JP2008285095A - Vehicle operation supporting device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vehicle operation supporting device capable of smoothly avoiding obstacles regardless of the condition of a road surface. <P>SOLUTION: This vehicle operation supporting device for supporting collision avoiding operation performed by a driver to avoid a collision with obstacles during traveling of a vehicle is provided with an obstacle detecting means 801 for detecting an obstacle before the vehicle; a collision determination means 802 for determining the possibility that the vehicle may collide with the obstacle based on the traveling condition of the vehicle and the condition of the obstacle; a road surface condition estimating means 803 for estimating the road surface condition during traveling; and an deceleration control means 804 for controlling the deceleration of the vehicle based on the possibility of the collision and the estimated road surface condition. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a vehicle operation support device that supports a collision avoidance operation performed by a driver to avoid a collision with an obstacle when the vehicle is traveling.

  Conventionally, many researches and developments have been made on vehicle operation support devices. Further, in recent years, when an obstacle ahead of the own vehicle (own vehicle) in the traveling direction is detected, the road surface state is estimated, and the driver's driving operation is supported according to the road surface state. Vehicle operation support devices have been developed that facilitate the operation to avoid contact (collision) with the vehicle.

For example, in Patent Document 1, in order to ensure traveling stability during automatic braking (automatic braking) even on a road surface with a low friction coefficient (hereinafter referred to as “low μ road”), A technique is disclosed in which a brake pressure increase rate of a hydraulic actuator operated by an automatic braking device is set low, and a predetermined target deceleration is gradually reached.
JP-A-5-310110

  However, in general, in order to avoid contact with an obstacle, in addition to braking (manual or automatic), direction change (turning) of the vehicle by turning operation (turning the steering handle) can be considered. . Further, when obstacle avoidance is performed by turning operation in addition to braking, on a low μ road, if the deceleration is large, slip is likely to occur and the lateral force is reduced. The lateral force is a lateral force with respect to the traveling direction that the vehicle tire receives from the ground, and is determined depending on the friction coefficient of the road surface.

  In the technique of Patent Document 1, the brake pressure increasing rate is changed in accordance with the friction coefficient of the road surface, but the target deceleration is constant regardless of the friction coefficient of the road surface, so that the obstacle avoidance operation is performed. At times, there is a problem that it is difficult to secure a sufficient lateral force according to the situation.

  Accordingly, the present invention has been made in view of the above problems, and a vehicle that can smoothly avoid obstacles regardless of the road surface state by changing the deceleration according to the road surface state. An object is to provide an operation support apparatus.

  In order to solve the above-mentioned problem, the invention according to claim 1 is directed to a vehicle operation support device that supports a collision avoidance operation performed by a driver to avoid a collision with an obstacle when the vehicle is running. Obstacle detection means for detecting obstacles, collision judgment means for judging the possibility of collision of the own vehicle with the obstacle based on the running state of the own vehicle and the state of the obstacle, and estimation of the road surface condition during traveling And a deceleration control means for controlling the deceleration of the host vehicle based on the estimated road surface condition.

  According to this invention, the vehicle travels when the vehicle avoids the obstacle by controlling the deceleration based on the possibility that the vehicle collides with the obstacle and the road surface condition at that time to avoid the obstacle. Stability can be improved.

  In the invention according to claim 2, when the road surface state estimating means estimates the road surface friction coefficient as the road surface state and the deceleration control means is less than a predetermined value, the deceleration control means decreases as the possibility of collision increases. 2. The vehicle operation support apparatus according to claim 1, wherein the speed is set to be small.

  According to this invention, when the estimated road surface friction coefficient is small, the steering operation is performed in addition to the braking control by controlling the deceleration to be smaller as the possibility that the own vehicle collides with the obstacle is higher. Even if it is performed, the lateral force can be ensured, so that the direction change (turning) of the host vehicle is performed smoothly, so that it is possible to improve the running stability during obstacle avoidance.

  In the invention according to claim 3, the road surface state estimating means estimates the road surface friction coefficient as the road surface state, and the deceleration control means has a higher possibility of collision when the estimated road surface friction coefficient is larger than a predetermined value. 3. The vehicle operation support device according to claim 1, wherein the deceleration is set to be large.

  According to this invention, when the estimated road friction coefficient is large, the deceleration is set to be larger as the possibility that the own vehicle will collide with an obstacle is increased. It is possible to obtain the effects of both direction change (turning) and reduce unnecessary deceleration control when the possibility of collision is not so high, while ensuring the driver's degree of freedom in steering and braking operations. It is possible to improve running stability when avoiding obstacles.

  In the invention according to claim 4, when the deceleration control means controls the deceleration of the own vehicle, the possibility of collision is smaller than a predetermined magnitude, or the deceleration control of the own vehicle is predetermined. 4. The vehicle operation support device according to claim 2, wherein the control of the deceleration of the own vehicle is stopped when at least one of the conditions is satisfied or when at least one of the conditions is satisfied. is there.

  According to this invention, at least one of the conditions that the possibility that the own vehicle collides with the obstacle is smaller than the predetermined size or the deceleration control of the own vehicle has continued for the predetermined time length or more is satisfied. The deceleration control can be stopped at an appropriate timing by stopping the deceleration control of the own vehicle.

  The invention according to claim 5 is the vehicle operation support device according to claim 3, wherein the deceleration control means delays the control start of the deceleration of the own vehicle as the estimated road friction coefficient is larger. is there.

  According to this invention, when the estimated road friction coefficient is large, the greater the road friction coefficient is, the slower the start of the deceleration control of the host vehicle is, so that the degree of freedom of the driver's steering operation and brake operation is reduced. Can be improved.

  In the invention according to claim 6, when the estimated road surface friction coefficient exceeds a predetermined value, the deceleration control means estimates the road surface friction coefficient until the predetermined time elapses, and the predetermined time elapses. The control of the deceleration of the own vehicle is started when the estimated road surface friction coefficient is equal to or less than a predetermined value even before. This is a vehicle operation support device.

  According to this invention, when the estimated road surface friction coefficient is equal to or less than a predetermined value, the control of the deceleration of the own vehicle is started even if the predetermined time has not elapsed, so that the own vehicle is compared with the high μ road. Since the deceleration control can be started earlier as the value of μ (road friction coefficient) is smaller when the road is a low μ road that requires time to decelerate, the possibility of a collision can be reduced.

  ADVANTAGE OF THE INVENTION According to this invention, the vehicle operation assistance apparatus which enables obstacle avoidance to be performed smoothly irrespective of a road surface state by changing deceleration according to a road surface state can be provided.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is an overall configuration diagram of a vehicle equipped with a vehicle operation support device. In the vehicle V of FIG. 1, the left is the front side, and the right is the rear side.
As shown in FIG. 1, the vehicle V includes four wheels 1fr, 1fl, 1rr, and 1rl (hereinafter referred to as “wheel 1” unless otherwise distinguished. The same applies to other configurations). A brake disc 2 is provided near the center of the wheel 1, and a wheel speed sensor S is provided in the vicinity of the brake disc 2. The wheel speed sensor S detects the rotation of the wheel 1 and transmits the rotation speed to an ECU (Electronic Control Unit) 8 (vehicle operation support device).

The ECU 8 is the heart of the control of the vehicle V, and includes a CPU (Central Processing Unit) 81 and a storage unit 82 (details will be described later in FIG. 2).
A brake caliper 3 is provided on the wheel 1, and the brake caliper 3 realizes braking by moving the piston by the brake pressure controlled by the hydraulic control device 9 and sandwiching the brake disc 2. The hydraulic control device 9 operates according to an instruction from the ECU 8.

  The vehicle V is subjected to rear wheel drive control, and the wheels 1rr and 1rl, which are rear wheels, serve as drive wheels. The wheel 1rr and the wheel 1rl are connected to the shaft 11 and receive power transmitted from the driving device 10 to the shaft 11. The drive device 10 is specifically an engine, a transmission, or the like, and is controlled by an instruction from the ECU 8.

  A steering handle 5, an accelerator pedal A, and a brake pedal B that are operated by the driver are provided on the front right side of the vehicle V. An accelerator operation sensor Sa that detects the amount of operation of the accelerator pedal A and transmits it to the ECU 8 is provided in the vicinity of the accelerator pedal A, and the amount of operation of the brake pedal B is detected and transmitted to the ECU 8 in the vicinity of the brake pedal B. A brake operation sensor Sb is provided.

  The brake pedal B is connected to the master cylinder 7 via an electronically controlled negative pressure booster 6. The electronically controlled negative pressure booster 6 operates the master cylinder 7 by mechanically boosting the depression force of the brake pedal B using the intake negative pressure of the engine. The electronically controlled negative pressure booster 6 activates the master cylinder 7 regardless of the operation of the brake pedal B when an instruction (braking command signal) is received from the ECU 8 during automatic braking.

When a pedaling force is input to the brake pedal B and a braking command signal is input to the electronically controlled negative pressure booster 6 from the ECU 8, the electronically controlled negative pressure booster 6 outputs the brake hydraulic pressure in accordance with whichever is greater.
A radar device 4 is provided at the forefront of the vehicle V. The radar device 4 transmits an electromagnetic wave such as a millimeter wave toward the front of the vehicle V, detects the distance between the obstacle and the vehicle V, the size of the obstacle, and the like based on the reflected wave, and information about the information. Is sent to the ECU 8.

Next, the function of the ECU will be described with reference to FIG. 2 (see FIG. 1 as appropriate). FIG. 2 is a diagram showing the functional blocks of the ECU and its peripheral devices.
As shown in FIG. 2, the ECU 8 includes an obstacle detection unit 801, a collision determination unit 802, a road surface state estimation unit 803, a deceleration control unit 804, and a drive control unit 805 as functions realized by the CPU 81 and the storage unit 82. I have.

The obstacle detection unit 801 determines whether there is an obstacle in front of the vehicle V based on the detection signal from the radar device 4. If it is determined that there is an obstacle, the obstacle detection unit 801 notifies the collision determination unit 802 to that effect. Tell.
When the collision determination unit 802 receives an obstacle detection effect from the obstacle detection unit 801, the collision determination unit 802 calculates TTC (Time To Collision). TTC is a value obtained by dividing the distance between the obstacle and the vehicle V by the relative speed. For example, if the distance between the obstacle and the vehicle V is 30 m (meters), an obstacle (such as a preceding vehicle) is 15 m / s, and the vehicle V is traveling in the same direction at 20 m / s, the relative speed is 5 m / s, TTC is 30 (m) ÷ 5 (m / second) = 6 (second).

  The collision determination unit 802 can calculate the distance between the obstacle and the vehicle V based on information obtained from the radar device 4, can calculate the speed of the vehicle V based on information obtained from the wheel speed sensor S, and The relative speed can be calculated from the distance and the speed that change from moment to moment, and the TTC value (hereinafter simply referred to as “TTC”) is calculated from the information. The collision determination unit 802 calculates TTC at any time and transmits the TTC to the deceleration control unit 804.

  The road surface state estimating means 803 is triggered by an instruction from the deceleration control means 804, and based on inputs from the wheel speed sensor S and the brake operation sensor Sb, the road surface μ (friction coefficient) value (hereinafter simply referred to as “μ”). "). Specifically, the road surface state estimating means 803 calculates the vehicle body speed of the vehicle V by input from the wheel speed sensors Sfr and Sfl corresponding to the wheels 1fr and 1fl which are driven wheels, and the wheel 1rr which is a driving wheel. And the input from the wheel speed sensors Srr and Srl corresponding to 1rl are used to calculate the slip ratio of the drive wheel, and the brake torque is estimated based on the caliper pressure by the input from the brake operation sensor Sb. Furthermore, the instantaneous acceleration at the ground contact point of the wheel is calculated from the equation of motion related to the wheel using the driving torque generated by the driving device 10. Since the instantaneous acceleration is equivalent to the road surface μ at the ground contact point, the value can be converted to the road surface μ by, for example, low-pass filtering. The road surface state estimation unit 803 transmits the estimated μ to the deceleration control unit 804.

  The deceleration control means 804 automatically changes depending on the magnitude of μ based on the TTC received from the collision determination means 802, μ received from the road surface condition estimation means 803, and the brake operation amount input from the brake operation sensor Sb. Brake control is performed (details will be described later in FIG. 2). Note that the deceleration control means 804 may issue an instruction to the hydraulic control device 9 or an instruction to the electronically controlled negative pressure booster 6 when performing automatic brake control. At the same time, an instruction may be issued to the drive control means 805 to cause the drive control means 805 to control the drive device 10 (acceleration prohibition control or the like). The drive control unit 805 basically controls the drive device 10 by an input from the brake operation sensor Sb. However, as described above, the drive control unit 805 may be controlled by an instruction from the deceleration control unit 804.

  Next, the processing of the vehicle operation support device will be described with reference to FIG. 3 (see FIGS. 1 and 2 as appropriate). FIG. 3 is a flowchart showing processing of the vehicle operation support device (ECU). In the following description, it is assumed that there is an obstacle (preceding vehicle) in front of the vehicle V, and the collision determination unit 802 receives a signal indicating obstacle detection from the obstacle detection unit 801 as needed.

  First, during traveling of the vehicle V, the collision determination unit 802 calculates TTC as needed, and the deceleration control unit 804 acquires TTC from the collision determination unit 802 (step S5). Then, the deceleration control means 804 determines whether or not the TTC is less than or equal to a threshold value (predetermined magnitude, for example, 5 seconds) (step S10). Returning to S5, if it is below the threshold (Yes), the process proceeds to step S20.

  In step S20, the deceleration control means 804 issues a hydraulic control instruction to the hydraulic control device 9 so as to start the operation of the brake for estimating the road surface μ (details will be described later). The road surface state estimation unit 803 receives an instruction from the deceleration control unit 804 and estimates the road surface μ, and the deceleration control unit 804 acquires the estimated road surface μ from the road surface state estimation unit 803 (step S25).

  In step S30, the deceleration control means 804 determines whether or not μ is 0.4 (predetermined value) or less. If μ is not less than 0.4 (No), the process proceeds to step S40. If it is 0.4 or less (Yes), μ is small and it is highly necessary to apply the automatic brake early. Therefore, the process proceeds to step S50 without waiting for 500 milliseconds in step S40. Thereby, in the case of a low μ road (such as a snowy road), it is possible to realize a quick start of the automatic brake control.

  In step S40, the deceleration control means 804 determines whether 500 milliseconds (ms) (predetermined time) has elapsed since the start of the operation of the road surface μ estimating brake. If 500 milliseconds have not elapsed (No ) Return to Step 25, and if 500 milliseconds have elapsed (Yes), go to Step S80. The time length of 500 milliseconds is an example, and other time lengths may be used.

After Yes in step S30, the deceleration control means 804 determines that the road surface on which the vehicle V is traveling at that time is a low μ road (step S50) and stops because the brake for estimating the road surface μ is no longer necessary. (Step S60), the automatic brake control for the low μ road is performed (Step S70: details will be described later in FIG. 4). In this case, the automatic brake for estimating the road surface μ is at most 500 milliseconds, and if it is applied only to the rear wheels and the deceleration is set to about 1.2 m / s ² for example, the driver feels uncomfortable. The road surface μ can be estimated without giving

  Furthermore, the automatic brake for estimating the road surface μ may have an operation condition that the steering handle 5 is not operated or the brake pedal B is not operated by the driver. Alternatively, the vehicle V may be provided with a yaw rate sensor, a lateral acceleration sensor, or the like, and automatic braking control for estimating the road surface μ may not be performed when the vehicle V is turning.

  Returning to the flowchart of FIG. 3, if 500 milliseconds have elapsed from the start of operation of the road surface μ estimation brake (Yes in step S40), the deceleration control means 804 increases the road surface on which the vehicle V is traveling at that time. It is determined that the road is a μ road (such as a dry asphalt road) (step S80), and μ at the time when 500 milliseconds elapse is held (step S90). Thereafter, the deceleration control means 804 stops the operation of the brake for estimating the road surface μ (Step S100) and performs the automatic brake control for the high μ road (Step S110: details will be described later in FIG. 5).

  After step S70 or step S110, in step S120, the deceleration control means 804 determines whether the obstacle has been avoided, the obstacle has disappeared, or any of the conditions has been satisfied. If the condition is satisfied (Yes), the process is terminated. If neither condition is satisfied (No), the process returns to step S5. For example, if “No” is determined in step S72 of FIG. 4 or step S114 of FIG. 5 to be described later, “Yes” is determined in step S120.

Next, the automatic brake control for low μ road (step S70 in FIG. 3) will be described with reference to FIG. FIG. 4 is a flowchart of automatic brake control for a low μ road.
The deceleration control means 804 acquires TTC from the collision determination means 802 (step S71). Then, the deceleration control means 804 determines whether or not the TTC is equal to or less than a threshold value (as in step S10) (step S72). If the TTC is not equal to or less than the threshold value (No), the vehicle V is Since there is little possibility of collision with an obstacle and there is no need for automatic braking, the process ends. If TTC is equal to or less than the threshold value (Yes), the process proceeds to step 73.

  In step S73, the deceleration control means 804 determines whether or not 5 seconds (predetermined length of time) has elapsed since the start of the low-μ road automatic brake control. If 5 seconds have elapsed (Yes), the processing is performed. If 5 seconds have not elapsed (No), the process proceeds to step S74. Note that “5 seconds” set in step S73 is an example of a length that is considered necessary as the duration of the automatic brake control, and may be another time length. Moreover, the process of step S73 is not essential and may be omitted.

  The deceleration control means 804 performs strong automatic brake control when the TTC is large, and performs weak automatic brake control when the TTC is small (step S74), and returns to step S71. Here, the relationship between TTC and deceleration (automatic brake amount) in the automatic brake control on the low μ road will be described with reference to FIG. FIG. 6 is a graph showing the relationship between TTC and deceleration in automatic brake control on a low μ road.

  As shown in FIG. 6, in the relationship diagram, TTC below the threshold value is divided into three ranges (sections) TL1, TL2, and TL3 in ascending order. Then, the low μ road automatic brake amount BL is set to a deceleration L2 when the TTC is TL1, and is set as a value that approaches the deceleration L1 from the deceleration L2 as the TTC increases when the TTC is TL2. Is set to the deceleration L1 in the section of TL3.

Thus, in the case of a low μ road, the deceleration is set smaller as the TTC is smaller (the vehicle V is more likely to collide with an obstacle). Accordingly, since the deceleration is small when TTC is small (TL1 section), a certain lateral force can be secured even when the driver performs a steering operation to change the direction of the vehicle V, and the obstacle Travel stability during avoidance can be improved.
Further, since the deceleration is large when the TTC is relatively large (TL3 section), it is possible to realize a stronger appropriate deceleration control.

  Note that in the entire range of TTC in the relationship diagram of FIG. 6, it is not always necessary that the deceleration decreases as TTC decreases, and obstacle avoidance occurs when TTC decreases to some extent (eg, TL1 section). It is sufficient that the deceleration is small in order to improve running stability at the time.

Next, the high brake automatic brake control (step S110 in FIG. 3) will be described with reference to FIG. FIG. 5 is a flowchart of automatic brake control for a high μ road.
The deceleration control means 804 sets a longer delay time until the start of automatic brake control as the road surface μ (the value held in step S90 in FIG. 3) is larger (step S111). Here, the relationship between the road surface μ and the delay time until the start of the automatic brake control will be described with reference to FIG. FIG. 7A is a relationship diagram of the road surface μ and the delay time until the start of the automatic brake control.

As shown in the relationship diagram of FIG. 7A, as the road surface μ increases from 0.4 to 0.7, the delay time until the start of the automatic brake control becomes longer. Note that the numbers 0.4 and 0.7 are examples, and need not be limited to these.
As described above, the greater the road surface μ is, the longer the automatic brake control start of the vehicle V is delayed (about several seconds), thereby improving the degree of freedom of the driver's operation of the steering handle 5 and the brake pedal B.

Returning to the flowchart of FIG. 5, the deceleration control means 804 waits until the delay time elapses after step S111.
Thereafter, the deceleration control means 804 acquires TTC from the collision determination means 802 (step S113). Then, the deceleration control means 804 determines whether or not the TTC is equal to or less than a threshold value (same as in the case of Step S10) (Step S114), and if the TTC is not equal to or less than the threshold value (No), Since it is not necessary, the process is terminated, and if TTC is equal to or less than the threshold value (Yes), the process proceeds to step 115. The threshold value used in step S114 does not necessarily need to be the same value as in step S10. Since the braking effect is high on a high μ road, a slightly smaller value may be used. Good.

  In step S115, the deceleration control means 804 determines whether or not 5 seconds have elapsed from the start of the high-μ road automatic brake control. If 5 seconds have elapsed (Yes), the processing ends and 5 seconds have elapsed. If not (No), the process proceeds to step S116. Note that “5 seconds” set in step S115 is an example of a length that is considered necessary as the duration of the automatic brake control, and may be another time length. Moreover, the process of step S115 is not essential and may be omitted.

  The deceleration control means 804 performs weak automatic brake control when the TTC is large, and performs strong automatic brake control when the TTC is small (step S116), and returns to step 113. Here, the relationship between TTC and deceleration (automatic brake amount) in the automatic brake control on the high μ road will be described with reference to FIG. FIG. 7B is a relationship diagram between TTC and deceleration in the automatic brake control of the high μ road.

  As shown in the relationship diagram of FIG. 7B, the TTC below the threshold value is divided into three ranges (sections) TH1, TH2, and TH3 in order from the smallest. The high-μ road automatic brake amount BH is set to a deceleration H1 when the TTC is TH1, and is set as a value that approaches the deceleration H2 from the deceleration H1 as the TTC increases when the TTC is TH2. Is set to deceleration H2 in the section where TH3 is.

Thus, in the case of a high μ road, the deceleration is set larger as the TTC is smaller (the possibility that the vehicle V collides with an obstacle is higher). As a result, when TTC is small (TH1 section), the deceleration is large and the road surface μ is large, so that braking control is performed while preventing the occurrence of slip, and also the lateral force during the steering operation is secured. Therefore, it is possible to improve running stability when avoiding obstacles.
Further, since the deceleration is small when the TTC is relatively large (TH3 section), the degree of freedom of the driver's operation of the steering handle 5 and the brake pedal B can be maintained high.

  That is, according to the vehicle operation support apparatus for the vehicle V of the present embodiment, obstacle avoidance can be smoothly performed regardless of the road surface state by changing the deceleration (magnitude) according to the road surface state (coefficient of friction, etc.). Can be done. In other words, by performing obstacle avoidance by the deceleration control based on the possibility that the vehicle V collides with the obstacle and the road surface state, it is possible to improve traveling stability when the own vehicle avoids the obstacle. it can.

  Incidentally, in the automatic brake control for low μ road (see FIG. 4) and the automatic brake control for high μ road (see FIG. 5), the deceleration control means 804 (see FIG. 2) is operated by the hydraulic control device 9 (or electronically controlled negative pressure). It may be realized only by giving an instruction to the booster 6), or in addition, the drive control means 805 (see FIG. 2) receiving the instruction from the deceleration control means 804 gives the drive device 10 an instruction. It is also possible to implement the instruction in combination.

  Further, if 500 μm (ms) has elapsed from the start of the operation of the road surface μ estimating brake and the road surface μ is newly estimated, the automatic braking control for the low μ road or the automatic brake control for the high μ road is performed. Even during operation, the automatic brake control for low μ road or the automatic brake control for high μ road can be appropriately switched according to the newly acquired road surface μ.

  In FIG. 6, the deceleration is constant in the sections where the TTC is TL1 and TL3. However, the deceleration may be reduced as the TTC is reduced in all or part of the sections. Furthermore, in the section where TTC is TL2, the deceleration becomes smaller linearly (linear function) as TTC is smaller. However, the degree of the decrease is not linear but it is quadratic or exponential. Another degree may be used.

  Similarly, in FIG. 7, the deceleration is constant in the sections where the TTC is TH1 and TH3. However, in all or part of these sections, the deceleration is increased as the TTC is decreased. Good. Further, in the section where the TTC is TH2, the deceleration increases linearly as the TTC decreases. However, the degree of increase may be any other degree such as a quadratic function or an exponential function even if it is not linear. .

  6 and 7B, the values of the decelerations L1, L2, H1, and H2 may be freely set as long as at least the value of the deceleration L2 is smaller than the value of the deceleration H1. In the prior art, the value of the deceleration L2 and the value of the deceleration H1 are made the same so that the time to reach these values is different. Therefore, on the low μ road, a sufficient lateral force is secured during the obstacle avoidance operation. However, in this application, the value of the deceleration L2 is made smaller than the value of the deceleration H1, so that a sufficient lateral force can be secured during the obstacle avoiding operation even on a low μ road.

This is the end of the description of the embodiments, but the aspects of the present invention are not limited to these. For example, the threshold value of TTC in step S10 in FIG. 3 is not constant, and may be a value that increases as the speed of the vehicle V increases.
Further, immediately before the automatic brake control is performed, the driver may be notified of the automatic brake by tightening the driver's seat belt for a moment or by using a sound or a display.

Furthermore, it goes without saying that ABS (Anti-lock Brake System) can be used together in automatic brake control.
In addition, about a concrete structure, it can change suitably in the range which does not deviate from the main point of this invention.

1 is an overall configuration diagram of a vehicle equipped with a vehicle operation support device. It is a figure showing the functional block of ECU, and its peripheral device. It is the flowchart which showed the process of the vehicle operation assistance apparatus. It is a flowchart of the automatic brake control for low μ roads. It is a flowchart of the automatic brake control for high μ roads. FIG. 6 is a relationship diagram between TTC and deceleration in automatic brake control on a low μ road. (A) is a relationship diagram between the road surface μ of the high μ road and the delay time until the start of the automatic brake control, and (b) is a relationship diagram of TTC and deceleration in the automatic brake control of the high μ road.

Explanation of symbols

8 ECU
9 Hydraulic Control Device 10 Drive Device 81 CPU
82 Storage Unit 801 Obstacle Detection Unit 802 Collision Determination Unit 803 Road Surface State Estimation Unit 804 Deceleration Control Unit 805 Drive Control Unit S Wheel Speed Sensor V Vehicle

Claims (6)

In a vehicle operation support device that supports a collision avoidance operation performed by a driver to avoid a collision with an obstacle when the vehicle is running,
Obstacle detection means for detecting obstacles ahead of the vehicle;
A collision judging means for judging the possibility of the own vehicle colliding with the obstacle based on the traveling state of the own vehicle and the state of the obstacle;
Road surface state estimating means for estimating the road surface state during traveling;
Deceleration control means for controlling the deceleration of the vehicle based on the possibility of collision and the estimated road surface condition;
A vehicle operation support device comprising: The road surface state estimating means is
Estimating the road friction coefficient as the road surface state,
The deceleration control means includes
2. The vehicle operation support device according to claim 1, wherein when the estimated road surface friction coefficient is equal to or less than a predetermined value, the deceleration is set to be smaller as the possibility of the collision increases. The road surface state estimating means is
Estimating the road friction coefficient as the road surface state,
The deceleration control means includes
3. The vehicle operation support device according to claim 1, wherein when the estimated road friction coefficient is larger than a predetermined value, the deceleration is set to be larger as the possibility of the collision increases. 4. The deceleration control means includes
When controlling the deceleration of the own vehicle, at least one of the conditions that the possibility of the collision is smaller than a predetermined size or the deceleration control of the own vehicle has continued for a predetermined time length or more The vehicle operation support device according to claim 2 or 3, wherein the control of the deceleration of the own vehicle is stopped when the condition is satisfied. The deceleration control means includes
The vehicle operation support apparatus according to claim 3, wherein the start of deceleration control of the host vehicle is delayed as the estimated road surface friction coefficient increases. The deceleration control means includes
When the estimated road surface friction coefficient exceeds a predetermined value, the road surface friction coefficient is estimated until a predetermined time elapses,
The control of the deceleration of the own vehicle is started when the estimated road friction coefficient becomes a predetermined value or less even before the predetermined time elapses. The vehicle operation support device according to any one of the above.

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