JP2007168504A - Impact energy reducing device in rear-end collision of vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an impact energy reducing device at the time of rear-end collision of a vehicle capable of precluding a contacting interference with any obstacle lying ahead at the time of rear-end collision and also reducing the impact energy due to rear-end collision while the risk of making rear-end collision in the brake stopped condition is avoided. <P>SOLUTION: The impact energy reducing device is equipped with a backward inter-vehicle distance sensor to sense the condition of the following vehicle and an associated collision sensor, a forward inter-vehicle sensor to sense the inter-vehicle distance between any obstacle lying ahead and the vehicle concerned, and a forward movable distance setting means to set the forward movable distance from the stop position of the vehicle to the position not attaining the obstacle on the basis of the sensed value of the inter-vehicle distance given by an inter-vehicle distance sensing means, and a vehicle movement controlling means to weaken the braking force when judgement is such that at least a rear-end collision is possible on the basis of the backward vehicle condition given by a backward vehicle condition sensing means while it is the brake stopped situation, and to admit movement of the vehicle concerned for the forward movable distance set by the forward movable distance setting means. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention belongs to the technical field of a rear impact energy reduction device for a vehicle that reduces impact energy when a rear vehicle collides with the host vehicle.

2. Description of the Related Art Conventionally, there has been known one that detects the state of a following vehicle during vehicle travel and controls the braking force of an automatic brake so as to reduce the possibility of a collision (see, for example, Patent Document 1).
Japanese Patent Laid-Open No. 2001-122094

  However, the conventional automatic brake control device does not disclose any countermeasures in the case where the rear collision cannot be avoided when the brake is stopped, and the succeeding vehicle collides with the stopped own vehicle. In the case of the collision input from the following vehicle, the vehicle receives the collision input as it is, and the impact force peak value immediately after the collision becomes high, that is, the impact energy at the time of the rear collision cannot be reduced. was there.

  The present invention has been made paying attention to the above-mentioned problem. While preventing a rear collision when the brake is stopped, the present invention prevents contact interference with a front obstacle at the time of a rear collision and reduces impact energy due to the rear collision. It is an object of the present invention to provide a rear impact impact energy reduction device for a vehicle that can achieve the above.

In order to achieve the above object, in the present invention, a rear impact impact energy reducing device for a vehicle that reduces impact energy when a rear vehicle crashes against the host vehicle,
A rear vehicle state detecting means for detecting the state of the rear vehicle;
An inter-vehicle distance detecting means for detecting an inter-vehicle distance between the host vehicle and a front obstacle;
Based on the inter-vehicle distance detection value from the inter-vehicle distance detection means, a forward movable distance setting means for setting a forward movable distance from a stop position of the own vehicle to a position that does not reach the front obstacle;
When the brake is stopped and when it is determined that there is at least a possibility of a rear collision based on the rear vehicle state from the rear vehicle state detection means, the braking force is weakened and the front set by the forward movable distance setting means Own vehicle movement control means for allowing the movement of the own vehicle for a moving distance;
It is provided with.

Therefore, in the rear impact energy reduction device for a vehicle according to the present invention, when the brake is stopped, it is determined that there is a possibility of at least a rear impact based on the rear vehicle state from the rear vehicle state detection means. In the own vehicle movement control means, the braking force is weakened, and the movement of the own vehicle is permitted for a distance that allows forward movement from the stop position of the own vehicle to a position that does not reach the front obstacle.
That is, based on the judgment that there is a possibility of a rear-end collision with the brake-stopped vehicle, the braking force is weakened before the rear-end collision, and the vehicle is moved forward by the driver's accelerator operation, or When the host vehicle is automatically moved forward by applying the starting torque, it is possible to avoid a rear collision of the rear vehicle with respect to the host vehicle. However, the avoidance of rear collision is performed when the condition that the forward movement of the own vehicle starts at an earlier timing than the contact of the rear vehicle and the braking distance of the rear vehicle is shorter than the forward movement distance of the own vehicle is satisfied. Limited.
On the other hand, when there is a possibility of a rear-end collision with the vehicle in the brake stopped state, regardless of the forward movement of the own vehicle, or when the rear-end collision with the vehicle in the brake stopped state In addition, the braking force is weakened, and the vehicle is allowed to move for a distance that allows forward movement. For this reason, when the own vehicle escapes forward so as to receive the collision input from the rear vehicle, the collision input received by the own vehicle is alleviated, and the impact force peak value at the time of the collision is lowered. That is, the impact energy can be significantly reduced at the time of rear collision.
Furthermore, since the forward movable distance that allows the vehicle to move forward is defined from the stop position of the vehicle to a position that does not reach the front obstacle, the vehicle is allowed to move forward while allowing the vehicle to move forward. It is possible to reliably prevent contact interference with the front obstacle.
As a result, it is possible to achieve both the prevention of the contact interference with the front obstacle and the reduction of the impact energy due to the rear collision while the rear collision can be avoided in the brake stop state.

  BEST MODE FOR CARRYING OUT THE INVENTION The best mode for carrying out the rear impact energy reduction device for a vehicle according to the present invention will be described below based on Examples 1 to 3 shown in the drawings.

First, the configuration will be described.
FIG. 1 is an overall system diagram showing a hybrid vehicle (an example of a vehicle) to which the rear impact impact energy reducing device of Embodiment 1 is applied.

  As shown in FIG. 1, the hybrid vehicle according to the first embodiment includes a CPU 101, an auxiliary battery 102, a brake actuator 201, a mechanical brake 202, a high-power battery 301, an inverter 302, a motor 303, and a generator 304. Engine 305, power split mechanism 306, accelerator sensor 401, brake sensor 402, DC / DC converter 403, front inter-vehicle sensor 404 (inter-vehicle distance detecting means), and rear inter-vehicle sensor 405 (rear vehicle state detecting means) ), A shift position sensor 406, a direction indicator 501, an alarm device 502, and a collision sensor 503 (rear vehicle state detection means).

The CPU 101 monitors the high-power battery 301, calculates the input / output possible electric energy according to the SOC, temperature, and deterioration state, and controls the inverter 302 based on this to control the motor 303 (for front drive) and power generation. The machine 304 is operated and the engine 305 is controlled (including distribution of driving force between the motor and the engine).
Further, the CPU 101 considers the regenerative braking force by the motor 303 and transmits a braking force calculation command value (including front / rear braking force distribution) generated by the mechanical brake 202 to the brake actuator 201. In this proposal, a brake release / brake operation command is issued to the brake actuator 201 at an appropriate timing.
The CPU 101 collects the inter-vehicle distance and size between the host vehicle and the front vehicle (front obstacle) based on the signal from the front inter-vehicle sensor 404, and uses the signal from the rear inter-vehicle sensor 405 to detect the relative vehicle speed and the rear vehicle. Understand the possibility of a rear-end collision depending on the distance to the vehicle.
Further, when implementing the proposal, the shift position selected by the driver is grasped by the shift position sensor 406.
The vehicle speed is basically determined based on the number of rotations of the motor 303.
Finally, whether or not a rear collision has occurred is determined from the detection value from the collision sensor 503.

  The auxiliary battery 102 serves to provide an operating power source for the CPU 101. In this system, power is supplied by a DC / DC converter 403 that uses a high-power battery 301 as a power source.

  The brake actuator 201 receives a friction braking force calculation command value to be generated by the mechanical brake 202 calculated by the CPU 101, and applies a necessary hydraulic pressure to the mechanical brake 202 accordingly.

  The mechanical brake 202 generates a braking force according to the hydraulic pressure generated by the brake actuator 201.

  The high-power battery 301 assists the vehicle running by supplying electric power to the motor 303 via the inverter 302, and collects the electric power generated by the motor 303 and the generator 304 via the inverter 302. Have

  The inverter 302 is directly controlled by the CPU 101. The electric energy of the high-power battery 301 is supplied to the motor 303 according to the generated torque and the rotation speed of the engine 305, and the electric energy generated by operating the generator 304 is returned to the high-power battery 301. Since the motor 303, the generator 304, and the engine 305 are directly connected to the planetary gear mechanism (built in the power split mechanism 306), the vehicle operates normally unless controlled to maintain a balance between torque and rotational speed. I can't.

  The motor 303 alone generates drive torque when the vehicle speed is low. Further, when the vehicle speed is high, the driving torque of the engine 305 is assisted. Further, during deceleration, it has a function of generating electric energy by generating power (regenerative braking) and returning it to the high-power battery 301 via the inverter 302.

  The generator 304 basically has no starter in a hybrid electric vehicle. At the start of the vehicle to which this system is applied, power is supplied from the high-power battery 301 and the engine 305 is started by operating as a motor. During normal travel, electric energy is generated (power generation) by balancing the motor 303 and the engine 305 and is returned to the high-power battery 301. Sometimes, it is possible to cope with rapid acceleration by supplying the motor 303 directly.

  The engine 305 is directly controlled by the CPU 101. Specifically, when the vehicle speed is high, torque is generated for driving the vehicle (when the vehicle speed is low, the motor travels, so no control is required: control that does not start up is applied).

  The power split mechanism 306 has a planetary gear mechanism, and an engine 305 is directly connected to the carrier, a motor 303 is connected to the ring gear, and a generator 304 is directly connected to the sun gear. The transmission equivalent of the conventional system is also configured inside.

  The accelerator sensor 401 transmits to the CPU 101 the amount of accelerator pedal stroke that the driver has depressed during acceleration.

  The brake sensor 402 transmits to the CPU 101 the brake pedal stroke amount that the driver has depressed when decelerating.

  The DC / DC converter 403 converts the energy from the high voltage battery 301 into 12V and supplies it to the auxiliary battery 102. That is, it has the same function as an alternator in a conventional engine vehicle.

  The front inter-vehicle sensor 404 collects the distance from the vehicle in front of the host vehicle (or an obstacle) using a radar or the like, and inputs information obtained thereby to the CPU 101.

  The rear inter-vehicle sensor 405 collects the distance from the vehicle behind the host vehicle using a radar or the like, and inputs information obtained thereby to the CPU 101.

  The shift position sensor 406 detects the shift position selected by the driver, and inputs information obtained thereby to the CPU 101.

  In this control, the direction indicator 501 blinks in order to announce that there is a possibility of a collision with a rear vehicle. When the proposed system is in operation, the CPU 101 issues a blink command.

  The alarm device 502 is utilized when announcing to the passenger when the proposed system is in operation. The CPU 101 issues a warning instruction.

  The collision sensor 503 is used when determining whether or not the own vehicle has collided.

  FIG. 2 is a flowchart showing a flow of own vehicle movement control processing for reducing impact energy at the time of rear impact executed by the CPU 101 of the first embodiment. Each step will be described below (own vehicle movement control means).

  In step S1, the detection value of the shift position sensor 406 is confirmed, and the shift position is a position where the shift position can be advanced {D, B (2, S, etc. depending on the vehicle system)} or a neutral position (N), and It is determined whether or not the brake is stopped. If yes, the process proceeds to step S2, and if no, the determination in step S1 is repeated.

In step S2, at the time of selection of a position where advance is possible in step S1 and determination that the vehicle is stopped with brake ON, the relative vehicle speed from the rear vehicle distance sensor 405 and the vehicle behind the vehicle It is determined whether or not the operating point of the rear vehicle according to the distance is within the control application range in which the degree of approach to the host vehicle is high on the control application necessity determination map shown in FIG. If No, the process returns to step S1.
Here, as shown in FIG. 3, the “control application necessity determination map” is a distance to the rear vehicle when the horizontal axis represents the distance to the rear vehicle and the vertical axis represents the relative vehicle speed to the rear vehicle. As the vehicle speed becomes shorter and the vehicle speed relative to the vehicle behind (the vehicle speed approaching the host vehicle) increases, the degree of approach to the host vehicle increases, and this area is set as a control application range, which is set in the memory of the CPU 101 in advance. (Control application necessity determination map setting means).

  In step S3, following the determination that the operating point of the rear vehicle is in the control application range in step S2, the inter-vehicle distance between the host vehicle and the front obstacle is confirmed by the front inter-vehicle sensor 404, and the process proceeds to step S4. Transition.

In step S4, following the confirmation of the inter-vehicle distance between the host vehicle and the front obstacle in step S3, a forward movable distance from the stop position of the host vehicle to a position not reaching the front obstacle is set, and the process proceeds to step S5. (Forward movement possible distance setting means).
Here, the basic setting of the forward movable distance is, for example, by determining the minimum inter-vehicle distance α in consideration of the distance at which the own vehicle comes out in the event of a rear-end collision, and determining the inter-vehicle distance between the own vehicle and the front obstacle. When x, (x−α), that is, the distance from the stop position of the own vehicle to the position that maintains the minimum inter-vehicle distance α with respect to the front obstacle is set as the forward movable distance.
In addition to the above setting based on the distance between the vehicle and the obstacle ahead, whether it is “traffic signal state”, “presence / absence of emergency vehicle”, “travelable road surface (for example, not just before a cliff)” If this is the case, priority is given to the setting according to (x−α), and a forward movable distance in which the host vehicle can move forward is set. For example, in the case of a stop at a red light, an approaching emergency vehicle, or a road surface that cannot be traveled, a limit is imposed on the forward movable distance.

  In step S5, following the setting of the forward movable distance in step S4, the direction indicator 501 is blinked and a warning device 502 is used to occupy the passengers in order to alert the surrounding vehicles (particularly the rear vehicles). It is clearly indicated that this control is applied, and the process proceeds to step S6.

  In step S6, following the warning transmission in step S5, a mechanical brake 202 release command is issued to the brake actuator 201 regardless of the command value of the brake sensor 402, and the process proceeds to step S7.

  In step S7, following the brake release command in step S6 or the determination that the vehicle has not moved to the forward movable distance in step S9, the range of the forward movable distance set in step S4 by the front inter-vehicle sensor 404. Whether or not an obstacle has occurred is determined. If Yes, the process proceeds to step S10. If No, the process proceeds to step S8.

In step S8, following the determination that there is no obstacle within the forward movable distance in step S7, it is determined whether or not the accelerator is ON based on a signal from the accelerator sensor 401. If No, the process proceeds to step S9.
That is, if the accelerator is ON, it can be determined that the vehicle can be freely moved forward by the driver's accelerator operation, and thus this control is terminated.

  In step S9, following the determination that the accelerator is OFF in step S8, it is determined whether or not the vehicle has moved to the forward movable distance set in step S4. If yes, the process proceeds to step S10. In this case, the process returns to step S7.

  In step S10, when it is determined in step S7 that an obstacle has occurred within the forward movable distance, or following the determination in step S9 that the obstacle has moved to the forward movable distance, the mechanical brake is applied to the brake actuator 201. The operation command of 202 is issued, the brake released in step S6 is operated again, and the process proceeds to the end.

Next, the operation will be described.
[Background technology]
Conventionally, when a traveling state with a high possibility of collision is detected based on the vehicle speed detected by the vehicle speed sensor and the distance measured by the distance measuring sensor, the prediction unit generates a collision prediction, and based on the collision prediction, the collision avoidance unit In addition to performing at least one of the vehicle's alarm output and brake control as a collision avoidance process, the avoidance support means improves the driver's visibility so that the headlights when the vehicle is lit are turned on with a high beam or a low beam and a high beam. A technique for controlling the simultaneous lighting is known. With this technology, when there is a high possibility of a collision with a front obstacle such as a preceding vehicle, in addition to the collision avoidance alarm and brake control processing, effective assistance control for collision avoidance is performed, and collision avoidance performance is achieved. (See JP 2005-47383 A).
Further, conventionally, in at least one driving situation, automatic braking technology is known in which the braking force is increased independently of the driver and the increased braking force is reduced or restricted when a collision risk from the rear is detected. It has been. This technology makes it possible to reduce the risk that the following vehicle will collide with the host vehicle while the vehicle is running (Japanese Patent Laid-Open No. 2001-122094).
However, the former conventional technique is a driving assistance technique when there is a high possibility of a collision with a front obstacle such as a preceding vehicle, and the latter conventional technique has a high possibility of a collision from a subsequent vehicle during traveling. When automatic braking technology. That is, none of the techniques is a countermeasure against a rear-end collision such that a rear vehicle collides with the own vehicle while the host vehicle is stopped due to a signal or the like.
Therefore, when the following vehicle collides with the stopped vehicle, the vehicle receives the collision input as it is with respect to the collision input from the following vehicle, and the impact force peak value immediately after the collision becomes high. Impact energy at the time of a collision cannot be reduced.

[Reduction impact energy at rear impact]
On the other hand, in the rear impact energy reduction device of the first embodiment, the brake force is weakened when the brake is stopped and it is determined that there is a possibility of a rear impact, and only the set forward movement distance is obtained. By allowing the vehicle to move, it is possible to avoid a rear collision when the brake is stopped, and at the same time, prevent contact interference with front obstacles and reduce impact energy due to the rear collision. To be able to.

In other words, based on the judgment that there is a possibility of a rear-end collision with the vehicle in the brake-stopped state, the braking force is weakened before the rear-end collision, and the vehicle is moved forward by the driver's accelerator operation (implemented) In the case of Examples 1 and 2), or when the host vehicle is automatically moved forward by applying a starting torque (Example 2), it is possible to avoid a rear collision of the rear vehicle with respect to the host vehicle. However, the avoidance of rear collision is performed when the condition that the forward movement of the own vehicle starts at an earlier timing than the contact of the rear vehicle and the braking distance of the rear vehicle is shorter than the forward movement distance of the own vehicle is satisfied. Limited.
On the other hand, when there is a possibility of a rear-end collision with the host vehicle in the brake stopped state (respective embodiments 1 and 2) regardless of the forward movement of the host vehicle, In the case of collision (Embodiment 3), the braking force is weakened in any case, and the movement of the host vehicle is permitted for the forward movable distance. For this reason, when the own vehicle escapes forward so as to receive the collision input from the rear vehicle, the collision input received by the own vehicle is alleviated, and the impact force peak value at the time of the collision is lowered. That is, the impact energy can be significantly reduced at the time of rear collision.
Furthermore, since the forward movable distance that allows the vehicle to move forward is defined from the stop position of the vehicle to a position that does not reach the front obstacle, the vehicle is allowed to move forward while allowing the vehicle to move forward. It is possible to reliably prevent contact interference with the front obstacle.
As a result, it is possible to achieve both the prevention of the contact interference with the front obstacle and the reduction of the impact energy due to the rear collision while the rear collision can be avoided in the brake stop state.

[Vehicle movement control action when determining the possibility of rear collision]
When the host vehicle is stopped due to a signal waiting or the like, and when the rear vehicle stops while maintaining an appropriate inter-vehicle distance, the flow from step S1 to step S2 is repeated in the flowchart of FIG. It does not enter the own vehicle movement control.
That is, when the host vehicle is stopped and the operating point of the rear vehicle is point A in FIG. 3, when the driver of the rear vehicle decelerates by a brake operation, the relative vehicle speed with respect to the rear vehicle (= the vehicle speed of the rear vehicle) is reduced. Then, the rear vehicle stops at the point B in FIG. 3 that maintains the inter-vehicle distance L1 with the own vehicle. In this case, the operating point of the rear vehicle does not enter the proposed vehicle movement control by moving only in the non-application range.

When the host vehicle is stopped due to a signal waiting or the like and the vehicle moves forward by the driver's accelerator depression operation in response to the approach of the rear vehicle, in the flowchart of FIG. 2, step S1, step S2, step S3, It progresses to step S4-> step S5-> step S6-> step S7-> step S8-> step S9. In step S5, in order to urge a warning to surrounding vehicles (particularly the rear vehicle), the direction indicator 501 is blinked and it is clearly shown that the present control is applied to the occupant using the alarm device 502. In step S6, a release command for the mechanical brake 202 is issued to the brake actuator 201. Thereafter, in the course of repeating step S7 → step S8 → step S9, when it is confirmed in step S8 that the accelerator is ON, this control is terminated.
That is, when the own vehicle is stopped and the operating point of the rear vehicle approaches the own vehicle without decelerating from the point A in FIG. 3, the main control is entered at the point C in FIG. 3, and the brake is released together with the warning. . If the driver subsequently depresses the accelerator at point D in FIG. 3 according to the warning, the relative speed of the vehicle relative to the vehicle behind the vehicle is greatly reduced as the vehicle starts to travel, and the distance L2 between the vehicle and the vehicle is maintained. The rear vehicle stops at point E of 3.
Therefore, when the host vehicle is stopped due to a signal waiting, etc., and the vehicle behind is approaching, the driver can only perform the accelerator depressing operation according to the warning without performing the brake releasing operation, so that the rear collision may occur. Can be avoided.

When the host vehicle is stopped by waiting for a signal or the like and the rear vehicle collides, in the flowchart of FIG. 2, step S1, step S2, step S3, step S4, step S5, step S6, step S7, The process proceeds from step S8 to step S9. In step S5, in order to urge a warning to surrounding vehicles (particularly the rear vehicle), the direction indicator 501 is blinked and it is clearly shown that the present control is applied to the occupant using the alarm device 502. In step S6, a release command for the mechanical brake 202 is issued to the brake actuator 201. After that, step S7 → step S8 → step S9 is repeated, and in step S9, when the own vehicle moves the forward movable distance set in step S4, the process proceeds from step S9 to step S10, and mechanical brake is performed to the brake actuator 201. The operation command 202 is issued and this control is finished.
That is, when the own vehicle is stopped and the operating point of the rear vehicle approaches the own vehicle without decelerating from the point A in FIG. 3, the main control is entered at the point C in FIG. 3, and the brake is released together with the warning. . Thereafter, if the driver performs an accelerator operation at point F in FIG. 3 according to the warning, or if the driver of the rear vehicle performs a brake operation at point F in FIG. 3, the relative vehicle speed with respect to the rear vehicle is reduced. The rear vehicle collides with the own vehicle at point G in FIG. Thereafter, the host vehicle moves side by side as if pushed from the rear vehicle, and the host vehicle and the rear vehicle stop due to re-braking of the host vehicle at a point H in FIG.
Therefore, when the host vehicle is stopped due to a signal waiting or the like, and the rear vehicle collides with the host vehicle, the brake is released and the host vehicle is permitted to move forward by a possible distance. For this reason, the collision energy input from the rear vehicle is the deformation energy at the rear-end collision portion between the own vehicle and the rear vehicle, with the remainder used for the starting energy for moving the own vehicle released from the brake forward. In this way, the collision input received by the host vehicle is greatly relieved, and the impact force peak value at the time of the collision is lowered.
Furthermore, since the forward movable distance that allows the vehicle to move forward is defined from the stop position of the vehicle to a position that does not reach the front obstacle, the vehicle is allowed to move forward while allowing the vehicle to move forward. It is possible to reliably prevent contact interference with the front obstacle.

As described above, in the rear impact impact energy reducing device of the first embodiment, the own vehicle movement control means is set at the forward movement when it is determined that there is a possibility of a rear collision at the time of brake stop. The braking force weakened when the vehicle is moved by the possible distance is increased again (step S9 → step S10).
For example, when calculating the braking force according to the distance between the vehicle and the front obstacle, it is necessary to calculate the braking force for each control cycle, and high-speed calculation processing is required.
On the other hand, in Example 1, it is only necessary to increase the braking force once weakened at the time of moving the vehicle by the forward movable distance, without calculating the braking force according to the distance between the vehicle and the front obstacle, The vehicle can be braked with simple processing.

In the rear impact impact energy reducing device of the first embodiment, the forward movable distance setting means (step S4) determines the minimum inter-vehicle distance α in consideration of the distance that the host vehicle comes out when a rear-end collision occurs. The distance from the stop position of the host vehicle to the position that maintains the minimum inter-vehicle distance α with respect to the front obstacle is set as the forward movable distance.
For example, when the minimum inter-vehicle distance is given at a constant value, if the rear vehicle collides at low speed, there is too much room between the front obstacle and the rear vehicle collides at high speed when the vehicle's brake stops. When doing so, there is a risk of contact interference with the front obstacle due to the rear-end collision force from the rear vehicle when the brake of the own vehicle is stopped.
On the other hand, in the first embodiment, the minimum inter-vehicle distance α is determined in consideration of the distance that the host vehicle comes out in the case of a rear-end collision, regardless of whether the rear-end vehicle speed of the rear vehicle at the time of brake stop is high or low. It is possible to reliably prevent contact interference with the preceding vehicle.

In the rear impact energy reduction device of the first embodiment, the forward movable distance setting means (step S4) considers the state of a traffic signal, the presence or absence of an emergency vehicle, and whether or not the road surface can be traveled. Then, a forward movable distance that allows the vehicle to move forward is set.
For example, in the case of a green light when the signal is stopped, the preceding vehicle can be expected to move, so there are few restrictions on the setting of the distance that can be moved forward, but in the case of a red light, there is no movement of the preceding vehicle. It is necessary to set strictly. In addition, even when an emergency vehicle such as a fire truck is approaching, it is necessary to set a strict forward movable distance. Furthermore, it is necessary to set the forward movable distance strictly even when the road surface is under construction. Therefore, if the forward movable distance of the host vehicle is set based only on the distance between the vehicle and the front obstacle, there may be cases where it does not match the traveling environment.
On the other hand, in the first embodiment, the forward movable distance is set in consideration of the state of traffic signals, the presence / absence of an emergency vehicle, and whether or not the road surface can be traveled. It is possible to set an optimal forward movable distance to be matched.

In the rear impact impact energy reducing device according to the first embodiment, the control application range is a region in which the degree of approach to the host vehicle is high depending on the relative vehicle speed from the rear vehicle distance sensor 405 and the distance from the rear vehicle. A control application necessity determination map setting means for setting an application necessity determination map (FIG. 3) is provided, and the own vehicle movement control means is stopped by a brake operation at a range position where the selected range position can travel forward. When the control application necessity determination map enters the control application range where the degree of approach to the host vehicle is high, it is determined that there is a possibility of a rear-end collision and the host vehicle movement control is started (step S1 → Step S2 → Step S3).
For example, when the own vehicle movement control is started after confirming the fact of the rear collision (Example 3), the collision energy at the time of the rear collision can be reduced, but the rear collision cannot be avoided in advance. .
On the other hand, in the first embodiment, when it is determined that there is a possibility of a rear collision, by starting the own vehicle movement control, even in a situation where the conventional vehicle is surely a rear collision, It is possible to avoid a rear collision in advance.

In the rear impact energy reduction device of the first embodiment, the own vehicle movement control means (FIG. 2) warns the surrounding vehicle and the occupant when it is determined that there is a possibility of a rear impact when the brake is stopped. Is released, the brake is released, the vehicle is brought into a vehicle state in which the vehicle can move forward, and the brake is reactivated when the vehicle moves a set forward movable distance.
Therefore, it is possible to urge the surrounding vehicle to evacuate and to provide driving support for accelerating the accelerator operation for avoiding the rear collision, and at the time of the rear collision, the input energy is consumed as the starting energy of the own vehicle, thereby reducing the impact energy. It can be effectively reduced.

Next, the effect will be described.
In the rear impact impact energy reducing device of the hybrid vehicle of the first embodiment, the effects listed below can be obtained.

  (1) A rear impact impact energy reduction device for a vehicle that reduces impact energy when a rear vehicle collides with the host vehicle, the rear inter-vehicle sensor 405 and the collision sensor 503 for detecting the state of the rear vehicle; Based on the inter-vehicle distance sensor 404 that detects the inter-vehicle distance between the host vehicle and the front obstacle, and the inter-vehicle distance detection value from the inter-vehicle distance detection means, the position from the stop position of the host vehicle to a position that does not reach the front obstacle. A determination is made that there is a possibility of a rear-end collision based on the rear vehicle state from the rear vehicle state detection means when the brake is stopped and the forward movable distance setting means (step S4) for setting the forward movable distance The vehicle is provided with own vehicle movement control means (FIG. 2) that weakens the braking force and permits the movement of the own vehicle by the forward movement distance set by the forward movement possible distance setting means. Thus, it is possible to achieve both the prevention of the contact interference with the front obstacle and the reduction of the impact energy due to the rear collision while the rear collision can be avoided.

  (2) When the vehicle movement control means determines that there is a possibility of a rear-end collision when the brake is stopped, the braking force weakened at the time when the vehicle has moved the set forward movable distance is used. Since it is strengthened again (step S9 → step S10), it is not necessary to calculate the braking force according to the distance between the vehicle and the front obstacle, and the vehicle can be braked and stopped by a simple process.

  (3) The forward movable distance setting means (step S4) determines the minimum inter-vehicle distance α in consideration of the distance that the own vehicle will come forward when a rear-end collision occurs, and determines the forward obstacle from the stop position of the own vehicle. The distance to the position that maintains the minimum inter-vehicle distance α is set as the forward movable distance, so that it is possible to reliably prevent contact interference with the front vehicle regardless of the rear vehicle speed of the rear vehicle when the brake is stopped. it can.

  (4) The forward moving distance setting means (step S4) takes into consideration the state of traffic signals, the presence / absence of an emergency vehicle, and whether or not the road surface is capable of traveling, so that the vehicle moves forward. Therefore, it is possible to set an optimal forward movable distance that matches any driving environment.

  (5) A control application necessity determination map (FIG. 3) in which the control application range is a region where the degree of approach to the host vehicle is high depending on the relative vehicle speed from the rear vehicle distance sensor 405 and the distance from the rear vehicle. A control application necessity determination map setting means is provided, and the vehicle movement control means is arranged on the control application necessity determination map when the selected range position is stopped by a brake operation at a range position where the selected range position can travel forward. Thus, when entering the control application range in which the degree of approach to the host vehicle is high, it is determined that there is a possibility of a rear collision, and the host vehicle movement control is started (step S1 → step S2 → step S3). Even if it is a situation in which a general vehicle reliably causes a rear collision, it is possible to avoid the rear collision in advance.

  (6) When the vehicle movement control means (FIG. 2) determines that there is a possibility of a rear-end collision when the brake is stopped, it issues a warning to surrounding vehicles and passengers and releases the brake. The vehicle is in a state in which the vehicle can move forward, and the brake is reactivated when the vehicle moves within the set forward movable distance. The impact energy can be effectively reduced by exhausting the input energy as the starting energy of the own vehicle at the time of a rear-end collision while performing driving support for prompting the operation.

  The second embodiment is an example in which the host vehicle is automatically started when there is a possibility of a rear collision in order to improve the rear collision avoidance. The overall system configuration is the same as that of the first embodiment shown in FIG.

  FIG. 4 is a flowchart showing the flow of the own vehicle movement control process for reducing the impact energy at the time of rear impact executed by the CPU 101 of the second embodiment. Each step will be described below (own vehicle movement control means).

  In step S11, the detection value of the shift position sensor 406 is confirmed, and the shift position is a forward position {D, B (2, S, etc. depending on the vehicle system)} or a neutral position (N), and It is determined whether or not the brake is stopped. If yes, the process proceeds to step S12. If no, the determination in step S11 is repeated.

  In step S12, at the time of selection of a forward-possible position in step S11 and determination that the vehicle is stopped with the brake ON, the relative vehicle speed from the rear vehicle distance sensor 405 and the vehicle behind the vehicle It is determined whether the operating point of the rear vehicle according to the distance is within the control application range where the degree of approach to the host vehicle is high on the control application necessity determination map shown in FIG. If No, the process returns to step S11.

  In step S13, following the determination that the operating point of the rear vehicle is in the control application range in step S12, the front inter-vehicle sensor 404 confirms the inter-vehicle distance between the own vehicle and the front obstacle, and the own vehicle. The forward movable distance from the stop position to the position where the forward obstacle is not reached is set, and the process proceeds to step S14 (forward movable distance setting means).

In step S14, following the confirmation of the distance to the front obstacle and the setting of the movable distance, the detected value from the rear inter-vehicle sensor 405 is used as the collision avoidance start shown in FIG. 5 so that the own vehicle can move forward at an appropriate timing. The start timing (inter-vehicle distance) is set by collating with the timing setting map, and the detected value from the rear inter-vehicle sensor 405 is set to the start shown in FIG. The brake timing (= inter-vehicle distance) is set in comparison with the subsequent brake timing setting map, and the process proceeds to step S15.
Here, as shown in FIG. 5, the “collision avoidance start timing setting map” indicates that the relative vehicle speed with respect to the rear vehicle from the rear inter-vehicle distance sensor 405 (= the speed of the rear vehicle) when determining that there is a possibility of a rear collision. : The host vehicle speed is set to be about the creep), and the shorter the distance from the vehicle behind, the earlier the collision avoidance start timing is set (collision avoidance start timing setting means).
Further, as shown in FIG. 6, the “braking timing setting map after starting” is, as the relative vehicle speed with the rear vehicle is larger and the distance to the rear vehicle is shorter, the braking timing for stopping the own vehicle is delayed. In consideration of the collision energy with the rear vehicle, the brake is set to be on at the braking timing at which the distance to the front vehicle becomes shorter as the upper left in the map of FIG. 6 (braking timing setting means).

  In step S15, following the setting of the start timing in step S14, the direction indicator 501 blinks and the present control is performed to the occupant using the alarm device 502 in order to urge a warning to surrounding vehicles (particularly the rear vehicle). The application is clearly indicated, and the process proceeds to step S16.

  In step S16, following the warning transmission in step S15, it is determined whether or not the distance to the vehicle behind has reached the inter-vehicle distance (start timing) set in step S14. If yes, the process proceeds to step S17. If No, the determination in step S16 is repeated.

  In step S17, following the determination that the set inter-vehicle distance has been reached in step S16, a mechanical brake 202 release command is issued to the brake actuator 201 and driven by the motor 303 regardless of the command value of the brake sensor 402. Torque (starting torque) is generated, and the process proceeds to step S18.

  In step S18, following the brake release and the generation of the starting torque in step S17, it is determined whether or not an obstacle has occurred within the range of the forward movable distance set in step S4 by the front inter-vehicle distance sensor 404, If Yes, the process proceeds to step S21. If No, the process proceeds to step S19.

In step S19, following the determination that an obstacle does not occur within the forward movable distance in step S18, it is determined whether or not the accelerator is ON based on a signal from the accelerator sensor 401. If No, the process proceeds to step S20.
That is, if the accelerator is ON, it can be determined that the vehicle can be freely moved forward by the driver's accelerator operation, and thus this control is terminated.

  In step S20, following the determination that the accelerator is OFF in step S19, it is determined whether or not the vehicle has moved to the forward movable distance set in step S14. If yes, the process proceeds to step S21. In this case, the process returns to step S18.

  In step S21, when it is determined in step S18 that an obstacle has occurred within the forward movable distance, or following the determination that the vehicle has moved to the forward movable distance in step S20, the mechanical brake is applied to the brake actuator 201. The operation command 202 is issued, the brake released in step S17 is operated again, and the process proceeds to the end.

Next, the operation will be described.
[Vehicle movement control action when determining the possibility of rear collision]
When the host vehicle is stopped due to a signal waiting or the like and the vehicle behind is approaching, in the flowchart of FIG. 4, the process proceeds from step S11 → step S12 → step S13 → step S14 → step S15. The start timing for generating the starting torque and the braking timing after the starting are set. In step S15, the direction indicator 501 is flashed and the alarm device 502 is used to urge the surrounding vehicle (especially the rear vehicle) to warn. Clearly indicate that this control is being applied to passengers.
Then, the process proceeds from step S15 to step S16. In step S16, it is determined whether or not the distance to the rear vehicle has reached the inter-vehicle distance (start timing) set in step S14, and the inter-vehicle distance set in step S16 is set. When it is determined that the motor brake has been reached, the process proceeds to step S17, where a mechanical brake 202 release command is issued to the brake actuator 201, and a drive torque (starting torque) is generated by the motor 303.
Thereafter, in the course of repeating step S18 → step S19 → step S20, when the occurrence of an obstacle within the movable distance is confirmed in step S18, the process proceeds from step S18 to step S21, and the brake actuator 201 is moved to the mechanical brake 202. An operation command is issued and this control is terminated.
Further, in the course of repeating step S18 → step S19 → step S20, when the accelerator is turned on in step S19, the present control is terminated.
Step S18 → Step S19 → Step S20 is repeated, and when the host vehicle moves the forward movable distance set in Step S14 in Step S20, the process proceeds from Step S20 to Step S21, and the mechanical brake is performed to the brake actuator 201. The operation command 202 is issued and this control is finished.

In other words, when the host vehicle is stopped due to a signal, etc., if the vehicle behind the vehicle approaches the host vehicle, not only the brake is released, but also a starting torque is generated at the start timing before the rear collision. The car is automatically moved forward. After that, when the set braking timing is reached without causing an obstacle within the movable distance and without turning on the accelerator, the own vehicle stops due to re-braking of the own vehicle.
Therefore, by automatically moving the host vehicle forward by applying start torque, the host vehicle starts to move forward at a timing earlier than the contact of the rear vehicle, and brakes the rear vehicle more than the front vehicle travel distance. Although it is limited to the case where the condition that the distance is short is satisfied, it is possible to avoid a rear-end collision of the rear vehicle with respect to the own vehicle with a much higher probability than in the first embodiment where only the driver's accelerator operation is left. Is possible.
Further, when the rear vehicle does not decelerate or when the rear vehicle decelerates little, the rear vehicle collides with the own vehicle. However, the collision energy input from the rear vehicle at the time of this rear collision is (1) the relative vehicle speed with the rear vehicle becomes smaller due to the start of the own vehicle, and is kept lower than the collision energy with respect to the stopped vehicle. The collision input received by the vehicle is due to the fact that the remaining amount used for the traveling energy for moving the vehicle released from the vehicle becomes the deformation energy at the rear-end collision site between the vehicle and the rear vehicle, Compared with the first embodiment, it is further relaxed, and the impact force peak value at the time of collision becomes extremely low.
Of course, since the forward movable distance that allows the vehicle to move forward is defined from the stop position of the vehicle to a position that does not reach the front obstacle, the vehicle is allowed to move forward while allowing the vehicle to move forward. It is possible to reliably prevent contact interference with the front obstacle.

As described above, in the rear impact impact energy reducing device of the second embodiment, the vehicle movement control means (FIG. 4) is in the brake stop state and determines that there is a possibility of a rear impact, A warning is issued to the vehicle and the occupant, the brake is released, a starting torque is applied, the host vehicle is moved to the set forward movable distance, and the brake is reactivated when the host vehicle moves to the forward movable distance.
Therefore, it is possible to urge evacuation of surrounding vehicles, and by adopting an aggressive automatic start that does not wait for the accelerator operation, it avoids a rear collision with high probability, and even if it becomes a rear collision. The impact energy can be effectively reduced by suppressing the input energy itself by starting the own vehicle and consuming part of the running energy of the own vehicle.

In the rear impact energy reduction device according to the second embodiment, the vehicle is a hybrid vehicle having an engine 305 and a motor 303 as power sources, and the own vehicle movement control means uses a starting torque for forward movement as the motor. Give by 303.
For example, when it is determined that there is a possibility of a rear collision, it is possible to give a starting torque by the engine 305, but in the case of the engine 305, the response delay until the actual torque is output from the output of the command is larger than that of the motor 303. Even if the start timing of the starting torque is appropriately determined based on the degree of approach of the rear vehicle, there is a possibility that a rear collision cannot be avoided due to a response delay.
On the other hand, in the first embodiment, the start torque for forward movement is applied by the motor 303, so that the rear collision due to the start delay of the own vehicle can be surely avoided by generating the start torque with good response. Can do.

In the rear impact energy reduction device of the second embodiment, when it is determined that there is a possibility of a rear impact, the higher the relative vehicle speed from the rear vehicle sensor 405 to the rear vehicle and the shorter the distance from the rear vehicle, Collision avoidance start timing setting means (FIG. 5) for setting the avoidance start timing to be advanced is provided, and after the vehicle has moved forward, the relative vehicle speed from the rear vehicle sensor 405 is large and the distance from the rear vehicle is short. As shown, braking timing setting means (FIG. 6) for setting the braking timing for stopping the own vehicle to be delayed is provided, and the own vehicle movement control means (FIG. 4) starts when the set collision avoidance start timing is reached. Torque is applied to move the vehicle forward, and the brake is restarted when the set braking timing is reached.
For example, when the start timing for generating the starting torque is given by a constant value, there may be a rear collision due to a delay in starting torque generation start response. In addition, when the braking timing for applying the braking torque is given at a constant value, the impact energy determined by the rear-end vehicle speed of the rear vehicle becomes larger or smaller, resulting in variations.
On the other hand, in the first embodiment, by appropriately setting the collision avoidance start timing and the braking timing according to the degree of approach of the rear vehicle, it is possible to prevent a rear collision due to a start start response delay of the start torque, and Variations in impact energy at the time of a collision can be kept small.

Next, the effect will be described.
In the rear impact energy reduction device for a hybrid vehicle according to the second embodiment, the effects listed below can be obtained in addition to the effects (1) to (5) of the first embodiment.

  (7) When the vehicle movement control means (FIG. 4) determines that there is a possibility of a rear-end collision when the brake is stopped, it issues a warning to surrounding vehicles and passengers, releases the brake, and starts torque The vehicle is moved to the set forward movable distance and the brake is reactivated when the vehicle moves to the forward movable distance. By adopting aggressive automatic start that does not have to wait, while avoiding a rear impact with high probability, even if it becomes a rear impact, the input energy itself is kept low by starting the own vehicle, and the own vehicle The impact energy can be effectively reduced by consuming part of the running energy.

  (8) The vehicle is a hybrid vehicle having an engine 305 and a motor 303 as a power source, and the own vehicle movement control means provides a starting torque for forward movement by the motor 303, so that the starting torque with good response is provided. Due to this, it is possible to reliably avoid a rear collision caused by a delay in the start of the host vehicle.

  (9) When it is determined that there is a possibility of a rear collision, the collision avoidance is set so that the collision avoidance start timing is advanced as the relative vehicle speed from the rear vehicle distance sensor 405 is larger and the distance from the rear vehicle is shorter. A start timing setting means (FIG. 5) is provided, and after the host vehicle moves forward, the braking timing for stopping the host vehicle increases as the relative vehicle speed from the rear vehicle distance sensor 405 increases with the rear vehicle and the distance from the rear vehicle decreases. Braking timing setting means (FIG. 6) for setting to delay is provided, and the own vehicle movement control means (FIG. 4) applies a starting torque from the time when the set collision avoidance starting timing is reached and moves the own vehicle forward. Because the brakes are re-actuated when the set braking timing is reached, it is possible to prevent a rear collision due to a delay in starting torque generation start response and to reduce the impact energy at the time of the rear collision. Variations can be kept small.

  The third embodiment is an example in which the impact energy at the time of rear collision is reduced by allowing the movement of the host vehicle when the vehicle is rear-projected at the time of stop, not the possibility of rear-end collision. The overall system configuration is the same as that of the first embodiment shown in FIG.

  FIG. 7 is a flowchart showing the flow of own vehicle movement control processing for reducing impact energy at the time of rear impact executed by the CPU 101 of the third embodiment. Each step will be described below (own vehicle movement control means).

  In step S32, the vehicle speed is detected based on the number of rotations of the motor 303, and it is determined whether or not a collision has occurred by the collision sensor 503 when the vehicle speed is zero. If yes, the process proceeds to step S33. The determination of S32 is repeated.

  In step S33, following the rear collision detection at the time of stop in step S32, the inter-vehicle distance between the host vehicle and the front obstacle is confirmed by the front inter-vehicle distance sensor 404, and the stop position of the host vehicle is determined as in the first embodiment. Is set to a forward movable distance from the position to the position where the forward obstacle is not reached, and the process proceeds to step S34 (forward movable distance setting means).

  In step S34, following the forward safety distance confirmation in step S33, the detection value of the shift position sensor 406 is confirmed, and it is determined whether or not the shift position is the P range (parking range). If No, the process proceeds to step S36.

In step S35, following the determination that it is the P range in step S34, the P range is canceled so that the vehicle can move freely, and the shift position is changed to a forward range other than the P range. The process proceeds to S36.
In this case, it is desirable to suddenly change from the P range to the N range (neutral range).

  In step S36, following the determination other than the P range in step S34 or the P range release in step S35, the detection value of the shift position sensor 406 is checked to determine whether or not the shift position is the N range. If Yes, the process proceeds to step S37. If No, the process proceeds to step S38.

  In step S37, following the determination of the N range in step S36, a mechanical brake 202 release command is issued to the brake actuator 201 regardless of the command value of the brake sensor 402, and the process proceeds to step S39.

  In step S38, following the determination that it is not the N range in step S36, the range position is switched to the N range position, and the release command of the mechanical brake 202 is issued to the brake actuator 201 regardless of the command value of the brake sensor 402, Control goes to step S39.

  In step S18, following the brake release in step S37 or step S38, it is determined by the front inter-vehicle sensor 404 whether or not an obstacle has occurred within the range of the forward movable distance set in step S4. If so, the process proceeds to step S41. If No, the process proceeds to step S40.

  In step S40, following the determination that there is no obstacle within the forward movable distance in step S39, it is determined whether or not the vehicle has moved to the forward movable distance set in step S33. If YES, the process proceeds to step S41. If NO, the process returns to step S39.

  In step S41, when it is determined in step S39 that an obstacle has occurred within the forward movable distance, or following the determination in step S40 that the obstacle has moved to the forward movable distance, the mechanical brake is applied to the brake actuator 201. The operation command 202 is issued, the brake released in step S37 or step S38 is operated again, and the process proceeds to the end.

Next, the operation will be described.
[Vehicle movement control action when determining the possibility of rear collision]
When the rear vehicle collides when the host vehicle is stopped by selecting the P range due to waiting for a signal or the like, the process proceeds to step S32 → step S33 → step S34 → step S35 in the flowchart of FIG. Then, a forward movable distance is set, and the P range is canceled in step S35. In step S35, when the range is switched to the N range, the process proceeds from step S36 to step S37. In step S37, a release command for the mechanical brake 202 is issued to the brake actuator 201. On the other hand, when the position is switched to a range position other than the N range in step S35, the process proceeds from step S36 to step S38. In step S38, the switch is switched to the N range and then the brake actuator 201 is switched to the brake actuator 201. Issue a release command.
Thereafter, in the course of repeating step S39 → step S40, when the occurrence of an obstacle is confirmed within the movable distance in step S39, the process proceeds from step S39 to step S41, and an operation command for the mechanical brake 202 is sent to the brake actuator 201. To finish this control.
Also, step S39 → step S40 are repeated, and when the host vehicle moves in the forward movable distance set in step S33 in step S40, the process proceeds from step S40 to step S41, and the mechanical brake 202 is activated to the brake actuator 201. Issue a command to end this control.

That is, when the host vehicle is stopped due to a signal, etc., if the rear vehicle collides with the host vehicle, the brake is released after switching the range position to the N range so that the host vehicle can move. The vehicle is allowed to move forward. Thereafter, when the set forward movable distance is reached without causing an obstacle within the movable distance, the own vehicle stops due to re-braking of the own vehicle.
Therefore, in Example 3, although the rear collision of the rear vehicle with respect to the own vehicle cannot be avoided, the collision energy input from the rear vehicle at the rear collision when the rear vehicle collides with the own vehicle is N range. The remaining amount used for the starting travel energy to move the vehicle released from the brake forward becomes the deformation energy at the rear-end collision site between the vehicle and the rear vehicle, reducing the collision input received by the vehicle Thus, the impact force peak value at the time of collision is lowered.
Of course, since the forward movable distance that allows the vehicle to move forward is defined from the stop position of the vehicle to a position that does not reach the front obstacle, the vehicle is allowed to move forward while allowing the vehicle to move forward. It is possible to reliably prevent contact interference with the front obstacle.

Next, the effect will be described.
In the rear impact energy reduction device for the hybrid vehicle of the third embodiment, the effects listed below can be obtained in addition to the effects (1) to (5) of the first embodiment.

  (10) The vehicle movement control means (FIG. 7) releases the brake immediately when the vehicle is in a range position where the vehicle can move when it is determined that the vehicle is in a rear collision when the brake is stopped. If the vehicle is in a range position where the vehicle cannot move, the brake is released after changing the vehicle to a range position where the vehicle can move, and the vehicle moves into the vehicle state in which the vehicle can move forward, and the vehicle has moved the set forward movable distance. Because the brakes are reactivated at the time, impact energy is effectively eliminated by consuming part of the input energy as the starting travel energy of the vehicle while reliably avoiding contact interference with front obstacles at the time of a rear impact. Can be reduced.

  As mentioned above, although the impact energy reduction device at the time of rear impact of the vehicle of the present invention has been described based on the first to third embodiments, the specific configuration is not limited to these embodiments. Design changes and additions are permitted without departing from the spirit of the invention according to each claim of the scope.

  In the first embodiment, as the own vehicle movement control means, the position set together with the rear vehicle to which the rear-end collision is performed, except when the brake is released and the accelerator is operated, when the possibility of rear-end collision is determined with respect to the stopped own vehicle. In the second embodiment, as the own vehicle movement control means, the brake is released and the starting torque is given to the stopped own vehicle when judging the possibility of rear collision. An example of moving the host vehicle forward to a set position is shown. In the third embodiment, as a host vehicle movement control means, at the time of a rear collision with respect to a stopped host vehicle, the brake is released and the rear vehicle colliding The example which moved the own vehicle ahead to the set position was shown. On the other hand, for example, the brake may be weakened so that the vehicle can move forward without releasing the brake. In short, as the vehicle movement control means, when the brake is stopped and it is determined that there is a possibility of at least a rear collision based on the rear vehicle state, the braking force is weakened and the vehicle's movement control means Any device that allows movement is included in the present invention.

  In the first to third embodiments, the impact energy reduction device at the time of rear impact of the hybrid vehicle based on the front wheel drive base is shown, but it can also be applied to a hybrid vehicle and a hybrid four wheel drive vehicle based on the rear wheel drive base, It can also be applied to engine vehicles, electric vehicles, fuel cell vehicles, and the like.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an overall system diagram showing a hybrid vehicle to which a rear impact impact energy reducing device according to a first embodiment is applied. It is a flowchart which shows the flow of the own vehicle movement control process for the impact energy reduction at the time of a rear collision performed by CPU of Example 1. FIG. It is a figure which shows an example of the control application necessity judgment map used in the own vehicle movement control of Example 1. FIG. It is a flowchart which shows the flow of the own vehicle movement control process for the impact energy reduction at the time of a rear collision performed by CPU of Example 2. FIG. It is a figure which shows an example of the collision avoidance start timing setting map used by the own vehicle movement control of Example 2. FIG. It is a figure which shows an example of the brake timing setting map after the start used by the own vehicle movement control of Example 2. FIG. It is a flowchart which shows the flow of the own vehicle movement control process for the impact energy reduction at the time of a rear collision performed by CPU of Example 3.

Explanation of symbols

101 CPU
102 Auxiliary battery
201 Brake actuator
202 Mechanical brake
301 Heavy battery
302 inverter
303 motor
304 generator
305 engine
306 Power split mechanism
401 Accelerator sensor
402 Brake sensor
403 DC / DC converter
404 Front distance sensor (vehicle distance detection means)
405 Rear distance sensor (rear vehicle condition detection means)
406 Shift position sensor
501 Direction indicator
502 alarm device
503 Collision sensor (rear vehicle state detection means)

Claims (11)

A rear impact energy reduction device for a vehicle that reduces impact energy when a rear vehicle collides with the host vehicle.
A rear vehicle state detecting means for detecting the state of the rear vehicle;
An inter-vehicle distance detecting means for detecting an inter-vehicle distance between the host vehicle and a front obstacle;
Based on the inter-vehicle distance detection value from the inter-vehicle distance detection means, a forward movable distance setting means for setting a forward movable distance from a stop position of the own vehicle to a position that does not reach the front obstacle;
When the brake is stopped and when it is determined that there is at least a possibility of a rear collision based on the rear vehicle state from the rear vehicle state detection means, the braking force is weakened and the front set by the forward movable distance setting means Own vehicle movement control means for allowing the movement of the own vehicle for a moving distance;
A rear impact energy reduction device for a vehicle characterized by comprising: In the rear impact energy reduction device for a vehicle according to claim 1,
The host vehicle movement control means reinforces the weakened braking force when the host vehicle is moved by the set forward movable distance when it is determined that there is a possibility of a rear-end collision when the brake is stopped. A device for reducing impact energy at the time of rear impact of a vehicle. In the rear impact energy reduction device for a vehicle according to claim 1 or 2,
The forward movable distance setting means determines a minimum inter-vehicle distance in consideration of a distance that the host vehicle comes out when a rear-end collision occurs, and a position that keeps the minimum inter-vehicle distance from a stop position of the own vehicle to a front obstacle The impact energy reduction device at the time of rear impact of a vehicle, characterized in that the distance up to is set as a forward movable distance. In the rear impact energy reduction device for a vehicle according to any one of claims 1 to 3,
The forward movable distance setting means takes into account the state of traffic signals, whether or not an emergency vehicle is approaching, and whether or not the road surface is capable of traveling, and the forward movable distance that allows the vehicle to move forward A rear impact impact energy reducing device for a vehicle, characterized in that In the rear impact energy reduction device for a vehicle according to any one of claims 1 to 4,
The control application necessity setting that sets the control application necessity judgment map in which the area where the degree of approach to the host vehicle is high is set based on the relative vehicle speed from the rear vehicle state detection means and the distance from the rear vehicle. Judgment map setting means is provided,
The vehicle movement control means has a control application range in which a degree of approach to the vehicle is high on the control application necessity determination map when the selected range position is stopped by a brake operation at a range position where the vehicle can travel forward. When the vehicle enters the vehicle, it determines that there is a possibility of a rear collision, and starts its own vehicle movement control. In the rear impact energy reduction device for a vehicle according to any one of claims 1 to 5,
The vehicle movement control means is a vehicle capable of moving the vehicle forward by issuing a warning to surrounding vehicles and passengers and releasing the brake when it is determined that there is a possibility of a rear-end collision when the brake is stopped. A rear impact energy reduction device for a vehicle, wherein the brake is reactivated when the vehicle moves within the set forward movable distance. In the rear impact energy reduction device for a vehicle according to any one of claims 1 to 5,
When the vehicle movement control means determines that there is a possibility of a rear-end collision when the brake is stopped, it issues a warning to surrounding vehicles and passengers, releases the brake, and gives a starting torque A device for reducing impact energy at the time of rear impact of a vehicle, wherein the vehicle is moved to a movable distance and the brake is reactivated when the vehicle moves to a movable distance. In the rear impact energy reduction device for a vehicle according to claim 7,
The vehicle is a hybrid vehicle having an engine and a motor as a power source,
The apparatus for controlling impact energy at the time of rear impact of a vehicle, wherein the own vehicle movement control means applies a starting torque for forward movement by the motor. In the rear impact energy reduction device for a vehicle according to claim 7 or 8,
When it is determined that there is a possibility of a rear collision, the collision avoidance start is set so that the collision avoidance start timing is advanced as the relative vehicle speed from the rear vehicle state detection means to the rear vehicle is higher and the distance from the rear vehicle is shorter. Provide timing setting means,
A braking timing setting unit configured to delay the braking timing for stopping the host vehicle as the relative vehicle speed with the rear vehicle from the rear vehicle state detecting unit is higher after the host vehicle moves forward and the distance from the rear vehicle is shorter. Provided,
The own vehicle movement control means applies start torque from the time when the set collision avoidance start timing is reached, moves the own vehicle forward, and re-activates the brake when the set braking timing is reached. The impact energy reduction device at the time of rear impact of the vehicle. In the rear impact energy reduction device for a vehicle according to any one of claims 1 to 5,
If the vehicle movement control means is at a brake stop and it is determined that it is a rear-end collision, the vehicle movement control means immediately releases the brake if the vehicle is in a range position where the vehicle can move, and the vehicle movement control means is in a range position where the vehicle cannot move. If the vehicle is moved to a range position where the vehicle can move, the brake is released, the vehicle is brought into a vehicle state in which the vehicle can move forward, and the brake is reactivated when the vehicle moves the set forward movable distance. A device for reducing impact energy at the time of rear impact of a vehicle. A rear impact energy reduction device for a vehicle that reduces impact energy when a rear vehicle collides with the host vehicle.
When the brake is stopped and when it is determined that there is at least a possibility of a rear-end collision based on the state of the rear vehicle, the braking force is weakened and the vehicle is allowed to move forward until it does not reach the front obstacle. A device for reducing impact energy at the time of rear impact of a vehicle.

Images