JP3280283B2 - 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 control for causing a host vehicle to follow a preceding vehicle at a predetermined inter-vehicle distance, and to control the actual vehicle speed of the host vehicle so as not to exceed a preset set vehicle speed. The invention relates to an inter-vehicle distance control device.

[0002]

2. Description of the Related Art There has been known an inter-vehicle distance control apparatus for automatically driving a self-vehicle for the purpose of reducing the driving operation of a driver and improving safety when driving on a highway or the like. One of them is to perform vehicle speed feedback control.

In the vehicle speed feedback control, when a preceding vehicle exists in front of the own vehicle, the inter-vehicle distance between the preceding vehicle and the own vehicle becomes a predetermined inter-vehicle distance determined by the vehicle speed (in other words, The target vehicle speed is set so that the inter-vehicle time obtained by dividing the inter-vehicle distance by the vehicle speed is the set inter-vehicle time set by the driver or the like. If there is no preceding vehicle, the target vehicle speed is set in advance by the driver or the like. Set the set vehicle speed. Then, the driving force from a vehicle driving source such as an internal combustion engine is controlled so that the actual vehicle speed becomes the set target vehicle speed.

Here, an example of the operation of the inter-vehicle distance control device for realizing the vehicle speed feedback control by the throttle control of the internal combustion engine will be described with reference to a time chart shown in FIG. First, for example, when the actual vehicle speed V is controlled to the target vehicle speed Vt and the vehicle speed of the preceding vehicle accelerates at time t11, the target vehicle speed Vt also starts increasing so that the own vehicle follows the preceding vehicle. In the vehicle speed feedback control, control is started after a deviation occurs between the target vehicle speed Vt and the actual vehicle speed V. Therefore, after a deviation occurs between the actual vehicle speed V and the target vehicle speed Vt as the target vehicle speed Vt increases, the throttle valve is opened. Opening and causing a response delay before accelerating the vehicle. Therefore, when the target vehicle speed Vt starts increasing at the time point t11, the throttle valve is opened according to the vehicle speed deviation at the time point t12 when a predetermined response delay time has elapsed.

Then, since the vehicle enters an acceleration state, the actual vehicle speed V gradually approaches the target vehicle speed Vt after time t12.
Thereafter, even if the actual vehicle speed V reaches the target vehicle speed Vt at time t13, the actual vehicle speed V exceeds the target vehicle speed Vt because the vehicle remains in the accelerated state. Then, at time t14 when the excess vehicle speed deviation has increased to some extent, the throttle valve is driven in the closing direction. As a result, the actual vehicle speed V gradually approaches the target vehicle speed Vt.

At time t15, for example, if the target vehicle speed Vt changes from an increasing state to a constant state and the actual vehicle speed V reaches the target vehicle speed Vt at that time, the actual vehicle speed V temporarily exceeds the target vehicle speed Vt. The actual vehicle speed V converges quickly to the target vehicle speed Vt, and at time t16 when the vehicle speed deviation disappears, the throttle valve is opened at a substantially constant value. It is kept every time.

As described above, in the vehicle speed feedback control, the throttle opening is controlled so as to eliminate the vehicle speed deviation. Therefore, when the target vehicle speed is relatively stable, such as when the vehicle is traveling at a constant speed, the vehicle speed is reduced. The target vehicle speed can be maintained, but when the target vehicle speed changes greatly or when the difference between the target vehicle speed and the actual vehicle speed is large, such as when the preceding vehicle accelerates or decelerates or when the preceding vehicle interrupts, the control responds. A delay occurs, and after the start, the driving force of the vehicle is increased in accordance with the vehicle speed deviation, so that the vehicle is accelerated (or decelerated) more than necessary and it takes time to converge the actual vehicle speed to the target vehicle speed. There is. That is, in the vehicle speed feedback control, although stability of the control can be ensured, there is a problem in response and convergence.

On the other hand, as a means for solving such a problem, there is an inter-vehicle distance control device which performs acceleration feedback control. In the acceleration feedback control, when there is a preceding vehicle, a target acceleration is set so that the inter-vehicle time becomes the set inter-vehicle time, and when there is no preceding vehicle, a preset acceleration set as a target acceleration is set. I do. Then, the driving force of the vehicle is controlled so that the actual acceleration becomes the set target acceleration.

An example of the operation of the inter-vehicle distance control device for realizing such acceleration feedback control by the throttle control of the internal combustion engine will be described with reference to a time chart shown in FIG. In the time chart of FIG. 5B, in order to make it easier to understand the difference from the vehicle speed feedback control shown in FIG. 5A, the time chart corresponds to the actual acceleration ΔV and the target acceleration Dt used in the acceleration feedback control. And the actual vehicle speed V used in the vehicle speed feedback control.
And the target vehicle speed Vt.

As shown in the figure, for example, when the actual acceleration ΔV is controlled to the target acceleration Dt (zero), the time t
When the vehicle speed of the preceding vehicle increases at 21 (corresponding to the time point t11 in FIG. 5A), the target acceleration Dt suddenly changes from zero to a positive predetermined value so that the own vehicle follows the preceding vehicle. That is, in the acceleration feedback control, the target acceleration Dt
The throttle valve is opened so that the deviation between the target vehicle speed and the actual acceleration ΔV disappears. However, unlike the target vehicle speed Vt, the target acceleration Dt does not gradually increase but rises instantaneously from zero. Therefore, after the time point t21, the acceleration deviation sharply increases, and the throttle valve greatly changes according to the deviation. Therefore, the actual vehicle speed V can quickly follow the target vehicle speed Vt corresponding to the target acceleration Dt.

On the other hand, at time t22 (corresponding to time t15 in FIG. 5 (a)), the actual acceleration ΔV reaches the target acceleration Dt, and the own vehicle speed V also changes to the target vehicle speed V corresponding to the target acceleration Dt.
If it has reached t, the target acceleration Dt changes to zero.
However, at this time, the vehicle is accelerating, and the actual acceleration △
Since V remains positive, the actual acceleration ΔV and the target acceleration D
and the throttle valve is driven in the closing direction in accordance with the deviation, and the throttle valve is thereafter maintained at the opening at the time when the actual acceleration ΔV reaches the target acceleration Dt.

As described above, in the acceleration feedback control, the throttle opening is controlled so as to eliminate the acceleration deviation. Therefore, even when the target vehicle speed Vt greatly changes, the own vehicle speed V is reduced to the target vehicle speed Vt. It can be made to follow immediately. Therefore, the acceleration feedback control is suitable for control when the target vehicle speed changes greatly, such as when the preceding vehicle accelerates or decelerates or when the preceding vehicle interrupts.

However, as shown in FIG. 5 (b), when the actual vehicle speed V reaches the target vehicle speed Vt, the target acceleration Dt becomes zero. Depending on the undershoot state). Therefore, when the vehicle is driven at a constant speed at the set vehicle speed, for example, when there is no preceding vehicle, the actual vehicle speed V does not match the set vehicle speed, and the driver may feel uncomfortable.

Therefore, the present invention provides an inter-vehicle distance control device that can prevent a deviation between a set vehicle speed and an actual vehicle speed during traveling at a constant speed or the like while ensuring responsiveness to the behavior of a preceding vehicle. The purpose is to do.

[0015]

Means for Solving the Problems and Effects of the Invention In order to achieve the above object, in the following distance control apparatus according to the present invention, the vehicle speed control means determines the actual vehicle speed by the driver in advance. When the driving force is controlled to achieve the set vehicle speed (that is, during the execution of the vehicle speed feedback control), the actual vehicle speed becomes smaller than a control switching determination value obtained by subtracting a predetermined value from the set vehicle speed, or When the acceleration becomes a negative acceleration for decelerating the own vehicle, the vehicle speed feedback control by the vehicle speed control means is stopped, and instead, the acceleration feedback control by the acceleration control means is started.

Therefore, during the vehicle speed feedback control, when the deviation between the actual vehicle speed and the set vehicle speed becomes large, such as when the driver resets the set vehicle speed, or when the preceding vehicle is interrupted, the target acceleration becomes negative. For example, when the acceleration becomes the following, the inter-vehicle distance control is switched from the vehicle speed feedback control to the highly responsive acceleration feedback control.

Further, when the acceleration control means is executing acceleration feedback control for controlling the driving force so that the actual acceleration becomes the target acceleration, the target acceleration is a positive acceleration which should increase the speed of the vehicle. When the actual vehicle speed becomes equal to or higher than the set vehicle speed, the acceleration feedback control by the acceleration control means is stopped, and instead, the vehicle speed feedback control by the vehicle speed control means is started.

Therefore, for example, when the actual vehicle speed exceeds the target vehicle speed while accelerating the own vehicle by the acceleration feedback control so that the own vehicle follows the preceding vehicle, the following distance control is performed. The acceleration feedback control is switched to the vehicle speed feedback control capable of converging the vehicle speed to the target vehicle speed.

As a result, according to the inter-vehicle distance control device, when the deviation between the actual vehicle speed and the set vehicle speed is small, the actual vehicle speed can be controlled to the set vehicle speed by the vehicle speed feedback control. Conversely, when the deviation between the actual vehicle speed and the set vehicle speed is large and it is necessary to greatly accelerate or decelerate the own vehicle, acceleration feedback control is executed to ensure high responsiveness, Can be improved.

Further, the vehicle speed control means performs the vehicle speed feedback control so that the actual vehicle speed becomes the set vehicle speed. As set forth in claim 2, a differential between the actual vehicle speed detected by the vehicle speed detection means and the actual vehicle speed is provided. The vehicle speed control means may be provided with differential compensation vehicle speed calculation means for calculating a differential compensation vehicle speed representing a vehicle speed a predetermined time ahead from the value, and the vehicle speed control means may perform vehicle speed feedback control such that the differential compensation vehicle speed becomes the set vehicle speed.

According to this configuration, the differential compensation vehicle speed, which is the vehicle speed predicted after a predetermined time after the actual vehicle speed, is used instead of the actual vehicle speed, so that the delay generated when controlling the driving force can be reduced. Since the control can be performed in anticipation, the responsiveness of the vehicle speed feedback control can be improved.

Similarly, as set forth in claim 3, the control selection means calculates the control switching by the vehicle speed control means and the acceleration control means by the differential compensation vehicle speed calculation means instead of the actual vehicle speed. If the differential compensation vehicle speed is used, the responsiveness of the vehicle speed feedback control can be improved.

[0023]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below. FIG. 1 shows a schematic configuration of an inter-vehicle distance control device 1 of the present embodiment. The inter-vehicle distance control device 1 includes a CPU that performs various arithmetic controls for the inter-vehicle distance control, and an RO that stores programs and various maps for performing the arithmetic operations.
M, a well-known microcomputer (hereinafter, referred to as a computer) 11 mainly including a RAM for temporarily storing information necessary for the arithmetic operation, an input interface for receiving input information, an output interface for outputting control information, and the like. I have.

An input interface of the computer 11 includes an inter-vehicle distance sensor 13 for irradiating a laser beam forward to measure a distance between the vehicle and a vehicle traveling ahead.
A vehicle speed sensor 15 which is set in relation to the wheels of the vehicle and detects a signal corresponding to the rotation speed of the wheels; and a steering operation amount by the driver, that is, a steering which detects how much left or right the steering is operated. An input switch 17 for switching between the operation of the steering angle sensor 16 and the operation / stop of the inter-vehicle distance control device 1 and inputting the inter-vehicle time with the preceding vehicle and a set vehicle speed which is a predetermined vehicle speed when there is no preceding vehicle. And are connected.

On the other hand, a throttle valve actuator (actuator) 19 for driving a throttle mechanism for controlling the rotation speed of the engine is connected to an output interface of the computer 11. Then, the computer 11 executes the following distance control by turning on the input switch 17 for performing the following distance control.

Hereinafter, the inter-vehicle distance control will be described with reference to the flowchart (main routine) of FIG. First, in step (hereinafter referred to as s) 10, the presence or absence of a preceding vehicle is determined using the following distance sensor 13. If a preceding vehicle is present, a preceding vehicle recognition state is set, and a known preceding vehicle determination process is performed using the inter-vehicle distance of the preceding vehicle and the steering amount from the steering angle sensor 16. Identify the preceding vehicle as a control reference. If there is no preceding vehicle, an unrecognized state is set.

In the next s20, a calculation for calculating the target acceleration is performed. Specifically, in the case of the preceding vehicle recognition state,
The relative speed between the own vehicle and the preceding vehicle is calculated from the time change of the inter-vehicle distance, and the actual vehicle speed V (or the actual vehicle speed V) of the own vehicle is calculated.
The vehicle speed is calculated as a difference between the target vehicle distance and the actual vehicle distance corresponding to the preceding vehicle speed obtained by adding the relative speed to the vehicle speed, and the target acceleration Dt is obtained from the map recorded in the ROM using the relative speed and the vehicle distance deviation. Is calculated. In the unrecognized state, a predetermined set acceleration is used as the target acceleration Dt.

In the next step s40, a control selection routine for selecting whether to perform control of the actuator 19 by acceleration feedback control or vehicle speed feedback control is executed. A detailed description of the control selection routine will be described later. Then, by executing the control selection routine, a flag (selection flag) indicating the selected control is set. In the present embodiment, the selection flag is set to High for acceleration feedback control, and is set to Low for vehicle speed feedback.

In the next s50, the current selection flag is set to High.
Is determined. If the selection flag is high, s60 is executed to perform acceleration feedback control. If the selection flag is low instead of high, s70 is executed to perform vehicle speed feedback control.

At s60, which is executed when it is determined that the selection flag is High, the target throttle opening is calculated by the acceleration feedback control. Specifically, as shown in the following equation (1), a value obtained by multiplying a value obtained by differentiating the actual vehicle speed V from the actual acceleration ΔV from the target acceleration Dt by a predetermined control gain G1 and multiplying the value is obtained. The target throttle opening An-1 used in the current control is calculated by adding the previously obtained target throttle opening An-1 to the obtained value.

Current target throttle opening An = previous target throttle opening An−1 + control gain G1 · (target acceleration Dt−actual acceleration ΔV) (1) After calculating the target throttle opening An in this way,
Execute s80.

At s70, which is executed when the selection flag is determined to be Low, the target throttle opening is calculated by the vehicle speed feedback control. Specifically, as shown in the following equation (2), a value obtained by subtracting the differential compensation vehicle speed Vsk from the set vehicle speed VM input from the input switch 17 by the driver is multiplied by a predetermined control gain G2 and multiplied. The target throttle opening An-1 obtained last time is calculated based on the obtained value.
Is added to the target throttle opening An used for the current control.
Is calculated.

This time target throttle opening An = previous target throttle opening An−1 + control gain G2 · (set vehicle speed VM−differential compensation vehicle speed Vsk) (2) Here, the differential compensation vehicle speed Vsk is expressed by the following equation. As shown in (3), differential compensation is applied to the actual vehicle speed V in order to eliminate the control delay. That is, it indicates the estimated vehicle speed of the actual vehicle speed V after the predetermined time T.

Differential compensation vehicle speed Vsk = actual vehicle speed V + differential element (actual acceleration) ΔV · predetermined time T (3) After calculating the target throttle opening An in this way,
Execute s80. In the next s80, s60 or s7
The actuator 19 is controlled based on the target throttle opening An obtained at 0.

In the next s90, it is determined whether or not the input switch 17 is ON to perform the following distance control, thereby determining whether or not to continue the main routine control. If the input switch 17 is ON, s again
The process proceeds to step 10, and if the input switch 17 is OFF, the main routine ends.

Next, the control selection routine shown in the flowchart of FIG. 3 will be described. First, in s110, it is determined whether or not the acceleration feedback control is being performed based on the state of the selection flag stored in the RAM. If the state of the selection flag is High, since the acceleration feedback control is being executed, the flow shifts to s150 described later. If the state of the selection flag is low, the acceleration feedback control is not being executed (that is, the vehicle speed feedback control is being executed), and s120 is processed.

In the next s120, it is determined whether or not the target acceleration Dt is less than zero. If less than zero, s
Process 140, and if not less than zero, process s130. In next s130, it is determined whether or not the differential compensation vehicle speed Vsk is smaller than a control switching determination value obtained by subtracting a predetermined value (3 km / h in this embodiment) from the set vehicle speed VM. If it is smaller than the control switching determination value, s140 is processed, and if it is not smaller than the control switching determination value, this routine ends.

In the next s140, since the judgment condition of s120 or s130 is affirmed during the execution of the vehicle speed feedback control, the state of the selection flag is changed from the low state for executing the vehicle speed feedback control to the high state for executing the acceleration feedback control. Switch to

In step s150, where it is determined in step s110 that the acceleration feedback control is being executed, and in step s150, it is determined whether the differential compensation vehicle speed Vsk is equal to or higher than the set vehicle speed VM. If the set vehicle speed is not higher than VM,
This routine ends. If it is equal to or higher than the set vehicle speed VM, it is determined in s160 whether the target acceleration Dt is equal to or higher than zero. If it is not zero or more, this control selection routine is ended, and if it is zero or more, s1
Process 70.

In the next step s170, the judgment conditions of s150 and s160 are both affirmed during the execution of the acceleration feedback control. Therefore, the state of the selection flag is changed from the high state in which the acceleration feedback control is executed to the low state in which the vehicle speed feedback control is executed. Switch to state. Thereafter, the control selection routine ends.

Next, the control selection routine described above
The process of selecting the acceleration feedback control or the vehicle speed feedback control will be described using an example shown in FIG. In the present embodiment, when starting the automatic traveling by the following distance control device 1, the vehicle speed feedback control is started as an initial state. Note that the initial state may be acceleration feedback control instead of vehicle speed feedback control. Because, in either control state,
This is because the optimal control state at that time is selected by the control selection routine described above. Further, the control start time t0 is set, and the own vehicle is set at a predetermined set vehicle speed VM.
It is assumed that the target acceleration Dt is smaller than the control switching determination value obtained by subtracting 3 km / h, which is a predetermined value from, and the target acceleration Dt is positive.

First, at the start of the control as described above, the vehicle speed feedback control is performed.
Since k is smaller than the control switching determination value obtained by subtracting 3 km / h from the set vehicle speed VM, the above condition of s130 is satisfied. Therefore, at the time point t1, the acceleration feedback control is executed, so that high responsiveness is ensured.

Next, by the acceleration feedback control, the differential compensation vehicle speed Vsk reaches the set vehicle speed VM and the target acceleration Dt is a positive value.
The conditions of 50 and s160 are both satisfied. Accordingly, at time t2, the vehicle speed feedback control is executed.
By this vehicle speed feedback control, the differential compensation vehicle speed Vs
k eliminates a vehicle speed deviation from the set vehicle speed VM.

Next, it is assumed that a preceding vehicle is interrupted in front of the vehicle or that the preceding vehicle decelerates and approaches. Then, in s20 described above, it is determined that the vehicle is in the preceding vehicle detection state, and the target acceleration Dt is set to a negative acceleration. Therefore, the condition in s120 described above is satisfied. Therefore,
At time t3, the acceleration feedback control is performed. With this acceleration feedback control, the inter-vehicle distance can be quickly maintained even if the inter-vehicle distance between the host vehicle and the preceding vehicle decreases due to interruption or deceleration of the preceding vehicle.

After that, the set vehicle speed VM is reset, or the differential compensation vehicle speed Vsk is changed to the set vehicle speed Vsk.
When the speed becomes equal to or less than the control switching determination value obtained by subtracting 3 km / h from M, the same condition as at time t1 is established, and the differential compensation vehicle speed Vsk quickly approaches the set vehicle speed VM by the acceleration feedback control. The vehicle speed deviation can be eliminated by the control.

According to the inter-vehicle distance control device 1 of the present embodiment described above, during execution of the vehicle speed feedback control, the differential compensation vehicle speed Vsk is changed from the set vehicle speed VM to a predetermined value (3 k / h).
When the control switching determination value obtained by subtracting m) becomes smaller, or when the target acceleration Dt becomes a negative acceleration for decelerating the host vehicle, the vehicle speed feedback control is stopped, and instead, the acceleration feedback control is started.

Therefore, when the deviation between the differential compensation vehicle speed Vsk and the set vehicle speed VM becomes large during the vehicle speed feedback control, or when the target acceleration Dt becomes a negative acceleration due to interruption of the preceding vehicle, etc. Therefore, the vehicle speed feedback control is switched to the acceleration feedback control with high responsiveness.

Also, when executing the acceleration feedback control for controlling the driving force so that the actual acceleration ΔV becomes the target acceleration Dt, the target acceleration Dt is a positive acceleration for increasing the speed of the own vehicle, and When the differential compensation vehicle speed Vsk becomes equal to or higher than the set vehicle speed VM, the acceleration feedback control is stopped, and instead, the vehicle speed feedback control is started.

Therefore, for example, if the differential compensation vehicle speed Vsk exceeds the set vehicle speed VM while accelerating the own vehicle by the acceleration feedback control so that the own vehicle follows the preceding vehicle, the acceleration feedback is performed. The control is switched from the control to the vehicle speed feedback control capable of converging the differential compensation vehicle speed Vsk to the set vehicle speed VM.

As a result, according to the following distance control device 1,
When the difference between the differential compensation vehicle speed Vsk and the set vehicle speed VM is small, the differential compensation vehicle speed Vsk can be controlled to the set vehicle speed VM by the vehicle speed feedback control. Conversely, the differential compensation vehicle speed Vsk and the set vehicle speed VM can be controlled. VM
If the deviation from is large and it is necessary to greatly accelerate or decelerate the own vehicle, execute acceleration feedback control,
By ensuring high responsiveness, safety can be improved.

To summarize the correspondence between the above embodiment and the claims, the following distance sensor 13 is used as the following distance detecting means, the vehicle speed sensor 15 is used as the vehicle speed detecting means, and s2 of the main routine is used.
0 is sent to the target acceleration setting means by s of the main routine.
The processing in S60 is performed by the acceleration detecting means in s6 of the main routine.
The processing of 0 and s80 is performed by the acceleration control means, the processing of s70 and s80 of the main routine is performed by the vehicle speed control means, the processing of the control selection routine is performed by the control selection means, the processing of s70 of the main routine is performed by the differential compensation vehicle speed calculation means, Each corresponds.

Although one embodiment of the present invention has been described above, the present invention is not limited to the above-described embodiment, and it goes without saying that the present invention may be implemented in various other embodiments. In the present embodiment, the predetermined value is predetermined as 3 km / h, but this may not be particularly 3 km / h, and there may be a slight difference in some cases.

Further, in this embodiment, the vehicle speed deviation is calculated from the set vehicle speed VM and the differential compensation vehicle speed Vsk. However, the present invention can be configured using the actual vehicle speed V without using the differential compensation vehicle speed Vsk. It is possible. Further, in the present embodiment, the set vehicle speed VM is set by the input switch 17, but it may be configured to be set in conjunction with other settings of the input switch 17.

[Brief description of the drawings]

FIG. 1 is a configuration diagram schematically illustrating a configuration of an inter-vehicle distance control device 1 according to an embodiment.

FIG. 2 is a flowchart illustrating a main routine of inter-vehicle distance control processed by a microcomputer 11 of the inter-vehicle distance control device 1 according to the embodiment.

FIG. 3 is a flowchart illustrating a control selection routine processed by a microcomputer 11 of the following distance control apparatus 1 according to the embodiment.

FIG. 4 is a time chart of an inter-vehicle distance control performed by the inter-vehicle distance control device 1 according to the embodiment.

FIG. 5 is an explanatory diagram for explaining a problem in a vehicle speed feedback control and an acceleration feedback control of a conventional example.

[Explanation of symbols]

1. Inter-vehicle distance control device 11. Microcomputer
13: Inter-vehicle distance sensor 15: Vehicle speed sensor 16: Steering steering angle sensor
17 Input switch 19 Throttle valve actuator

──────────────────────────────────────────────────の Continued on the front page (72) Inventor Eiji Teramura 1-1-1, Showa-cho, Kariya-shi, Aichi Pref. (72) Inventor Hironori Miyakoshi 1 Toyota Town, Toyota City, Aichi Prefecture Inside Toyota Motor Corporation (72) Inventor Nobuyuki Furui 1 Toyota Town, Toyota City, Aichi Prefecture Inside Toyota Motor Corporation (72) Inventor Tsuneo Miyakoshi 1 Toyota Town, Toyota City, Aichi Prefecture Inside Toyota Motor Corporation (56) References JP-A-9-169225 (JP, A) JP-A-7-76236 (JP, A) JP-A-4-278835 (JP, A) JP-A-1-309830 (JP, A) JP-A-62-168730 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) B60K 31/00 F02D 29/02 301

Claims (3)

(57) [Claims] 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 an actual vehicle speed of the own vehicle; an acceleration detecting means for detecting an actual acceleration of the own vehicle; When the target acceleration required to cause the own vehicle to follow the preceding vehicle at the predetermined inter-vehicle distance based on the inter-vehicle distance and the actual vehicle speed is set, and the inter-vehicle distance is not detected by the inter-vehicle distance detection means, and there is no preceding vehicle. A target acceleration setting means for setting a preset acceleration as a target acceleration; and a host vehicle such that the actual acceleration detected by the acceleration detection means becomes the target acceleration set by the target acceleration setting means. Acceleration control means for controlling the driving force of the vehicle, and vehicle speed control means for controlling the driving force of the host vehicle such that the actual vehicle speed detected by the vehicle speed detection means becomes a preset set vehicle speed. When the vehicle speed control means is executing the control, the actual vehicle speed is smaller than a control switching determination value obtained by subtracting a predetermined value from the set vehicle speed, or the target acceleration decelerates the own vehicle. When the negative acceleration to be caused is reached, the control by the vehicle speed control means is stopped, and
The control by the acceleration control means is started, and when the acceleration control means is executing the control, the target acceleration is a positive acceleration to accelerate the own vehicle, and
When the actual vehicle speed is equal to or higher than the set vehicle speed, control selection means for stopping control by the acceleration control means and starting control by the vehicle speed control means; Control device. 2. The vehicle speed control device according to claim 1, further comprising: a differential compensation vehicle speed calculation unit that calculates a differential compensation vehicle speed representing a vehicle speed a predetermined time ahead from the actual vehicle speed detected by the vehicle speed detection unit and a differential value of the actual vehicle speed. The inter-vehicle distance control device according to claim 1, wherein the means controls the driving force of the own vehicle such that the differential compensation vehicle speed becomes the set vehicle speed. 3. The control selection means uses the differential compensation vehicle speed calculated by the differential compensation vehicle speed calculation means in place of the actual vehicle speed in the control switching determination by the vehicle speed control means and the acceleration control means. The inter-vehicle distance control device according to claim 2, wherein: