JP3194305B2 - Travel control device for vehicles - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cruise control device for a vehicle, and more particularly to a cruise control device which controls a throttle and follows a preceding vehicle only by controlling the driver's manual operation.

[0002]

2. Description of the Related Art Conventionally, various traveling control devices have been developed for the purpose of reducing the driving operation of a driver. A travel control device that detects the inter-vehicle distance to the preceding vehicle and controls the traveling state of the own vehicle so that the inter-vehicle distance is maintained constant to start, stop, and travel following the preceding vehicle is one of them. is there. In such a travel control device, for example, even when the road is congested with vehicles, the output torque of the engine and the brake control are automatically performed. This is freed from the above (for example, Japanese Utility Model Laid-Open No. 3-68126).

On the other hand, there has been proposed a simple automatic follow-up traveling device which does not control both the output torque of the engine and the brake but automatically controls only the throttle and makes the brake depend on the manual operation of the driver. .

[0004]

Here, in any of the following traveling apparatus that automatically controls only the throttle and the following traveling apparatus that controls both the throttle and the brake,
When the inter-vehicle distance with the preceding vehicle increases, the vehicle accelerates to follow the preceding vehicle.For example, when the vehicle stops at the head of an intersection due to a red light, or when stopping at the head of a railroad crossing,
Even if the preceding vehicle starts and the inter-vehicle distance to the preceding vehicle increases, it is often not appropriate to immediately accelerate the own vehicle. In the prior art (Japanese Utility Model Laid-Open No. 3-68126), a manual operation switch for prohibiting the start of the vehicle is provided in order to prepare for such a situation. Therefore, the purpose of the travel control device for reducing the driver's driving operation cannot be achieved.

On the other hand, in a simple follow-up traveling apparatus in which only the throttle is controlled and the brake is manually controlled, in addition to the above-described problems, the driver must constantly depress the brake pedal to maintain the stopped state. This imposes a burden on the driver.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems of the prior art, and has as its object to provide a traveling control device that controls only a throttle and follows a preceding vehicle to immediately accelerate and start following the preceding vehicle. It is an object of the present invention to provide a vehicular travel control device that can automatically determine a situation where it is not appropriate to perform the operation, and that can more safely and reduce the driver's operation.

[0007]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention relates to a vehicle travel control device which controls the speed of an own vehicle based on an inter-vehicle distance to a preceding vehicle and follows the preceding vehicle. A vehicle speed detecting means for detecting the own vehicle speed, an inter-vehicle distance detecting means for detecting an inter-vehicle distance to a preceding vehicle, a relative speed detecting means for detecting a relative speed to a preceding vehicle, an accelerator pedal operation and a brake pedal by a driver Pedal operation detecting means for detecting the presence / absence of operation; and brake holding means for holding the brake operating state even when the driver stops the brake pedal operation when the driver performs the brake pedal operation and the vehicle speed is zero. brake holding by said brake holding means when the accelerator pedal operation by the driver has Tsu Oh <br/>
Is canceled and the distance between the vehicle and the preceding vehicle is
If the relative speed of the
Even if there is no brake
Key is released and the distance between the vehicle and the preceding vehicle exceeds the specified value.
If there is no operation of the accelerator pedal,
Release means for maintaining the brake holding by the brake holding means .

[0008]

As described above, if the vehicle stops at the head of the intersection at the red light or stops at the head of the railroad crossing, the vehicle immediately follows the preceding vehicle even if the preceding vehicle starts moving. It is not appropriate to launch. Such a situation
It is characterized in that the vehicle speed is zero and the inter-vehicle distance to the preceding vehicle is larger than the normal stopping distance. Therefore, such a situation can be determined from the vehicle speed and the inter-vehicle distance.

Therefore, in the present invention, the brake operation state is held by the brake holding means when the brake pedal is operated and the vehicle speed is zero, and when the inter-vehicle distance to the preceding vehicle is equal to or more than a predetermined value, When the inter-vehicle distance with the preceding vehicle increases, that is, when the relative speed becomes positive, the brake holding state is not released, and when the inter-vehicle distance with the preceding vehicle is equal to or less than a predetermined value and the relative speed with the preceding vehicle is positive. Only the brake holding state is released.

[0010] Thus, in the above situation, the brake holding state is maintained, and the start can be started at a desired time by the driver's operation of the accelerator pedal.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of a vehicle travel control device according to the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing the configuration of this embodiment. A vehicle speed sensor 10 and an inter-vehicle distance sensor 12 are provided at predetermined positions of the vehicle, respectively, and detect the own vehicle speed and the inter-vehicle distance and supply the detected vehicle speed and inter-vehicle distance to an electronic control unit ECU 14 for following and running. As the inter-vehicle distance sensor 12, for example, a laser radar device or a millimeter-wave radar device is used. A brake pedal switch 16 for detecting the presence or absence of a brake pedal operation by the driver and an accelerator pedal switch 18 for detecting the presence or absence of an accelerator pedal operation are provided, and supply detection signals to the ECU 14. Follow-up ECU 14
Calculates a target inter-vehicle distance based on the vehicle speed data supplied from the vehicle speed sensor 10, and calculates a relative speed based on the inter-vehicle distance data supplied from the inter-vehicle distance sensor 12. Then, inter-vehicle distance L, the calculated target inter-vehicle distance L _d, and based on the relative velocity V _r, the target driving force F F = M {k
Is calculated by _{1 (L-L d) +} k 2 V r}. Note that M
Is the mass of the vehicle, and k ₁ and k ₂ are control gains. The calculated target driving force F is supplied to the driving force control means 20 to perform throttle control, and the vehicle speed is controlled so that the inter-vehicle distance to the preceding vehicle becomes the target inter-vehicle distance.

On the other hand, when the driver operates the brake pedal during the follow-up running control, the brake pedal switch 16 detects this brake pedal operation and sends a detection signal to the ECU 1.
4 When the driver decelerates the vehicle by operating the brake pedal, and eventually becomes zero, the vehicle speed sensor 10 supplies a vehicle speed zero signal to the ECU 14. At this time, the ECU 14 supplies a control signal to the brake oil pressure holding means 22 based on the detection signal from the brake pedal switch 16 and the vehicle speed zero signal from the vehicle speed sensor 10, and controls the brake oil pressure regardless of whether the driver operates the brake pedal. And keep the oil pressure at zero vehicle speed. Thus, even if the driver stops operating the brake pedal while the host vehicle is stopped, it is possible to automatically prohibit starting such as creep operation in an automatic vehicle.

In the conventional follow-up cruise control device, when the preceding vehicle and the own vehicle both stop and the preceding vehicle starts and the inter-vehicle distance with the preceding vehicle increases, the ECU 14 controls the driving force control means 20. A signal is supplied to control the throttle so that the target driving force can be obtained, and the vehicle starts following the preceding vehicle. However, when the vehicle stops at the head of an intersection or a railroad crossing as described above, the vehicle immediately starts following the vehicle. That is not appropriate.

Therefore, the ECU 14 in the present embodiment comprises:
Such a stop state is automatically determined based on the vehicle speed signal from the vehicle speed sensor 10 and the inter-vehicle distance signal from the inter-vehicle distance sensor, and when it is determined that the above state is established, the brake operation state by the brake hydraulic pressure holding means 22 is determined. This is to maintain and stop the vehicle. The features common to the above situations are that the inter-vehicle distance between the preceding vehicle and the own vehicle is large, and that the relative speed to the preceding vehicle becomes positive with the start of the preceding vehicle. Therefore, the ECU 14 determines whether or not the above situation exists based on the vehicle speed signal from the vehicle speed sensor 10 and the relative speed data obtained by differentiating the following distance data from the following distance sensor 12. And if the relative speed is positive, the brake hydraulic pressure holding means 22
Is set to the operation continuation state, and the start of the own vehicle is prohibited. On the other hand, when the above situation is not the case, that is, when the inter-vehicle distance to the preceding vehicle is equal to or less than a predetermined value and the inter-vehicle distance to the preceding vehicle increases, that is, when the relative speed becomes positive, the normal preceding vehicle following start is performed. The ECU 14 is configured to supply a control signal to the brake hydraulic pressure holding means 22 to release the brake holding state and permit the vehicle to start.

Hereinafter, EC will be described with reference to the flowchart of FIG.
The operation of U14 will be described in more detail.

First, it is determined whether a brake operation detection signal is supplied from the brake pedal switch 16 (S101). When the driver has not operated the brake pedal, it is further determined whether or not the brake is being held by the brake oil pressure holding means 22 (S105). When the brake pedal is not operated and the brake hydraulic pressure holding means 22 is not operated, the target driving force F is changed to F = M ｛k ₁ (L−L _d ) + k _{2 in} order to perform the normal following travel.
_Vr } (S110), and the driving force control means 2
Supply 0. The driving force control means 20 calculates the throttle opening θ for realizing the target driving force F from a map based on the vehicle speed and the gear position, and performs throttle control (S11).
1, S112).

When the driver operates the brake pedal while following the preceding vehicle, the operation is detected by the brake pedal switch 16. At this time, the ECU 14 determines whether the vehicle speed is zero (S102). If the vehicle speed is not zero, the ECU 14 determines that the vehicle is decelerating, sets the throttle opening θ to zero, and performs throttle control (S104, S112). As a result, deceleration according to the driver's operation amount of the brake pedal is performed. When the deceleration is completed and the vehicle stops, the brake switch is ON and the vehicle speed becomes zero. Therefore, the ECU 14 supplies a control signal to the brake hydraulic pressure holding means 22 to start holding the brake (S10).
3). At this time, the throttle opening θ remains set to zero (S104).

When the preceding vehicle starts running from the situation where both the preceding vehicle and the own vehicle are stopped, the driver stops the operation of the brake pedal. The ECU 14 next determines whether or not the brake is being held, and if the brake is being held by the hydraulic pressure holding means 22, further determines whether or not the accelerator pedal is operated based on a signal from the accelerator pedal switch 18 ( S106). When the accelerator pedal is operated, it indicates that the driver intends to start.
2 is released (S109), and starting is started with the target driving force F (S110, S111). on the other hand,
When the brake is being held and the driver has not operated the accelerator pedal, the ECU 14 determines whether or not the inter-vehicle distance to the preceding vehicle detected by the inter-vehicle distance sensor 12 is a predetermined position, that is, 10 m or less. Judgment (S10
7). This determination is a process for determining whether or not the own vehicle is stopped at the intersection or at the head of a railroad crossing, and the inter-vehicle distance from the preceding vehicle is large. If the inter-vehicle distance is 10 m or more, it is determined that it is not appropriate to start immediately following the preceding vehicle, and the brake holding state is continued, and the throttle opening θ is set to zero (S104, S112). .
On the other hand, if the inter-vehicle distance is 10 m or less, and the preceding vehicle starts and the relative speed becomes positive, it is determined that the preceding vehicle has started from the normal stop state and the normal following travel is performed. The brake holding by the brake hydraulic pressure holding means 22 is released (S109), and the vehicle starts with the target driving force (S11).
0, S111).

As described above, in this embodiment, when the driver stops the brake pedal operation by operating the brake pedal, the brake operation state is maintained even if the driver stops operating the brake pedal. Holds the stopped state, and if the inter-vehicle distance to the preceding vehicle is equal to or greater than the predetermined value and corresponds to the first stop at an intersection or railroad crossing, the brake holding state is maintained without immediately following the start even if the preceding vehicle starts By doing so, safer following, starting, and stopping can be performed. In this embodiment, in order to shift from the brake holding operation state to the start state, the driver only has to operate the accelerator pedal, and since the driver is not forced to perform an operation different from the normal driving operation, the vehicle can smoothly follow the vehicle. Can continue.

[0021]

As described above, according to the vehicle travel control device of the present invention, even if the vehicle stops at the intersection or at the head of a railroad crossing while following the preceding vehicle, the situation described above is avoided. Automatically discriminates and follows the start of the preceding vehicle, and does not start immediately, but starts at an appropriate time according to the start request by the driver's accelerator pedal, so that safer following can be performed. Become.

[Brief description of the drawings]

FIG. 1 is a configuration block diagram of an embodiment of the present invention.

FIG. 2 is an operation flowchart of an ECU of the embodiment.

[Explanation of symbols]

 Reference Signs List 10 vehicle speed sensor 12 inter-vehicle distance sensor 14 ECU 16 brake pedal switch 18 accelerator pedal switch 20 driving force holding means 22 brake oil pressure control means

Continuation of the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) B60T 7/12 B60K 28/10 B60K 31/00 B60K 41/20 F02D 29/02 301

Claims (1)

(57) [Claims] 1. A vehicle travel control device for controlling a vehicle speed of a host vehicle based on a distance between the host vehicle and a preceding vehicle and following the host vehicle, comprising: vehicle speed detecting means for detecting the host vehicle speed; Inter-vehicle distance detecting means for detecting a distance, relative speed detecting means for detecting a relative speed with respect to a preceding vehicle, pedal operation detecting means for detecting presence or absence of an accelerator pedal operation and a brake pedal operation by a driver, and braking by a driver There is a pedal operation, and a brake holding means for holding a braking state even driver when the vehicle speed is zero to stop the brake pedal operation, the blanking when the Tsu accelerator pedal operation there by the driver
Release the brake holding by the rake holding means, and
Is less than a predetermined value and the relative speed with the preceding vehicle is positive.
When the accelerator pedal is not operated
Release the brake holding by the brake holding means, and
If the distance between the two vehicles exceeds the specified value, access
If there is no pedal operation, the brake holding means
A vehicle travel control device, comprising: release means for maintaining brake holding .