JP3389287B2 - Vehicle travel 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 a vehicle running control system for controlling the speed of a vehicle based on the distance between the vehicle and a preceding vehicle.

[0002]

2. Description of the Related Art Conventionally, as a vehicle travel control device,
It is known to control the vehicle speed so as to maintain the vehicle-to-vehicle distance (actual vehicle-to-vehicle distance) between the own vehicle and the preceding vehicle at a predetermined safety vehicle-to-vehicle distance. There is an inconvenience that hunting occurs in the vehicle speed control and the riding comfort is reduced. For this reason, in the past, it has been
As disclosed in Japanese Patent No. 52157, a predetermined range is set as a dead zone before and after the safe inter-vehicle distance which is a target inter-vehicle distance in the vehicle speed control, and the actual inter-vehicle distance is within the predetermined range before and after the dead zone. If the vehicle is in the state of control, the vehicle speed is controlled so as not to change even if it does not match the safe inter-vehicle distance, so that hunting is suppressed and riding comfort is improved.

[0003]

However, the above traveling control device has the following problems.

That is, when the preceding vehicle accelerates or decelerates, the actual inter-vehicle distance changes, and when the actual inter-vehicle distance deviates from the front-rear predetermined range, the actual inter-vehicle distance becomes the front-rear predetermined range. The vehicle speed increase / decrease is controlled accordingly. Therefore, for example, when the driver of the preceding vehicle repeatedly performs rapid acceleration / deceleration, if the width of the predetermined front and rear range is set narrow, the own vehicle also repeats rapid acceleration / deceleration. There is a problem that it will end up. On the other hand, when the width of the above-mentioned predetermined range is set to be wide, it is possible to avoid sudden acceleration / deceleration of the vehicle, but when the preceding vehicle is in a normal traveling state close to constant speed traveling, Is unnecessarily long.

In the travel control device described in the above publication, the longer the safety inter-vehicle distance, the wider the predetermined front and rear range. At that time, the safety inter-vehicle distance is calculated from the vehicle speed of the host vehicle. I am supposed to do so,
As the vehicle speed of the host vehicle increases, the width of the front-rear predetermined range becomes wider, but since it does not correspond to the vehicle speed change state of the preceding vehicle, the above problem cannot be solved.

The present invention has been made in view of the above circumstances, and when a vehicle speed change occurs in a preceding vehicle, it is possible to prevent the vehicle speed change more than necessary from occurring. It is an object of the present invention to provide a travel control device for a vehicle, which is capable of preventing the vehicle-to-vehicle distance from becoming unnecessarily long.

[0007]

In order to achieve the above-mentioned object, the present invention provides an inter-vehicle distance detecting means for detecting an inter-vehicle distance between a vehicle and a preceding vehicle, as described in claim 1. Vehicle speed detecting means for detecting the vehicle speed, target vehicle distance setting means for setting the target vehicle distance, target vehicle speed setting means for setting the target vehicle speed, the detected vehicle distance and the vehicle speed of the own vehicle, and the above-mentioned set In a vehicle travel control device including a vehicle speed control means for controlling the vehicle speed of the own vehicle based on the target inter-vehicle distance and the target vehicle speed, the vehicle speed control means comprises:
When the inter-vehicle distance is longer than a first value which is longer than the target inter-vehicle distance by a predetermined distance, the vehicle speed of the host vehicle is controlled to be the target vehicle speed, while the inter-vehicle distance is set to the target inter-vehicle distance. On the other hand, when it is shorter than the second value, which is shorter by the predetermined distance, the vehicle speed of the host vehicle is controlled so that the inter-vehicle distance approaches the target inter-vehicle distance, and the inter-vehicle distance is equal to or less than the first value and When the value is 2 or more, keep the throttle valve opening of the vehicle constant.
And the predetermined distance is set to a larger value as the vehicle speed variation rate of the preceding vehicle increases.

[0008]

As described above, according to the present invention, when the vehicle speed of the preceding vehicle changes abruptly or when the vehicle speed of the preceding vehicle changes greatly, the greater the vehicle speed fluctuation rate of the preceding vehicle becomes, Predetermined distance (area between constant speed running control and inter-vehicle distance control ( throttle valve opening constant
Is configured so as to greatly change the width) of the region) to maintain, it is possible to prevent the vehicle speed of the vehicle is changed more than necessary, whereas, the preceding vehicle is close to constant speed running It is possible to prevent the inter-vehicle distance from becoming unnecessarily long in the normal traveling state.

As described above, according to the present invention, when the vehicle speed of the host vehicle is controlled by switching between the constant speed traveling control and the inter-vehicle distance control, when the vehicle speed of the preceding vehicle changes, the vehicle speed is changed accordingly. It is possible to prevent the vehicle from changing its vehicle speed more than necessary, and also to prevent the inter-vehicle distance from becoming unnecessarily long.

Further, as described in claim 2, the predetermined distance may be set to a larger value as the variation rate of the relative positional deviation in the left-right direction between the own vehicle and the preceding vehicle increases.

That is, the fact that the relative positional deviation between the own vehicle and the preceding vehicle in the left-right direction changes indicates that unstable driving is being performed in the preceding vehicle, and the preceding vehicle speed also changes. It can be assumed that it is occurring. Therefore,
When the variation rate of the relative positional deviation becomes large, the predetermined distance (the width of the region between the constant speed traveling control and the inter-vehicle distance control) is increased and corrected, so that the sudden movement of the preceding vehicle can be performed similarly to the invention of claim 1. While it is possible to avoid repeated rapid acceleration / deceleration of the own vehicle due to acceleration / deceleration, the inter-vehicle distance becomes unnecessarily long when the preceding vehicle is in a normal running state close to constant speed running. Can be prevented.

[0012]

Embodiments of the present invention will be described in detail below with reference to the drawings.

FIG. 1 is a block diagram showing a first embodiment of a vehicle travel control device according to the present invention.

This traveling control device comprises an automatic cruise control circuit 12, a throttle control actuator 14, a vehicle speed sensor 16, a manual switch 18, a radar device 20, and an obstacle detection circuit 22.

The vehicle speed sensor 16 inputs the own vehicle speed V _{A and the} manual switch 18 inputs a target vehicle speed setting signal to the auto cruise control circuit 12. And the auto cruise control circuit 1
The reference numeral 2 designates the own vehicle speed (actual vehicle speed) V _A when the target vehicle speed setting signal is input from the manual switch 18 as the target vehicle speed V ₀ , and thereafter performs the constant speed running control to bring the own vehicle speed V closer to the target vehicle speed V _0. It has become. This constant speed traveling control is performed by outputting an operation signal corresponding to the difference between the own vehicle speed V _A and the target vehicle speed V ₀ to the throttle control actuator 14 to adjust the throttle valve opening TVO. .

The obstacle detection circuit 22 receives the distance between the vehicle and the obstacle ahead of the vehicle detected by the radar device 20 provided at the front end of the vehicle. If the rate of change in distance (that is, the relative speed) is less than or equal to a predetermined value, this obstacle is recognized as the preceding vehicle, and the distance at that time is output to the auto cruise control circuit 12 as the inter-vehicle distance D between the own vehicle and the preceding vehicle. It is like this.

When the inter-vehicle distance D becomes shorter than the lower limit value of the predetermined range ± d before and after the target inter-vehicle distance D0, the automatic cruise control circuit 12 performs inter-vehicle distance control instead of the constant speed traveling control. There is. As shown in FIG. 2, this inter-vehicle distance control controls the own vehicle speed VA so that the inter-vehicle distance D between the own vehicle A and the preceding vehicle B approaches the target inter-vehicle distance D0. The control of the host vehicle speed VA is performed by outputting an operation signal for increasing or decreasing the throttle valve opening from the automatic cruise control circuit 12 to the throttle control actuator 14 to adjust the throttle valve opening TVO.

Next, details of the constant speed traveling control and the inter-vehicle distance control by the auto cruise control circuit 12 will be described with reference to the flowchart shown in FIG.

First, when the ignition switch is on, the manual switch 18 is operated to input a target vehicle speed V ₀ setting signal (step S).
1) The target vehicle speed V ₀ , the own vehicle speed V _A, and the inter-vehicle distance D are read (step S2). Then, the relative vehicle speed ΔV between the host vehicle A, the preceding vehicle B, and the relative vehicle speed ΔV is calculated from the rate of change of the inter-vehicle distance D (step S3), and the vehicle speed of the preceding vehicle B, that is, the preceding vehicle speed V _B is calculated from the relative vehicle speed ΔV and the own vehicle speed V _A. The calculation is performed (step S4), and the variation rate dV _B (which will be described later) is calculated from the preceding vehicle speed V _B (step S5). Then, from the variation rate dV _B of vehicle speed V _A and the preceding vehicle speed V _B, calculates the absolute value d (predetermined distance) of the target inter-vehicle distance D ₀ and before and after the predetermined range ± d as shown in FIG. 4 (step S6).

The target inter-vehicle distance D ₀ shown in FIG. 4 is the reference target inter-vehicle distance D ₀ ′ set in accordance with the own vehicle speed V _A shown in FIG. 5A, and the fluctuation rate dV shown in FIG. 5B. It is calculated as the sum (D ₀ = D ₀ ′ + α) with the correction value α set according to _B. That is, the target inter-vehicle distance D ₀ is the change rate dV _B becomes equal to or greater than the predetermined value dV _B1, is increased corrected with an increase in variation rate dV _B. Further, the absolute value d of the front-rear predetermined range ± d in FIG. 4 is the reference front-rear predetermined range d ′ set according to the vehicle speed V _A shown in FIG. 6A, and the variation shown in FIG. 6B. The sum of the correction value β set according to the rate dV _B (d = d ′
+ Β). That is, the front and rear predetermined range d is
When the variation rate dV _B reaches a predetermined value dV _B2 (dV _B1 ≦ dV _B2 ), the variation rate dV _B is increased and corrected.

Here, the fluctuation rate dV _B is calculated as follows. That is, prior to sampling the vehicle speed V _B for example at one-second intervals, calculates a difference [Delta] V _B of the maximum and minimum values for preceding vehicle speed V _B that these samples, for example, every 10 seconds, the calculated difference [Delta] V _B It is calculated by calculating the average value of 10 data when they are collected.

In FIG. 3, next, the inter-vehicle distance D is an upper limit value (D ₀ + d; first value) within a predetermined range ± d before and after the target inter-vehicle distance D ₀ .
Value) or less (step S7).
If this determination is NO, it is determined that the inter-vehicle distance D is sufficient, and the vehicle moves to the constant speed running control, and the throttle valve opening TVO adjustment operation signal corresponding to the difference between the own vehicle speed V _A and the target vehicle speed V ₀ is throttled. Output to the control actuator 14 (step S8).

On the other hand, if the above determination is YES, the process moves to the inter-vehicle distance control in steps S9 to S11. In this inter-vehicle distance control, it is determined whether or not the inter-vehicle distance D is equal to or greater than the lower limit value (D ₀ -d; second value) of a predetermined range ± d before and after the target inter-vehicle distance D ₀ (step S9). If this determination is NO, it is assumed that the inter-vehicle distance D has become too short, and the inter-vehicle distance D
A throttle valve opening TVO decrease operation signal for lengthening the valve is output to the throttle control actuator 14 (step S10). On the other hand, if the above determination is YES, an operation signal for maintaining the throttle valve opening TVO constant is output to the throttle control actuator 14 (step S11).

In the present embodiment, the obstacle detection circuit 22
Is a vehicle-interval distance detecting means for detecting an inter-vehicle distance between the own vehicle and the preceding vehicle, the vehicle speed sensor 16 is a vehicle speed detecting means for detecting a vehicle speed of the own vehicle, and the manual switch 18 is
The target vehicle speed setting means for setting the target vehicle speed is configured, and the auto-cruise control circuit 12 sets the target inter-vehicle distance setting means, the detected inter-vehicle distance, the vehicle speed of the own vehicle, and the set target. The vehicle speed control means for controlling the vehicle speed of the own vehicle is configured based on the inter-vehicle distance and the target vehicle speed.

As described in detail above, in this embodiment, the vehicle speed V is controlled by switching between the constant speed traveling control and the inter-vehicle distance control.
In controlling the _A, leading the vehicle speed V variation ratio dV _B of _B is configured to increase the correction width (i.e. predetermined distance d) before and after the predetermined range ± d when increased, the operation of the preceding vehicle B Even when the person performs a driving operation in which rapid acceleration / deceleration is repeated, it is possible to prevent the own vehicle A from repeating the rapid acceleration / deceleration in response to the rapid acceleration / deceleration of the preceding vehicle B. on the other hand,
When the preceding vehicle B is in a normal traveling state close to constant speed traveling, it is possible to prevent the inter-vehicle distance D from becoming unnecessarily long.

Thus, according to this embodiment, the preceding vehicle B
When a vehicle speed change occurs in the vehicle, it is possible to prevent the vehicle speed change more than necessary from occurring in the own vehicle A, and it is possible to prevent the inter-vehicle distance D from being unnecessarily long.

Furthermore, in this embodiment, is configured so as to increase correct the target inter-vehicle distance D ₀ when the variation rate dV _B also preceding vehicle speed V _B for the target inter-vehicle distance D ₀ is increased, When the width of the front-rear predetermined range ± d is increased and corrected, it is possible to prevent or suppress the inter-vehicle distance D at the lower limit value from being shortened, and it is possible to improve safety.

Next, a second embodiment of the vehicle travel control device according to the present invention will be described.

FIG. 7 is a block diagram showing the present embodiment, and FIG. 8 is an explanatory diagram showing its operation.

As shown in FIG. 7, the traveling control device according to the present embodiment is provided with a motor 24 in addition to the configuration of the first embodiment. With this motor 24, the radar device 20 is shown in broken line in FIG. It is designed to scan within the angle range indicated by. The obstacle detection circuit 22 receives the inter-vehicle distance signal from the radar device 20 and the scanning angle signal from the motor 24. The obstacle detection circuit 22 detects the inter-vehicle distance D between the own vehicle A and the preceding vehicle B from the inter-vehicle distance signal, and the deflection angle θ of the left and right center of the preceding vehicle B with respect to the left and right center of the own vehicle A from the scanning angle signal. Detect. Furthermore, the obstacle detection circuit 2
2 calculates a relative positional deviation L between the own vehicle A and the preceding vehicle B in the left-right direction from the inter-vehicle distance D and the deflection angle θ, and calculates the calculation result together with the inter-vehicle distance D in the automatic cruise control circuit 1
It is designed to output to 2.

The auto-cruise control circuit 12 stores the relative positional deviation L at predetermined time intervals, calculates the variation rate dL of the stored relative positional deviation L, and when the variation rate dL becomes large, the target inter-vehicle distance. The width of a predetermined range ± d before and after D ₀ is increased and corrected.

Next, the operation of this embodiment will be described.

The fact that the relative positional deviation L between the own vehicle A and the preceding vehicle B in the left-right direction is changed means that the unstable operation is performed in the preceding vehicle B (due to the operation of the own vehicle A). In some cases, it can be estimated that the preceding vehicle B is performing unstable operation, and it can be inferred that the preceding vehicle speed V _B is also changing.

Therefore, when the variation rate dL of the relative positional deviation L becomes large, the driver of the preceding vehicle B can perform rapid acceleration / deceleration by increasing the width of the predetermined range ± d before and after the target inter-vehicle distance D _0. Even when driving such as repeating,
It is possible to prevent the host vehicle A from repeating rapid acceleration / deceleration as the preceding vehicle B accelerates / decelerates. On the other hand, the preceding vehicle B
It is possible to prevent the inter-vehicle distance D from becoming unnecessarily long when the vehicle is in a normal traveling state close to constant speed traveling.

Thus, according to this embodiment, the preceding vehicle B
When a vehicle speed change occurs in the vehicle, it is possible to prevent the vehicle speed change more than necessary from occurring in the own vehicle A, and it is possible to prevent the inter-vehicle distance D from being unnecessarily long.

[Brief description of drawings]

FIG. 1 is a block diagram showing a first embodiment of a vehicle travel control device according to the present invention.

FIG. 2 is an explanatory view showing the operation of the first embodiment.

FIG. 3 is a flowchart showing the operation of the first embodiment.

FIG. 4 is a graph showing the operation of the first embodiment.

FIG. 5 is a graph showing the operation of the first embodiment.

FIG. 6 is a graph showing the operation of the first embodiment.

FIG. 7 is a block diagram showing a second embodiment of the vehicle travel control device according to the present invention.

FIG. 8 is an explanatory view showing the operation of the second embodiment.

[Explanation of symbols]

12 auto cruise control circuit (vehicle speed control means, target vehicle distance setting means) 14 throttle control actuator 16 vehicle speed sensor (vehicle speed detecting means) 18 manual switch (target vehicle speed setting means) 20 radar device 22 obstacle detection circuit (vehicle distance detecting means) ) 24 motors

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Claims (2)

(57) [Claims] 1. An inter-vehicle distance detecting means for detecting an inter-vehicle distance between an own vehicle and a preceding vehicle, a vehicle speed detecting means for detecting a vehicle speed of the own vehicle, a target inter-vehicle distance setting means for setting a target inter-vehicle distance, and a target vehicle speed. And a vehicle speed control means for controlling the vehicle speed of the host vehicle based on the detected inter-vehicle distance and the vehicle speed of the host vehicle and the set target inter-vehicle distance and target vehicle speed. When the inter-vehicle distance is longer than a first value that is longer than the target inter-vehicle distance by a predetermined distance, the vehicle speed control means sets the vehicle speed of the host vehicle to the target vehicle speed. On the other hand, when the inter-vehicle distance is shorter than a second value which is shorter than the target inter-vehicle distance by a predetermined distance, the vehicle speed of the host vehicle is controlled so that the inter-vehicle distance approaches the target inter-vehicle distance. Up Following distance, the and equal to or less than a first value when it is the second value or more, the vehicle of the throttle valve
The vehicle travel control is characterized in that the opening is maintained constant, and the predetermined distance is set to a larger value as the vehicle speed fluctuation rate of the preceding vehicle increases. apparatus. 2. An inter-vehicle distance detecting means for detecting an inter-vehicle distance between the own vehicle and a preceding vehicle, a vehicle speed detecting means for detecting a vehicle speed of the own vehicle, a target inter-vehicle distance setting means for setting a target inter-vehicle distance, and a target vehicle speed. And a vehicle speed control means for controlling the vehicle speed of the host vehicle based on the detected inter-vehicle distance and the vehicle speed of the host vehicle and the set target inter-vehicle distance and target vehicle speed. When the inter-vehicle distance is longer than a first value that is longer than the target inter-vehicle distance by a predetermined distance, the vehicle speed control means sets the vehicle speed of the host vehicle to the target vehicle speed. On the other hand, when the inter-vehicle distance is shorter than a second value which is shorter than the target inter-vehicle distance by a predetermined distance, the vehicle speed of the host vehicle is controlled so that the inter-vehicle distance approaches the target inter-vehicle distance. Up Following distance, the and equal to or less than a first value when it is the second value or more, the vehicle of the throttle valve
It is configured to maintain a constant opening degree, and the predetermined distance is configured to be set to a larger value as the variation rate of the relative positional deviation in the left-right direction between the own vehicle and the preceding vehicle increases. A travel control device for a vehicle.