JP6739871B2 - Vehicle control device - Google Patents

Description

The present invention relates to a control device that controls a vehicle.

A recent vehicle is equipped with a collision avoidance assistance system that warns a driver when the presence of an approaching preceding vehicle is detected or automatically executes braking by a brake device. Basically, the vehicle-to-vehicle distance and the relative speed between the vehicle and the preceding vehicle are calculated at any time, and based on these, the presence or absence of a collision is determined, and if there is a possibility of a collision, warning or automatic braking is performed. Execute.

The braking distance of the vehicle changes according to the friction coefficient of the road surface. When traveling on a road surface having a reduced friction coefficient such as a frozen road surface, the braking distance becomes long. In the following patent documents, the friction coefficient of the road surface on which the vehicle is currently traveling is measured through a road surface μ sensor installed in advance in the vehicle, and a warning to the driver or automatic detection of the vehicle according to the magnitude of the friction coefficient. A technical idea of changing a condition for starting braking is disclosed.

However, in reality, it is difficult to accurately measure the friction coefficient of the road surface by the sensor mounted on the running vehicle. In addition, the frozen state of the road surface differs depending on the location, and therefore the friction coefficient of the road surface also varies depending on the location. What the sensor measures is the coefficient of friction at the point where the vehicle has already passed, not the coefficient of friction ahead. Therefore, it is not always useful for increasing the certainty of automatic braking to be performed in the future.

Japanese Patent Laid-Open No. 05-050901

An object of the present invention is to further reduce the possibility that a vehicle traveling on a road surface having a reduced friction coefficient will collide with a preceding vehicle.

In the present invention, when the inter-vehicle distance and the relative speed between the own vehicle and the preceding vehicle satisfy predetermined conditions, a warning is given in a manner appealing to the driver's sight or hearing, or the vehicle is automatically braked. a is, if detects a blink of the preceding vehicle direction indicator or brake light and preceding vehicle deceleration is below a predetermined value, different from the otherwise conditions for performing the above warning or the automatic braking The control device of the vehicle was changed to one.

The direction indicator or brake light of the preceding vehicle is blinking, and the deceleration of the preceding vehicle is small, which means that the friction coefficient of the road surface on which the preceding vehicle is traveling (which is also the road surface ahead of the vehicle) Indicates that the preceding vehicle ABS (Antilock Brake System) is operating. Therefore, in the host vehicle, warning is given to the driver at an earlier stage than in normal times, or automatic braking of the vehicle is started to surely avoid a collision with a preceding vehicle, and a collision should occur. Also, we will try to reduce the damage.

According to the present invention, it is possible to further reduce the possibility that a vehicle traveling on a road surface having a reduced friction coefficient collides with a preceding vehicle.

The figure which shows schematic structure of the control apparatus of the vehicle in one Embodiment of this invention. The flowchart which shows the example of a procedure of the process which the control apparatus of the same embodiment performs according to a program.

An embodiment of the present invention will be described with reference to the drawings. The vehicle control device (Electronic Control Unit) 0 in the present embodiment is a microcomputer system having a processor, a memory, an input interface, an output interface, etc., and interprets and executes a program stored in the memory in advance in the processor. , Which implements the functions of a vehicle collision avoidance support system.

As shown in FIG. 1, the ECU 0 includes a vehicle speed sensor 1 that measures the traveling speed of the host vehicle, that is, a vehicle speed, an acceleration sensor 2 that measures the acceleration or deceleration of the host vehicle, and a preceding vehicle that exists in front of the host vehicle. Means for detecting other obstacles, for example, a camera sensor 3 for photographing the front of the vehicle, a radar for emitting an electromagnetic wave in front of the vehicle and receiving a reflected wave thereof (laser radar, infrared radar, millimeter wave radar) Etc.) 4) and the like, and based on the information, the relative speed between the own vehicle and the preceding vehicle, the inter-vehicle distance between the own vehicle and the preceding vehicle, etc. are repeatedly calculated.

Then, assuming that the own vehicle and the preceding vehicle continue to travel at the same speed as each other, a margin time until the own vehicle and the preceding vehicle collide, that is, how many seconds after which the own vehicle collides with the preceding vehicle. If the margin time is less than or equal to the threshold value, a warning is given in a manner appealing to the driver's sight or hearing, and/or the vehicle is automatically braked. The warning is given by, for example, sounding a buzzer 5 installed in the cockpit of the vehicle, lighting or blinking an indicator lamp 6 installed in the cockpit, or displaying it on a screen of a display. In the automatic braking of the vehicle, the output of the internal combustion engine 7 or the electric motor, which is the travel drive source, is forcibly reduced without depending on the driver's operation of the accelerator pedal, and the vehicle is forcibly braked without depending on the driver's operation of the brake pedal. The device 8 is activated. That is, the working fluid pressure is supplied to the brake caliper of the disc brake or the wheel cylinder of the drum brake, or the working fluid pressure supplied is increased to increase the braking force by the disc brake or the drum brake.

Then, as shown in FIG. 2, the ECU 0 of the present embodiment detects the blinking of the direction indicator or the brake light of the preceding vehicle (step S1), and the deceleration of the preceding vehicle is smaller than a predetermined value or less ( At step S2), the condition for warning or automatic braking is changed to a condition different from the normal condition (step S3).

In step S1, by analyzing the captured image in front of the own vehicle, the direction indicator or the brake light installed in the back of the preceding vehicle is turned on or off by the driver's operation. It is determined whether or not the blinking is performed at high speed in a cycle shorter than the cycle (180 times or more and 300 times or less per minute). Such blinking is called an emergency stop signal (emergency braking display). The condition for generating an emergency stop signal is that the current vehicle speed of the preceding vehicle is higher than a specified value and the deceleration of the preceding vehicle is higher than the specified value when the driver of the preceding vehicle is stepping on the brake pedal. The vehicle is decelerating or the ABS of the preceding vehicle is operating.

In step S2, the deceleration of the preceding vehicle is estimated from the acceleration or deceleration of the own vehicle and the amount of change in the inter-vehicle distance between the own vehicle and the preceding vehicle per unit time.

If both steps S1 and S2 are true, the friction coefficient of the road surface on which the preceding vehicle is traveling, in other words, the road surface ahead of the vehicle is small, and the ABS is operating in the preceding vehicle. Conceivable. Therefore, in step S3, the warning or automatic braking start condition is changed so as to warn the driver at an earlier stage than in normal times or to start automatic braking of the vehicle. In particular,
・When issuing a warning on condition that the vehicle-to-vehicle distance between the vehicle and the preceding vehicle is less than or equal to the threshold value, raise the threshold value above normal.・Check that the vehicle-to-vehicle distance between the vehicle and the preceding vehicle is less than or equal to the threshold value. When executing automatic braking as a condition, raise the threshold above normal.When executing a warning on condition that the time until the own vehicle collides with the preceding vehicle is less than the threshold, set the threshold during normal operation.・When performing automatic braking under the condition that the margin time until the own vehicle collides with the preceding vehicle is equal to or less than the threshold, at least one of raising the threshold above normal is executed. ..

Further, when the ABS of the preceding vehicle is operating, it can be said that the deceleration of the preceding vehicle indicates the magnitude of the friction coefficient of the road surface on which the preceding vehicle is located. Therefore, in step S3, under the current relative speed between the own vehicle and the preceding vehicle and the inter-vehicle distance, even if the own vehicle decelerates at the same deceleration as the deceleration of the preceding vehicle, the own vehicle and the preceding vehicle collide. It is preferable to set the threshold value of the automatic braking start condition so that the automatic braking can be started at a timing that avoids.

If either or both of steps S1 and S2 are false, the threshold value to be compared with the above-described inter-vehicle distance or the margin time is set to a value in normal times (step S4).

In the present embodiment, when the inter-vehicle distance and the relative speed between the own vehicle and the preceding vehicle satisfy predetermined conditions, a warning is given in a manner appealing to the driver's eyesight or hearing, or the vehicle is automatically braked. When the blinking of the direction indicator or the brake light of the preceding vehicle is detected and the deceleration of the preceding vehicle is equal to or less than the predetermined value, the above-mentioned warning or the condition for performing the automatic braking is set as the normal condition. Configures a vehicle controller 0 that changes to a different one. According to the present embodiment, it is possible to effectively avoid a collision between the own vehicle and the preceding vehicle on the road surface having a reduced friction coefficient, and the safety of the vehicle is increased.

The present invention is not limited to the embodiment described in detail above. Various modifications can be made to the specific configuration of each unit and the specific processing content and procedure without departing from the spirit of the present invention.

The present invention can be applied to a control device mounted on a vehicle.

0... Control unit (ECU)
1... Vehicle speed sensor 2... Acceleration sensor 3... Camera sensor 4... Radar 5... Buzzer 6... Indicator lamp 7... Travel drive source (internal combustion engine)
8...Brake device

Claims (1)

When the inter-vehicle distance and the relative speed between the own vehicle and the preceding vehicle satisfy predetermined conditions, a warning is given in a manner appealing to the driver's sight or hearing, or the vehicle is automatically braked,
When detecting blinking preceding vehicle direction indicator or brake light and preceding vehicle deceleration is less than or equal to a predetermined value, to change different than the otherwise conditions for performing the above warning or the automatic braking Vehicle control device.

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