JP4558754B2 - Vehicle control device - Google Patents

Description

  The present invention relates to a vehicle control device that performs control of a traveling state (traveling speed, distance between vehicles, etc.) and control for collision avoidance based on a distance and relative speed with a target existing in front of the vehicle.

  Conventionally, as a vehicle control device of this type, a preceding vehicle is detected as a target existing in front of the vehicle, and a target acceleration set based on the distance from the preceding vehicle, the relative speed, and the traveling state of the host vehicle is obtained. As described above, adaptive cruise control (ACC) is known that automatically controls the engine, gears, and brakes of the host vehicle to maintain an appropriate inter-vehicle distance from the preceding vehicle.

  Usually, in ACC, the maximum deceleration (minimum acceleration) when braking control is performed for the safety of passengers is limited. However, in some cases, a collision with a preceding vehicle may not be avoided even if control is performed with the maximum deceleration. For this reason, during ACC, when it is determined that the vehicle approaches the preceding vehicle and is in a dangerous state, an alarm is issued to prompt the driver to intervene (see, for example, Patent Document 1), or the driver intervenes. There is known an apparatus that performs collision avoidance control such as making the braking force generated when a brake operation is performed larger than usual to make it easier to avoid a collision (see, for example, Patent Document 2).

  In addition, when there is a possibility of a collision with a preceding vehicle regardless of the ACC, an apparatus that automatically decelerates the host vehicle by generating an acceleration (deceleration) that can avoid the collision (for example, Patent Document 3). See also).

By combining these technologies, when the vehicle is in a situation where a collision with the preceding vehicle cannot be avoided at the maximum deceleration during ACC, a deceleration exceeding the maximum deceleration (negative acceleration) is generated, A device that performs collision avoidance control that automatically decelerates can be considered.
JP 2000-177429 A Japanese Patent Laid-Open No. 11-139278 JP 10-338110 A

  However, in the device that automatically executes the collision avoidance control in addition to the ACC, even if the host vehicle falls into a dangerous situation, the driver does not notice the situation, or overconfidently believes the device, and performs control. There is a risk of not intervening. These devices only support the driver, and there is a problem in that various risks are increased when the driver does not intervene in the control.

  In other words, depending on the behavior of the preceding vehicle (for example, rapid deceleration) and the road surface condition (for example, freezing of the road surface), the collision may not be avoided even if the collision avoidance control is performed, or the preceding vehicle is detected. If a detection error occurs in the sensor, the collision avoidance control is performed on roadside objects that do not actually have a risk of collision, which increases the risk of collision with the following vehicle. .

  Furthermore, ACC generally suppresses acceleration and deceleration when there is a suspicion that the target detected by the sensor is not a vehicle, or when there is a possibility that the vehicle is not detected normally. Has also been done. In such a case, if the same treatment is performed in the collision avoidance control, there is a problem that the collision avoidance cannot be performed when the target is a genuine preceding vehicle.

  In order to solve the above problems, the present invention is in a dangerous situation in which collision avoidance control is performed in a vehicle control device that performs collision avoidance control when collision with a preceding vehicle cannot be avoided by running state control. The goal is to improve the safety of driving by ensuring the driver's intervention in case of falling.

In the vehicle control device of the present invention made to achieve the above object, the traveling state control means sets the target control amount based on the distance and relative speed with the preceding vehicle that is the target existing in front of the vehicle, By accelerating / decelerating the vehicle in accordance with the target control amount, the running state of the vehicle is controlled to adjust the inter-vehicle distance from the preceding vehicle . When the collision with the target cannot be avoided by the control by the traveling state control means, the collision avoidance control means performs control for collision avoidance.

  Note that the traveling state here includes at least the traveling speed or the inter-vehicle distance (inter-vehicle time). Hereinafter, the control by the traveling state control means is also referred to as traveling state control, and the control by the collision avoidance control means is also referred to as collision avoidance control.

When the collision avoidance control is executed at the time of setting the operation mode for executing the traveling state control, the cancel unit cancels the operation mode.
Therefore, according to the present invention, when the collision avoidance control is executed during the execution of the running state control, the driver does not automatically return to the running state control after that, but the driver always operates the vehicle. It will be. Therefore, it is possible to prevent excessive dependence on the device so that the driver expects execution of the collision avoidance control and knows that the situation is dangerous and does not intervene (brake operation). Further, when the driver does not recognize that the situation is dangerous, the driver can be surely noticed that the situation is such that the collision avoidance control is executed. As a result, a dangerous situation in which collision avoidance control is repeatedly executed is not left as it is, and driver intervention (brake operation) is performed at an early stage, thus improving driving safety. Can be made.

  By the way, when the traveling state control unit is configured to control the target acceleration to the limit acceleration when the target acceleration is smaller than the preset negative limit acceleration, at least start the collision avoidance control unit. In some cases, the control is performed with an avoidance acceleration smaller than the limit acceleration, and the avoidance acceleration has a difference in the vehicle behavior between the running state control and the collision avoidance control that can be discerned by the occupant's experience. It is desirable to set a large size. Specifically, the difference between the limited acceleration and the avoidance acceleration is desirably 1/10 or more of the gravitational acceleration.

  In this way, by giving a difference between the limit acceleration of the running state control and the avoidance acceleration of the collision avoidance control, the driver is notified that the collision avoidance control has started beyond the limit (limit acceleration) of the running state control. It can be surely recognized. In particular, when the above-described canceling means is provided, the driver can be surely recognized why the traveling state control is automatically canceled.

Further, the alarm unit may be configured to generate an alarm when the collision avoidance control unit is highly likely to operate.
Furthermore, in order to prevent the collision avoidance control for the wrong target, only when the target that should avoid the collision is the target of control by the traveling state control means for a preset monitoring time or longer, The permitting unit may be configured to permit the operation of the avoidance control unit.

Embodiments of the present invention will be described below with reference to the drawings.
FIG. 1 is a block diagram illustrating a schematic configuration of an adaptive cruise control (ACC) system according to an embodiment.

  As shown in FIG. 1, the ACC system includes an inter-vehicle control electronic control device (hereinafter referred to as “inter-vehicle control ECU”) 2, an engine electronic control device (hereinafter referred to as “engine ECU”) 3, a brake electronic control device ( (Hereinafter referred to as “brake ECU”) 4 and meter electronic control device (hereinafter referred to as “meter ECU”) 5, which are connected to each other via a LAN communication bus. Each of the ECUs 2, 3, 4, and 5 is configured around a known microcomputer, and includes at least a bus controller for performing communication via a LAN communication bus. In this embodiment, data communication between ECUs performed via a LAN communication bus uses a CAN (“Controller Area Network” proposed by Robert Bosch, Germany) protocol generally used in an in-vehicle network. ing.

The inter-vehicle control ECU 2 is also connected to a radar sensor 6, an alarm buzzer 7, a cruise control switch 8, and a target inter-vehicle setting switch 9.
Among these, the radar sensor 6 is configured as a so-called “laser radar sensor”, and more specifically, is an electronic circuit mainly configured by a laser scanning rangefinder and a microcomputer.

  Then, the scanning rangefinder scans and irradiates laser light in a predetermined angle range in the vehicle width direction, and detects the angle and distance of the target detected based on the reflected light, the current vehicle speed and the curve curvature radius received from the inter-vehicle control ECU 2. Based on an estimated value (hereinafter referred to as “estimated R”) or the like, attribute information indicating the own lane probability indicating the probability that the target exists on the own lane or the target attribute (vehicle / non-vehicle / unknown, etc.) is obtained. . At the same time, the collision flag is set for the target coming toward the host vehicle. Then, the own lane probability, attribute information, and collision flag are transmitted to the inter-vehicle control ECU 2 as preceding vehicle information including information such as distance and relative speed. Further, the diagnosis signal of the radar sensor 6 itself is also transmitted to the inter-vehicle distance control ECU 2. Here, laser light is used as the radar wave, but radio waves (for example, millimeter waves) may be used.

  The cruise control switch 8 includes a main switch for starting and stopping the inter-vehicle control ECU 2, a set switch for starting inter-vehicle control described later, a cancel switch for ending the inter-vehicle control, and a stored set vehicle speed. It has an accelerator lever that increases, and a coast lever that decreases the set speed.

  The target inter-vehicle setting switch 9 is a time required for the host vehicle to travel a distance corresponding to the target inter-vehicle distance between the preceding vehicle and the host vehicle in ACC (hereinafter referred to as “target inter-vehicle time”). Is a switch for setting. The target inter-vehicle time can be set within a predetermined range.

  Next, the engine ECU 3 detects the current vehicle speed and the accelerator pedal based on sensor signals from a vehicle speed sensor 10 that detects the vehicle speed, an accelerator pedal opening sensor 11 that detects the accelerator pedal opening, and a throttle opening sensor (not shown). A pedal state (accelerator) indicating the operation state and a control state (idle) indicating whether or not the engine is in the idle state are transmitted to the inter-vehicle distance control ECU 2. On the other hand, the inter-vehicle control ECU 2 receives an inter-vehicle control flag indicating whether or not the vehicle is in ACC, a target acceleration, a brake request, a diagnosis signal, and the like, according to the driving state determined from the information obtained by the reception. A drive command is output to the electronic throttle 12 or the like that adjusts the throttle opening of the engine.

  The brake ECU 4 includes a steering sensor 13 for detecting the steering angle of the vehicle, a brake pedal depression force sensor 15 for detecting the depression state of the brake pedal, in addition to the steering angle and the yaw rate from the yaw rate sensor 14 for detecting the yaw rate indicating the vehicle turning state. This pedal state (brake) is transmitted to the inter-vehicle distance control ECU 2. On the other hand, the inter-vehicle control ECU 2 receives the inter-vehicle control flag, the target acceleration, the brake request, etc., and controls the brake hydraulic circuit W to control the braking force according to the driving state determined from the information obtained by the reception. A drive command is output to the brake actuator 16 or the like that controls the / C pressure.

  The meter ECU 5 receives information on the vehicle speed, the engine speed, the door open / close state, the shift range of the transmission, and the like via the LAN, displays various states of the vehicle on a meter display (not shown), An inter-vehicle control flag, a collision avoidance warning, a diagnosis signal, and the like are received from the control ECU 2 and displayed on the head-up display 17 and the like.

  The inter-vehicle control ECU 2 receives the current vehicle speed (Vn), the engine control state, the pedal state (accelerator) from the engine ECU 3, and the steering angle (str-eng, S0), the yaw rate, the pedal state (brake), etc. from the brake ECU 4. Receive. Then, a preceding vehicle to be controlled by the ACC is determined based on the own lane probability included in the preceding vehicle information received from the radar sensor 6, and based on detection signals from the cruise control switch 8 and the target inter-vehicle setting switch 9. In addition, the inter-vehicle distance control flag is transmitted to each of the ECUs 3, 4, 5, and a target acceleration, a brake request, a diagnosis signal, etc. are transmitted to the engine ECU 3 as control command values for appropriately adjusting the inter-vehicle distance from the preceding vehicle. The brake ECU 4 transmits a target acceleration, a brake request, etc., and the meter ECU 5 transmits a collision avoidance warning, a diagnosis signal, and the like. Further, the inter-vehicle control ECU 2 determines whether an alarm is generated, and sounds the alarm buzzer 7 when it is necessary to generate an alarm.

Next, main processing executed by the inter-vehicle control ECU 2 will be described along the flowchart shown in FIG.
In this processing, first, radar data such as preceding vehicle information is received from the radar sensor 6 (S100), and then the current vehicle speed (Vn), engine control state (idle), pedal state (accelerator, accelerator) are transmitted from the engine ECU 3 and brake ECU 4. Brake), steering angle (str-eng, S0), and CAN data such as yaw rate are received (S200).

Then, based on the steering angle, yaw rate, and current vehicle speed acquired in S200, an estimated R representing the traveling direction of the host vehicle is calculated, and based on the own lane probability, attribute information, and the like of the radar data acquired in S100, A target (preceding vehicle) to be controlled is selected (S300). Specifically, a target that is closest to the host vehicle is extracted as a preceding vehicle from vehicles whose probability of own lane is high to some extent and whose attribute information is unknown or unknown. Further, with the preceding vehicle selected in S300 The target acceleration Ga is determined according to the distance, relative speed, attribute information of the preceding vehicle, and the target inter-vehicle distance set by the target inter-vehicle setting switch 9 (S400).

  Specifically, when the preceding vehicle is not selected in S300, a target acceleration Ga is determined so that the vehicle travels at a constant speed at the set vehicle speed set by operating the accelerator lever and the coast lever. On the other hand, when the preceding vehicle is selected in S300, the target acceleration Ga is obtained using a preset control map with the inter-vehicle deviation ratio and the relative speed with the preceding vehicle as parameters.

  The inter-vehicle deviation ratio (%) is a value obtained by dividing a value obtained by subtracting the target inter-vehicle distance set by the target inter-vehicle setting switch 9 from the current inter-vehicle distance (inter-vehicle deviation) by the target inter-vehicle and multiplying by 100. However, in the control map, the target acceleration Ga is set to be larger as the inter-vehicle deviation ratio is larger. However, the target acceleration Ga is provided with a maximum value Gamax (0.5 m / s2 in the present embodiment) and a minimum value Gamin (-2 m / s2 in the present embodiment), and is limited to a value between these values. Is set to be. In addition, the relative speed is subjected to low-pass filter processing in order to suppress fluctuations in value due to measurement errors.

  Next, based on the distance D (m) to the preceding vehicle, the relative speed V (m / s), and the acceleration A (m / s2) of the preceding vehicle, the collision avoidance request acceleration Gr (m / S2) is obtained (S500).

Gr = A−V 2 / (2 · (D−Dfin)) (1)
However, Dfin is a minimum distance (2 m in this embodiment) that is desired to be secured. In other words, the acceleration at which the relative speed V becomes zero when the relative distance to the preceding vehicle becomes Dfin is obtained as the collision avoidance request acceleration Gr.

  Hereinafter, using the radar data and CAN data received in S100 and S200, the target acceleration Ga and the collision avoidance request acceleration Gr calculated in S400 and S500, the collision avoidance alarm determination (S600) and the collision avoidance control determination (S700). Each process of the state transition / state handling process (S800) is executed. Details of these processes will be described later.

  Thereafter, CAN data such as target acceleration, brake request, diagnosis signal, and display data is transmitted to the engine ECU 3, brake ECU 4 and meter ECU 5 (S900), and the current vehicle speed (Vn) and estimated R are transmitted to the radar sensor 6. Such data is transmitted (S1000), and this processing is terminated.

Below, the detail of each process shown to S500-S700 is demonstrated in order.
First, in the collision avoidance alarm determination executed in S600, as shown in the flowchart of FIG. 3, it is determined whether or not the collision avoidance alarm flag XA that is set first when the collision avoidance alarm should be generated is set to 1. If it is determined (S601) and it is not set, the following processing (S602 to S606) for determining whether or not a condition for generating a collision avoidance alarm is established is executed.

  That is, whether or not the preceding vehicle has been selected in the previous S300 (S602), and whether or not the selected preceding vehicle has been selected continuously for a preset monitoring time T1 (5 seconds in the present embodiment). (S603) Whether the vehicle is approaching the preceding vehicle (relative speed R <0) (S604), whether the collision avoidance request acceleration Gr obtained in S500 is smaller than the lower limit value Gamin of the target acceleration Ga, that is, It is sequentially determined whether or not a collision cannot be avoided by normal inter-vehicle control in which the target acceleration Ga is limited (S605). If any one of the determinations is negative, that is, whether the preceding vehicle is not selected, whether the preceding vehicle has not been selected continuously for the monitoring time T1 or more, whether R ≧ 0 or Gr ≧ Gamin. If any one of them is applicable, the present process is terminated without operating the collision avoidance warning flag.

  On the other hand, when an affirmative determination is made in any of S602 to S605, that is, the preceding vehicle is selected, the preceding vehicle is continuously selected for the monitoring time T1 or more, and R <0 and Gr <Gamin. If this is the case, the collision avoidance warning flag XA is set to 1 (S606), and this process ends.

  Further, when it is determined in the previous S601 that the collision avoidance warning flag XA is set to 1, the following processing (S607 to S611) for determining whether or not a condition for canceling the collision avoidance alarm is satisfied. ).

  That is, whether or not the preceding vehicle has been selected in the previous S300 (S607), the state where the collision avoidance warning flag XA is set to 1 continues for a preset minimum duration T2 (1 second in this embodiment) or more. Whether or not the vehicle is approaching the preceding vehicle (relative speed R <0) (S609), and the collision avoidance request acceleration Gr determined in S500 is set to a lower limit value Gamin of the target acceleration Ga. It is sequentially determined whether or not the value Gaoff (in this embodiment, 0.5 m / s @ 2) is equal to or greater than the sum (S610).

  If it is determined in S607 that the preceding vehicle is not selected, or if it is determined that the preceding vehicle is selected in S607, XA = 1 is a grace period in S608 to S609. If it continues for more than T2 and is not approaching the preceding vehicle, or in S608 to S610, XA = 1 continues for the grace period T2 and is approaching the preceding vehicle, and Gr ≧ If Gamin + Gaoff, the collision avoidance warning flag XA is reset to 0 (S611), and this process ends.

  On the other hand, it is determined in S607 that the preceding vehicle is selected, and in S608 to S610, the duration of XA = 1 is less than the minimum duration T2 or is approaching the preceding vehicle, and If it is determined that Gr <Gamin + Gaoff, this processing is terminated without operating the collision avoidance warning flag XA.

  In other words, in this process, when the collision avoidance warning flag XA is reset, it is highly possible that the selected preceding vehicle exists and only when the preceding avoiding vehicle is approaching, according to the collision avoidance request acceleration Gr. It is determined whether or not the collision avoidance warning flag XA is set. Further, when the collision avoidance warning flag XA is set and the preceding vehicle is not selected, the collision avoidance warning flag XA is unconditionally reset, and only when the selected preceding vehicle is approaching, the collision is avoided. It is determined whether or not to reset the collision avoidance warning flag XA according to the avoidance request acceleration Gr. Further, the threshold value of the collision avoidance request acceleration Gr used when setting or resetting the collision avoidance alarm flag XA has hysteresis, and once the collision avoidance alarm flag XA is set, the preceding vehicle is being selected. The set state is set to continue for at least the minimum duration T2.

  Next, in the collision avoidance control determination executed in S700, as shown in the flowchart of FIG. 4, first, whether or not the collision avoidance control flag XC that is set when the collision avoidance control is to be executed is set to 1 or not. (S701), and if not set, the following processing (S702 to S706) for determining whether or not the condition for executing the collision avoidance control is satisfied is executed.

  That is, whether the attribute of the preceding vehicle selected in the previous S300 is a vehicle (S702), whether the collision flag of the preceding vehicle is set to 1 (S703), the own lane of the preceding vehicle Whether the probability is greater than a threshold value Pf (80% in the present embodiment) at which it is possible to determine that there is a high possibility that the preceding vehicle is on the own lane (S704), the collision avoidance request acceleration Gr determined in S500 Is smaller than a determination value Gc (Gc = Gamin−0.98 [m / s 2] in the present embodiment) set to a value smaller than the lower limit value Gamin of the target acceleration Ga (so as to have a larger deceleration). (S705) are sequentially determined. The determination value Gc corresponds to the avoidance acceleration in the present invention, and the lower limit value Gamin corresponds to the limit acceleration in the present invention.

  And when negative determination is made in any one of S702 to S705, that is, whether the preceding vehicle attribute is not a vehicle, the collision flag is reset to 0, or the own lane probability is less than or equal to the threshold value Pf If any one of Gr ≧ Gc is true, the present process is terminated without operating the collision avoidance control flag XC.

  On the other hand, if an affirmative determination is made in any of S702 to S705, that is, the preceding vehicle attribute is a vehicle, the collision flag is set to 1, the own lane probability is greater than the threshold value Pf, and Gr < If it is Gc, the collision avoidance control flag XC is set to 1 (S706), and this process is terminated.

  If it is determined in the previous S701 that the collision avoidance control flag XC is set to 1, the following processing (S707 to S711) for determining whether or not a condition for canceling the collision avoidance control is satisfied. ).

  That is, whether the attribute of the preceding vehicle selected in the previous S300 is a vehicle (S707), whether the collision flag of the preceding vehicle is set to 1 (S708), whether the preceding vehicle is in the own lane Whether the probability is equal to or less than the threshold value Pf (S709), and the collision avoidance request acceleration Gr obtained in S500 is a value obtained by adding a predetermined value Gcoff (0.5 m / s2 in the present embodiment) to the determination value Gc. It is sequentially determined whether or not this is the case (S710).

  In S607 to S610, it is determined that the preceding vehicle attribute is not a vehicle, the collision flag is reset to zero, the own lane probability is equal to or less than the threshold value Pf, or Gr ≧ Gc + Gcoff. If it is determined, the collision avoidance control flag XC is reset to 0 (S711), and this process is terminated.

  On the other hand, if it is determined in S607 to S610 that the preceding vehicle attribute is a vehicle, the collision flag is set to 1, the own lane probability is greater than the threshold value Pf, and Gr <Gc + Gcoff, This process is ended as it is without operating the collision avoidance control flag XC.

  That is, in this process, when the collision avoidance control flag XC is reset, the collision avoidance requested acceleration is only when the selected preceding vehicle is a vehicle that is on the own lane and is heading toward the own vehicle. It is determined whether or not the collision avoidance control flag XC is set based on Gr. Further, when the collision avoidance control flag XC is set, the collision avoidance control flag XC is unconditionally set if the preceding vehicle is not a vehicle, does not face the own vehicle, or is not on the own lane. Only when it is not reset, whether or not to reset the collision avoidance control flag XC is determined based on the collision avoidance request acceleration Gr. Further, the threshold used when the collision avoidance control flag XC is set or reset is set to have hysteresis.

Next, the state transition / state handling process executed in S800 will be described.
In this processing, there are a “cancel” state and a “controlling” state as transitionable states, and among these, the “controlling” state is further “controlling: inter-vehicle control” state, “controlling: collision avoidance warning” ”State and“ during control: collision avoidance control ”state.

  Then, according to the collision avoidance alarm flag XA set in S600, the collision avoidance control flag XC set in S700, and the pedal state (accelerator, brake), the state transition according to the state transition diagram shown in FIG. Do.

  First, immediately after the main switch is turned on, a “cancel” state (inter-vehicle control flag FC = 0) is entered. In this “cancel” state, when the set switch is turned on, an “in-control: inter-vehicle control” state (inter-vehicle control) Transition to the middle flag FC = 1). That is, an operation mode for executing the inter-vehicle distance control is set.

  Further, in the “in control” state, in any of the three states, a transition to the “cancel” state is made when an operation of the brake pedal is detected. That is, the operation mode for executing the inter-vehicle distance control is canceled.

Next, in the “controlling: inter-vehicle control” state in the “controlling” state, when the collision avoidance warning flag XA is set, the state transits to the “controlling: collision avoidance warning” state.
Further, in the “controlling: collision avoidance warning” state, when the collision avoidance warning flag XA is reset or the operation of the accelerator pedal is detected, a transition is made to the “controlling: inter-vehicle control” state. At this time, it is desirable to prohibit the execution of the collision avoidance alarm determination for a predetermined time in order to prevent transition to the “controlling: inter-vehicle control” state and the transition to the “controlling: collision avoidance alarm” state again immediately. When the collision avoidance control flag XC is set, the state transits to the “controlling: collision avoidance control” state.

  Further, in the “controlling: collision avoidance control” state, the state shifts to the “cancel” state when the collision avoidance control flag XC is reset or the operation of the accelerator pedal is detected. That is, after the transition to the “controlling: collision avoidance control” state, the “controlling” state is always canceled once.

  Then, as the state corresponding process, when in the “controlling: inter-vehicle control” state, it is determined whether or not the vehicle needs to be braked according to the target acceleration Ga calculated in S400, and a brake request is set. Processing for transmitting the target acceleration Ga and the brake request to the engine ECU 3 and the brake ECU 4 is performed.

  The engine ECU 3 obtains a throttle opening command value based on the target acceleration Ga, determines whether control is possible based on the brake request, and drives and controls the electronic throttle 12, and the brake ECU 4 controls W / W based on the target acceleration Ga. Acceleration / deceleration is performed according to the target acceleration Ga by obtaining a C pressure command value, determining whether control is possible based on the brake request, and controlling the drive of the brake actuator 16. Specifically, when the actual acceleration is larger than the target acceleration (actual deceleration is smaller than the target deceleration), a throttle opening command value that closes the throttle, or a W / C pressure command that increases the braking force Calculate the value.

  Further, when in the “controlling: collision avoidance alarm” state, the alarm buzzer 7 is sounded to generate an alarm for notifying the driver that the collision avoidance process is likely to operate in the near future. At the same time, a process of transmitting to the meter ECU 5 a signal indicating that a collision avoidance alarm is being performed is performed.

  At this time, the meter ECU 5 prompts the driver to intervene by displaying a message prompting the brake operation on the head-up display 17, and at the same time, provides a visual notification for the driver to prepare for deceleration by collision avoidance control. I do.

  Further, when in the “controlling: collision avoidance control” state, the collision avoidance request acceleration Gr obtained in S500 is set as the target acceleration Ga as it is, and the following processing is executed in the same manner as in the inter-vehicle distance control.

  In the present embodiment, the process executed in the “controlling: inter-vehicle control” state is the running state control means, the process executed in the “controlling: collision avoidance alarm” state is the warning means, and “controlling: The process executed in the “collision avoidance control” state corresponds to the collision avoidance control means. Further, S603 corresponds to permission means.

  In the ACC system of this embodiment configured as described above, as shown in FIG. 6, when the collision avoidance required acceleration Gr becomes smaller than the minimum value Gamin of the target acceleration Ga during the inter-vehicle distance control, the collision avoidance alarm is started. Is done.

  Thereafter, when the collision avoidance request acceleration Gr returns to a value larger than the value Gamin + Gaoff without reaching the determination value Gc, the collision avoidance alarm is canceled and the vehicle distance control is restored. However, when the time until the return to a value larger than the value Gamin + Gaoff is less than the minimum duration T2, the collision avoidance alarm is continued until the minimum duration T2 elapses. Although not shown, when the operation of the accelerator pedal is detected during the collision avoidance alarm, the collision avoidance alarm is immediately canceled and the vehicle distance control is restored.

  On the other hand, when the collision avoidance warning becomes smaller than the collision avoidance request acceleration Gr determination value Gc during the collision avoidance alarm, the collision avoidance control is started. Thereafter, when the collision avoidance request acceleration Gr returns to a value larger than the value Gc + Gcoff, the operation mode for performing these controls is canceled without returning to the inter-vehicle distance control or the collision avoidance control.

  As described above, in the present embodiment, after the collision avoidance control is executed, the control is canceled instead of automatically returning to the inter-vehicle distance control, and the driver is allowed to drive the vehicle. Therefore, the driver can be surely noticed that the vehicle has entered a situation where the collision avoidance control is executed. As a result, a dangerous situation in which collision avoidance control is repeatedly executed is not left as it is, and driver intervention (brake operation) is performed at an early stage, thus improving driving safety. Can be made.

  Further, in the present embodiment, there is a large difference (0.98 m / s 2 = 0.1 G) between the lower limit value Gamin of the target acceleration set in the inter-vehicle control and the collision avoidance request acceleration Gr when the collision avoidance control is executed. ), And when collision avoidance control is started, a difference that can be discerned by bodily sensation is generated in the behavior of the vehicle. For this reason, the driver can be surely recognized that the collision avoidance control has been started, and thus the reason why the ACC is automatically canceled after the collision avoidance control.

  Furthermore, in this embodiment, before the collision avoidance control is started, a collision avoidance alarm is generated, and at that time, an operation indicating that the collision avoidance control is unnecessary (in this case, the operation of the accelerator pedal) is detected. In some cases, the normal vehicle distance control is restored without executing the collision avoidance control. In other words, when there is an indication of the driver's intention, it is considered that there is a high possibility of a false detection of the target. Therefore, the collision avoidance control that does not require such a target increases the risk of a collision with the following vehicle. It is possible to reliably prevent the driver from bothering the driver by canceling the ACC following the unnecessary collision avoidance control.

  In the present embodiment, the generation of the collision avoidance alarm and the operation of the collision avoidance control are permitted only for the target (preceding vehicle) that has been controlled for the monitoring time T1 or more in the inter-vehicle distance control. At the same time, when there is a low possibility that the target to be controlled is a vehicle, the collision avoidance control is not activated, and a collision avoidance alarm is generated.

  Therefore, in this embodiment, it is possible to prevent the collision avoidance control from being performed on a false target that is erroneously detected or a target that is not a vehicle, and even if the target is a real vehicle, the minimum necessary amount can be achieved by alarm control. It is possible to reliably carry out a limited treatment, that is, prompting the driver to intervene.

As mentioned above, although one Embodiment of this invention was described, this invention is not limited to the said embodiment, It is possible to implement in various aspects.
For example, in the above-described embodiment, when the accelerator pedal is operated in the “controlling: collision avoidance warning” state, the state is changed to the “controlling: inter-vehicle control” state. In addition, a specific switch designated in advance may be used. Further, this state transition may be omitted.

  Further, in the above embodiment, S702 is provided, and the collision avoidance control is prohibited when the possibility that the target is a vehicle is low. Further (or instead of this), the radar sensor 6 The collision avoidance control may be prohibited when it is determined that the detection accuracy of the radar sensor 6 is lowered based on a diagnosis signal or the like.

It is a block diagram which shows schematic structure of an adaptive cruise control (ACC) system. It is a flowchart which shows the content of the main process which vehicle control ECU performs. It is a flowchart which shows the content of the collision avoidance warning determination. It is a flowchart which shows the content of collision avoidance control determination. It is a state transition diagram for demonstrating the content of the process in a state transition / state response process. It is explanatory drawing which shows the relationship between a collision avoidance request | requirement acceleration and a state transition.

Explanation of symbols

  2 ... inter-vehicle control ECU, 3 ... engine ECU, 4 ... brake ECU, 5 ... meter ECU, 6 ... radar sensor, 7 ... alarm buzzer, 8 ... cruise control switch, 9 ... target inter-vehicle setting switch, 10 ... vehicle speed sensor, 11 Accelerator pedal opening sensor, 12 Electronic throttle, 13 Steering sensor, 14 Yaw rate sensor, 15 Brake pedal depression sensor, 16 Brake actuator, 17 Head up display.

Claims (6)

The target control amount is set based on the distance and relative speed with the preceding vehicle that is the target in front of the vehicle, and the vehicle distance is adjusted according to the target control amount to adjust the inter-vehicle distance with the preceding vehicle. Traveling state control means for controlling the traveling state of the vehicle,
In the control by the running state control means, when collision with the target cannot be avoided, collision avoidance control means for performing control for collision avoidance,
In a vehicle control device comprising:
A vehicle control apparatus, comprising: a canceling unit for canceling the operation mode when the control by the collision avoidance control unit is executed when the operation mode for executing the control by the running state control unit is set.   The target control amount is a target acceleration, and when the target acceleration is smaller than a preset negative limit acceleration, the running state control unit performs control by limiting the target acceleration to the limit acceleration. The collision avoidance control means controls at least at an avoidance acceleration smaller than the limit acceleration at the start of operation, and the avoidance acceleration is controlled by the control by the traveling state control means and the control by the collision avoidance control means. The vehicle control device according to claim 1, wherein the vehicle control device is set to a size that causes a difference that can be identified by a passenger's experience. A vehicle that adjusts the inter-vehicle distance from the preceding vehicle by setting a target acceleration based on the distance and relative speed with the preceding vehicle that is the target that is in front of the vehicle, and accelerating / decelerating the vehicle according to the target acceleration. Traveling state control means for controlling the traveling state of
In the control by the running state control means, when collision with the target cannot be avoided, collision avoidance control means for performing control for collision avoidance,
In a vehicle control device comprising:
When the target acceleration is smaller than a preset negative limit acceleration, the running state control means performs actual control by limiting the target acceleration to the limit acceleration, and the collision avoidance control means includes at least At the start of control, control is performed with an avoidance acceleration smaller than the limit acceleration. It ’s set to a size that produces a discernable difference ,
Provided with permission means for permitting operation of the avoidance control means only when a target to avoid a collision is a target of control by the traveling state control means for a preset monitoring time or longer. A vehicle control device.   The vehicle control device according to claim 2 or 3, wherein a difference between the limited acceleration and the avoidance acceleration is 1/10 or more of a gravitational acceleration.   The vehicle control device according to any one of claims 1 to 4, further comprising alarm means for generating an alarm when the collision avoidance control means is highly likely to operate. The permission means for permitting the operation of the avoidance control means is provided only when the target to avoid the collision is the target of the control by the traveling state control means for a preset monitoring time or longer. The vehicle control device according to claim 1 or 2 , characterized in that

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