JP3747617B2 - Brake assist system - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a brake assist system.
[0002]
[Prior art]
Examples of conventional brake assist systems include the following.
In Japanese Examined Patent Publication No. 4-25182, the distance from the front is detected by a laser radar or the like, and when the distance falls below a preset safety distance, a warning is given to the driver and the brake is applied when the brake is depressed. Attempts to assist pressure braking have been proposed.
[0003]
[Problems to be solved by the invention]
However, in the above-described prior art, when there is an obstacle on the traveling extension line of the own vehicle, it can be detected reliably. For example, while traveling in a busy shopping street, However, there is a safety problem because there is a possibility that it may be on the running extension line immediately after it cannot be detected. In addition, if all such situations are detected and auxiliary braking is performed, the control works even when it is not so urgent, causing a problem in smooth running.
The present invention has been made paying attention to such a conventional problem, and a laser radar or a camera or the like is used to monitor the front of the vehicle at a certain angle. When a moving object (assuming a pedestrian or a bicycle) is detected, if the detection exceeds a predetermined frequency and continues for a predetermined time, it is determined that the vehicle is traveling in a warning area where there is a possibility of collision. having means, in this case, Ri and easily enter the control by changing the control thresholds of the brake assist system that detects to supplementary braking the emergency brake operation by the driver, the brake immediately against braking operation Ri force were standby to allow reaction, oPERATION's accelerator action ensures performed automatic brake prior to the determination by the driver's brake operation of the emergency from the depressing force changing according to the footrest to lower the vehicle speed Ri, by the Turkey give an alarm to the luck rolling person, while maintaining a smooth running, it is possible to prevent a collision even for the difficult situation prediction of movement of pedestrians and bicycles.
[0004]
[Means for Solving the Problems]
That is, the invention described in claim 1 comprises means for monitoring the front of the host vehicle within a predetermined angle range, and means for detecting a stationary object or an object moving at a low speed by the monitoring means , When the detection is continued for a predetermined time, it is determined that the vehicle is traveling in the alert area. In the brake assist system , when it is determined that the vehicle is traveling in the alert area, a minute value close to 0 is obtained only when the driver is not operating the brake. It was set as the structure provided with the means to generate | occur | produce brake force.
According to a second aspect of the present invention, there is provided: means for monitoring the front of the host vehicle within a predetermined angle range; means for detecting a stationary object or an object moving at a low speed by the monitoring means; Means for detecting an operation; means for determining an emergency when a brake operation amount exceeds a predetermined threshold; and an auxiliary braking means for generating a braking force higher than a braking force operated by a driver in an emergency. When the stationary object or the object moving at a low speed is detected continuously for a predetermined time, it is determined that the vehicle is in a warning area, the threshold value of the brake operation amount is reduced, and In the brake assist system that makes it easy to enter the determination, the means for detecting the accelerator pedal operation amount of the driver and the accelerator pedal return speed are calculated from the detected accelerator operation amount. And automatic braking means for generating an arbitrary braking force regardless of the driver's brake operation, and when it is determined that the vehicle is traveling in the warning area, the driver is not operating the brake and the accelerator Only when the return speed of the pedal is equal to or higher than a predetermined value, automatic braking by the automatic braking means is performed.
According to a third aspect of the present invention, there is provided: means for monitoring the front of the host vehicle within a predetermined angle range; means for detecting a stationary object or an object moving at a low speed by the monitoring means; Means for detecting an operation; means for determining an emergency when a brake operation amount exceeds a predetermined threshold; and an auxiliary braking means for generating a braking force higher than a braking force operated by a driver in an emergency. When the stationary object or the object moving at a low speed is detected continuously for a predetermined time, it is determined that the vehicle is in a warning area, the threshold value of the brake operation amount is reduced, and In the brake assist system that makes it easy to enter the determination, the means for detecting the pedaling force applied to the footrest of the driver, the means for calculating the increasing speed of the pedaling force, Automatic braking means that generates an arbitrary braking force regardless of whether the driver is not operating the brake and the footrest pedal force increasing speed is equal to or higher than a predetermined value when it is determined that the vehicle is traveling in the alert area. Only, automatic braking by the automatic braking means is performed.
The invention according to claim 4 comprises means for monitoring the front of the host vehicle within a predetermined angle range, and means for detecting a stationary object or an object moving at a low speed by the monitoring means, In the brake assist system, it is determined that the vehicle is traveling in a warning area when the detection is continued for a predetermined time. In the brake assist system, a means for detecting the speed of the vehicle, and an automatic braking means for generating an arbitrary braking force regardless of the driver's brake operation, When it is determined that the vehicle is traveling in the warning area, automatic braking by the automatic braking means is performed only when the driver is not operating the brake and the vehicle speed is equal to or higher than a predetermined value.
In the brake assist system according to any one of claims 1 to 4, the brake operation speed is detected as the driver's brake operation.
Furthermore, the invention according to claim 6 is a configuration in which, in the brake assist system according to any one of claims 1 to 5, a warning is given to the driver when it is determined that the vehicle is traveling in the alert area. It was.
[0005]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
1 and 2 are diagrams showing an embodiment of the present invention. FIG. 1 is an overall configuration diagram, and FIG. 2 is a configuration diagram of a negative pressure booster.
First, the configuration will be described. In FIG. 1, 20 is an accelerator pedal, 21 is a brake pedal, 22 is an accelerator stroke sensor for detecting the operation amount of the accelerator pedal, and 23 is a brake stroke sensor for detecting the operation amount of the brake pedal.
[0006]
Reference numeral 25 denotes a negative pressure booster with a built-in electromagnetic valve, the details of which are shown in FIG. 26 is a master cylinder, 27 is each wheel, and the rotational speed thereof is detected by a wheel speed sensor 28. Reference numeral 30 denotes a footrest pedal force sensor for detecting a pedaling force applied to the footrest. Reference numeral 31 denotes a laser radar attached to the front front grille of the vehicle, which detects the distance between the vehicle and the front vehicle.
[0007]
Reference numeral 29 denotes a control device that performs brake assist, and a control routine thereof will be described later. Information on the accelerator stroke, the brake stroke, the wheel rotation speed, the inter-vehicle distance, and the vehicle front-rear G is input to the control device 29, and a control signal for driving a solenoid valve 5 described later is output.
[0008]
FIG. 2 illustrates the structure of the negative pressure booster 25.
Reference numeral 1 denotes a variable pressure chamber, which is in a negative pressure state when the brake is not braked, and balances the pressure with a negative pressure chamber 2 described later. At the time of braking, the atmosphere is introduced, a differential pressure with the negative pressure chamber 2 is generated, and the boosted load is transmitted to the master cylinder 26. Reference numeral 2 denotes a negative pressure chamber, and a predetermined negative pressure is always generated during engine startup. Reference numeral 3 denotes a vacuum valve, which is closed when the brake pedal 21 is stroked by a driver or when an electromagnetic valve 5 described later is excited, thereby blocking communication between the negative pressure chamber 2 and the variable pressure chamber 1. Reference numeral 4 denotes an atmospheric valve, which opens when the brake pedal 21 is stroked by the driver or when an electromagnetic valve 5 described later is excited, and introduces the atmosphere into the variable pressure chamber 1. 5 is a solenoid valve, 6 is an operating rod, 7 is a solenoid valve interlocking member, 8 is a push rod, and when the solenoid valve 5 is excited, the solenoid valve interlocking member 7 strokes to the left in the figure, and the vacuum valve 3 and the atmosphere The opening / closing operation of the valve 4 is performed. Thereby, a differential pressure is generated between the negative pressure chamber 2 and the variable pressure chamber 1, and a force is transmitted to the push rod 8 and the master cylinder 26 via the reaction disk 9, and a brake is generated for each wheel 27.
[0009]
Next, the operation will be described.
3, 4, and 5 are flowcharts showing calculation processing of the control device 29. This routine is an interrupt processing routine executed at a predetermined cycle (in this embodiment, a cycle that flows once every 10 msec).
[0010]
First, in step S100, the vehicle speed v is read from the rotational speed of the wheel.
Next, in step S101, based on the host vehicle speed v, a safety distance x1 for the forward obstacle is calculated. In the present embodiment, the stopping distance physically possible by v (= v ** 2 / 2g, g = 0.6G) and the free running distance (= T) from when the danger is recognized until the brake operation is performed. * V, T = 1.0 sec).
[0011]
In step S102, the distance x between the actual vehicle and the front obstacle is read from the laser radar 31.
[0012]
Next, in step S103, it is determined whether or not the detected x is larger than the safety distance target value x1, that is, whether or not it is too close. If it is too close, the process proceeds to step S104 and the counter value cnt of the proximity information is reached. Is incremented, otherwise the process proceeds to step S105.
[0013]
In step S105, it is determined whether or not the proximity information counter value within a predetermined time (for example, 5 seconds) is equal to or greater than a predetermined number of times Cs. In step S106, a brake assist threshold (to be described later) is set to be small so that the brake assist is easily entered. In step S107, a warning sound is emitted to the driver. In step S108, the vehicle is in the warning area. Is set to 1, and the process proceeds to step 200 and subsequent steps.
[0014]
On the other hand, if it is determined in step S105 that cnt <Cs, it is determined that the vehicle is not traveling in the alert area. In step S109, a threshold value for a brake assist system, which will be described later, is set to normal (not to make an erroneous determination to enter control) In step S110, the alarm sound is terminated, and in step S111, the CA flag indicating that the vehicle is traveling in the alarm region is cleared to 0, and the process proceeds to step S200 and subsequent steps.
[0015]
In step S200, it is determined whether or not the accelerator pedal 20 is depressed. If the accelerator pedal 20 is depressed, the ACC flag indicating the state of the accelerator pedal is cleared to 0 in step S210, and the routine is terminated. If not, step S201 is performed. Proceed to
[0016]
In step S201, the ACC flag indicating the state of the accelerator pedal 20 is set to 1. In step S202, the stroke amount of the brake pedal 21 is detected.
In step S203, the brake stroke speed is calculated from the past history of the detected brake throttle amount.
[0017]
In step S204, it is determined whether or not the brake pedal 21 is depressed, and if it is not depressed (that is, neither the accelerator nor the brake is depressed), the process proceeds to step S300. A flag is determined.
The BA flag is a flag that is set to 1 when it is estimated that the driver's stroke speed is large and is in an emergency state, and is reset to 0 when the brake pedal 21 is returned (step S300).
[0018]
If the BA flag is set in step S205, the process proceeds to step S207 and assist control is continued. If not, whether or not the brake stroke speed is greater than the BA threshold value in step S206, that is, whether it is an emergency state. Is determined.
If it is determined in step S206 that the brake stroke speed is greater than the BA threshold value, the process proceeds to step S207 to perform assist control. Otherwise, the assist control is canceled (or not performed) in step S208.
[0019]
As a specific example of performing the assist control in step S207, the electromagnetic valve 5 is driven so that the vacuum valve 3 of the negative pressure booster 25 is in the closed position and the atmospheric valve 4 is in the open position, and the atmosphere is introduced into the variable pressure chamber 1. As a result, a differential pressure with respect to the negative pressure chamber 2 is generated, and a hydraulic pressure is generated by the master cylinder 26 to the wheel cylinder.
[0020]
On the other hand, as a specific example of releasing the assist control in step S208, the electromagnetic valve 5 is driven so that the vacuum valve 3 of the negative pressure booster 25 is in the open position and the atmospheric valve 4 is in the closed position, thereby terminating the control. . Note that even if the energization of the solenoid valve 5 is cut off, the vacuum valve 3 is in the open position and the atmospheric valve 4 is in the closed position by the biasing force of the spring.
[0021]
Next, a description will be given of the case where it is determined in step S204 that the brake pedal is off.
In this case, the process proceeds to step S300, and the BA flag is reset to 0 as already described.
[0022]
Next, in step S301, if the CA flag indicating whether or not the vehicle is traveling in the alert area is on and the flag is set and the vehicle is traveling in the alert area, the process proceeds to step S302. If not, the process proceeds to step S306 and the automatic brake described later is performed. Not performed.
[0023]
In step S302, the ACC flag indicating the state of the accelerator pedal 20 is viewed. When the ACC flag is set, that is, when the accelerator pedal 20 is off, the process proceeds to step S303 and subsequent steps, and when the accelerator pedal 20 is depressed. Proceeding to step S306, the automatic braking described later is not performed.
[0024]
In step S303, it is determined whether or not the return speed of the accelerator pedal 20 is greater than or equal to a predetermined value. If it is greater than or equal to the predetermined value, the process proceeds to step S307, and if not, the changeover time from the accelerator pedal 20 to the brake pedal 21 is determined in step S304. Is determined within a predetermined time.
[0025]
If it is not less than the predetermined time, the process proceeds to step S307. If not, it is determined in step S305 whether or not the amount of increase in the footrest pedal force per unit time is equal to or greater than the predetermined value. If not, the process proceeds to step S306 and automatic braking described later is not performed.
[0026]
That is, in the routine of steps S303 to S305, the driver senses the danger and determines whether the accelerator is quickly returned, quickly switched, or the footrest is powered. In such a case, the automatic brake is activated. Yes.
[0027]
As a specific example of performing the automatic brake control in step S307, the electromagnetic valve 5 is driven so that the vacuum valve 3 of the negative pressure booster 25 is in the closed position and the atmospheric valve 4 is in the open position. By introducing, a differential pressure with respect to the negative pressure chamber 2 is generated, and a hydraulic pressure is generated by the master cylinder 26 to the wheel cylinder.
[0028]
On the other hand, as a specific example of releasing the automatic brake control in step S306, the control is finished by driving the electromagnetic valve 5 so that the vacuum valve 3 of the negative pressure booster 25 is in the open position and the atmospheric valve 4 is in the closed position. To do. Note that even if the energization of the solenoid valve 5 is cut off, the vacuum valve 3 is in the open position and the atmospheric valve 4 is in the closed position by the biasing force of the spring.
[0029]
【The invention's effect】
As described above, in the brake assist system of the present invention, it is possible to prevent a collision with an object even in a situation where it is difficult to predict the movement of an object moving at low speed while maintaining smooth running. The effect that it can prevent is obtained.
[Brief description of the drawings]
FIG. 1 is a diagram showing an overall configuration of an embodiment of the present invention.
FIG. 2 is a configuration diagram of a negative pressure booster according to an embodiment.
FIG. 3 is a flowchart showing a calculation process of the control device according to the embodiment.
FIG. 4 is a flowchart showing a calculation process of the control device according to the embodiment.
FIG. 5 is a flowchart showing calculation processing of the control device according to the embodiment;
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Variable pressure chamber 2 Negative pressure chamber 3 Vacuum valve 4 Atmospheric valve 5 Solenoid valve 6 Operating rod 7 Electromagnetic valve interlocking member 8 Push rod 9 Reaction disk 20 Accelerator pedal 21 Brake pedal 22 Accelerator stroke sensor 23 Brake stroke sensor 25 Negative pressure booster 26 Master Cylinder 27 Wheel 28 Wheel speed sensor 29 Control device 30 Footrest tread force sensor 31 Laser radar

Claims (6)

Means for monitoring the front of the vehicle within a predetermined angle range;
Means for detecting a stationary object or an object moving at a low speed by the monitoring means ,
When the detection is continued for a predetermined time, in the brake assist system that determines that the vehicle is traveling in the alert area ,
A brake assist system comprising means for generating a minute braking force close to 0 only when the driver is not operating the brake when it is determined that the vehicle is traveling in the warning area. Means for monitoring the front of the vehicle within a predetermined angle range;
  Means for detecting a stationary object or an object moving at a low speed by the monitoring means;
  Means for detecting the driver's brake operation;
  Means for determining an emergency when the amount of brake operation exceeds a predetermined threshold;
  Auxiliary braking means for generating a braking force higher than the braking force operated by the driver in case of an emergency,
  When the stationary object or the object moving at a low speed is detected continuously for a predetermined time, it is determined that the vehicle is in a warning area, the threshold value of the brake operation amount is reduced, and an emergency determination can be easily made. In the brake assist system designed to
  Means for detecting a driver's accelerator pedal operation amount;
  Means for calculating the return speed of the accelerator pedal from the detected accelerator operation amount;
  Automatic braking means for generating an arbitrary braking force regardless of the driver's braking operation, and
  When it is determined that the vehicle is traveling in the warning area, automatic braking by the automatic braking means is performed only when the driver does not operate the brake and the return speed of the accelerator pedal is equal to or higher than a predetermined value. Brake assist system. Means for monitoring the front of the vehicle within a predetermined angle range;
  Means for detecting a stationary object or an object moving at a low speed by the monitoring means;
  Means for detecting the driver's brake operation;
  Means for determining an emergency when the amount of brake operation exceeds a predetermined threshold;
  Auxiliary braking means for generating a braking force higher than the braking force operated by the driver in case of an emergency,
  When the stationary object or the object moving at a low speed is detected continuously for a predetermined time, it is determined that the vehicle is in a warning area, the threshold value of the brake operation amount is reduced, and an emergency determination can be easily made. In the brake assist system designed to
  Means for detecting the pedaling force applied to the driver's footrest;
  Means for calculating the increasing speed of the pedal force;
  Automatic braking means for generating an arbitrary braking force regardless of the driver's braking operation, and
  When it is determined that the vehicle is traveling in the warning area, the brake is automatically braked by the automatic braking means only when the driver does not operate the brake and the footrest pedal force increasing speed is equal to or higher than a predetermined value. system. Means for monitoring the front of the vehicle within a predetermined angle range;
  Means for detecting a stationary object or an object moving at a low speed by the monitoring means,
  When the detection is continued for a predetermined time, in the brake assist system that determines that the vehicle is traveling in the alert area,
  Means for detecting the speed of the vehicle;
  Automatic braking means for generating an arbitrary braking force regardless of the driver's braking operation; Prepared,
  A brake assist system that performs automatic braking by the automatic braking means only when the driver is not operating a brake and the speed of the vehicle is equal to or higher than a predetermined value when it is determined that the vehicle is traveling in the warning area. . The brake assist system according to any one of claims 1 to 4, wherein a brake operation speed is detected as the driver's brake operation. The brake assist system according to any one of claims 1 to 5, wherein when it is determined that the vehicle is traveling in the warning area, a warning is given to the driver.

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