JP6170472B2 - Vehicle control device - Google Patents

Description

  The present invention relates to a vehicle control device that stops a vehicle with a braking force that does not depend on a driver's brake operation after a vehicle collision.

  Patent Document 1 describes a braking control device that makes an automatic brake control time variable based on a vehicle speed after a collision. The braking control device includes a collision detection sensor that detects a collision of the host vehicle and a vehicle speed sensor that detects a vehicle speed of the host vehicle. The braking / driving force control unit is a time for automatically generating a braking force based on the vehicle speed detected by the vehicle speed sensor after detecting the collision when the collision detection sensor detects a collision of the host vehicle. The brake control device is operated by controlling the automatic braking time.

JP 2012-001091 A

  However, in the braking control device according to Patent Document 1, optimal braking control may not be performed depending on the type of collision. For example, even when the collision avoidance control is performed, depending on the traveling state of other vehicles, when a collision between the vehicles occurs or the road surface is slippery, the vehicle may collide with an obstacle or the vehicle. In such a case, if the braking distance after the collision becomes long, there is a possibility of a secondary collision in which the collision occurs again.

  The present invention has been made in consideration of such a problem. For example, even when a collision occurs during collision avoidance control, it is possible to suppress an increase in the braking distance after the collision, and re-collision. An object of the present invention is to provide a vehicle control device capable of appropriately controlling the braking force of a brake so as to suppress the occurrence of secondary damage such as the above.

  The vehicle to which the present invention is applied includes an internal combustion engine and / or a drive motor as a vehicle drive source. In addition to an internal combustion engine vehicle, an EV (electric vehicle), an HEV (hybrid vehicle), and a PHEV. Electric vehicles such as (plug-in hybrid vehicles) and FCVs (fuel cell vehicles) are included.

[1] A vehicle control apparatus according to the present invention includes first target value setting means for setting a first target value to avoid a collision, and first braking control for increasing a braking force toward the first target value. Means, second target value setting means for setting a second target value to reduce collision damage at the time of a collision, second braking control means for increasing the braking force toward the second target value, and a control unit; And the control unit has a comparison means for comparing the first target value and the second target value when the second braking control means is actuated after the first braking control means is actuated , The control unit increases the braking force toward a value higher than the second target value when the comparison result by the comparing means is equal to the first target value and the second target value. Features.

  For example, even if the collision avoidance control is performed based on the first target value, depending on the traveling state of other vehicles, when the collision between the vehicles occurs or the road surface is slippery, the vehicle collides with an obstacle or the vehicle. There is a case. In such a case, even if the braking control is performed with the target value equivalent to the first target value, the braking distance after the collision may be increased. Therefore, when the first target value and the second target value are equal, the braking force after the collision can be shortened by increasing the braking force toward a value higher than the second target value. The occurrence of the next collision can be suppressed.

[2] In the present invention, the second braking control means is actuated after the first braking control means is actuated, and the comparison result of the comparing means is that the second target value is the first braking value. The control unit may increase the second target value when it is lower than one target value.

  When the second target value is set after the collision based on the image from the camera or the reflected wave of the output wave from the radar, the value may be lower than the first target value. In addition, an abnormal value may be set when setting the second target value due to the influence of the collision. In such a case, the second target value is set with reference to the first target value, that is, when the second target value is lower than the first target value, the second target value is increased, The braking distance after the collision can be shortened, and the occurrence of the secondary collision can be suppressed.

  According to the present invention, for example, even when a collision occurs during collision avoidance control, it is possible to suppress an increase in the braking distance after the collision, and to suppress the occurrence of secondary damage such as a re-collision. In addition, the braking force of the brake can be appropriately controlled.

It is a block diagram which shows the structure of the vehicle control apparatus which concerns on this Embodiment. It is a flowchart which shows the processing operation of the vehicle control apparatus which concerns on this Embodiment. FIG. 3A is a time chart showing a case where the second deceleration set at the time of collision is higher than the first deceleration set at the time of collision avoidance, and FIG. 3B shows the first deceleration and the second deceleration. It is a time chart which shows the case where and are equivalent. FIG. 4A is a time chart showing an example when the second deceleration set at the time of collision is lower than the first deceleration set at the time of collision avoidance, and FIG. 2 is a time chart showing another example when the deceleration is low.

  Hereinafter, an embodiment of a vehicle control device according to the present invention will be described with reference to FIGS. 1 to 4B.

  As shown in FIG. 1, the vehicle control device 10 includes an ECU 12 (electronic control unit) configured to include various control units. As is well known, the ECU 12 is a computer including a microcomputer, a CPU (Central Processing Unit), a ROM (including an EEPROM), a RAM (Random Access Memory), a RAM (Random Access Memory), an A / D converter, a D / A converter and other input / output devices, a timer as a timekeeping unit, etc., and various function implementation units (function implementation means) such as a control unit when the CPU reads and executes a program recorded in the ROM , Functions as a calculation unit, a processing unit, and the like. These functions can also be realized by hardware. Further, the ECU 12 can be integrated into one, and can be further divided.

  In the present embodiment, the ECU 12 includes an airbag control unit 14, a travel control unit 16, a hydraulic control unit 18, an engine control unit 20, and a braking force control unit 22. A vehicle speed sensor 24, a collision detection sensor 26, and a G sensor 28 are connected to the ECU 12. Further, an airbag 30 is connected to the ECU 12 via an inflator 32, a brake pedal 34 is connected via a brake pedal depression amount sensor 36, and an accelerator pedal 38 is connected via an accelerator pedal operation amount sensor 40. Yes.

  A vehicle on which the vehicle control apparatus 10 according to the present embodiment is mounted has four wheels 44, and each of the four wheels 44 includes a brake actuator 46 configured by a disc brake or the like that generates a braking force. Is provided. The brake hydraulic pressure (braking force, braking pressure, brake pressure) of the brake actuator 46 is controlled by four pressure adjusting devices (not shown) in the hydraulic pressure control unit 18, respectively. The hydraulic control unit 18 is driven under the control of a travel control unit 16 described later.

  The driving force is transmitted from the engine 50 to the left and right wheels of the four wheels 44 through the transmission 52 (denoted as “T / M” in FIG. 1), for example.

  The engine 50 has a rotational speed (engine rotational speed) and the like through an engine control unit 20 that adjusts an opening (throttle opening) TH of a throttle valve (indicated as “THV” in FIG. 1) 54 provided in the engine 50. Be controlled.

  The throttle opening TH of the throttle valve 54 is adjusted through the engine control unit 20 in accordance with the operation amount θa of the accelerator pedal 38 detected by the accelerator pedal operation amount sensor 40.

  Each wheel 44 is provided with a wheel speed sensor (not shown), and the wheel speed detected by the four wheel speed sensors and the average value thereof are supplied to the ECU 12 as the vehicle speed detected by the vehicle speed sensor 24.

  The airbag control unit 14 is connected to the travel control unit 16, the collision detection sensor 26, the G sensor 28, and the inflator 32.

  The collision detection sensor 26 is, for example, a pressure sensor, and is provided in a vehicle. Although not shown, a right front collision detection sensor and a left front collision detection sensor are provided on the left and right sides of the front frame of the vehicle. A right side collision detection sensor and a left side collision detection sensor are provided on the left and right sides of the vehicle, and a right rear collision detection sensor and a left rear collision detection sensor are provided on the left and right sides of the rear frame of the vehicle.

  Furthermore, a high-sensitivity G sensor, roll rate sensor, yaw rate sensor, and low-sensitivity orthogonality that detect acceleration in the three orthogonal axes (vehicle length direction, vehicle width direction, vehicle height direction) of the vehicle at the center of gravity of the vehicle. A G sensor 28 including a biaxial G sensor (vehicle length direction, vehicle width direction) is provided.

  When a collision is detected by the collision detection sensor 26, the airbag control unit 14 is supplied with a collision detection signal Sc corresponding to the pressure at the time of collision from the collision detection sensor 26, and from the G sensor 28, an acceleration signal at the time of the collision. Sa (convertible to G) is supplied.

  The airbag control unit 14 generates an airbag deployment signal Sab that deploys the airbag 30 corresponding to the location where the collision occurred based on the collision detection signal Sc and the acceleration signal Sa (G), and drives the inflator 32. .

  On the other hand, the travel control unit 16 includes at least a normal brake control unit 60, a collision avoidance support control unit 62, an automatic brake control unit 64, and a braking force command value output unit 66.

  The normal brake control unit 60 sets a deceleration corresponding to the depression amount θb of the brake pedal 34 detected by the brake pedal depression amount sensor 36 in the braking force command value output unit 66.

  The collision avoidance support control unit 62 detects the possibility of a collision with an obstacle or another vehicle based on an image from a camera (not shown) or a reflected wave of an output wave from a radar. A first deceleration Ga that does not depend on the depression amount θb is generated. The collision avoidance assistance control unit 62 sets the generated first deceleration Ga in the braking force command value output unit 66, and further notifies the occupant of the danger of collision. The first deceleration Ga may be a fixed deceleration set in advance (for example, 0.5 G or the like), or to avoid a collision based on an image from a camera, a reflected wave of an output wave from a radar, or the like. The calculated deceleration may be used.

  In addition, the collision avoidance support control unit 62 stops the collision avoidance control when the accelerator pedal or the brake pedal is operated by the occupant during the collision avoidance control or when the vehicle is stopped.

  The automatic brake control unit 64 generates a second deceleration Gb that does not depend on the depression amount θb of the brake pedal 34 and sets it in the braking force command value output unit 66. This process is performed when a vehicle collision is recognized by the collision detection signal Sc from the collision detection sensor 26 or the acceleration signal Sa (G) from the G sensor 28. The second deceleration Gb may be a fixed deceleration set in advance (for example, 0.5 G), or to reduce collision damage based on an image from a camera, a reflected wave of an output wave from a radar, or the like. It may be the deceleration calculated in Note that the airbag 30 is deployed by the collision.

  The hydraulic control unit 18 feeds back, for example, a braking hydraulic pressure (brake pressure) in which the deceleration calculated from the acceleration signal Sa (G) from the G sensor 28 becomes the deceleration set in the braking force command value output unit 66. It is generated while being controlled and output to the brake actuator 46. As a result, the vehicle is decelerated at the generated brake pressure, that is, the brake pressure corresponding to the set deceleration.

  Further, the traveling control unit 16 determines the slip / lock state of each wheel 44 and has an ABS function for independently adjusting the braking hydraulic pressure of each wheel 44 during braking via the hydraulic control unit 18. When the posture / behavior of the vehicle is disturbed, the vehicle has a function of preventing the skidding of the vehicle and improving the directional stability. A vehicle posture stabilization system that improves the directional stability is known as a technology related to a VSA (Vehicle Stability Assist) system, for example.

  The traveling control unit 16 senses the attitude / behavior of the vehicle with the G sensor 28 and the vehicle speed sensor 24 (each wheel speed sensor), and determines that the vehicle is oversteered. The hydraulic control unit 18 is controlled to be applied.

  Conversely, when the traveling control unit 16 determines that understeering occurs, the driving force of the engine 50 is reduced (reduced) by reducing the throttle opening TH of the throttle valve 54 through the engine control unit 20, and the rear wheel in the vehicle. The hydraulic control unit 18 is controlled so as to brake the wheel 44 on the inner side of the turn.

  And the braking force control unit 22 of the vehicle control apparatus 10 which concerns on this Embodiment has the deceleration comparison part 70, the deceleration change part 72, and the vehicle stop determination part 74, as shown in FIG. The braking force control unit 22 is driven together with the automatic brake control unit 64 of the traveling control unit 16 when a collision between the vehicle and an obstacle or another vehicle is detected.

  The deceleration comparison unit 70 compares the first deceleration Ga set by the collision avoidance assistance control unit 62 with the second deceleration Gb set by the automatic brake control unit 64, and reduces the comparison result. Output to the speed changing unit 72.

  The deceleration changing unit 72 sets a deceleration to be set in the braking force command value output unit 66 when the comparison result from the deceleration comparing unit 70 indicates that the first deceleration Ga and the second deceleration Gb are equivalent. The deceleration is higher than the second deceleration Gb (high deceleration Gh). Here, “equivalent” refers to a level at which the absolute value | Ga−Gb | of the difference between the first deceleration Ga and the second deceleration Gb is less than 0.05 G, for example.

  The deceleration changing unit 72 controls the automatic brake control unit 64 when the comparison result from the deceleration comparison unit 70 is lower than the first deceleration Ga, and controls the automatic brake control. The second deceleration Gb generated from the unit 64 is increased.

  The braking force command value output unit 66 outputs a braking force command value corresponding to the set deceleration to the hydraulic control unit 18. The hydraulic control unit 18 outputs a braking hydraulic pressure (brake pressure) that provides a set deceleration to the brake actuator 46. As a result, the vehicle decelerates with the brake pressure corresponding to the set deceleration.

  The vehicle stop determination unit 74 determines that the vehicle is stopped when the vehicle speed of the vehicle is 0 [km / h] and this state is maintained for 2.0 seconds, for example.

  Next, processing operations of the vehicle control device 10, mainly processing operations in the travel control unit 16 and the braking force control unit 22, will be described with reference to the flowchart of FIG.

  First, in step S1, the collision avoidance support control unit 62 of the travel control unit 16 determines whether or not collision avoidance is necessary. This determination is made by detecting the possibility of a collision with an obstacle or another vehicle based on an image from a camera (not shown), a reflected wave of an output wave from a radar, or the like.

  If it is determined that collision avoidance is necessary, the process proceeds to the next step S <b> 2, and the collision avoidance assistance control unit 62 generates the first deceleration Ga and sets it in the braking force command value output unit 66. As a result, the vehicle is decelerated at the brake pressure corresponding to the set first deceleration Ga.

  Thereafter, in step S3, the automatic brake control unit 64 of the traveling control unit 16 determines whether or not there has been a collision to the extent that the airbag 30 is deployed. This determination is made based on whether or not the collision detection signal Sc from the collision detection sensor 26 and the acceleration signal Sa (G) from the G sensor 28 have been input.

  If there is a collision, the process proceeds to the next step S4, where the automatic brake control unit 64 generates the second deceleration Gb and sets it in the braking force command value output unit 66. As a result, the vehicle decelerates at the brake pressure corresponding to the set second deceleration Gb.

  In step S5, the deceleration comparison unit 70 of the braking force control unit 22 determines whether or not the first deceleration Ga and the second deceleration Gb are equivalent. If they are equal, the process proceeds to the next step S6, and the deceleration changing unit 72 sets a deceleration (high deceleration Gh) higher than the current second deceleration Gb in the braking force command value output unit 66. As a result, the vehicle decelerates with the brake pressure corresponding to the set high deceleration Gh.

  In step S7, the vehicle stop determination unit 74 determines whether or not the vehicle is stopped. When it is determined that the vehicle is not stopped, the process returns to step S4, and the processes after step S4 are repeated.

  When it is determined in step S5 described above that the first deceleration Ga and the second deceleration Gb are not equal, the process proceeds to step S8, and the deceleration comparison unit 70 determines that the second deceleration Gb is the first deceleration Ga. It is determined whether it is lower than or not. This determination is performed, for example, based on whether the value obtained by subtracting the second deceleration Gb from the first deceleration Ga is, for example, 0.05 G or more.

  When the 2nd deceleration Gb is lower than the 1st deceleration Ga, it progresses to Step S9, and the deceleration change part 72 controls the automatic brake control part 64, and is an additional deceleration to the present 2nd deceleration Gb. A value (Gb ← Gb + Gc) obtained by adding Gc is generated as a new second deceleration Gb. The additional deceleration Gc may be a fixed deceleration set in advance (for example, 0.5 G), or in order to shorten the braking distance based on the image from the camera, the reflected wave of the output wave from the radar, or the like. The calculated deceleration may be used. The automatic brake control unit 64 sets the generated new second deceleration Gb in the braking force command value output unit 66. As a result, the vehicle decelerates at the brake pressure corresponding to the set new second deceleration Gb.

  When the process in step S9 is completed, the process returns to step S5, and the processes after step S5 are repeated. In Step S8 described above, when it is determined that the second deceleration Gb is higher than the first deceleration Ga, the process proceeds to Step S7, and the processes after Step S7 are repeated.

  And when it determines with the vehicle having stopped in step S7 mentioned above, it progresses to step S13 and stops the control in the automatic brake control part 64 and the braking force control unit 22. FIG.

  On the other hand, if it is determined in step S3 described above that there is no collision, the process proceeds to step S10, where the collision avoidance assistance control unit 62 generates the first deceleration Ga and sets it in the braking force command value output unit 66. . As a result, the vehicle is decelerated at the brake pressure corresponding to the set first deceleration Ga.

  In the next step S11, the collision avoidance assistance control unit 62 determines whether or not the accelerator pedal 38 or the brake pedal 34 has been operated by the occupant based on the operation amount θa of the accelerator pedal 38 and the depression amount θb of the brake pedal 34. Is determined. If neither the accelerator pedal 38 nor the brake pedal 34 is operated, the process proceeds to the next step S12, and the vehicle stop determination unit 74 determines whether or not the vehicle (own vehicle) is stopped. When it is determined that the vehicle is not stopped, the process returns to step S3, and the processes after step S3 are repeated.

  If it is determined in step S12 that the vehicle is stopped, or if it is determined in step S11 that the accelerator pedal 38 or the brake pedal 34 is operated, the process proceeds to step S13. Then, the control by the collision avoidance support control unit 62 and the braking force control unit 22 is stopped.

  When the process in step S13 is completed, or when it is determined in step S1 that collision avoidance is not necessary, the process proceeds to step S14, and the ECU 12 has an end request (power cut, maintenance, etc.). Determine whether or not. If there is no end request, the process returns to step S1, and the processes after step S1 are repeated. If there is an end request, the processing operation in the vehicle control device 10 ends.

  Here, some main operations in the collision avoidance support control unit 62, the automatic brake control unit 64, and the braking force control unit 22 will be described with reference to the time charts of FIGS. 3A to 4B.

  First, as shown in FIG. 3A, when the collision avoidance assistance control unit 62 detects the possibility of a collision with an obstacle or another vehicle at time t1, the collision avoidance assistance control unit 62 detects the first deceleration Ga. Is set in the braking force command value output unit 66. The vehicle is decelerated at a brake pressure corresponding to the set first deceleration Ga.

  When the vehicle collides with an obstacle or another vehicle at a subsequent time t2, the automatic brake control unit 64 generates the second deceleration Gb and sets it in the braking force command value output unit 66. In this case, since the generated second deceleration Gb is higher than the first deceleration Ga, the second deceleration Gb is not changed by the deceleration changing unit 72 of the braking force control unit 22.

  On the other hand, as shown in FIG. 3B, when the second deceleration Gb set at the time point t2 is equal to the first deceleration Ga, the braking force control unit 22 reduces the deceleration higher than the second deceleration Gb. The speed (high deceleration Gh) is set in the braking force command value output unit 66. The vehicle is decelerated at a brake pressure corresponding to the set high deceleration Gh.

  This is because, for example, even if collision avoidance control is performed based on the first deceleration Ga, depending on the traveling state of other vehicles, when a collision between vehicles occurs or the road surface is slippery, May collide with the vehicle. In such a case, even if the braking control is performed at the second deceleration Gb equivalent to the first deceleration Ga, the braking distance after the collision may be increased. Therefore, when the first deceleration Ga and the second deceleration Gb are equal, the braking force is increased toward a higher deceleration (higher deceleration Gh) than the second deceleration Gb. As a result, the braking distance after the collision can be shortened, and the occurrence of a secondary collision can be suppressed.

  Also, as shown in FIG. 4A, when the second deceleration Gb set at time t2 is lower than the first deceleration Ga, the braking force control unit 22 controls the automatic brake control unit 64 to A value obtained by adding the additional deceleration Gc to the 2 deceleration Gb is generated as a new second deceleration Gb. The new second deceleration Gb is set in the braking force command value output unit 66. The vehicle is decelerated with the brake pressure corresponding to the set new second deceleration Gb. If the new second deceleration Gb is higher than the first deceleration Ga, the change by the deceleration changing unit 72 of the braking force control unit 22 is not performed.

  When the second deceleration Gb is set after the collision based on the image from the camera or the reflected wave of the output wave from the radar, it may be lower than the first deceleration Ga. Also, an abnormal value may be set when setting the second deceleration Gb due to the influence at the time of collision. In such a case, the second deceleration Gb is set with reference to the first deceleration Ga. That is, when the second deceleration Gb is lower than the first deceleration Ga, the second deceleration Gb itself is set. By increasing to a new second deceleration Gb, the braking distance after the collision can be shortened, and the occurrence of a secondary collision can be suppressed.

  Of course, as shown in FIG. 4B, when the generated second deceleration Gb is equivalent to the first deceleration Ga, the deceleration change of the braking force control unit 22 is changed as in FIG. 3B. By the unit 72, a deceleration (high deceleration Gh) higher than the new second deceleration Gb is set in the braking force command value output unit 66. Since the vehicle is decelerated at a brake pressure corresponding to the set high deceleration Gh, the braking distance after the collision can be shortened, and the occurrence of a secondary collision can be suppressed.

[Summary of embodiment]
As described above, the vehicle control device 10 according to the present embodiment increases the braking force toward the first target value (first deceleration Ga) set to avoid a collision. Means (collision avoidance support control unit 62) and second braking control means (automatic brake) for increasing the braking force toward a second target value (second deceleration Gb) set to reduce collision damage at the time of collision A control unit 64) and a control unit (braking force control unit 22). The control unit is a case where the second braking control means is actuated after the first braking control means is actuated, and the first When the target value is equal to the second target value, the braking force is increased toward a value higher than the second target value.

  In the present embodiment, when the second braking control unit is operated after the first braking control unit is operated and the second target value is lower than the first target value, the control unit The second target value may be increased by controlling the second braking control means.

  Note that the present invention is not limited to the above-described embodiment, and it is needless to say that various configurations can be adopted based on the content described in this specification.

DESCRIPTION OF SYMBOLS 10 ... Vehicle control apparatus 12 ... ECU
DESCRIPTION OF SYMBOLS 16 ... Travel control unit 18 ... Hydraulic control unit 22 ... Braking force control unit 26 ... Collision detection sensor 28 ... G sensor 34 ... Brake pedal 36 ... Brake pedal depression amount sensor 38 ... Accelerator pedal 40 ... Accelerator pedal operation amount sensor 60 ... Normal Brake control unit 62 ... collision avoidance support control unit 64 ... automatic brake control unit 66 ... braking force command value output unit 70 ... deceleration comparison unit 72 ... deceleration change unit 74 ... vehicle stop determination unit

Claims (2)

First target value setting means for setting a first target value in order to avoid a collision ;
A first braking control means for increasing the braking force toward the first target value,
A second target value setting means for setting a second target value in order to reduce collision damage at the time of collision ;
And second braking control means for increasing the braking force toward the second target value,
A control unit,
The control unit includes a comparison unit that compares the first target value with the second target value when the second braking control unit is operated after the first braking control unit is operated .
The control unit increases the braking force toward a value higher than the second target value when the comparison result by the comparing means is equal to the first target value and the second target value. A vehicle control device. The vehicle control device according to claim 1,
When the second braking control means is actuated after the first braking control means is actuated, and the comparison result by the comparing means is lower than the first target value. Moreover, the control unit increases the second target value.

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