JP7511252B2 - Exit assistance device - Google Patents

Description

The present invention relates to a disembarkation assistance device that can suppress unnecessary operation of disembarkation assistance control.

There is known a disembarkation support device capable of executing disembarkation support control to support a vehicle occupant to safely disembark from a vehicle. The disembarkation support device is configured to execute disembarkation support control when, for example, an obstruction target that may obstruct the occupant's safe disembarkation while the vehicle is stopped (in other words, passing by the side of the vehicle) is detected and the occupant's intention to disembark is detected.

For example, the vehicle rear monitoring device of Patent Document 1 is configured to notify the rear seat occupants of the approach of a moving vehicle when a stop of the vehicle is detected and disembarking start from the rear seat of the vehicle is detected, and a moving vehicle that may prevent the rear seat occupants from disembarking safely is detected behind the vehicle. Specifically, this vehicle rear monitoring device is configured to calculate the moving direction and moving speed of the moving vehicle, and when it is determined that the moving vehicle will enter a dangerous area (an area located behind the vehicle) within a predetermined time from the time the moving vehicle is detected based on the calculated moving direction and moving speed, to determine that the moving vehicle may prevent the rear seat occupants from disembarking safely.

JP 2009-78674 A

By executing disembarkation assistance control, it is possible to reduce the possibility that the door or the occupant will come into contact with an obstruction object. However, on the other hand, if disembarkation assistance control is executed in a situation where the control is not necessary, it may cause inconvenience to the occupant and may actually hinder the occupant from disembarking safely. Here, a "situation where disembarkation assistance control is not necessary" is, for example, a situation where an object that is not actually an obstruction object is temporarily erroneously detected as an obstruction object due to a change in the direction of travel. For this reason, it is necessary to suppress unnecessary operation of disembarkation assistance control and improve the reliability of the control.

The present invention has been made to address the above-mentioned problems. That is, one of the objects of the present invention is to provide a disembarkation assistance device that can suppress unnecessary operation of disembarkation assistance control.

The disembarking assistance device according to the present invention (hereinafter referred to as the "device of the present invention") is
a target information acquisition device (12) that detects a target present behind the vehicle and acquires information about the detected target as target information;
A control unit (10) capable of executing a vehicle exit assistance control for assisting a passenger in safely exiting the vehicle;
Equipped with.
The control unit (10)
determining whether or not an obstruction target that may obstruct the safe disembarking of the occupant while the vehicle is stopped is detected based on the target information;
determining whether or not a dismounting assistance condition is satisfied when at least the obstruction object is detected;
If the dismount assistance condition is satisfied, determine whether or not a specific condition is satisfied when a magnitude (|ω|) of a rate of change of an angle (θ) between a forward/rearward direction (x-axis direction) of the host vehicle and a traveling direction of the obstruction target is equal to or greater than a predetermined rate of change threshold (ωth);
When the specific condition is not satisfied, the vehicle dismounting assistance control is executed.
When the specific condition is satisfied, the vehicle dismount assistance control is not executed.
It is structured as follows.

Conventional disembarkation assistance devices execute disembarkation assistance control when an execution condition is met, which is met, for example, when an obstruction target is detected while the vehicle is stopped and the occupant's intention to disembark is detected. With this configuration, disembarkation assistance control is executed when the execution condition is met even when a target that is not actually an obstruction target is erroneously detected as an obstruction target due to a change in the direction of travel, which causes unnecessary operation.

Here, the inventors of the present application have found that during a period in which a target is erroneously detected as an obstruction target due to a change in the travel direction, the target tends to move so that the magnitude of the rate of change of the angle between the longitudinal direction of the vehicle and the travel direction of the target is equal to or greater than a predetermined change rate threshold. Based on this finding, the inventors of the present application have configured the device of the present invention as follows. That is, when the dismounting support condition is satisfied, the device of the present invention is configured to determine whether or not a specific condition, that is, a condition that is satisfied when the magnitude of the rate of change of the angle is equal to or greater than the change rate threshold, is satisfied, rather than immediately executing the dismounting support control. If the specific condition is not satisfied, the device is configured to determine that the target is unlikely to have been erroneously detected as an obstruction target and execute the dismounting support control, and if the specific condition is satisfied, the device is configured to determine that the target is likely to have been erroneously detected as an obstruction target due to a change in the travel direction and not execute the dismounting support control.

This configuration makes it possible to appropriately execute disembarkation assistance control when it is actually necessary, while suppressing unnecessary operation of the control, thereby improving the reliability of the disembarkation assistance control.

In one aspect of the invention,
If a portion of the front end of the obstruction target that is closest to the host vehicle in the vehicle width direction of the host vehicle is defined as a proximity portion (np),
The control unit (10)
Furthermore, it is determined that the specific condition is satisfied when a distance in the vehicle width direction (y-axis direction) from the host vehicle to the proximity portion (np) of the obstruction target exceeds a predetermined distance threshold.
It is structured as follows.

The inventors of the present application have found that during a period in which a target is erroneously detected as an obstruction target due to a change in the direction of travel of the target, the distance in the vehicle width direction from the vehicle to the nearby portion tends to exceed a predetermined distance threshold. Based on this finding, in one aspect of the present invention, a specific condition is further configured to be satisfied when the distance in the vehicle width direction from the vehicle to the nearby portion exceeds the distance threshold. With this configuration, the accuracy of determining whether or not dismount assistance control is unnecessary can be increased, and dismount assistance control can be executed more appropriately.

In one aspect of the invention,
A portion of the front end of the obstruction target that is closest to the host vehicle in a vehicle width direction of the host vehicle is defined as a nearby portion (np);
If imaginary lines each having a predetermined length extending from the left and right rear corners of the vehicle in a vehicle widthwise outward direction are defined as intersection determination lines (LL, LR),
The control unit (10)
When the detected target passes through the intersection judgment line (LL, LR) assuming that the target continues to move along the current traveling direction, if a predicted time (TTC) that is predicted to be required for the target to cross the intersection judgment line (LL, LR) is equal to or less than a predetermined time threshold (TTCth), the target is determined to be an obstruction target.
It is structured as follows:
Furthermore, it is determined that the specific condition is satisfied when the proximate portion (np) of the obstruction target is located in a vehicle width outer direction from the end of the intersection determination line (LL, LR).
It is structured as follows.

The inventors of the present application have found that during a period in which a target is erroneously detected as an obstruction target due to a change in the direction of travel, the adjacent portion of the target tends to be located in the vehicle width direction outward from the end of the intersection judgment line. Based on this finding, in one aspect of the present invention, a specific condition is further configured to be satisfied when the adjacent portion of the obstruction target is located in the vehicle width direction outward from the end of the intersection judgment line. With this configuration, the accuracy of determining whether or not dismount assistance control is unnecessary can be increased, and dismount assistance control can be executed more appropriately.

In one aspect of the invention,
The control unit (10)
Furthermore, it is determined that the specific condition is satisfied when the magnitude (|vy|) of the speed (vy) of the obstruction object in the vehicle width direction (y-axis direction) of the host vehicle is greater than a predetermined speed threshold (vyth).
It is structured as follows.

The inventors of the present application have found that during a period in which a target is erroneously detected as an obstruction target due to a change in the direction of travel, the target tends to move such that the magnitude of the speed in the vehicle width direction of the host vehicle is greater than a predetermined speed threshold. Based on this finding, in one aspect of the present invention, a specific condition is further configured to be established when the magnitude of the speed of the obstruction target in the vehicle width direction of the host vehicle is greater than the speed threshold. With this configuration, the accuracy of determining whether or not dismount assistance control is unnecessary is further improved, and dismount assistance control can be executed more appropriately.

In one aspect of the invention,
The control unit (10)
Furthermore, it is determined that the specific condition is satisfied when the magnitude (|θ|) of the angle (θ) between the front-rear direction (x-axis direction) of the host vehicle and the traveling direction of the obstruction target is equal to or greater than a predetermined angle threshold (θth).
It is structured as follows.

The inventors of the present application have found that during a period in which a target is erroneously detected as an obstruction target due to a change in the direction of travel of the target, the target tends to move so that the angle between the fore-and-aft direction of the vehicle and the direction of travel of the obstruction target is equal to or greater than a predetermined angle threshold. Based on this finding, in one aspect of the present invention, a specific condition is further established when the angle is equal to or greater than the angle threshold. This configuration further increases the accuracy of determining whether or not dismount assistance control is unnecessary, and allows dismount assistance control to be executed more appropriately.

In one aspect of the invention,
The control unit (10)
Furthermore, it is determined that the specific condition is satisfied when a ratio (Δx/Δy) of a total movement amount (Δx) of the obstruction target in the front-rear direction (x-axis direction) to a total movement amount (Δy) of the obstruction target in the vehicle width direction (y-axis direction) of the host vehicle during a period from when the obstruction target is first detected by the target information acquisition device (12) to the current time is less than a predetermined movement amount ratio threshold value ((Δx/Δy)th).
It is structured as follows.

The inventors of the present application have found that during a period in which a target is erroneously detected as an obstruction target due to a change in the direction of travel, the target tends to move such that the ratio of the total amount of movement of the obstruction target in the front-rear direction to the total amount of movement in the width direction of the vehicle during the period from when the target was first detected by the target information acquisition device to the current time is less than a predetermined movement amount ratio threshold. Based on this finding, in one aspect of the present invention, a specific condition is further established when the ratio is less than the movement amount ratio threshold. With this configuration, the accuracy of determining whether or not the dismount assistance control is unnecessary is further improved, and the dismount assistance control can be executed more appropriately.

In the above explanation, to aid in understanding the invention, the symbols used in the embodiments are enclosed in parentheses with respect to the constituent elements of the invention corresponding to the embodiments, but each constituent element of the invention is not limited to the embodiment defined by the symbols.

1 is a schematic configuration diagram of an alighting assistance device (embodiment device) according to an embodiment of the present invention; 1 is a diagram showing a three-dimensional object detection range of a radar sensor provided in the present embodiment, and is a diagram for explaining a method of calculating the TTC of a target detected by the radar sensor. FIG. 10 is a diagram for explaining a specific condition, and is a diagram illustrating a case in which unnecessary operation of the warning control is suppressed when the warning condition is satisfied. FIG. 10 is a diagram for explaining a specific condition, and is a diagram illustrating a case in which warning control is appropriately executed when a warning condition is satisfied. FIG. 4 is a flowchart showing a routine executed by a CPU of a vehicle dismounting assistance ECU of the embodiment of the present invention. 4 is a flowchart showing a routine executed by a CPU. 4 is a flowchart showing a routine executed by a CPU.

(composition)
Hereinafter, a vehicle exit assistance device according to an embodiment of the present invention (hereinafter also referred to as "the present embodiment device") will be described with reference to the drawings. As shown in FIG. 1, the present embodiment device includes a vehicle exit assistance ECU 10, and a vehicle speed sensor 11, a radar sensor 12, a door opening/closing sensor 13, and a buzzer 20 connected thereto. The vehicle exit assistance ECU 10 includes a microcomputer as a main part. ECU is an abbreviation of Electronic Control Unit. The microcomputer includes a CPU, a ROM, a RAM, an interface (I/F), etc., and the CPU is adapted to realize various functions by executing instructions (programs, routines) stored in the ROM. Hereinafter, a vehicle equipped with the present embodiment device will be referred to as a "host vehicle".

The dismounting support ECU 10 is configured to acquire the signals generated or output by the sensors 11 to 13 at predetermined intervals and control the buzzer 20 based on the acquired signals. Hereinafter, the dismounting support ECU 10 is also referred to simply as "ECU 10."

The vehicle speed sensor 11 generates a signal corresponding to the traveling speed of the vehicle (hereinafter referred to as "vehicle speed"). The ECU 10 acquires the signal generated by the vehicle speed sensor 11 and calculates the vehicle speed based on the signal. If the vehicle speed is zero, the ECU 10 determines that the vehicle is stopped (hereinafter also referred to as "parked").

The radar sensor 12 (target information acquisition device) has the function of acquiring information about three-dimensional objects (targets) that exist behind (directly behind and to the rear sides of) the vehicle. Three-dimensional objects are moving objects such as vehicles, bicycles, and pedestrians.

As shown in FIG. 2, the radar sensor 12 includes a left radar sensor 12L provided at the left rear corner of the vehicle V and a right radar sensor 12R provided at the right rear corner of the vehicle V. The radar sensor 12 irradiates millimeter wave band radio waves to the surroundings of the vehicle. Specifically, the left radar sensor 12L irradiates radio waves to an area including a left region RL on the left rear of the vehicle, and the right radar sensor 12R irradiates radio waves to an area including a right region RR on the right rear of the vehicle. The left region RL and the right region RR are both shaped to become longer in the outboard and inboard directions as they move away from the vehicle V rearward. Note that in FIG. 2, for convenience, the ratios of the regions RL and RR to the vehicle V are changed.

When a three-dimensional object is present within the range of the radio waves, the radar sensor 12 receives reflected waves from the object. The radar sensor 12 calculates the presence or absence of a three-dimensional object and the relative relationship between the vehicle and the object (the distance from the vehicle to the object, the orientation of the object relative to the vehicle, and the relative speed of the object relative to the vehicle, etc.) based on the timing of the radio waves being emitted and received. In other words, the radar sensor 12 detects a three-dimensional object that exists behind the vehicle. Hereinafter, a three-dimensional object detected by the radar sensor 12 (i.e., a three-dimensional object that exists in the region RL or RR) is also referred to as a "target". The radar sensor 12 outputs this information about the target to the ECU 10 as target information.

The sensor that acquires the target information is not limited to the radar sensor 12. For example, a laser radar sensor, an ultrasonic sensor, and/or a camera sensor may be used instead of or in addition to the radar sensor 12. Alternatively, a sensor used for blind spot monitor control may be used as the radar sensor 12. Blind spot monitor control is a control that alerts the driver of the vehicle when a vehicle approaching the vehicle from behind (especially a vehicle in an area that is difficult to see with the side mirrors) is detected.

Returning to FIG. 1, the explanation will be continued. The door opening/closing sensor 13 is provided on each of the multiple doors (more specifically, the side doors) of the vehicle. The door opening/closing sensor 13 detects the open/closed state of the door. When the door opening/closing sensor 13 detects that a door is in an open state, it generates an open signal indicating that the door is in an open state while the open state is detected. When the door opening/closing sensor 13 detects that a door is in a closed state, it generates a close signal indicating that the door is in a closed state while the closed state is detected. The ECU 10 detects whether each of these door opening/closing sensors 13 is generating an open signal or a close signal, and based on the detection result, detects whether the door corresponding to that door opening/closing sensor 13 is in an open state or a closed state.

The buzzer 20 is built into the meter panel (not shown) and is configured to sound based on a drive command from the ECU 10.

(Details of operation)
A conventional disembarking assistance device is configured to execute disembarking assistance control when an obstruction target that may obstruct a passenger from disembarking safely while the vehicle is stopped is detected and the passenger's intention to disembark is detected. With this configuration, a target that is not actually an obstructing target may be erroneously detected as an obstructing target temporarily due to a change in the traveling direction, and as a result, unnecessary disembarking assistance control may be executed.
Therefore, in the present embodiment, when an obstruction object is detected while the vehicle is stopped and an occupant's intention to disembark is detected, if a specific condition (described later) is satisfied, which is "a condition that is likely to be satisfied when the obstruction object changes its traveling direction", the device determines that the obstruction object is not actually an obstruction object and does not execute disembarkation assistance control. In this embodiment, the ECU 10 executes warning control as disembarkation assistance control. The warning control is a control that executes a process to sound the buzzer 20. The operation of the ECU 10 will be described in detail below.

The ECU 10 determines that the warning condition is satisfied when all of the following conditions 1 to 3 are satisfied. The warning condition corresponds to an example of a "vehicle disembarkation assistance condition."
(Condition 1) The vehicle is stopped.
(Condition 2) An obstructing target is detected.
(Condition 3) The door of the host vehicle is open.

First, we will explain condition 1. If the vehicle speed acquired from the vehicle speed sensor 11 is zero, the ECU 10 determines that condition 1 is met.

Next, condition 2 will be described. An obstruction target is a moving object that may approach the vehicle from behind and obstruct the safe disembarking of occupants. The ECU 10 detects obstruction targets as follows. That is, when the ECU 10 determines that a target is present in the left region RL or the right region RR based on target information acquired from the radar sensor 12, it calculates a predicted time required for the target to contact or come closest to the vehicle. Hereinafter, for ease of explanation, this predicted time is also referred to as "TTC (Time To Collision)". If the TTC is equal to or less than a predetermined time threshold TTCth, the ECU 10 detects the target as an obstruction target and determines that condition 2 is met.

A more detailed explanation will be given with reference to Figure 2. Figure 2 shows another vehicle Vt approaching the host vehicle V from behind. As shown in Figure 2, when the host vehicle V is stopped (i.e., when condition 1 is met), the ECU 10 sets an xy coordinate system with the origin at the center of the rear end of the host vehicle V. The x axis extends in the front-rear direction of the host vehicle V, and the y axis extends in the vehicle width direction (left-right direction) of the host vehicle V.

In addition, when the vehicle V is stopped, the ECU 10 sets a crossing judgment line L on the vehicle V. The crossing judgment line L is a virtual line set to calculate the TTC, and includes a left crossing judgment line LL and a right crossing judgment line LR. The left crossing judgment line LL extends from the left rear corner of the vehicle V in the -y axis direction (toward the outside of the vehicle width) on the y axis, and the right crossing judgment line LR extends from the right rear corner of the vehicle V in the +y axis direction (toward the outside of the vehicle width) on the y axis. The lengths of the left and right crossing judgment lines LL and LR are the same (for example, about 1.3 [m]), and in this embodiment, are approximately equal to the lengths of the regions RL and RR in the y axis direction at the left and right rear corners of the vehicle V. The lengths of the left and right intersection determination lines LL and LR are preset through experiments or simulations so that if a target passes any position on these determination lines LL and LR while an occupant of the vehicle V is getting off, there is a possibility that the target may come into contact with the door or occupant of the vehicle V.

When the vehicle V is stopped, the ECU 10 calculates the velocity vector A of the target (the other vehicle Vt in the example of FIG. 2) based on the target information and sets the starting point of the vector to the proximity portion np of the target. The proximity portion np is the portion of the front end of the target that is closest to the vehicle V in the y-axis direction. The velocity vector A can be calculated, for example, by the time differentiation of the target position (distance and direction).

When an extension line of the target's speed vector A intersects with either the left or right intersection judgment line LL or LR, the ECU 10 calculates the "time predicted to be required for the target to intersect with the intersection judgment line L (in other words, the time predicted to be required for the target to reach the intersection point between the extension line of the target's speed vector A and the intersection judgment line L)" as the TTC. The TTC can be calculated using the target information, for example, by dividing the "distance from the proximity part np to the intersection point" by the "current speed of the target."

If the TTC when the target object will cross the left crossing judgment line LL in the future is equal to or less than TTCth, the ECU 10 judges that the target object may hinder the occupants from safely disembarking from the left door, and detects the target object as an obstruction target for the left door.
On the other hand, if the TTC when the target object will cross the right crossing judgment line LR in the future is equal to or less than TTCth, the ECU 10 determines that the target object may hinder the occupants from safely disembarking through the right door, and detects the target object as an obstruction target for the right door.
In these cases, the ECU 10 determines that the condition 2 is satisfied.

On the other hand, if the target object will cross either the left or right crossing judgment line LL or LR in the future but the TTC exceeds TTCth, the ECU 10 determines that the target object is not likely to hinder the occupants from safely disembarking (at this time) and does not detect the target object as an obstruction object.
In contrast, if the extension line of the target's velocity vector A does not intersect with either of the left and right intersection determination lines LL, LR, the TTC cannot be calculated, and therefore the ECU 10 does not detect the target as an obstructing object.
In these cases, the ECU 10 determines that the condition 2 is not satisfied.

In the example of FIG. 2, the other vehicle Vt will cross the right crossing judgment line LR in the future according to the current speed vector A. Therefore, the ECU 10 calculates the TTC for the other vehicle Vt, and if the TTC is equal to or less than TTCth, it detects the other vehicle Vt as an obstruction target for the right door, and if the TTC exceeds TTCth, it does not detect the other vehicle Vt as an obstruction target.

Next, condition 3 will be described. If the ECU 10 determines that the door on the side where the obstruction object is detected is open based on the signal obtained from the door opening/closing sensor 13, it determines that condition 3 is met.

When the warning condition is satisfied, the ECU 10 judges whether or not the specific condition is satisfied for the obstruction object that satisfies the warning condition. The specific condition was set as follows. That is, the inventors of the present application assumed, through experiments and/or simulations, a situation in which an object that is not actually an obstruction object (in other words, an object that does not ultimately pass beside the vehicle, i.e., does not pass the intersection judgment line L) is temporarily erroneously detected as an obstruction object due to a change in the traveling direction (i.e., condition 2 is satisfied) in multiple patterns. Then, during the period in which the object is erroneously detected, the characteristics of the object observed in common in these multiple patterns were extracted. Here, the multiple patterns can be assumed by changing various parameters such as the trajectory, speed, and acceleration (including deceleration) of the object, and the orientation of the vehicle (i.e., the orientation of the vehicle in the longitudinal direction relative to the extension direction of the lane). The following conditions a to e are conditions introduced based on the extracted characteristics. In this embodiment, the ECU 10 judges that the specific condition is satisfied when all of conditions a to e are satisfied.

(Condition a) The magnitude of the rate of change |ω| of the angle θ between the longitudinal direction of the host vehicle and the traveling direction of the obstruction object is equal to or greater than a predetermined rate of change threshold ωth.
(Condition b) The obstruction target is located outside the left and right intersection determination lines LL and LR in the y-axis direction.
(Condition c) The magnitude |vy| of the y-axis component of the velocity v of the obstruction target is greater than a predetermined velocity threshold value vyth.
(Condition d) The magnitude |θ| of the angle θ is equal to or greater than a predetermined angle threshold θth.
(Condition e) The movement amount ratio Δx/Δy, which is the ratio of the total movement amount Δx in the x-axis direction to the total movement amount Δy in the y-axis direction of the obstruction target during the period from the time the obstruction target is first detected by the radar sensor 12 to the present time, is less than a predetermined movement amount ratio threshold (Δx/Δy)th.

First, condition a will be described. The ECU 10 calculates the angle between the x-axis and the velocity vector A of the obstruction object as angle θ, and calculates the absolute value of the time differential of angle θ as the magnitude of the rate of change of angle θ, |ω|. Condition a is met when the obstruction object satisfies |ω|≧ωth. According to experiments and/or simulations, in any pattern, the angle θ changes at a relatively large rate of change during the period in which the object is erroneously detected as an obstruction object. For this reason, condition a is introduced. The change rate threshold ωth is set to a value that makes it easy for |ω|≧ωth to be met during such a period, and makes it difficult for |ω|≧ωth to be met when the obstruction object does not change its traveling direction.

Next, condition b will be described. Condition b is satisfied when the magnitude |npy| of the y coordinate of the proximal portion np of the obstruction target is greater than the magnitude |Ly| of the y coordinate of the end of the intersection determination line L. According to experiments and/or simulations, in any pattern, |npy|>|Ly| is satisfied during the period in which the target is erroneously detected as an obstruction target. For this reason, condition b was introduced. In other words, condition b can be said to be a condition that is satisfied when the distance d in the y-axis direction from the rear end center of the vehicle (i.e., the origin) to the proximal portion np of the obstruction target exceeds a predetermined distance threshold (|Ly| in this embodiment). However, the distance d is not limited to a configuration based on the rear end center of the vehicle, and may be, for example, a distance based on the rear corner on the side where the obstruction target is located with respect to the x-axis, among the left and right rear corners of the vehicle. In addition, the distance threshold is not limited to |Ly|, and may be, for example, a value obtained by adding a predetermined margin to |Ly|.

Next, condition c will be explained. Condition c is satisfied when the obstruction target satisfies |vy|>vyth. According to experiments and/or simulations, in any pattern, during the period in which the target is erroneously detected as an obstruction target, the target moves at a speed v such that the magnitude |vy| of the y-axis component is a relatively large value. For this reason, condition c is introduced. Note that the speed threshold vyth is set to a value that makes it easy for |vy|>vyth to be satisfied during such a period, and makes it difficult for |vy|>vyth to be satisfied when the obstruction target does not change its direction of travel.

Next, condition d will be explained. Condition d is satisfied when the obstruction target satisfies |θ|≧θth. Experiments and/or simulations have shown that in any pattern, the magnitude of the angle θ, |θ|, is a relatively large value during the period in which the target is erroneously detected as an obstruction target. For this reason, condition d is introduced. The angle threshold θth is set to a value that makes it easy for |θ|≧θth to be satisfied during such a period, and makes it difficult for |θ|≧θth to be satisfied when the obstruction target does not change its direction of travel.

Finally, condition e will be explained. When the radar sensor 12 detects a target, the ECU 10 calculates a total movement amount Δy by integrating the movement amount (positive value) of the target in the y-axis direction during the period from the time when the target was first detected to the current time, and calculates a total movement amount Δx by integrating the movement amount (positive value) of the target in the x-axis direction during the same period. Condition e is satisfied when the obstruction target satisfies Δx/Δy<(Δx/Δy)th. According to experiments and/or simulations, in any pattern, during the period when the target is erroneously detected as an obstruction target, the target moves with a relatively small movement amount ratio Δx/Δy (in other words, the target moves so that the total movement amount Δy in the y-axis direction is larger than the total movement amount Δx in the x-axis direction). For this reason, condition e was introduced. The movement ratio threshold (Δx/Δy)th is set to a value that makes it easier for Δx/Δy<(Δx/Δy)th to hold during such a period, and makes it harder for Δx/Δy<(Δx/Δy)th to hold when the obstruction target has not changed its direction of travel.

When all of conditions a through e are met, it is highly likely that the obstruction target (or the target determined to be an obstruction target) has changed its direction of travel. In other words, the specific condition is a condition that is highly likely to be met when the obstruction target has changed its direction of travel. When the specific condition is met, the ECU 10 determines that the "target determined to be an obstruction target due to the satisfaction of condition 2" is not actually an obstruction target (i.e., condition 2 has only been temporarily met due to the target changing its direction of travel), and does not execute warning control. On the other hand, when the specific condition is not met, the ECU 10 determines that it is unlikely that the obstruction target has changed its direction of travel (i.e., it is highly likely that the target is actually an obstruction target), and executes warning control.

The effect of the specific condition will be described with reference to Figures 3A and 3B. Both Figures 3A and 3B show a situation in which an occupant is about to exit the stopped vehicle V by opening the right door (i.e., a situation in which conditions 1 and 3 are met), and another vehicle Vt is approaching the vehicle V from behind while changing lanes to the left. As shown in Figures 3A and 3B, the lane-changing trajectory of the other vehicle Vt is the same in both figures.

The situation illustrated in Figures 3A and 3B may typically occur in countries where driving on the left side is mandatory (a country where a lane layout is adopted in which the oncoming lane is located on the right side of the driving lane). In countries where driving on the right side is mandatory (a country where a lane layout is adopted in which the oncoming lane is located on the left side of the driving lane), a similar situation may occur when the occupant of the host vehicle V opens the left door to exit the vehicle when the other vehicle Vt in Figures 3A and 3B is moved symmetrically about the x-axis. However, in countries where driving on the left side is mandatory, a situation in which unnecessary activation of the alarm control occurs is not limited to when the occupant attempts to exit the vehicle through the right door, but may also occur when the occupant attempts to exit the vehicle through the left door. This is also true in countries where driving on the right side is mandatory.

First, FIG. 3A will be described. States S1 to S5 in FIG. 3A show the process of the other vehicle Vt changing lanes over time. Specifically, state S1 shows the state at the time when the lane change is started, state S3 shows the state at the time when the amount of steering to the left is maximum, and state S5 shows the state at the time when the lane change is completed. State S2 shows the state of the other vehicle Vt at one point in the process of transitioning from state S1 to state S3, and state S4 shows the state of the other vehicle Vt at one point in the process of transitioning from state S3 to state S5. Arrows A1 to A5 show the speed vectors of the other vehicle Vt in states S1 to S5, respectively.

After the other vehicle Vt finishes changing lanes in state S5, it is considered that the other vehicle Vt will move straight in the direction of the speed vector A5 at this time point. As shown in FIG. 3A, the extension line of the speed vector A5 does not intersect with either of the left and right intersection determination lines LL and LR. Therefore, the other vehicle Vt in this example does not correspond to an obstruction object. In other words, there is no need to execute warning control for the other vehicle Vt.
In addition, the extension lines of the velocity vectors A1 and A3 of the other vehicle Vt in the states S1 and S3 do not intersect with either of the left and right intersection determination lines LL and LR. Therefore, when the other vehicle Vt is in any of the states S1, S3, or S5, the other vehicle Vt is not detected as an obstruction object.

In contrast, the extensions of the speed vectors A2 and A4 of the other vehicle Vt in states S2 and S4 intersect with the right crossing judgment line LR and the left crossing judgment line LL, respectively. In the example of FIG. 3A, if we assume that TTC≦TTCth always holds for the other vehicle Vt, the other vehicle Vt is detected as an obstruction target in the period in which the extensions of the speed vector A of the other vehicle Vt intersect with the right crossing judgment line LR and the left crossing judgment line LL in the process of the other vehicle Vt transitioning from state S1 to state S3 (hereinafter also referred to as the "first crossing period") and in the period in which the extensions of the speed vector A of the other vehicle Vt intersect with the left crossing judgment line LL and the right crossing judgment line LR in the process of the other vehicle Vt transitioning from state S3 to state S5 (hereinafter also referred to as the "second crossing period"). As a result, the warning condition is established in the first and second crossing periods.

Therefore, the ECU 10 judges whether the specific condition is satisfied in the first and second intersection periods. In this example, the other vehicle Vt changes its traveling direction due to a lane change. Therefore, it is considered that |ω|≧ωth (condition a), |vy|＞vyth (condition c), |θ|≧θth (condition d), and Δx/Δy＜(Δx/Δy)th (condition e) are all satisfied in the first and second intersection periods. Also, as is clear from FIG. 3A, |npy|＞|Ly| (condition b) is satisfied in the first and second intersection periods. Therefore, the ECU 10 judges that the specific condition is satisfied and does not execute warning control for the other vehicle Vt. That is, even if the other vehicle Vt is detected as an obstruction target in the first and second intersection periods and the warning condition is satisfied as a result, when the specific condition is satisfied, the ECU 10 judges that the other vehicle Vt has been temporarily erroneously detected as an obstruction target due to a change in traveling direction, and does not execute warning control. This configuration prevents unnecessary activation of the alarm control.

Next, FIG. 3B will be described. States S6 to S10 in FIG. 3B show the process of the other vehicle Vt changing lanes over time. Specifically, state S6 shows the state at the time when the lane change is started, state S8 shows the state at the time when the leftward steering amount is at its maximum, and state S10 shows the state at the time when the lane change is completed. State S7 shows the state of the other vehicle Vt at one point in the process of transitioning from state S6 to state S8, and state S9 shows the state of the other vehicle Vt at one point in the process of transitioning from state S8 to state S10. Arrows A6 to A10 show the speed vectors of the other vehicle Vt in states S6 to S10, respectively.

After the other vehicle Vt finishes changing lanes in state S10, it is considered that the other vehicle Vt moves straight in the direction of the speed vector A10 at this time point. As shown in FIG. 3B, an extension line of the speed vector A10 intersects with the right crossing determination line LR. Therefore, the other vehicle Vt in this example corresponds to an obstruction target. In other words, it is necessary to execute a warning control for the other vehicle Vt.
On the other hand, the extension lines of the velocity vectors A6 and A8 of the other vehicle Vt in states S6 and S8 do not intersect with either of the left and right intersection determination lines LL and LR. Therefore, when the other vehicle Vt is in either state S6 or S8, the other vehicle Vt is not detected as an obstruction object.

On the other hand, the extensions of the speed vectors A7 and A9 of the other vehicle Vt in states S7 and S9 intersect with the right crossing judgment line LR and the left crossing judgment line LL, respectively. Here, assuming that TTC≦TTCth is always satisfied for the other vehicle Vt in the example of FIG. 3B, the other vehicle Vt is detected as an obstruction target in the period in which the extensions of the speed vector A of the other vehicle Vt intersect with the right crossing judgment line LR and the left crossing judgment line LL in the process of the other vehicle Vt transitioning from state S6 to state S8 (hereinafter also referred to as the "third crossing period") and in the period in which the extensions of the speed vector A of the other vehicle Vt intersect with the left crossing judgment line LL and the right crossing judgment line LR in the process of the other vehicle Vt transitioning from state S8 to state S10 (hereinafter also referred to as the "fourth crossing period"). As a result, the warning condition is satisfied in the third and fourth crossing periods. In this example, the time point of state S10 is included in the fourth crossing period.

Therefore, the ECU 10 judges whether the specific condition is satisfied in the third and fourth intersection periods. In this example, the other vehicle Vt changes its traveling direction due to a lane change. Therefore, it is considered that |ω| ≧ ωth (condition a), |vy| > vyth (condition c), |θ| ≧ θth (condition d), and Δx/Δy < (Δx/Δy)th (condition e) are all satisfied in the third and fourth intersection periods. However, as is clear from FIG. 3B, although |npy| > |Ly| (condition b) is satisfied in the third intersection period, |npy| > |Ly| (condition b) is not satisfied in the fourth intersection period. Therefore, the ECU 10 judges that the specific condition is satisfied in the third intersection period and does not execute warning control, but judges that the specific condition is not satisfied in the fourth intersection period because condition b is not satisfied, and executes warning control.

In addition, during the period from the end of the fourth intersection period (i.e., the time of state S10) to the time when the other vehicle Vt (strictly speaking, the nearby portion np) passes the right intersection determination line LR, the other vehicle Vt is detected as an obstruction target, and the warning condition is satisfied. Therefore, the ECU 10 judges whether the specific condition is satisfied during this period as well. As is clear from FIG. 3B, it is considered that none of conditions a, c, d, and e are satisfied during this period. Furthermore, since |npy|<|Ly|, condition b is also not satisfied. Therefore, the ECU 10 judges that the specific condition is not satisfied during this period due to the non-satisfaction of conditions a to e, and executes warning control.

That is, in the example of FIG. 3B, the ECU 10 executes warning control for the other vehicle Vt during the period from the start of the fourth intersection period to the time when the other vehicle Vt passes the right intersection determination line LR. With this configuration, warning control is executed appropriately when the target actually corresponds to an obstruction target. In other words, it becomes less likely that a situation will occur in which warning control is not executed even when it is actually necessary due to the introduction of a specific condition.

According to conventional disembarkation support devices, when an alarm condition is met, alarm control is executed, and therefore, even if an object is not actually an obstruction object, if it is erroneously detected as an obstruction object due to a change in the direction of travel, alarm control is executed, resulting in unnecessary operation. In contrast, according to the present embodiment, as illustrated in Figs. 3A and 3B, when an alarm condition is met, alarm control is not executed immediately, but a determination is made as to whether or not a specific condition is met, and alarm control is executed only when the specific condition is not met. Therefore, when an alarm control is actually required, the control is executed appropriately, while unnecessary operation of the control is suppressed, and the reliability of the alarm control can be improved.

(Specific operation)
Next, a description will be given of a specific operation of the ECU 10. The CPU of the ECU 10 is configured to repeatedly execute the routines shown in the flowcharts of Figures 4 to 6 in this order every time a predetermined time period elapses while power is being supplied to the ECU 10 (described later).

At a predetermined timing, the CPU starts processing from step 400 in FIG. 4 and proceeds to step 410, where it determines whether or not the host vehicle is in a stopped state based on the vehicle speed obtained from the vehicle speed sensor 11 (condition 1). If the host vehicle is in a moving state, the CPU determines "No" at step 410 (i.e., determines that condition 1 is not satisfied (the warning condition is not satisfied)), proceeds to step 495, and temporarily ends this routine. On the other hand, if the host vehicle is in a stopped state, the CPU determines "Yes" at step 410 (i.e., determines that condition 1 is satisfied), and proceeds to step 420.

In step 420, the CPU determines whether or not a target has been detected based on the target information acquired from the radar sensor 12. If a target has not been detected, the CPU determines "No" in step 420, proceeds to step 495, and temporarily ends this routine. On the other hand, if a target has been detected, the CPU determines "Yes" in step 420, and proceeds to step 430.

In step 430, the CPU calculates the velocity vector A of the detected target based on the target information, and if an extension line of the velocity vector A intersects with either the left or right crossing determination line LL or LR, it calculates the TTC for that target. The CPU then proceeds to step 440.

In step 440, the CPU determines whether TTC≦TTCth is true for the detected target (condition 2). If TTC>TTCth, the CPU determines "No" in step 440 (i.e., determines that condition 2 is not true (the warning condition is not true)), proceeds to step 495, and ends this routine. On the other hand, if TTC≦TTCth, the CPU determines "Yes" in step 440 (i.e., determines that condition 2 is true (the target is an obstructing target)), and proceeds to step 450.

In step 450, the CPU determines whether the door (the door on the side where the obstruction target was detected) is open based on the signal obtained from the door opening/closing sensor 13. If the door is closed, the CPU determines "No" in step 450 (i.e., determines that condition 3 is not met (the alarm condition is not met)), proceeds to step 495, and ends this routine. On the other hand, if the door is open, the CPU determines "Yes" in step 450 (i.e., determines that condition 3 is met), proceeds to step 460, and determines that the alarm condition is met. The CPU then proceeds to step 495, and ends this routine.

If it is determined in step 460 that the warning condition is met, the CPU starts processing from step 500 in FIG. 5 and proceeds to step 510, where it determines whether the target determined as "Yes" in step 440 in FIG. 4 (i.e., the obstruction target) satisfies |ω|≧ωth (condition a). If |ω|<ωth, the CPU determines "No" in step 510 (i.e., determines that condition a is not met (the specific condition is not met)), proceeds to step 595, and ends this routine for the time being. On the other hand, if |ω|≧ωth, the CPU determines "Yes" in step 510 (i.e., determines that condition a is met), and proceeds to step 520.

In step 520, the CPU determines whether the obstruction target satisfies |npy|>|Ly| (condition b). If |npy|≦|Ly|, the CPU determines "No" in step 520 (i.e., determines that condition b is not met (specific condition is not met)), proceeds to step 595, and temporarily ends this routine. On the other hand, if |npy|>|Ly|, the CPU determines "Yes" in step 520 (i.e., determines that condition b is met), and proceeds to step 530.

In step 530, the CPU determines whether the obstruction target satisfies |vy|>vyth (condition c). If |vy|≦vyth, the CPU determines "No" in step 530 (i.e., determines that condition c is not met (the specific condition is not met)), proceeds to step 595, and temporarily ends this routine. On the other hand, if |vy|>vyth, the CPU determines "Yes" in step 530 (i.e., determines that condition c is met), and proceeds to step 540.

In step 540, the CPU determines whether the obstruction target satisfies |θ|≧θth (condition d). If |θ|<θth, the CPU determines "No" in step 540 (i.e., determines that condition d is not met (the specific condition is not met)), proceeds to step 595, and temporarily ends this routine. On the other hand, if |θ|≧θth, the CPU determines "Yes" in step 540 (i.e., determines that condition d is met), and proceeds to step 550.

In step 550, the CPU determines whether the obstruction target satisfies Δx/Δy<(Δx/Δy)th (condition e). If Δx/Δy≧(Δx/Δy)th, the CPU determines "No" in step 550 (i.e., determines that condition e does not hold (the specific condition does not hold)) and proceeds to step 595 to temporarily end this routine. On the other hand, if Δx/Δy<(Δx/Δy)th, the CPU determines "Yes" in step 550 (i.e., determines that condition e holds) and proceeds to step 560 to determine that the specific condition holds. The CPU then proceeds to step 595 to temporarily end this routine.

Then, the CPU starts processing from step 600 in FIG. 6 and proceeds to step 610, where it determines whether or not the warning condition is met based on the determination result of the routine in FIG. 4. If the warning condition is not met (if the determination is "No" in any of steps 410, 420, 440, or 450), the CPU determines "No" in step 610, proceeds to step 695, and temporarily ends this routine. In other words, the CPU does not execute warning control. On the other hand, if the warning condition is met (step 460), the CPU determines "Yes" in step 610, and proceeds to step 620.

In step 620, the CPU determines whether or not a specific condition is satisfied based on the determination result of the routine in FIG. 5. If the specific condition is not satisfied (if the determination is "No" in any of steps 510, 520, 530, 540, or 550), the CPU determines "No" in step 620 (i.e., determines that a situation requires warning control) and proceeds to step 630. In step 630, the CPU sends a drive command to the buzzer 20 to sound the buzzer 20. This executes warning control. The CPU then proceeds to step 695 and temporarily ends this routine.

On the other hand, if the specific condition is met (step 560), the CPU judges "Yes" in step 620 (i.e., it judges that the alarm condition is met only because an object that is not actually an obstruction object has been erroneously detected as an obstruction object due to a change in direction of travel), and proceeds to step 695 and ends this routine for the time being. In other words, the CPU does not execute alarm control. This makes it possible to appropriately execute alarm control in situations where it is actually necessary, while suppressing unnecessary operation of the control, thereby improving the reliability of the alarm control. After that, the CPU proceeds to step 695 and ends this routine for the time being.

The power supply to the ECU 10 continues even after the ignition switch is turned off until a predetermined condition is met. This condition may be configured to be met, for example, when the doors are locked, or when a predetermined stop time has elapsed since the vehicle was stopped. This configuration reduces the possibility that warning control will not be executed when it is necessary, and allows warning control to be executed more appropriately.

The above describes the disembarking assistance device according to this embodiment, but the present invention is not limited to the above embodiment, and various modifications are possible without departing from the purpose of the present invention.

For example, in the above embodiment, the specific condition is satisfied when all of conditions a to e are satisfied, but the requirements for the specific condition to be satisfied are not limited to this. For example, the specific condition may be configured to be satisfied when condition a is satisfied. When the alarm condition is satisfied and |ω|≧ωth is satisfied, it is highly likely that the target has been erroneously detected as an obstructing target due to a change in the travel direction. Therefore, even if the specific condition is configured to be satisfied when only condition a is satisfied, unnecessary operation of the alarm control can be suppressed. Alternatively, the specific condition may be configured to be satisfied when condition a and at least one of conditions b to e are satisfied.

In addition, in the above embodiment, alarm control is executed as the disembarkation assistance control, but the type of disembarkation assistance control is not limited to this. For example, door opening restriction control that restricts the degree of door opening, or door lock control that locks the door may be executed as the disembarkation assistance control. Alternatively, in addition to alarm control, door opening restriction control or door lock control may be executed as the disembarkation assistance control.

In addition, in the above embodiment, the process of sounding the buzzer 20 is executed as the warning control, but the contents of the warning control process are not limited to this. For example, the following processes may be executed as warning control instead of or in addition to the process of sounding the buzzer 20: turning on the side mirror indicator (an indicator provided at a predetermined position on each of the left and right side mirrors of the vehicle) on the side where the obstruction object is detected, displaying a predetermined mark on the meter panel (e.g., a mark indicating whether the obstruction object is approaching from the left rear or the right rear), and/or having a speaker (a component of the navigation system) speak a predetermined message (e.g., a message saying "Please be careful of approaching vehicles").

In addition, in the above embodiment, condition 2 is met when TTC≦TTCth is met for the target, but the requirements for meeting condition 2 are not limited to this. For example, condition 2 may be met when TTC≦TTCth for the target continues for a predetermined duration. Condition 3 may be met when the door on the side where the obstruction target is detected changes from a closed state to an open state. Alternatively, condition 3 may be met when an occupant is detected operating a door operating part (typically an inner door lever) based on image data captured by a camera installed inside the vehicle (a camera capable of capturing an image of an occupant inside the vehicle).

In addition, in the above embodiment, the alarm condition is satisfied when all of conditions 1 to 3 are satisfied, but the requirements for the alarm condition to be satisfied are not limited to this. For example, the alarm condition does not have to include condition 3, and may be configured to be satisfied when conditions 1 and 2 are satisfied. In other words, the alarm control may be configured to be executed regardless of whether or not the occupant intends to exit the vehicle.

Alternatively, the warning control may be executed in two stages. Specifically, the warning control includes two types of control, namely, normal warning control and mild warning control (control with a milder degree of assistance than the normal warning control). The mild warning control is, for example, a control that executes the above-mentioned side mirror indicator lighting process, and the normal warning control is, for example, a control that executes at least one of the above-mentioned "buzzer sounding process, mark display process on the meter panel, and speaker speech process" in addition to the side mirror indicator lighting process. The mild warning control is executed when Condition 1 and Condition 2 are satisfied (i.e., an obstruction target is detected while the vehicle is stopped, but the door is closed). The normal warning control is executed when Condition 3 is further satisfied in addition to Condition 1 and Condition 2 (i.e., an obstruction target is detected while the vehicle is stopped and the door is open).
When the door is closed, it is not possible to determine whether the occupant is about to exit the vehicle through the door. In other words, there are two possibilities: the occupant has the intention to exit the vehicle but has not yet opened the door, and the occupant has no intention to exit the vehicle and the door will continue to be kept closed. Therefore, by executing the mild warning control when the door is closed, it is possible to simultaneously "notify the occupant who has the intention to exit the vehicle of the presence of an obstruction target in advance" and "prevent the occupant who has no intention to exit the vehicle from feeling annoyed due to the execution of the normal warning control."
When all of the conditions 1 to 3 are satisfied, the above-described door opening restriction control or door lock control may be executed as the disembarking assistance control instead of the normal warning control. Alternatively, the door opening restriction control or door lock control may be executed as the disembarking assistance control in addition to the normal warning control.

Furthermore, in the above embodiment, the crossing determination line L is introduced and an obstruction target is detected based on the TTC of the target, but the method of detecting an obstruction target is not limited to this. For example, a virtual area (more specifically, an area within the irradiation range of the radar sensor 12) having a predetermined size and shape may be set behind the vehicle (typically on the left rear side and the right rear side), and if a target detected by the radar sensor 12 is located within this area, the target is detected as an obstruction target. In this case, the shape of the area is not particularly limited and may be, for example, a trapezoid or a rectangle.

10: Exit assistance ECU, 11: Vehicle speed sensor, 12: Radar sensor, 13: Door opening/closing sensor, 20: Buzzer

Claims (6)

a target information acquisition device that detects a target present behind the vehicle and acquires information about the detected target as target information;
a control unit capable of executing a vehicle exit assistance control for assisting a passenger in safely exiting the vehicle;
In the disembarking assistance device,
The control unit
determining whether or not an obstruction target that may obstruct the safe disembarking of the occupant while the vehicle is stopped is detected based on the target information;
determining whether or not a dismounting assistance condition is satisfied when at least the obstruction object is detected;
If the dismount assistance condition is satisfied, it is determined whether or not a specific condition is satisfied when a magnitude of a rate of change of an angle between a forward/rearward direction of the host vehicle and a traveling direction of the obstruction target is equal to or greater than a predetermined rate of change threshold;
When the specific condition is not satisfied, the vehicle dismounting assistance control is executed.
When the specific condition is satisfied, the vehicle dismount assistance control is not executed.
It was configured as follows:
Disembarkation assistance device. The dismounting support device according to claim 1,
When a portion of the front end of the obstruction target that is closest to the host vehicle in the vehicle width direction of the host vehicle is defined as a proximate portion,
The control unit
Furthermore, it is determined that the specific condition is satisfied when a distance in the vehicle width direction from the host vehicle to the nearby portion of the obstruction target exceeds a predetermined distance threshold.
It was configured as follows:
Disembarkation assistance device. The dismounting support device according to claim 1,
A portion of a front end of the obstruction target that is closest to the host vehicle in a vehicle width direction of the host vehicle is defined as a proximate portion;
If imaginary lines each having a predetermined length extending from the left and right rear corners of the vehicle in a vehicle widthwise outward direction are defined as intersection determination lines,
The control unit
When the detected target passes through the intersection judgment line assuming that the target continues to move along the current traveling direction, if a predicted time required for the target to cross the intersection judgment line is equal to or less than a predetermined time threshold, the target is determined to be an obstruction target.
It is structured as follows:
Furthermore, it is determined that the specific condition is satisfied when the adjacent portion of the obstruction target is located in a vehicle width direction outside an end of the intersection determination line.
It was configured as follows:
Disembarkation assistance device. The dismounting support device according to any one of claims 1 to 3,
The control unit
Furthermore, it is determined that the specific condition is satisfied when the magnitude of the speed of the obstruction object in a vehicle width direction of the host vehicle is greater than a predetermined speed threshold value.
It was configured as follows:
Disembarkation assistance device. The dismounting support device according to any one of claims 1 to 4,
The control unit
Furthermore, it is determined that the specific condition is satisfied when the magnitude of an angle formed between the forward/rearward direction of the host vehicle and the traveling direction of the obstruction object is equal to or greater than a predetermined angle threshold value.
It was configured as follows:
Disembarkation assistance device. The dismounting support device according to any one of claims 1 to 5,
The control unit
Furthermore, it is determined that the specific condition is satisfied when a ratio of a total movement amount of the obstruction object in the front-rear direction to a total movement amount in the vehicle width direction of the host vehicle during a period from a time point when the obstruction object is first detected by the object information acquisition device to a current time point is less than a predetermined movement amount ratio threshold value.
It was configured as follows:
Disembarkation assistance device.

Images