JP3266081B2 - Inter-vehicle distance control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an inter-vehicle distance that measures the inter-vehicle distance between a host vehicle and a preceding vehicle and causes the host vehicle to follow the preceding vehicle so that the inter-vehicle distance becomes a predetermined distance determined by the vehicle speed or the like. It relates to a control device.

[0002]

2. Description of the Related Art Conventionally, an inter-vehicle distance control apparatus for automatically following a preceding vehicle has been known as a technique for improving the driving safety of an automobile and reducing the operation burden on a driver. I have. In this type of device, in order to prevent unnecessary deceleration control of the roadside object, for example, up to about 20 km / h in consideration of the margin of the relative speed of the stationary object or the stationary object determination. Objects including low-speed moving objects are excluded from the control targets of the inter-vehicle distance control, that is, constant-speed running control is performed. This is because there is a possibility that a roadside object that is not actually a preceding vehicle may be erroneously recognized as a preceding vehicle when the road shape ahead of the traveling road cannot be sufficiently detected. Further, in this type of device, when the vehicle driver operates the brake, it is general that the inter-vehicle distance control is canceled with priority given to the driver's operation.

Among such inter-vehicle distance control devices, an inter-vehicle distance control device that controls only an acceleration device (mainly a throttle valve of an internal combustion engine, which is a power source of the vehicle) has a relatively moderate acceleration and deceleration during traveling. It is assumed that the vehicle will be used on a highway, and the lower limit of the vehicle speed at which control is permitted is set to, for example, a legal minimum speed of about 50 km / h. When the preceding vehicle slowly decelerates while following the vehicle to perform the following distance control, as a result of the control of maintaining the predetermined following distance, the own vehicle also follows and slowly decelerates. Therefore, the host vehicle falls below the host vehicle speed lower limit permitted for control before the preceding vehicle stops, and the control is stopped. In addition, the maximum deceleration when the vehicle is decelerated is a deceleration during coasting of the vehicle (mainly, in a vehicle, mainly in a fully closed state of a throttle valve), and is relatively small. Therefore, if the preceding vehicle suddenly decelerates while following the vehicle by performing the inter-vehicle distance control, the above-described inertial traveling becomes insufficiently decelerated, and it is necessary to rely on the brake operation by the vehicle driver. In other words, even if the preceding vehicle suddenly decelerates and stops, if the own vehicle does not fall below the lower limit of the own vehicle speed for which control is permitted, control is stopped by the driver's brake operation before the preceding vehicle stops. I have.

[0004] Therefore, even if a stationary object (including the low-speed moving object described above) is excluded from the control target of the following distance control, no substantial adverse effect occurs.

[0005]

An inter-vehicle distance control device that controls only the above-mentioned acceleration device has been developed to provide a relatively large acceleration / deceleration rate of a preceding vehicle such as an expressway or a general road during a traffic jam. In order to be able to apply the inter-vehicle distance control even in a traveling environment, it is necessary to control not only an acceleration device but also a deceleration device (mainly a braking device or an auxiliary brake by downshifting in an automobile).

As described above, if the deceleration control is positively performed by controlling the reduction gear, the following problem occurs. In other words, in order to operate the inter-vehicle distance control even during a traffic jam, the lower limit of the vehicle speed at which control is permitted is set to 20 km / h.
It is necessary to reduce the speed to a low speed such as 0 km / h. In this case, even if the preceding vehicle decelerates and stops while the following distance control is being performed and the vehicle is following, the own vehicle does not fall below the lower limit of the own vehicle speed for which the above control is permitted. Occurs. That is, the control is continued in the determination based on the own vehicle speed lower limit. In this state, if the stationary object (including the low-speed moving object described above) is excluded from the control target of the inter-vehicle distance control as described above, the inter-vehicle distance control is stopped by stopping the preceding vehicle, and the process shifts to the constant speed traveling control. As a result, the vehicle deceleration after the release of the deceleration control is greatly reduced as compared with the case where the deceleration control has been performed until then. Due to the decrease in the deceleration, the host vehicle may suddenly approach the preceding vehicle too quickly against the driver's feeling, which may cause discomfort. Also, if the driver is required to perform a brake operation, the system cannot be said to be comfortable.

In view of the above, the present invention provides control when the preceding vehicle falls below the control permission speed during deceleration control by inter-vehicle distance control so that the vehicle behaves more in accordance with the driver's feeling. The object is to prevent the driver from feeling uncomfortable.

[0008]

According to a first aspect of the present invention, there is provided an inter-vehicle distance detecting means for detecting an inter-vehicle distance between a host vehicle and a preceding vehicle, and a speed of the host vehicle. Vehicle speed detecting means for detecting the vehicle speed, accelerating means and decelerating means capable of being operated independently of the accelerating and braking operations by the vehicle driver, and driving the accelerating means and decelerating means based on the inter-vehicle distance and the speed of the own vehicle. Control means for controlling the distance between the vehicles by maintaining the target distance between the vehicles and running the own vehicle; and controlling the acceleration means to drive the vehicle while maintaining the target vehicle speed. Detecting the speed of an object including the preceding vehicle
And a object speed detecting means, speed of the object including the preceding vehicle detected by the object speed detecting means, from a predetermined control permission lower limit rate should remove from the target inter-vehicle distance control
If it is smaller, the object including the preceding vehicle is
In the inter-vehicle distance control device that is not subject to the separation control, even when the speed of the preceding vehicle is lower than a predetermined control permission lower limit speed, the preceding vehicle is moved to the inter-vehicle distance before the speed falls below the control permission lower limit speed. When the vehicle is selected as a control target by the control means,
Release the control to maintain the target inter-vehicle distance by the step
For maintaining the target vehicle speed by the constant speed traveling control means.
Control is prohibited, and the following distance control is continued.
It is characterized by comprising a control switching prohibiting means for causing

As described above, the inter-vehicle distance control can be applied to a traveling environment in which the acceleration / deceleration of the preceding vehicle is relatively large, such as a highway or a general road in a traffic jam. Allowable lower limit speed is, for example, 20k
It is necessary to reduce the speed to a low speed such as m / h or 0 km / h. In this case, even if the preceding vehicle decelerates and stops while the following distance control is being performed and the vehicle is following, the own vehicle does not fall below the lower limit of the own vehicle speed for which the above control is permitted. Occurs. That is, the control is continued in the determination based on the own vehicle speed lower limit. In this state, the stationary object (including the low-speed moving object described above) as described above
Is excluded from the control target of the inter-vehicle distance control, the inter-vehicle distance control is stopped by stopping the preceding vehicle, and the vehicle shifts to the constant speed traveling control. The subsequent vehicle deceleration is greatly reduced. Due to the decrease in the deceleration, the host vehicle may suddenly approach the preceding vehicle too quickly against the driver's feeling, which may cause discomfort. Also, if the driver is required to perform a brake operation, the system is not a comfortable system.

Therefore, the inter-vehicle distance control device according to the present invention provides the inter-vehicle distance control means even before the speed of the preceding vehicle falls below the predetermined control permission lower limit speed before the speed falls below the control permission lower limit speed. If the vehicle has been selected as a control target, it is determined that deceleration control is necessary, and
Control for maintaining target inter-vehicle distance by distance control means
And maintain the target vehicle speed by the cruise control means
Transfer to the control for the purpose is prohibited. That is, the following distance control (in this case, deceleration control) is continued. of course,
Before the control permission lower limit speed is included, the preceding vehicle is included
If the object has not been selected as a control target by the inter-vehicle distance control means, it is determined that it is not necessary to continue the inter-vehicle distance control, and the control for maintaining the target inter-vehicle distance by the inter-vehicle distance control means is released .

When the inter-vehicle distance control is stopped,
Switching to the constant speed traveling control is conceivable. Inter-vehicular distance
If control is simply stopped, control is stopped every time a roadside object that does not need to be controlled is erroneously recognized as a preceding vehicle.
Each time the driver is that, without an operation to resume the control is because troublesome to Kuna' a must.

By doing so, for example, even if the preceding vehicle is stopped, the deceleration control is continued if the preceding vehicle is to be controlled, so that the deceleration control is uniformly released by stopping the preceding vehicle. Inconvenience in the case where it does not occur. In other words, the inconvenience that the vehicle deceleration is greatly reduced due to the inter-vehicle distance control cancellation and the own vehicle suddenly approaches the preceding vehicle too much contrary to the driver's sense, which causes discomfort. It does not happen. Specifically, if the preceding vehicle is stopped, smooth deceleration control will be executed until the own vehicle stops at a position that maintains an appropriate inter-vehicle distance with respect to the preceding vehicle.

[0013] The "control permission lower limit speed" is 0 km if only a complete stationary object is targeted as described above.
/ H, but is generally set to, for example, about 20 km / h in consideration of the margin of the relative speed of the stationary object determination. On the other hand, the invention according to claim 2 has an object speed detecting means for detecting the speed of an object including a preceding vehicle.
If the speed of the object including the preceding vehicle detected by the object speed detection means is smaller than a predetermined control permission lower limit speed to be excluded from the subject of the following distance control,
In an inter-vehicle distance control device that excludes an object including a traveling vehicle from the target of the inter-vehicle distance control, even if the speed of a preceding vehicle falls below a predetermined control permission lower limit speed, the control permission lower limit In a state where the preceding vehicle has been selected as a control target by the following distance control means before the vehicle speed falls below the target speed, the target following distance by the following distance control means is maintained.
And a gradual decrease control means for executing a gradual decrease control for controlling the deceleration means to gradually reduce the deceleration of the own vehicle after canceling the control for the vehicle.

In the case of the above-mentioned inter-vehicle distance control device according to the first aspect, the inter-vehicle distance control is performed by continuing the inter-vehicle distance control. The distance control itself is released,
Instead, the gradual decrease control means responds by executing a gradual decrease control for gradually decreasing the deceleration of the host vehicle. In other words, the deceleration of the vehicle is greatly reduced due to the cancellation of the inter-vehicle distance control, and the self-vehicle suddenly comes too close to the preceding vehicle contrary to the driver's sensation. Was. Therefore, even if the inter-vehicle distance control itself is released, if the gradual decrease control that gradually reduces the deceleration of the own vehicle is executed, “the deceleration of the vehicle is greatly reduced, and the self- The situation in which the vehicle approaches the preceding vehicle too rapidly can be prevented, and the inconvenience of causing discomfort does not occur.

The gradual deceleration control means executes gradual deceleration control for gradually decreasing the deceleration of the host vehicle. As set forth in claim 3, the deceleration of the host vehicle is smaller than a predetermined value. If it does, the gradual decrease control may be ended. Further , as shown in claim 4, when the inter- vehicle distance control is released and the process shifts to the gradual decrease control by the gradual decrease control means, the notifying means mounted on the own vehicle is operated, A notification control means for notifying the control transition may be provided. Since the inter-vehicle distance control that has been executed up to that point is cancelled, the driver is notified of this fact, so that the driver can perform a predetermined operation to switch to manual driving if necessary. Since the gradual decrease control is performed by the gradual decrease control means, it is possible to give the driver time to switch to the manual operation, which is preferable in terms of securing comfort. The notification in this case may be, for example, a method of appealing to the auditory sense by a notification sound or a method of appealing to the visual sense through blinking of a lamp or display on a display device. Of course, the driver may be notified by appealing to the other five senses.

In the above-mentioned inter-vehicle distance control device, the deceleration means may be, for example,
The vehicle may be decelerated by a braking force generated by adjusting a brake pressure applied to a brake device mounted on the host vehicle. Alternatively, for example, the throttle valve of the internal combustion engine may be fully closed. In this case, a braking force (so-called engine brake) may be generated in the internal combustion engine. Alternatively, the braking force may be applied to the automatic transmission by shifting down the automatic transmission. May be generated. Further, these controls may be combined to generate a braking force on the vehicle.

[0017]

Next, embodiments of the present invention will be described with reference to the drawings. FIG. 1 shows a system block diagram of an auto cruise control device 1 to which the present invention is applied. The auto cruise control device 1 is a device configured to perform constant-speed running control when there is no preceding vehicle, and to execute control to maintain an appropriate inter-vehicle distance when a preceding vehicle is captured.

The auto cruise control device 1 is mainly composed of a computer 4, and includes a scanning distance measuring device 6, a steering angle sensor 8, a vehicle speed sensor 10, a cruise control switch 12, and an operation detection switch 13 for detecting an operation of a vehicle driver. , Display 14, a brake control unit 18, and an engine output control unit 20. In addition, the notification buzzer 19 shown by a broken line in FIG. 1 is a configuration required in another embodiment described later, and is not necessary in the embodiment described below.

The computer 4 has an input / output interface (I / O) and various drive circuits and detection circuits. Since these hardware configurations are general, detailed description will be omitted. Note that the computer 4 performs a constant-speed traveling control for maintaining the vehicle speed at the set speed when the preceding vehicle is not captured, in addition to the following distance control described in the present embodiment.

Here, the scanning distance measuring device 6 includes a transmitting / receiving section 6a and a distance / angle calculating section 6b.
a outputs a laser beam while scanning in a range of a predetermined angle from the front of the vehicle, and detects the reflected light,
This is a device that detects the relative speed and distance of a forward object, and also its position coordinates, based on the time until the reflected light is captured by the distance / angle calculation unit 6b. Therefore, the scanning distance measuring device 6 functions as "inter-vehicle distance detecting means" and " object speed detecting means". Since such a device is already well known, a detailed description is omitted. In addition,
Instead of using the scanning laser light, a distance measuring device using radio waves such as microwaves, ultrasonic waves, or the like may be used.

The steering angle sensor 8 detects the amount of change in the steering angle of the steering wheel, and can detect the relative steering angle from the value. Therefore, when the power of the auto cruise control device 1 is turned on, the steering angle storage address in the memory is set to “0”, and thereafter, the deviation of the neutral position of the steering angle is determined by the steering angle data during traveling. The relative steering angle is determined by integrating the detected steering angle change amounts while correcting by the average value calculation. Based on the steering angle, it is possible to detect data (curve data) relating to the turning state of the own vehicle such as the turning direction and the turning radius of the own vehicle. This curve data is stored in the scanning rangefinder 6
Is used to determine whether or not the preceding vehicle detected by the above is subject to inter-vehicle distance control. More specifically, when the own vehicle is turning right, the preceding vehicle captured on the left side of the center of the ranging range is determined to be a vehicle in another lane, and this is excluded from the target of the inter-vehicle distance control. In other words, it is used to grasp the preceding vehicle captured on the right side as an object of the following distance control. In other words, the curve data is data necessary for grasping the traveling direction of the own vehicle and identifying the preceding vehicle existing in the traveling direction of the own vehicle.

The vehicle speed sensor 10 functions as "own vehicle speed detecting means", and is a sensor for detecting a signal corresponding to the rotational speed of the wheel. Operation detection switch 1
Numeral 3 is for detecting a driver's manual operation, and includes a brake switch 13a for detecting a driver's manual operation of a foot brake and an accelerator switch 13b for detecting a driver's manual accelerator operation. In the case of a vehicle equipped with a manual transmission, a clutch switch for detecting a shift-up or shift-down operation of a clutch is also included. Here, a vehicle equipped with an automatic transmission is targeted.

On the other hand, the cruise control switch 12
Has a main switch 12a, a set switch 12b, a resume switch 12c, a cancel switch 12d, and a tap switch 12e. The role of each switch will be described in order.

First, the main switch 12a is a switch for starting a cruise control, and when the main switch 12a is turned on, a state in which the constant speed traveling control can be started. The inter-vehicle distance control process is also executed in the constant speed traveling control.

The set switch 12b is a switch which, when depressed, takes in the vehicle speed Vn at that time, sets the vehicle speed Vn to the target vehicle speed Vm, and starts constant speed traveling control. The resume switch 12c is
When the target vehicle speed Vm is stored while the cruise control is released and the target vehicle speed Vm is stored,
The vehicle speed is returned from the current vehicle speed to the target vehicle speed Vm.

The cancel switch 12d is for canceling the constant speed control when it is pressed during the cruise control. The tap switch 12e is for setting the distance between the vehicle and the preceding vehicle. Display 14
Can display a set vehicle speed, a current inter-vehicle distance, a sensor abnormality, and the like.

The engine output control unit 20 adjusts the opening of the throttle valve in the case of a gasoline type internal combustion engine and adjusts the position of the control rack in the case of a diesel type internal combustion engine in accordance with instructions from the computer 4. Also in this case, the speed is controlled by adjusting the engine output. It should be noted that the gear position of the automatic transmission may be selected to adjust the engine output.

The brake control unit 18 adjusts the pressure of each wheel cylinder according to an instruction from the computer 4.
This brake control may be performed by an exhaust brake or a retarding device that is widely used in large vehicles. The computer 4 includes a CPU, ROM, and R (not shown).
A well-known arithmetic and control unit configured by an AM or the like,
The above-mentioned "inter-vehicle distance control means" and "constant speed traveling control means "
And a function as "control switching prohibition means".
A detailed description of each function will be described later.

The computer 4 includes a power switch (not shown), and is configured to be supplied with power by an ON operation thereof and start a predetermined process. And
With such a configuration, the processing as the auto cruise control device and the constant speed traveling control processing are executed.

FIG. 2 shows a flowchart of a process for releasing the control from the following distance control in the control logic of the computer 4. This processing is performed after power is supplied from the main power supply (not shown) to each unit of the auto cruise control device 1.
The operation is started when the operation of the auto cruise control device 1 is selected by the cruise control switch 12.

First, in the first step S10, an estimated curve radius is calculated. The estimated curve radius is used when determining whether or not the preceding vehicle detected by the scanning distance measuring device 6 is to be subjected to the following distance control, as described above. And the vehicle speed from the vehicle speed sensor 10.

In S20, the preceding vehicle is selected based on the estimated curve radius, the distance to the obstacle, the relative speed, and the own lane probability calculated in S10. For example, if the own vehicle is turning right, the preceding vehicle captured to the left of the center of the ranging range is determined to be a vehicle in another lane, and this is excluded from the subject of inter-vehicle distance control, and The captured front vehicle is grasped as a vehicle to be subjected to the inter-vehicle distance control. That is, the front vehicle existing in the traveling direction of the own vehicle is identified. If there are a plurality of front vehicles existing in the traveling direction of the own vehicle, the vehicle with the shortest distance from the own vehicle is selected as the preceding vehicle. It is also determined whether the selected preceding vehicle is the same vehicle as the preceding vehicle selected in S20 when the previous processing routine was executed.

Then, in S30, it is determined whether or not there is a vehicle to be selected as a preceding vehicle. If it is determined that there is no preceding vehicle (S30: NO), the preceding vehicle selection flag is reset in S40. Then, at S50, the constant-speed running control is executed, and then the present processing routine is temporarily ended. On the other hand, when it is determined that there is a preceding vehicle (S30: YES),
The process proceeds to S60 to determine whether the preceding vehicle speed is lower than the control permission lower limit speed. The control permission lower limit speed is, for example, a speed of 20 km / h.

Then, a negative determination is made in S60, that is, the preceding vehicle speed becomes the control permission lower limit speed (for example, 20 km / h).
If the above is the case, the preceding vehicle selection flag is set in S70, and the flow shifts to S100 to execute the following distance control. This inter-vehicle distance control instructs deceleration when approaching the preceding vehicle, and conversely, instructs acceleration when it is lagging behind the preceding vehicle to maintain an appropriate inter-vehicle distance with respect to the preceding vehicle. Things. FIG. 3 shows the specific contents of this inter-vehicle distance control.

In the inter-vehicle distance control, first, an appropriate target inter-vehicle distance with respect to the preceding vehicle is calculated from the running state of the preceding vehicle and the speed of the own vehicle (S110). Next, an acceleration / deceleration of the own vehicle for obtaining an appropriate inter-vehicle distance is calculated (S120), and a target vehicle speed is calculated by integrating the acceleration / deceleration (S130).

Then, the actual vehicle speed is compared with the target vehicle speed (S140), and if the actual vehicle speed <the target vehicle speed, an acceleration command is output to the engine output control unit 20 (S150).
On the other hand, if the actual vehicle speed is greater than the target vehicle speed, a deceleration command is output to the brake control unit 18 (S160). If the actual vehicle speed is equal to the target vehicle speed, no acceleration / deceleration command is issued.

When an acceleration command is issued, in the case of a gasoline-type internal combustion engine, the opening of the throttle valve is increased to increase the engine output and perform speed-up control. On the other hand, when a deceleration command is issued, the above-described throttle valve is fully closed to generate a braking force (so-called engine brake) in the internal combustion engine or to shift down the automatic transmission to apply the braking force to the automatic transmission. The deceleration control is performed by generating the braking force or by increasing the wheel cylinder pressure to generate the braking force.

After the acceleration command at S150 or the acceleration command at S160 is output, the present inter-vehicle distance control routine ends. In FIG. 2 as well, when the inter-vehicle distance control in S100 ends, this processing routine ends once. Also, S6
If the result is 0, that is, if the preceding vehicle speed is lower than the control permission lower limit speed (for example, 20 km / h),
In S80, it is determined whether or not the preceding vehicle selection flag is set. If the processing of S60 is performed when the processing routine up to the previous time is executed and the preceding vehicle selection flag is set, an affirmative determination is made in S80 in the current processing routine, and the process proceeds to S90 to return to the previous processing routine. It is determined whether the selected vehicle is the same vehicle as the preceding vehicle selected. Here, if they are the same vehicle (S90: YES), S1
The process proceeds to 00 to execute the following distance control.

On the other hand, when the preceding vehicle selection flag is not set (S80: NO), or when the preceding vehicle selected in the previous processing routine is not the same as the preceding vehicle (S80).
(90: NO), the process proceeds to S40, resets the preceding vehicle selection flag, and switches to the constant speed traveling control of S50.

Here, in the processing performed by the computer 4, the processing performed in S100 corresponds to the operation of the above-mentioned "inter-vehicle distance control means", and the processing performed in S50 corresponds to the operation of the above-mentioned "constant-speed running control means". Corresponds to. Also, the process performed in S 80, S90 corresponds to act as a "control switching prohibition means" described above.

As described above, according to the auto cruise control device 1 of the present embodiment, even if the speed of the preceding vehicle is lower than the predetermined control permission lower limit speed (S50: YES), the control permission lower limit speed is not changed. If the preceding vehicle has been selected as a control target by the following distance control means before the vehicle falls below the predetermined distance (S90: YES), it is determined that deceleration control is necessary, and the following distance control is continued (S100). Of course, if the preceding vehicle has not been selected as a control target before the speed falls below the control permission lower limit speed (S90:
NO), it is determined that there is no need to continue the inter-vehicle distance control, the inter-vehicle distance control is released (S40), and the control is switched to the constant speed traveling control (S50).

By doing so, for example, even if the preceding vehicle is stopped, the deceleration control is continued when the preceding vehicle is to be controlled, so that the deceleration control is uniformly released by stopping the preceding vehicle. The inconvenience of the case does not occur. In other words, the inconvenience that the vehicle deceleration is greatly reduced due to the inter-vehicle distance control cancellation and the own vehicle suddenly approaches the preceding vehicle too much contrary to the driver's sense, which causes discomfort. It does not happen. This point will be supplementarily described with reference to FIGS.

FIG. 4 shows the behavior of the vehicle when the inter-vehicle distance control is immediately released when the control permission lower limit speed for the preceding vehicle is set at 20 km / h and the preceding vehicle speed falls below the control permission lower limit speed. . On the other hand, in FIG. 5, as in the control according to the above-described embodiment, the control permission lower limit speed for the preceding vehicle is set to 20 km / h, and the preceding vehicle speed is lower than the control permission lower limit speed. 9 shows the behavior of the vehicle when the inter-vehicle distance control is continued without being released.

First, look at FIG. In FIG. 4A, both the host vehicle and the preceding vehicle are traveling at a speed of 60 km / h. Therefore, in order to maintain an appropriate inter-vehicle distance in the inter-vehicle distance control, the vehicle is driven at a constant speed as a result by the accelerator control. Control. Then, as shown in FIG. 4B, if the preceding vehicle decelerates to 30 km / h due to traffic congestion ahead, deceleration control is performed as inter-vehicle distance control. In FIG. 4B, the own vehicle is 40 km /
h is shown. FIG. 4C shows a state in which the preceding vehicle is further decelerated to 10 km / h, and the own vehicle is reduced to 25 km / h as the inter-vehicle distance control is performed as the preceding vehicle decelerates. ing. In this state, since the speed of the preceding vehicle is lower than the control permission lower limit speed of 20 km / h, the following distance control in the own vehicle is released. That is, the state is changed from the state where the deceleration control is performed to a state where the deceleration is not performed. Then, as shown in FIG. 4D, even when the preceding vehicle is at 0 km / h, the own vehicle approaches the preceding vehicle without decelerating. For a person, it is a feeling that the host vehicle approaches the preceding vehicle too rapidly.

On the other hand, if the behavior shown in FIG.
Such inconvenience can be solved. FIG. 5 (a), (b)
Is the same as the situation shown in FIGS. 4A and 4B, and the description is omitted. In the following FIG. 5 (c), the preceding vehicle is further decelerated to 10 km / h, and the deceleration control is performed as the inter-vehicle distance control in accordance with the deceleration of the preceding vehicle, and the own vehicle becomes 2 km / h.
This shows a state where the speed has reached 5 km / h. In this state, the speed of the preceding vehicle is 20 k which is the control permission lower limit speed.
Although it is lower than m / h, as shown in FIGS. 5A and 5B, it has been a controlled object as a preceding vehicle before that. Therefore, the inter-vehicle distance control in the own vehicle is continued without being canceled. Therefore, as shown in FIG. 5 (d), even when the preceding vehicle is at 0 km / h, the own vehicle performs a smooth deceleration control until it stops at a position maintaining an appropriate inter-vehicle distance with respect to the preceding vehicle. Will be done.

As described above, according to the auto cruise control device 1 of the present embodiment, the control performed when the preceding vehicle falls below the control permission speed during the deceleration control by the following distance control is further performed. It is possible to prevent the driver from feeling uncomfortable by setting the vehicle behavior to match the driver's feeling.

As described above, the present invention is not limited to such an embodiment, and can be implemented in various forms without departing from the gist of the present invention. For example, in the above-described embodiment, even if the speed of the preceding vehicle is lower than the control permission lower limit speed of 20 km / h, if the preceding vehicle has been controlled as the preceding vehicle, the inter-vehicle distance control is continued. Was corresponding. Other than the corresponding method, for example, the inter-vehicle distance control itself is released,
Instead, a gradual reduction control that gradually reduces the deceleration of the host vehicle may be performed to cope with the situation.
In other words, the deceleration of the vehicle is greatly reduced due to the cancellation of the inter-vehicle distance control, and the self-vehicle suddenly comes too close to the preceding vehicle contrary to the driver's sensation. Was. Therefore, even if the inter-vehicle distance control itself is released, if the gradual decrease control that gradually reduces the deceleration of the own vehicle is executed, “the deceleration of the vehicle is greatly reduced, and the self- A situation in which the vehicle approaches the preceding vehicle too quickly "can be prevented, and the inconvenience of causing discomfort does not occur.

When the deceleration of the host vehicle is gradually reduced, the gradual reduction control may be terminated when the deceleration of the host vehicle becomes smaller than a predetermined value. Further, when the inter-vehicle distance control is released and the control shifts to the gradually decreasing control,
The control transition may be notified to the driver. Since the inter-vehicle distance control that has been executed up to that point is cancelled, the driver is notified of this fact, and the driver can perform a predetermined operation (for example, a brake operation) to switch to manual driving if necessary. it can. Since the gradual decrease control is performed by the gradual decrease control means, it is possible to give the driver time to switch to the manual operation, which is preferable in terms of securing comfort.

The configuration of this alternative embodiment is similar to that of the system block diagram of the auto cruise control device 1 shown in FIG.
This is a configuration to which a notification buzzer 19 indicated by a broken line is added. The notification buzzer 19 functions as the above-described “notification means”, and when a notification request signal is input from the computer 4, notifies the control transition described later. The description of the other components is omitted.

FIG. 6 is a flowchart of a process for canceling the control from the following distance control in the control logic of the computer 4 in the case of this another embodiment. FIG.
S10 to S10 in each step in the flowchart of
Since steps 70 and S90 are exactly the same, in the flowchart of FIG. 6, the detailed description will be omitted, and only different parts will be described.

In the flowchart of FIG.
After the preceding vehicle selection flag is set at S10 and at S80 and S90, an affirmative determination is made, that is, both when the preceding vehicle selection flag is set and the vehicle is the same as the previous vehicle, S10
The inter-vehicle distance control at 0 was executed. However, in the flowchart of FIG. 6, after the preceding vehicle selection flag is set in S70, the process proceeds to S180, and S1 in FIG.
The same inter-vehicle distance control as in 00 is executed, but in the case of a positive determination in S80, the inter-vehicle distance control in S180 is not executed,
The processes of S200, S210, and S220 are sequentially executed.
This processing will be described.

At S200, a notification of control transition is issued. This is performed by operating the notification buzzer 19 by outputting a notification request signal from the computer 4. In addition, the notification may be displayed on the display unit 14 and the notification may be displayed together with the notification sound by the notification buzzer 19.

After the control transition is notified in S200,
In S210, the following distance control is canceled. And the following S
At 220, the deceleration is gradually reduced. When gradually decreasing the deceleration of the own vehicle in this gradual decrease control,
For example, the deceleration may be gradually reduced at a predetermined deceleration reduction rate according to the deceleration at the time of the control transition, and the deceleration control may be terminated when the deceleration of the own vehicle becomes smaller than a predetermined value. Can be considered.

In the case of this alternative embodiment, the notification buzzer 19 functions as "notification means" and the computer 4
Function as “inter-vehicle distance control means” , “ gradual decrease control means”, and “notification control means”. In addition, when the notification is made by displaying the notification on the display 14 together with the notification sound by the notification buzzer 19, the notification buzzer 19 and the display 14
Functions as “notification means”.

In the processing performed by the computer 4, the processing performed in S180 in FIG. 6 corresponds to the above-described operation as the "inter-vehicle distance control means".
0 , S210 and S220 correspond to the operation as the above-mentioned "gradual decrease control means".

[Brief description of the drawings]

FIG. 1 is a system block diagram of an embodiment.

FIG. 2 is a control flowchart according to the embodiment.

FIG. 3 is a control flowchart according to the embodiment.

FIG. 4 is an explanatory diagram showing the behavior of the vehicle when the inter-vehicle distance control is immediately released when the preceding vehicle speed falls below the control permission lower limit speed.

FIG. 5 is an explanatory diagram showing the behavior of the vehicle when the preceding vehicle speed has fallen below the control permission lower limit speed, but the control has been performed before, so that the inter-vehicle distance control is continued without being released.

FIG. 6 is a control flowchart according to another embodiment.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Auto cruise control device 4 ... Computer 6 ... Scanning distance measuring device 8 ... Steering angle sensor 10 ... Vehicle speed sensor 12 ... Cruise control switch 13 ... Operation detection switch 13a ... Brake switch 13b ... Accelerator switch 14 ... Display 18 ... Brake control Unit 19: Notification buzzer 20: Engine output control unit

Continuation of front page (56) References JP-A-7-17297 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) B60K 31/00 F02D 29/02 B60T 7/12 G08G 1 / 16

Claims (7)

(57) [Claims] An inter-vehicle distance detecting means for detecting an inter-vehicle distance between a host vehicle and a preceding vehicle; a self-vehicle speed detecting means for detecting a speed of the host vehicle; operating independently of an acceleration operation and a braking operation by a vehicle driver. Acceleration means and deceleration means, and inter-vehicle distance control means for driving the own vehicle while maintaining the target inter-vehicle distance by controlling the driving of the acceleration means and deceleration means based on the inter-vehicle distance and the speed of the own vehicle, , by controlling the driving of the said acceleration means includes a cruise control means for driving the vehicle to maintain the target vehicle speed, and the object speed detecting means for detecting the speed of an object including the preceding vehicle, the object the preceding vehicle detected by the speed detecting means
If the speed of the included object is smaller than a predetermined control permission lower limit speed to be excluded from the subject of the following distance control , the preceding vehicle
In an inter-vehicle distance control device that excludes an object including both from the subject of the inter-vehicle distance control, even if the speed of the preceding vehicle is lower than a predetermined control permission lower limit speed, before the speed falls below the control permission lower limit speed. in the state that selects the preceding vehicle as a control target by the inter-vehicle distance control means, said inter-vehicle distance system
Release control to maintain target inter-vehicle distance by control means
To maintain the target vehicle speed by the constant speed traveling control means.
Transfer to the control for
An inter-vehicle distance control device comprising a control switching prohibition unit for causing the vehicle to run . 2. An inter-vehicle distance detecting means for detecting an inter-vehicle distance between a host vehicle and a preceding vehicle; a self-vehicle speed detecting means for detecting a speed of the host vehicle; and operating independently of an acceleration operation and a braking operation by a vehicle driver. Acceleration means and deceleration means, and inter-vehicle distance control means for driving the own vehicle while maintaining the target inter-vehicle distance by controlling the driving of the acceleration means and deceleration means based on the inter-vehicle distance and the speed of the own vehicle, , and a object speed detecting means for detecting the speed of an object including the preceding vehicle, the preceding vehicle detected by the object speed detecting means
If the speed of the included object is smaller than a predetermined control permission lower limit speed to be excluded from the subject of the following distance control , the preceding vehicle
In an inter-vehicle distance control device that excludes an object including both from the subject of the inter-vehicle distance control, even if the speed of the preceding vehicle is lower than a predetermined control permission lower limit speed, before the speed falls below the control permission lower limit speed. in the state that selects the preceding vehicle as a control target by the inter-vehicle distance control means, said inter-vehicle distance system
Release control to maintain target inter-vehicle distance by control means
After inter-vehicle distance control apparatus, characterized in that it comprises a gradual decrease control means for executing a decreasing control to gradually reduce the deceleration of the controlled deceleration means vehicle. 3. The gradual decrease control means is configured to terminate the gradual decrease control when the deceleration of the host vehicle becomes smaller than a predetermined value.
The inter-vehicle distance control device according to claim 1. 4. Further, when the previous SL distance control shifts to decreasing control by the gradual decrease control means is released, by operating the notification means mounted on the vehicle, thereby notifying the control transfer notification The inter-vehicle distance control device according to claim 2 or 3, further comprising control means. 5. The inter-vehicle distance control device according to claim 1, wherein said deceleration means is configured to decelerate the vehicle by a braking force generated by adjusting a brake pressure. 6. A vehicle according to claim 1, wherein said speed reduction means is configured to decelerate the vehicle by a braking force of said internal combustion engine generated by fully closing a throttle valve of the internal combustion engine. An inter-vehicle distance control device according to any one of the above. 7. The vehicle according to claim 1, wherein said speed reduction means is configured to decelerate the vehicle by a braking force of said automatic transmission generated by shifting down the automatic transmission. An inter-vehicle distance control device according to any of the claims.