vehicle, and out of the threshold time based on the accelerator depression amount and the threshold time based on the acceleration of the vehicle The collision notification device for vehicles , wherein the threshold time on the longer side is used as a comparison target of the predicted collision time . Object detection means for detecting an object around the vehicle; and (14);
Collision prediction time calculating means for the vehicle before Symbol object body to calculate a predicted time until the collision with (S122),
Acceleration / deceleration operation detecting means (10, 11, 12) for detecting the acceleration / deceleration operation of the driver of the vehicle;
A collision avoidance threshold time setting means for setting a threshold time required for (S105, S106, S111, S112 , S118, S119) with the previous SL was member every predetermined time based on the previous SL acceleration and deceleration operation,
Collides with the risk determination means (S123) determines whether there is a risk of collision with the previous SL product body based on a comparison between the threshold time and the collision prediction time,
A notification output means (16) for notifying the driver of the vehicle of the collision risk when the collision risk determination means determines that there is a collision risk;
Equipped with a,
The threshold time setting means calculates the threshold time based on the brake depression amount and the threshold time based on the vehicle deceleration, and the threshold time based on the brake depression amount and the threshold time based on the vehicle deceleration. Among them, the longer threshold time is used as a comparison target of the predicted collision time . 3. The vehicle collision notification according to claim 1, wherein the threshold time setting means makes the threshold time longer than a predetermined threshold time when the driver is performing an acceleration operation (S < b > 105, S < b > 106). apparatus. 4. The vehicle collision notification device according to claim 3 , wherein the threshold time setting unit increases the threshold time as the operation amount of the acceleration operation increases. 5. The vehicle threshold notification according to claim 1 or 2 , wherein the threshold time setting means makes the threshold time shorter than a predetermined threshold time when the driver is decelerating (S111, S112). apparatus. If the specified time has not passed since the driver released the brake pedal,
6. The vehicle collision notification device according to claim 5 , wherein the threshold time setting means sets the threshold time assuming that the driver is decelerating (S119). The threshold time setting unit, as the operation amount of the deceleration operation is large, vehicle collision notification apparatus according to claim 5 or 6, characterized in that to shorten the threshold time. The threshold time setting means is shorter than the threshold time when the driver is performing an accelerating operation and longer than the threshold time when the driver is performing a decelerating operation when the driver is not accelerating or decelerating. (S118) The vehicle collision notification device according to claim 1 or 2 ,