JP4670841B2 - Vehicle travel control device - Google Patents

Description

  The present invention relates to a vehicular travel control apparatus that performs travel control according to a relative positional relationship with an object in front of the host vehicle.

As a conventional vehicle travel control device, when a stop (a delineator on the front road side) is detected by a sensor that recognizes an object in front of the host vehicle, the movement trajectory is statistically processed, whereby the optical axis of the sensor is detected. It is known that a deviation amount (a deviation amount from the front-rear axis direction of the vehicle) is detected, and relative position information with respect to a front object is corrected based on the optical axis deviation amount (see, for example, Patent Document 1).
JP-A-10-132939

  However, in the above conventional vehicle travel control device, since the optical axis deviation of the sensor is detected by statistically processing the movement trajectory of the stationary object, the optical axis deviation actually occurs. It cannot be detected until the time has passed. Therefore, when an optical axis shift occurs due to a light collision or the like, there is an unsolved problem that the system operates with the optical axis shifted until the optical axis shift is detected.

  Accordingly, the present invention has been made paying attention to the unsolved problems of the conventional example described above, and when a deviation occurs in the detection range of a sensor for recognizing an object ahead of the host vehicle, it is immediately detected. It is an object of the present invention to provide a vehicular travel control device that can do this.

In order to achieve the above object, the vehicular travel control apparatus according to the present invention performs automatic braking control of the host vehicle when the collision avoidance determining means determines that collision avoidance is impossible and a predetermined operating condition is satisfied. After the end of automatic braking control, when the detection range of the front object detecting means changes due to a collision determined by the collision avoidance determining means that collision avoidance is impossible, automatic braking control by the automatic braking control means or traveling The operating conditions are changed so that the travel control by the control means is hardly operated.

According to the present invention, when the detection range of the front object detection unit changes due to a collision that the collision avoidance determination unit determines that collision avoidance is impossible, the automatic braking control by the automatic braking control unit or the traveling control by the traveling control unit is performed. Since the operating condition is changed so that it is difficult to be operated, it is ensured that automatic braking control or traveling control is performed without being able to accurately recognize the position of the front object due to a change in the detection range of the front object detection means due to a collision. In addition to preventing this, it is possible to obtain an effect of ensuring safe driving.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
First, the first embodiment will be described.
FIG. 1 is a schematic configuration diagram showing an embodiment in which the present invention is applied to a rear wheel drive vehicle equipped with a collision speed reduction device. In the figure, 1FL and 1FR are front wheels as driven wheels, 1RL and 1RR are The rear wheels 1RL and 1RR as driving wheels are driven to rotate by the driving force of the engine 2 being transmitted through the automatic transmission 3, the propeller shaft 4, the final reduction gear 5 and the axle 6.

The front wheels 1FL, 1FR and the rear wheels 1RL, 1RR are each provided with a brake actuator 7 composed of, for example, a disc brake that generates a braking force, and the braking hydraulic pressure of these brake actuators 7 is controlled by a braking control device 8. Is done.
Here, the braking control device 8 generates a braking hydraulic pressure in response to depression of a brake pedal (not shown), and also generates a braking hydraulic pressure in accordance with a braking pressure command value P _BR from the travel control controller 20, and this is generated as a brake actuator. 7 to output to. Further, a vehicle speed sensor 13 for detecting the host vehicle speed Vs by detecting the rotation speed of the output shaft provided on the output side of the automatic transmission 3 is provided.

On the other hand, a front object sensor 14 as a front object detection means is provided at the lower part of the vehicle body on the front side of the vehicle, and is periodically scanned in the forward direction of the vehicle while being shifted in the horizontal direction by a predetermined angle by a scanning laser radar. Is irradiated with a fine laser beam within a predetermined irradiation range (for example, 12 ° to 24 ° in the horizontal direction and 4 ° in the vertical direction), and the reflected light reflected and returned from the front object is received, and the emission timing As shown in FIG. 2, the relative distance dr between the host vehicle MC and the front object PC at each angle is detected based on the time difference from the received light timing to the reflected light reception timing. The relative speed Vr between the front object and the host vehicle is calculated from the detected temporal change in the relative distance dr to the front object, and the traveling direction of the host vehicle is determined based on the detection signal of the front object sensor 14 and its scanning angle. As a reference, the angle ranges θ _R and θ _L of the left and right edges of the front object relative to this are detected.

  The front object sensor 14 is usually attached with a fastener or the like with a high accuracy whose optical axis direction is within an allowable error range (for example, ± 0.5 °) from the longitudinal axis of the host vehicle. If the sensor's optical axis direction deviates from the front / rear axis direction of the host vehicle to the left or right, for example, due to an impact, the object in front of the vehicle is misrecognized as the object in front of the host vehicle and shifts up and down. Therefore, the relative positional relationship with the front object cannot be detected accurately.

  Further, this vehicle is provided with an acceleration sensor 15 for detecting the longitudinal acceleration Xg generated in the host vehicle and a yaw rate sensor 16 for detecting the yaw rate φ generated in the host vehicle. Further, an optical axis misalignment display device 17 is provided in the vehicle interior. When the optical axis misalignment notification command is input from the travel controller 20 by detecting the optical axis misalignment of the front object sensor 14, a light is transmitted to the driver. Presents the off-axis state.

Then, the host vehicle speed Vs output from the vehicle speed sensor 13, the relative distance dr output from the front object sensor 14, the relative speed Vr, the angle ranges θ _R and θ _L , the acceleration Xg output from the acceleration sensor 15, and the yaw rate sensor 16 is input to the travel controller 20, and is input from the vehicle controller 13 by any one of the vehicle speed sensor 13, the front object sensor 14, the acceleration sensor 15, and the yaw rate sensor 16. Based on the signal, it is determined whether or not an impact that changes the detection range is applied to the front object sensor 14, and the optical axis deviation amount Δθ of the front object sensor 14 is estimated. The travel controller 20 also determines a braking pressure command when the relative distance dr detected by the front object sensor 14 is equal to or less than the braking control operating distance d _SET set based on the optical axis deviation amount Δθ. The value P _BR is output to the braking control device 8 to permit the braking control of the host vehicle.

Next, the operation of the first embodiment will be described with reference to FIG. 3 showing a braking control operation determination processing procedure executed by the travel controller 20.
This brake control operation determination process is executed as a timer interruption process at predetermined time intervals (for example, 10 msec). First, in step S1, the relative distance dr, the relative speed Vr, the angle range θ _R detected by the front object sensor 14, It reads the θ _L.

Next, the process proceeds to step S2, in which an impact change in the detection range to the front object sensor 14 is detected in an impact determination process described later, a brake control prohibition determination and a brake control operating distance _dSET are set. The process proceeds to S3.
In this step S3, it is determined whether or not the braking control prohibition flag F _CA set in step S2 is set to “1” indicating control prohibition, and whether or not automatic braking is inactive, and F _CA = 1 and when the automatic braking is not in operation, the process proceeds to step S4, the operation of the braking control is prohibited, the timer interruption process is terminated, and the process returns to the predetermined main program.

If the determination result in step S3 is F _CA = 0 or the automatic braking operation is being performed, the process proceeds to step S5 to determine whether or not the host vehicle is traveling in the braking control permission area. This determination is made based on whether or not the relative distance dr with the front object exceeds the braking control operating distance d _SET set in step S2, and when F _CA = 0 and dr> d _SET , the host vehicle brakes. It is determined that the vehicle is traveling in the control prohibited area, and the process proceeds to step S4. On the other hand, in other cases, the process proceeds to step S6, and it is determined whether or not the collision with the front object can be avoided by the driver's braking operation.

In step S6, it is determined whether or not the relative distance dr and the relative speed Vr read in step S1 have a relationship as shown in the following equation (1). If the following formula (1) is not satisfied, it is determined that the possible collision avoidance by the braking proceeds to step S7, sets to "1" the braking collision avoidance flag F _B. On the other hand, when the following equation (1) is satisfied, the collision by the braking avoidance is determined that it is impossible proceeds to step S8, is reset to "0" the braking collision avoidance flag F _B.

dr <−Vr · Td + Vr ² / 2a (1)
Here, Td is a dead time until deceleration occurs when the driver operates the brake, and a is a deceleration generated by the driver's braking operation.
Next, it is determined whether or not a collision with a front object can be avoided by a driver's steering operation. First, in step S9, a lateral movement amount necessary for avoiding steering is calculated. When the host vehicle MC and the front object PC are in a relationship as shown in FIG. 4, the lateral movement amount Y _R necessary for avoiding steering to the right side and the lateral movement amount Y _L necessary for avoiding steering to the left side. Are expressed by the following equations (2) and (3), respectively.

Y _R = dr · tan θ _R −dr · tan {1/2 · sin ⁻¹ (φ / Vs)}
+ W _b / 2 + W _S (2)
Y _L = −dr · tan θ _L + dr · tan {1/2 · sin ⁻¹ (φ / Vs)}
+ W _b / 2−W _S (3)
Here, as shown in FIG. 2, θ _R is the angle range of the right end of the front object detected by the front object sensor 14, θ _L is the angle range of the left end of the front object detected by the front object sensor 14, W _b is the width of the host vehicle, and W _S is the amount of offset from the host vehicle center of the sensor mounting position.

Lateral movement amount Y required for steering avoidance is set by selecting the smaller lateral movement amount Y _L required when steering avoidance in lateral movement amount Y _R and the left required when steering avoidance on the right.
Y = min (Y _R , Y _L ) (4)
Here, min () is a function that selects the smaller one in parentheses.
At a step S10, from the lateral movement amount Y required steering avoidance calculated in step S9, the steering avoidance based on the relationship between the time T _y according to the lateral movement amount Y and the lateral movement shown in FIG. 5 The time T _y is calculated, and the process proceeds to step S11. In FIG. 5, the horizontal axis is the lateral movement amount Y necessary for steering avoidance, and the vertical axis is the time T _y required for lateral movement. The larger the lateral movement amount Y necessary for operation avoidance, the lateral movement is required. The time T _{y is} also set to increase.

In step S11, it is determined whether the following equation (5) is satisfied. If the following equation (5) is not established, it is determined that collision avoidance by steering is possible, the process proceeds to step S12, and the steering collision avoidance flag F _S is set to “1”. On the other hand, if the following expression (5) is satisfied, it is determined that collision avoidance by steering is impossible, the process proceeds to step S13, and the steering collision avoidance flag F _S is reset to “0”.

dr <Vr · T _y (5)
Then at step S14, the collision avoidance by the collision avoidance and is not steering by braking it is equal to or impossible, braking collision avoidance flag F _B indicates the possible collision avoidance "0", and steering collision If the avoidance flag F _S is “0” indicating that collision avoidance is impossible, the process proceeds to step S15, and automatic braking is operated for a predetermined time for a predetermined magnitude. On the other hand, when the determination result in step S14 is F _B = 1 or F _S = 1, the process proceeds to step S16 and the automatic braking is released.

  In the impact determination process in step S2, as shown in FIG. 6, first, in step S201, it is determined whether or not an impact that causes a change in the detection range has occurred in the front object sensor. The determination of the occurrence of the impact is made based on the acceleration signal Xg detected by the acceleration sensor 15, and when the acceleration sensor 15 detects a deceleration of a predetermined value or more, it is determined that an impact with a magnitude that causes an optical axis shift has occurred. Further, it is determined that the optical axis deviation is larger as the deceleration is larger in the negative direction, and the optical axis deviation amount Δθ based on the deceleration detected by the acceleration sensor 15 is estimated with reference to a map as shown in FIG. Then, the optical axis deviation amount Δθ is stored. In FIG. 7, the horizontal axis represents the absolute value of deceleration, the vertical axis represents the optical axis deviation amount Δθ, and the optical axis deviation amount Δθ is set to change linearly with respect to the deceleration.

  Next, the process proceeds to step S202, and it is determined whether or not the optical axis adjustment of the front object sensor 14 is performed. If the optical axis adjustment has not been performed at a maintenance shop, a store, or the like, the process proceeds to step S203, the stored optical axis deviation amount Δθ is held, and then the process proceeds to step S205 described later. On the other hand, if the result of determination in step S202 is that optical axis adjustment has been performed, the process shifts to step S204 to reset the stored optical axis deviation amount Δθ to “0” and to display the optical axis deviation display device. After the 17 optical axis deviation display is not displayed, the process proceeds to step S205.

In this step S205, it is determined whether or not the optical axis deviation amount Δθ is equal to or larger than the optical axis deviation display threshold value Δθ _SET . If Δθ ≧ Δθ _SET , the process proceeds to step S206 and the optical axis deviation display device 17 receives the optical axis deviation. After displaying the shift state, the process proceeds to step S207, and when Δθ <Δθ _SET , the previous display state is maintained, and the process proceeds to step S207 as it is.

In step S207, it is determined whether or not the optical axis deviation amount Δθ is equal to or _smaller than a predetermined value ΔθTH2. If Δθ ≦ _ΔθTH2 , the process proceeds to step S208, and the braking control prohibition flag _FCA is set to indicate that the control is permitted. In addition to resetting to 0 ″, the braking control operating distance d _SET is set according to the optical axis deviation amount Δθ as shown in FIG. The braking control operating distance d _SET is fixed to the same distance range d ₁ as when there is no optical axis deviation when the optical axis deviation amount Δθ is equal to or less than the predetermined value Δθ _TH1 , and when Δθ _TH1 <Δθ ≦ Δθ _TH2 , is set as the light axis deviation is large short is set by [Delta] [theta] = [Delta] [theta] _TH2 in distance range d _2.

On the other hand, when the determination result in step S207 is Δθ> _ΔθTH2 , the process proceeds to step S209, and the braking control prohibition flag _FCA is set to “1” indicating control prohibition.
In the process of FIG. 3, the processes of steps S6 to S13 correspond to the collision avoidance determining means, and the processes of steps S14 to S16 correspond to the automatic braking control means. In the process of FIG. 6, the processes in steps S207 to S209 correspond to the operating condition changing means.

Accordingly, it is assumed that the host vehicle is currently traveling with automatic braking being inoperative. In this state, when some impact is applied to the host vehicle and an optical axis shift larger than the predetermined value Δθ _TH2 occurs in the front object sensor 14, the acceleration sensor 15 reduces the acceleration sensor 15 in step S201 in the impact determination process of FIG. A value greater than or equal to a predetermined value is detected in the speed direction, and an optical axis deviation amount Δθ larger than the predetermined value Δθ _TH2 is estimated. Since the optical axis is not adjusted at a maintenance shop or a store, the process shifts from step S202 to step S203 to store the stored optical axis deviation amount Δθ. The optical axis deviation amount Δθ is the optical axis deviation display threshold value Δθ _SET. Therefore, the process proceeds to step S206 based on the determination in step S205, and the optical axis deviation display device 17 displays the optical axis deviation. Since Δθ> Δθ _TH2 , the process proceeds from step S207 to step S208, and the braking control prohibition flag _FCA is set to “1” indicating control prohibition. Since F _CA = 1 and the host vehicle is not in automatic braking, in the braking control operation determination process of FIG. 3, the process proceeds from step S3 to step S4 to prohibit automatic braking, and depending on the driver's accelerator and brake operation. Continue running.

Further, in the case where the host vehicle is running with automatic braking in an operating state, when some sort of impact is applied to the host vehicle and an optical axis shift greater than the predetermined value Δθ _TH2 occurs in the front object sensor 14, FIG. In the impact determination process, the process proceeds from step S207 to step S208, and the braking control prohibition flag _FCA is set to “1” indicating control prohibition. Since the host vehicle is under automatic braking, the process proceeds from step S3 to step S5 in the braking control operation determination process of FIG. Since F _CA = 1, the process proceeds to step S6 based on the determination in step S5 to determine whether or not the driver can avoid braking, and then determines whether or not the driver can avoid steering. If it is determined that the vehicle can be avoided by either braking avoidance or steering avoidance, the process proceeds from step S14 to step S16, the automatic braking is canceled, and the vehicle travels according to the driver's accelerator and brake operation. . Therefore, thereafter, the state of Δθ> Δθ _TH2 is continued until the optical axis adjustment is performed, and F _CA = 1 and automatic braking is not activated. Therefore, the process _proceeds from step S3 to step S4 to prohibit the automatic braking, The vehicle continues to travel according to the accelerator and brake operation of the person. In other words, even when the front object sensor 14 detects the relative distance dr that is equal to or less than the braking control working distance d _SET and the host vehicle is traveling in the braking control permission area, automatic braking is prohibited and driving is performed. The traveling according to the accelerator and brake operation of the person is continued.

In this way, when it is determined that an impact that would cause an optical axis deviation has occurred, the optical axis deviation amount Δθ is estimated, and automatic braking is performed when the optical axis deviation amount Δθ is greater than a predetermined value Δθ _TH2. Since the prohibition is prohibited, it is possible to reliably prevent the traveling control from being performed in a state where the relative positional relationship with the front object cannot be accurately recognized due to the optical axis deviation.
On the other hand, the _host vehicle is traveling in the braking control prohibition region in which the relative distance dr with the front object exceeds the braking control operating distance d _SET in a state where a slight optical axis deviation of the predetermined value Δθ _TH2 or less occurs. And In this case, first, in the impact determination process of FIG. 6, an optical axis deviation amount Δθ that satisfies Δθ ≦ Δθ _TH2 is estimated in step S201. Since the optical axis is not adjusted at a maintenance shop or a store, the process shifts from step S202 to step S203 to store the stored optical axis deviation amount Δθ, and the optical axis deviation amount Δθ is the optical axis deviation display threshold value Δθ _SET. In the case above, the process proceeds to step S206 based on the determination in step S205, and the optical axis deviation display device 17 displays the optical axis deviation. Then, the process proceeds from step S207 to step S209, where the braking control prohibition flag _FCA is reset to “0” indicating control permission, and the distance range corresponding to the optical axis deviation Δθ is braked as shown in FIG. Set as control working distance d _SET . Since F _CA = 0 and dr> d _SET , in the braking control operation determination process of FIG. 3, the process proceeds from step S5 to step S4 to prohibit automatic braking and travel according to the driver's accelerator and brake operation. Do.

Thereafter, when the relative distance dr with the front object becomes equal to or less than the braking control operating distance d _SET and the vehicle is traveling in the braking control permission area, the braking control can be performed so as to suppress the approach of the host vehicle to the front object. It becomes. Since F _CA = 0 and dr ≦ d _SET , the process proceeds from step S5 to step S6 to determine whether or not braking by the driver can be avoided, and then whether or not steering by the driver can be avoided. If it is determined that the vehicle can be avoided in either braking avoidance or steering avoidance, the process proceeds from step S14 to step S16, and the traveling according to the driver's accelerator and brake operation is continued.

On the other hand, when the braking avoidance and steering avoidance is judged to be impossible, the process proceeds from step S14 to step S15, braking control device the braking pressure command value P _BR such as the braking hydraulic pressure of a predetermined magnitude is generated 8 to shift to the braking control of the own vehicle.
Here, the braking control operating distance d _SET is set to a smaller value as the optical axis deviation amount Δθ is larger. Therefore, when Δθ _TH1 <Δθ ≦ Δθ _TH2 , the front object is compared with the case where there is no optical axis deviation. Therefore, the braking control is performed only for those having a relative positional relationship closer to that.

  As described above, in the first embodiment, when a change occurs in the detection range of the sensor due to some impact on the host vehicle and a shift of the sensor mounting position for recognizing an object in front of the host vehicle. Since this is detected immediately and the braking control operation is prohibited when the vehicle is not in automatic braking, it is possible to reliably prevent the traveling control from operating while the detection range of the sensor is changed, and to perform automatic braking. When the vehicle is in the middle, it is determined whether or not braking by the driver can be avoided and steering can be avoided, and the braking control operation is released only when it is determined that collision can be avoided, so that safe driving can be ensured.

  Furthermore, the larger the detection range change amount of the sensor for recognizing the object in front of the host vehicle, the more the braking control is performed only on the object whose relative positional relationship with the detected front object is closer. Since the braking control is also performed for the object whose relative positional relationship with the detected front object is far compared with the case where the amount is large, the position of the front object can be detected without deteriorating the accuracy of the front object position, Optimal braking control can be performed according to the state of change of the detection range.

Also, since the magnitude of the impact applied to the front object sensor is detected using the acceleration signal of the acceleration sensor that is widely used for airbags, a new sensor for detecting the impact is installed. There is no need to do so, and cost increases can be reduced.
In the first embodiment, the case where the acceleration sensor is applied as the acceleration detecting means has been described. However, the present invention is not limited to this, and the acceleration is calculated from the vehicle speed detected by the vehicle speed sensor. It may be.

Next, a second embodiment of the present invention will be described.
In the second embodiment, in the first embodiment described above, the determination of the impact that changes the detection range of the front object sensor 14 is performed using the signal of the yaw rate sensor 16.
FIG. 9 is a flowchart showing a processing procedure of impact determination processing executed in the travel controller 20 in the second embodiment. In the impact determination processing in the first embodiment shown in FIG. Except that the processing is replaced with the processing in step S221 in which the impact of the optical axis deviation is detected and the optical axis deviation amount Δθ is estimated by the change rate of the yaw rate φ detected by the yaw rate sensor 16. The same processing as in FIG. 6 is performed, the same reference numerals are given to the same parts as in FIG. 6, and the detailed description thereof is omitted.

  According to the second embodiment, in step S221, the rate of change of the yaw rate φ detected by the yaw rate sensor 16 is calculated, and if the absolute value of the calculated value is greater than or equal to a predetermined value, the front object sensor 14 is illuminated. It is determined that an impact that causes an axis deviation has occurred. Further, it is determined that the larger the absolute value of the calculated value is, the larger the optical axis deviation is, and an optical axis deviation amount Δθ based on the rate of change of the yaw rate φ is estimated with reference to a map as shown in FIG. After storing the axis deviation amount Δθ, the process proceeds to step S202 described above. In FIG. 7, the horizontal axis represents the absolute value of the change rate of the yaw rate φ, the vertical axis represents the optical axis deviation amount Δθ, and the optical axis deviation amount Δθ changes linearly with respect to the absolute value of the change rate of the yaw rate φ. Is set as follows.

Thus, in the second embodiment, since the magnitude of the impact applied to the front object sensor is detected using the yaw rate signal of the yaw rate sensor that is also used for the sensor for recognizing the front object, It is not necessary to newly install a sensor for detecting an impact, and cost increase can be reduced.
Next, a third embodiment of the present invention will be described.

In the third embodiment, in the first embodiment described above, the determination of an impact that changes the detection range of the front object sensor 14 is performed using a signal from the vehicle speed sensor 13.
FIG. 10 is a flowchart showing a processing procedure of impact determination processing executed in the travel controller 20 in the third embodiment. In the impact determination processing in the first embodiment shown in FIG. That the processing is replaced with the processing in step S231 in which the impact of the optical axis deviation is detected and the optical axis deviation amount Δθ is estimated by the change rate of the own vehicle speed Vs detected by the vehicle speed sensor 13. Except for this, the same processing as in FIG. 6 is performed, and the same parts as in FIG.

  According to the third embodiment, the rate of change of the vehicle speed Vs of the vehicle speed sensor 13 is calculated in step S231, and if the calculated value is equal to or greater than a predetermined value in the deceleration direction, the front object sensor 14 is shifted in optical axis. It is determined that an impact has occurred. Further, it is determined that the optical axis deviation is larger as the calculated value is larger in the deceleration direction, the optical axis deviation amount Δθ based on the rate of change of the own vehicle speed is estimated with reference to a map as shown in FIG. After storing the axis deviation amount Δθ, the process proceeds to step S202 described above. In FIG. 7, the horizontal axis represents the absolute value of the change rate of the own vehicle speed Vs, the vertical axis represents the optical axis deviation amount Δθ, and the optical axis deviation amount Δθ is linear with respect to the absolute value of the change rate of the own vehicle speed Vs. Set to change.

As described above, in the third embodiment, since the magnitude of the impact applied to the front object sensor is detected using the own vehicle speed change rate of the vehicle speed sensor used in most vehicles, a new impact is applied. It is not necessary to install a sensor for detection, and cost increase can be reduced.
Next, a fourth embodiment of the present invention will be described.

In the fourth embodiment, in the first embodiment described above, an impact that changes the detection range of the front object sensor 14 is determined using a signal from the front object sensor 14.
FIG. 11 is a flowchart showing a processing procedure of impact determination processing executed in the travel controller 20 in the fourth embodiment. In the impact determination processing in the first embodiment shown in FIG. The process is replaced with the process of step S241 in which the impact of the magnitude of the optical axis deviation is detected based on the relative distance dr and the relative speed Vr detected by the front object sensor 14 and the optical axis deviation amount Δθ is estimated. Except for this, the same processing as in FIG. 6 is performed, and the same parts as in FIG.

  According to the fourth embodiment, when the relative distance dr detected by the front object sensor 14 in step S241 is equal to or smaller than a predetermined value, the front object sensor 14 has a collision that causes an optical axis shift. to decide. Further, it is determined that the optical axis deviation is larger as the relative speed Vr in the approaching direction is larger at that time, and the optical axis deviation amount Δθ based on the relative speed in the approaching direction is estimated with reference to a map as shown in FIG. After storing the optical axis deviation amount Δθ, the process proceeds to step S202 described above. In FIG. 7, the horizontal axis represents the relative speed Vr in the approach direction, the vertical axis represents the optical axis deviation amount Δθ, and the optical axis deviation amount Δθ is set to change linearly with respect to the relative speed Vr in the approach direction. The

As described above, in the fourth embodiment, since the magnitude of the impact applied to the front object sensor is detected using the detection value of the front object sensor, it is necessary to newly install a sensor for detecting the impact. The cost increase can be greatly reduced.
In the fourth embodiment, the case has been described in which it is determined that an impact that causes an optical axis shift occurs when the relative distance to the front object is equal to or less than a predetermined value. However, the present invention is not limited to this. In step S14, when collision avoidance by braking and collision avoidance by steering are impossible, and during automatic braking, it is determined that an impact has occurred in a sensor for recognizing a front object after the end of automatic braking. You may make it do. In this case, when the relative speed is equal to or greater than a predetermined value in the approach direction, it is determined that an impact that causes an optical axis shift has occurred, and it is determined that the greater the relative speed in the approach direction, the greater the optical axis shift. do it. This makes it possible to estimate that a collision has occurred even if a forward object cannot be detected after detecting a state where collision avoidance is impossible. The occurrence of impact can be detected more reliably.

Next, a fifth embodiment of the present invention will be described.
In the fifth embodiment, the present invention is applied to a rear wheel drive vehicle equipped with an inter-vehicle distance control device.
That is, as shown in FIG. 12, the schematic configuration in the fifth embodiment is provided with an engine output control device 11 for controlling the engine output, and the front object sensor 14 having the scanning type configuration in the first embodiment described above. Instead, a front object sensor 18 having a radar-type configuration is provided, and the target vehicle speed is set so that the inter-vehicle distance becomes the target inter-vehicle distance when the vehicle ahead of the host vehicle is captured instead of the travel controller 20. The following control controller 30 is provided for controlling the own vehicle speed and controlling the own vehicle speed Vs to the set vehicle speed V _SET set by the driver when the vehicle ahead of the own vehicle is not captured. 1 has the same configuration as that of FIG. 1, the same reference numerals are given to corresponding parts in FIG.

The forward object sensor 18 has a radar-type configuration in which laser light is swept within a predetermined irradiation range (for example, 9 ° in the horizontal direction and 3 ° in the vertical direction) to receive reflected light from the preceding vehicle. The inter-vehicle distance D between the vehicle and the preceding vehicle is detected. Then, the relative speed ΔV between the preceding vehicle and the host vehicle is calculated from the temporal change in the inter-vehicle distance D.
The front object sensor 18 is usually attached to the front part of the vehicle with a fastener or the like with a high accuracy whose optical axis direction is within an allowable error range (for example, ± 0.5 °) from the longitudinal axis of the host vehicle. If the optical axis direction of the sensor deviates from the front / rear axis direction of the host vehicle beyond the allowable error range due to some impact on the vehicle, the vehicle traveling diagonally forward in the adjacent lane If the vehicle is misrecognized as a vehicle in front of the lane and the vehicle is shifted up and down, the relative position relationship with the preceding vehicle cannot be accurately detected.

The own vehicle speed Vs output from the vehicle speed sensor 13, the inter-vehicle distance D output from the front object sensor 18, the relative speed ΔV, the acceleration Xg output from the acceleration sensor 15, and the yaw rate φ output from the yaw rate sensor 16 are track-controlled. Input to the controller 30, and the follow-up control controller 30 causes the front object sensor 18 to receive the signal from any one of the vehicle speed sensor 13, the front object sensor 18, the acceleration sensor 15, and the yaw rate sensor 16. It is determined whether or not an impact that changes the detection range is applied, and the optical axis deviation amount Δθ of the front object sensor 18 is estimated. Further, the tracking controller 30 controls the own vehicle speed by setting the target vehicle speed so that the inter-vehicle distance becomes the target inter-vehicle distance when the vehicle ahead of the traveling lane of the own vehicle is captured. When the vehicle ahead of the lane is not captured, the braking pressure command value P _BR and the target throttle opening θ ^* for controlling the own vehicle speed V _S to the set vehicle speed V _SET set by the driver are set to the braking control device 8 and the engine output control. Output to the device 11.

The follow-up control controller 30 includes a microcomputer and its peripheral devices, and constitutes a control block shown in FIG. 13 according to the software form of the microcomputer.
This control block measures the time from when the front object sensor 18 sweeps the laser light until it receives the reflected light of the preceding vehicle, and calculates a distance D between the preceding vehicle and a ranging signal processing unit 21; An inter-vehicle distance control unit 40 that calculates a target vehicle speed V _L ^* that maintains the inter-vehicle distance D at the target inter-vehicle distance D ^* based on the inter-vehicle distance D, the host vehicle speed Vs, and the relative speed ΔV calculated by the ranging signal processing unit 21; The vehicle speed control unit 50 that calculates the target drive shaft torque T _W ^* based on the target vehicle speed V _L ^* calculated by the inter-vehicle distance control unit 40, and the target drive shaft torque T _W ^* calculated by the vehicle speed control unit 50 based calculates a throttle opening command value theta _R and the braking pressure command value P _BR to the throttle actuator 12 and a brake actuator 7, these throttle actuator 12 and the brake actuator 7 And a drive shaft torque controller 60 for force.

The inter-vehicle distance control unit 40 calculates a target inter-vehicle distance setting unit 42 that calculates a target inter-vehicle distance D ^* between the preceding vehicle and the host vehicle based on the preceding vehicle speed Vt calculated from the host vehicle speed Vs and the relative speed ΔV. The inter-vehicle distance D matches the target inter-vehicle distance D ^* based on the target inter-vehicle distance D ^* calculated by the target inter-vehicle distance setting unit 42, the inter-vehicle distance D input from the ranging signal processing unit 21, and the own vehicle speed Vs. And an inter-vehicle distance control calculation unit 43 that calculates a target vehicle speed V _L ^* for causing the vehicle to travel.

Here, the target inter-vehicle distance setting unit 42 calculates a target inter-vehicle distance that is following the preceding vehicle at a constant vehicle speed and a constant inter-vehicle distance, that is, a steady target inter-vehicle distance D ^* between the preceding vehicle and the host vehicle. In this embodiment, in order to make the inter-vehicle time constant, the steady target inter-vehicle distance D ^* is calculated by the following equation (6).
D ^* = Vt × Th (6)
Here, Vt is the preceding vehicle speed, and Th is the inter-vehicle time.

Further, the inter-vehicle distance control calculation unit 43 calculates a target vehicle speed V _L ^* for traveling following the preceding vehicle while maintaining the inter-vehicle distance D at the target inter-vehicle distance D ^* based on the inter-vehicle distance D and the relative speed ΔV. Calculate based on the formula.
V _L ^* = K _L (D−D ^* ) + K _V (ΔV−ΔV ^* ) + Vt (7)
Here, K _L is distance control gain, the K _V is the relative velocity control gain.

When the vehicle speed control unit 50 is in the following control state, the target vehicle speed V _L ^* input from the inter-vehicle distance control unit 40 and the set vehicle speed V _SET set by the driver when the preceding object sensor 18 is capturing the preceding vehicle. Is set as the target vehicle speed V ^* , and when the preceding vehicle is not captured, the target vehicle speed setting unit 51 that sets the set vehicle speed V _SET set by the driver as the target vehicle speed V ^* , and the target vehicle speed A target drive shaft torque calculator 53 for calculating a target drive shaft torque T _W ^* for making the host vehicle speed Vs coincide with the target vehicle speed V ^* set by the setting unit 51.

Further, the drive shaft torque control unit 60 calculates a throttle opening command value θ _R and a brake fluid pressure command value P _BR for realizing the target driving torque T _W ^*, and uses the throttle opening command value θ _R as the engine. In addition to outputting to the output control device 11, the brake fluid pressure command value P _BR is output to the braking control device 8.
The inter-vehicle distance control unit 40, the vehicle speed control unit 50, and the drive shaft torque control unit 60 described above constitute travel control means.

Further, the target vehicle speed setting unit 51 executes a target vehicle speed setting process shown in FIG.
This target vehicle speed setting process is executed as a timer interrupt process at predetermined time intervals (for example, 10 msec). First, in step S101, the vehicle speed Vs detected by the vehicle speed sensor 13 and the preceding vehicle detected by the front object sensor 18 are detected. The inter-vehicle distance D is read, and then the process proceeds to step S102, where an impact that changes the detection range to the front object sensor 18 is detected in an impact determination process, which will be described later, and an inter-vehicle distance control prohibition determination and an inter-vehicle distance detection limit D _MAX are set. Set up.

In step S103, it is determined whether follow-up running control is being performed. This determination is performed by whether or has detected the preceding vehicle with the preceding object sensor 18, and vehicle control inhibition flag F _CA set in step S102 is reset to "0" representing the control permission, the forward object sensor It is determined whether or not the inter-vehicle distance D detected in 18 is less than or equal to the inter-vehicle distance detection limit D _MAX set in step S102. If F _CA = 0 and D ≦ D _MAX , the preceding vehicle is detected. It is determined that the following traveling control is being performed, and the process proceeds to step S104.

In step S104, the target vehicle speed V _L ^* calculated by the inter-vehicle distance control calculation unit 43 using the equation (7) is compared with the set vehicle speed V _SET set by the driver, and the smaller value is set as the target vehicle speed. After setting as V ^* , the process proceeds to step S105, the target vehicle speed V ^* is input to the target drive shaft torque calculation unit 53, the timer interruption process is terminated, and the process returns to the predetermined main program.

V ^* = min (V _L ^* , V _SET ) (8)
Here, min () is a function that selects the smaller one in parentheses.
On the other hand, when the determination result in step S103 is F _CA = 1 or D> D _MAX , it is determined that the inter-vehicle distance control is prohibited or the preceding vehicle is not detected, the process proceeds to step S106, and the driver is There proceeds to step S105 to set vehicle speed V _sET set after setting the target vehicle speed V ^*.

FIG. 15 is a flowchart showing the optical axis deviation determination processing procedure in step S102. In the impact determination processing in the first embodiment shown in FIG. 6, the processing in steps S208 and S209 is the inter-vehicle distance detection limit D _MAX. The same processing as in FIG. 6 is performed except that the processing is replaced by the processing in step S251 for setting the distance and S252 for prohibiting the inter-vehicle distance control, and the same parts as in FIG. Is omitted.

In step S207, it is determined whether or not the optical axis deviation amount Δθ is equal to or _smaller than a predetermined value Δθ _TH2 . If Δθ ≦ Δθ _TH2 , the process proceeds to step S251, and the inter-vehicle control prohibition flag F _CA indicates control permission. In addition to resetting to “0”, the inter-vehicle distance detection limit D _MAX is set according to the optical axis deviation Δθ as shown in FIG. On the other hand, when the determination result in step S207 is Δθ> Δθ _TH2 , the process proceeds to step S252, and the inter-vehicle control prohibition flag F _CA is set to “1” indicating the control prohibition so as not to operate the inter-vehicle distance control. To do.

Therefore, it is assumed that the host vehicle is currently traveling in a state where the optical axis adjustment is not performed in the front object sensor 18 by adjusting the optical axis at a maintenance shop or a store. In this case, in the impact determination process of FIG. 15, the process proceeds from step S202 to step S204 to reset the stored optical axis deviation amount Δθ to “0” and the optical axis deviation of the optical axis deviation display device 17. Hide display. Since the optical axis deviation amount Δθ = 0, the process proceeds from step S207 to step S251, the inter-vehicle control prohibition flag F _CA is reset to “0” indicating control permission, and the inter-vehicle distance D as shown in FIG. ₁ is set as the inter-vehicle distance detection limit D _MAX. If the host vehicle has not detected the preceding vehicle, the forward object sensor 18 detects the inter-vehicle distance D that is greater than the inter-vehicle distance detection limit D _{MAX, and} therefore, in the target vehicle speed setting process of FIG. and migrated, by transition from set to set vehicle speed V _sET set by the driver as the target vehicle speed V ^* in step S105, and inputs the target vehicle speed V ^* to the target drive shaft torque calculating unit 53, vehicle speed Vs Is controlled to match the set vehicle speed V _SET set by the driver.

From this state, when the predetermined value [Delta] [theta] _TH2 greater than the optical axis shifted in the forward object sensor 18 applied is any impact on the vehicle occurs, the impact judgment processing of FIG. 15, a predetermined value in the deceleration direction at step S201 by detecting the above values, estimating a larger amount of optical axis misalignment [Delta] [theta] a predetermined value [Delta] [theta] _TH2. Next, the process proceeds from step S202 to step S203, and the stored optical axis deviation amount Δθ is held. Since the optical axis deviation amount Δθ is equal to or larger than the optical axis deviation display threshold value Δθ _SET , the process proceeds to step S206 according to the determination in step S205. Then, the optical axis deviation display device 17 displays the optical axis deviation. Since Δθ> Δθ _TH2 , the process proceeds from step S207 to step S208, and the inter-vehicle control prohibition flag F _CA is set to “1” indicating control prohibition. Since F _CA = 1, in the target vehicle speed setting process of FIG. 14, the process proceeds from step S103 to step S106, the set vehicle speed V _SET set by the driver is set as the target vehicle speed V ^* , and then the process proceeds to step S105. By inputting the target vehicle speed V ^* to the target drive shaft torque calculation unit 53, even if the inter-vehicle distance D is equal to or less than the inter-vehicle distance detection limit D _MAX , the follow-up travel control does not operate and the own vehicle speed Travel control is continued so that Vs matches the set vehicle speed V _SET set by the driver.

In this way, when it is determined that an impact that would cause an optical axis deviation has occurred, the optical axis deviation amount Δθ is estimated, and if this optical axis deviation amount Δθ is greater than a predetermined value Δθ _TH2 , the inter-vehicle distance control is performed. Therefore, it is possible to reliably prevent the following traveling control from being performed in a state where the distance between the preceding vehicle and the preceding vehicle cannot be accurately recognized due to a large optical axis deviation.
On the other hand, it is assumed that the vehicle is traveling in a state in which a slight optical axis deviation of a predetermined value Δθ _TH2 or less occurs in the front object sensor 18. In this case, in the impact determination process of FIG. 15, the optical axis deviation amount Δθ that satisfies Δθ ≦ Δθ _TH2 is estimated in step S201. Since the optical axis is not adjusted at a maintenance shop or a store, the process shifts from step S202 to step S203 to store the stored optical axis deviation amount Δθ, and the optical axis deviation amount Δθ is the optical axis deviation display threshold value Δθ _SET. When it is above, the process proceeds to step S206 based on the determination in step S205, and the optical axis deviation display device 17 displays the optical axis deviation. Then, the process proceeds from step S207 to step S209, and the inter-vehicle distance according to the optical axis deviation amount Δθ is set as the inter-vehicle distance detection limit D _MAX as shown in FIG.

When the front object sensor 18 detects the inter-vehicle distance D equal to or less than the inter-vehicle distance detection limit D _MAX and the own vehicle detects the preceding vehicle, the process proceeds from step S103 to step S104 in the target vehicle speed setting process of FIG. By setting a target vehicle speed V ^* to follow the vehicle while keeping the inter-vehicle distance D at the target inter-vehicle distance D ^* , the process proceeds to step S105 to input the target vehicle speed V ^* to the target drive shaft torque calculation unit 53. Run control.

Here, since the inter-vehicle distance detection limit D _MAX is set to a smaller value the larger the amount of optical axis misalignment [Delta] [theta], when it is Δθ _TH1 <Δθ ≦ Δθ _TH2, compared with the case where there is no optical axis misalignment, the preceding vehicle The follow-up running control is performed only for those having a relative positional relationship closer to.
As described above, in the fifth embodiment, when a change in the detection range occurs in the sensor due to, for example, an attachment of the sensor for recognizing the preceding vehicle due to some impact applied to the own vehicle, Since it detects this and prohibits inter-vehicle distance control, it is possible to reliably prevent the follow-up running control from operating while the detection range of the sensor is changed, and when the detection range has not changed, Since the normal follow-up running control is performed, it is possible to perform the running control without feeling uncomfortable for the driver.

  Furthermore, the greater the detection range change amount of the sensor for recognizing the preceding vehicle, the more the inter-vehicle distance control is performed only for the detected relative positional relationship with the preceding vehicle, and the smaller the change amount, the more the change amount. The inter-vehicle distance control is performed even when the relative positional relationship with the preceding vehicle is far compared with the case where it is large, so that the position of the preceding vehicle can be detected and detected without deteriorating the accuracy of the preceding vehicle position. Optimal inter-vehicle distance control can be performed according to the state of range change.

In addition, since the magnitude of the impact applied to the sensor for recognizing the preceding vehicle is detected using the acceleration signal of the acceleration sensor that is widely used in airbags and the like, a new impact detection sensor is provided. There is no need for installation, and the cost increase can be reduced.
In the fifth embodiment, the case where the acceleration sensor is applied as the acceleration detecting means has been described. However, the present invention is not limited to this, and the acceleration is calculated from the vehicle speed detected by the vehicle speed sensor. It may be.

  In the fifth embodiment, the case where the acceleration signal of the acceleration sensor is used in step S201 in the impact determination process of FIG. 15 has been described. However, the present invention is not limited to this, and FIG. The change rate of the yaw rate detected by the yaw rate sensor may be used in the same manner as in step S221 in the second embodiment shown. In step S201, the vehicle speed sensor is used in the same manner as in step S231 in the third embodiment shown in FIG. The change rate of the detected vehicle speed may be used, and the inter-vehicle distance and relative speed with the preceding vehicle detected by the front object sensor in step S201 as in step S241 in the fourth embodiment shown in FIG. You may make it use.

  In each of the above embodiments, when it is determined in step S202 that the optical axis adjustment has been performed in the impact determination processing of FIGS. 6, 9 to 11 and 15, the optical axis deviation amount Δθ in step S204. However, the present invention is not limited to this, but the detection locus of a conventional stationary object (forward roadside delineator) after it is determined that the detection range has changed due to a collision or the like. When the vehicle travels a distance required for the detection range change determination process based on the above and no change in the detection range is detected, the stored optical axis deviation amount Δθ may be reset to “0”.

Further, in each of the above embodiments, when the optical axis deviation amount Δθ is equal to or larger than the optical axis deviation display threshold Δθ _SET , the optical axis deviation display device installed in the passenger compartment is immediately in the optical axis deviation state. The case of displaying was explained, but the present invention is not limited to this. When the optical axis misalignment display device remembers that the optical axis is misaligned, and when a diagnostic device is connected at a maintenance shop or a store, etc. The diagnostic apparatus may display that the optical axis is shifted. Further, instead of displaying the optical axis deviation state on the monitor, it may be notified by voice or buzzer.

Further, in each of the above embodiments, the case where the laser radar is used as the front object sensor 14 has been described. However, the present invention is not limited to this, and other ranging devices such as a millimeter wave radar may be applied. .
In each of the above embodiments, the case where the present invention is applied to a rear wheel drive vehicle has been described. However, the present invention can also be applied to a front wheel drive vehicle, and the case where the engine 2 is applied as a rotational drive source. Although explained, it is not limited to this, An electric motor can also be applied, Furthermore, this invention is applicable also to the hybrid specification vehicle which uses an engine and an electric motor.

It is a schematic structure figure showing an embodiment of the present invention. It is explanatory drawing of a front object sensor. It is a flowchart which shows the brake control action | judging determination process performed with the traveling controller 20 in embodiment of this invention. It is explanatory drawing of the amount of lateral movement required for steering avoidance. It is a relationship diagram between the amount of lateral movement and the time required for lateral movement. It is a flowchart which shows the impact determination process in 1st Embodiment. It is a calculation map of the amount of optical axis deviation. FIG. 5 is a relationship diagram between an optical axis deviation amount and a braking control working distance. It is a flowchart which shows the impact determination process in 2nd Embodiment. It is a flowchart which shows the impact judgment process in 3rd Embodiment. It is a flowchart which shows the impact judgment process in 4th Embodiment. It is a schematic block diagram which shows the 5th Embodiment of this invention. It is a block diagram which shows the specific example of the tracking control controller of FIG. It is a flowchart which shows the target vehicle speed setting process of the target vehicle speed setting part of FIG. 13 in 5th Embodiment. It is a flowchart which shows the impact judgment process in 5th Embodiment. FIG. 6 is a relationship diagram between the amount of optical axis deviation and the inter-vehicle distance detection limit.

Explanation of symbols

2 Engine 3 Automatic transmission 7 Disc brake 8 Braking control device 11 Engine output control device 13 Vehicle speed sensor 14 Front object sensor 15 Acceleration sensor 16 Yaw rate sensor 17 Optical axis deviation display device 20 Travel control controller 30 Follow-up control controller 50 Vehicle speed control unit 51 Target vehicle speed setting unit 53 Target drive shaft torque calculation unit 60 Drive shaft torque control unit

Claims (4)

Based on the forward object detection means for detecting an object in front of the host vehicle and the relative positional relationship between the forward object detected by the forward object detection means and the host vehicle, it is determined that a collision with the forward object cannot be avoided. A collision avoidance determining means for determining whether the collision avoidance determining means determines that the collision avoidance is impossible and a predetermined operation condition is satisfied ; After completion , when the detection range of the front object detection means changes due to a collision that the collision avoidance determination means determines is impossible to avoid collision, the automatic braking control by the automatic braking control means becomes difficult to operate. the vehicle control system, characterized in that it comprises an actuating condition changing means for changing the operation condition of the automatic brake control, to. Said operating condition changing means, vehicle control system according to claim 1, characterized in that prohibiting the operation of the automatic brake control by the prior SL automatic brake control means. Based on the forward object detection means for detecting an object in front of the own vehicle and the relative position relation between the forward object detected by the forward object detection means and the own vehicle, the own vehicle so that the relative positional relation becomes a predetermined relation. A collision avoidance determination that determines that it is impossible to avoid a collision with a front object based on a relative positional relationship between the front object detected by the front object detection means and the host vehicle. and means, the collision avoidance judging means judges that not collision avoidance, and an automatic braking control means for automatic braking control vehicle when a predetermined operating condition is satisfied, met after the completion of the automatic brake control Te, wherein if the detection range of the forward object detecting unit by the collision avoidance determining unit determines that not the collision avoidance collision is changed, the running control means according to the running control of the running control such that hardly operated Serial vehicle control system characterized in that it and a operating condition changing means for changing operating conditions. Said operating condition changing means, vehicle control system according to claim 3, characterized in that prohibiting the operation of the travel control by the prior SL running control means.

Images