JP2000251171A - Lane deviation alarming device for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make a driver surely and promptly recognize the condition that a vehicle deviates from a traveling path. SOLUTION: A vehicle 10 is provided with a steering motor 20 for generating driving force corresponding to the steering angle θas assist force when the driver operates a steering wheel 14. Based on the output signals of an image sensor 22, lanes 32 and 34 for separating the traveling path 30 where the vehicle 10 travels are recognized. In the case that wheels provided on the vehicle are on the lanes 32 and 34, a fine vibration component is superimposed on a motor current to be supplied to the steering motor 20. When the fine vibration component is superimposed on the motor current, by the change of the assist force, the steering wheel 14 is finely vibrated. Thus, the driver bodily feels the sensation that the vehicle travels on a rugged road. As a result, the condition that the vehicle 10 deviates from the traveling path 30 is surely and promptly recognized.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle lane departure warning device, and more particularly to a vehicle lane departure warning device suitable for issuing a warning to a driver when the vehicle deviates from a traveling road. .

[0002]

2. Description of the Related Art Conventionally, for example, Japanese Patent Application Laid-Open No. Sho 63-2149.
As disclosed in No. 00, there is known a device that warns a driver when a vehicle deviates from a traveling road. Such a device generates a sound from a speaker and turns on a warning lamp when the vehicle deviates from a traveling road. Therefore, according to the above-described conventional device, a warning is issued to the driver in a situation where the vehicle deviates from the traveling road, so that the driver can recognize the deviation.

[0003]

In the above-mentioned conventional device, the warning to the driver is performed by stimulating the driver's hearing and vision. However, while the vehicle is running, the driver is listening to music, talking with a passenger, etc.,
In some cases, the driver may be delayed in recognizing the warning by the sound from the speaker or may not be able to recognize the warning. In addition, if the driver misses the lighting of the warning lamp, the recognition of the warning by light may be delayed or may not be possible. For this reason, in the above-mentioned conventional device, the situation where the vehicle deviates from the traveling path is reliably and
The driver cannot be immediately recognized.

[0004] The present invention has been made in view of the above points, and a vehicle lane departure warning that allows a driver to reliably and promptly recognize a situation in which a vehicle deviates from a traveling road. It is intended to provide a device.

[0005]

The above object is achieved by the present invention.
As described in the above, in a vehicle lane departure warning device having a steering mechanism that steers wheels based on operation of a steering wheel, and an actuator that applies a driving force to the steering mechanism, the vehicle deviates from a traveling road And a driving means for driving the actuator so that the steering wheel vibrates when it is determined that the vehicle deviates from the travel path. This is achieved by a lane departure warning device.

According to the present invention, a steering mechanism for turning a wheel based on an operation of a steering wheel,
It is determined whether or not the vehicle having the actuator that applies the driving force to the steering mechanism deviates from the traveling path. When the vehicle deviates from the road, the actuator is driven so that the steering wheel vibrates. For this reason, according to the present invention, when the vehicle deviates from the traveling road, it is possible to give the driver a feeling that the steering wheel vibrates. Therefore, according to the present invention, the driver can be made to recognize the situation in which the vehicle deviates from the traveling road reliably and promptly.

Another object of the present invention is to provide a vehicle lane departure warning device having an actuator for changing a relative position between a wheel and a vehicle body, a departure determining means for determining whether the vehicle deviates from a traveling road, and a vehicle. And a driving unit for driving the actuator so that the vehicle body vibrates in the vertical direction when it is determined that the vehicle deviates from the traveling road.

In the present invention, it is determined whether or not a vehicle having an actuator for changing a relative position between a wheel and a vehicle body deviates from a traveling path. When the vehicle deviates from the traveling path, the actuator is driven so that the vehicle body vibrates in the vertical direction. For this reason, according to the present invention, when the vehicle deviates from the traveling road, it is possible to give the driver the feeling of the vehicle body moving up and down. Therefore, according to the present invention, the driver can be made to recognize the situation in which the vehicle deviates from the traveling road reliably and promptly.

[0009]

FIG. 1 is a system configuration diagram of a vehicle lane departure warning device according to a first embodiment of the present invention. The lane departure warning device of the present embodiment is mounted on the vehicle 10,
An electronic control unit (hereinafter, referred to as an ECU) 12 is provided. The lane departure warning device of the present embodiment is controlled by the ECU 12 to issue a warning when the vehicle deviates from the traveling road.

The vehicle 10 has a steering wheel 14. A steering shaft 16 that rotates together with the steering wheel 14 is fixed to the steering wheel 14. A steering angle sensor 18 is provided on the steering shaft 16. The steering angle sensor 18 outputs a signal corresponding to the steering angle θ of the steering wheel 14 to the ECU 12. The ECU 12 detects the steering angle θ of the steering wheel 14 based on the output signal of the steering angle sensor 18.

The left and right wheels F are connected to the steering shaft 16 via a steering gear box (not shown).
A rack bar (not shown) connecting L and FR is connected. The steering gear box has a function of converting the rotational movement of the steering shaft 16 into a linear movement of the rack bar in the vehicle width direction. Therefore, according to the above configuration, the wheels FL and FR can be steered in the vehicle width direction according to the operation of the steering wheel 14.

In the vicinity of the steering shaft 16, a steering motor 20 having a drive shaft fitted to the steering shaft 16 is provided. The steering motor 20 is EC
It is connected to U12 and transmits a driving force according to the motor current supplied from the ECU 12 to the steering shaft 16. According to this configuration, by supplying an appropriate motor current to the steering motor 20, a steering torque for rotating the steering shaft 16 can be generated. Therefore, according to the present embodiment, by supplying an appropriate motor current to the steering motor 20, the steering torque required for the driver to operate the steering wheel 14 can be reduced.

The ECU 12 is connected to an image sensor 22 provided on a console, for example. The image sensor 22 is configured by a CCD camera or the like, and outputs an electric signal corresponding to an image in a predetermined area in front of the vehicle to the ECU 12. The ECU 12 recognizes a lane such as a white line or a yellow line provided on a traveling path on which the vehicle 10 travels based on an output signal of the image sensor 22, and calculates a relative position of the vehicle 10 with respect to the recognized lane. In this embodiment, the ECU 12 stores the trajectory of the lane, and estimates the position of the lane deviating from a predetermined area in front of the vehicle. The ECU 12 also controls the wheels FL, F mounted on the vehicle 10.
The position of the vehicle body to which R, RL, and RR are attached is stored in advance. Therefore, the ECU 12 can determine whether each wheel is on the lane.

The ECU 12 is connected to speakers 24 and 25 for outputting sound into the vehicle interior. ECU1
2 drives the speakers 24 and 25 by outputting an ON signal in accordance with a predetermined logic when the wheels are on the lane. The speakers 24 and 25 maintain an off state in a normal state, and output a predetermined sound when an on signal is supplied from the ECU 12. As a result, the vehicle occupant is alerted.

FIG. 2 is a diagram schematically showing a situation realized when the vehicle 10 equipped with the lane departure warning device of the present embodiment travels on a traveling road. As shown in FIG.
The travel path 30 on which 0 travels is a lane 3 having a predetermined width d.
2,34. The driver who drives the vehicle 10 normally steers the steering wheel 14 so that the vehicle 10 travels in the travel path 30, that is, between the left lane 32 and the right lane 34.

[0016] By the way, the vehicle 1
0 may deviate from the traveling path 30 in some cases. If the vehicle 10 deviates from the traveling path 30, there is a possibility that the vehicle 10 will collide with another vehicle or the like, and the safety of the vehicle cannot be ensured. Therefore, to ensure the safety of the vehicle in such a case,
It is necessary to make the driver aware of the situation where the vehicle 10 deviates from the traveling path 30.

However, in order to make the driver recognize that the vehicle 10 has deviated from the traveling path 30, even if a voice is emitted from a speaker or a warning lamp is turned on, the driver is listening to music or the like, or the warning lamp is turned on. If the driver misses the situation, the driver may be late in recognizing such a situation or may not be able to recognize it. For this reason, it is difficult to ensure the safety of the vehicle by the sound from the speaker or the warning by the lighting of the warning lamp. Therefore, when the vehicle 10 deviates from the traveling path 30, the vehicle 10 reliably and promptly
It is necessary to make the driver aware of such a situation.

In order for the driver to recognize the situation where the vehicle 10 deviates from the traveling path 30 reliably and promptly,
It is effective to cause the steering wheel 14 to slightly vibrate. In the present embodiment, the vehicle has a steering motor 20 that generates a steering torque according to the motor current supplied from the ECU 12. Therefore, in order to make the steering wheel 14 minutely vibrate, it is effective to superimpose a minute vibration component on the motor current supplied to the steering motor 20. When a minute vibration component is superimposed on the motor current, the steering torque at which the steering motor 20 rotates the steering shaft 16 slightly changes. In this case, the steering wheel 14 slightly vibrates, and as a result, the driver experiences a feeling that the vehicle is traveling on an uneven road. Therefore, according to such a method, the situation in which the vehicle 10 deviates from the traveling path 30 is ensured.
In addition, the driver can be promptly recognized.

The lane departure warning device of the present embodiment
In order for the driver to recognize the situation in which the vehicle deviates from the travel path 30 reliably and promptly, the steering wheel 1
4 is characterized in that it vibrates. Hereinafter, the characteristic portions will be described. FIG. 3 shows a flowchart of an example of a control routine executed by the ECU 12 in the present embodiment in order to realize the above functions. The routine shown in FIG. 3 is a routine that is repeatedly started each time the processing is completed. When the routine shown in FIG. 3 is started, first, the process of step 100 is executed.

In step 100, the steering angle θ of the steering wheel 14 is detected based on the output signal of the steering angle sensor 18. In step 102, the image sensor 2
2 on which the vehicle 10 travels based on the output signal
Lanes 32 and 34, which are boundaries of 0, are recognized. In step 104, the lane 3 recognized in step 102
2, 34, the vehicle 10 for the lanes 32, 34
Are detected. As described above, the ECU 10
The position of the vehicle body to which each wheel is attached is stored in advance. Therefore, when this step 104 is executed, the lane 32,
The relative position of each wheel with respect to 34 is detected.

In step 106, the wheels are moved to the lanes 32, 3
4 is determined. Wheels 32, 34
If so, it is necessary to inform the driver of the situation where the vehicle 10 deviates from the traveling path 30. Therefore, when it is determined that the wheels are on the lanes 32 and 34, the process of step 108 is executed next. In step 108, a process of turning on the vibration flag Fr is executed. The vibration flag Fr is a flag for displaying a state where the wheels are on the lanes 32 and 34. After the processing of step 108 is executed, it is determined that the wheels are on the lanes 32 and 34 thereafter.

In step 110, a process is executed to make the motor current I supplied to the steering motor 20 a value obtained by adding a predetermined value α to a current I (θ) corresponding to the steering angle θ of the steering wheel 14. Is done. The predetermined value α is a sine wave having a predetermined cycle and is stored in the ECU 12 in advance. The predetermined value α is set to a small value so that the wheel is not steered by the current value.

FIG. 4 is a diagram for explaining a change in the motor current I supplied to the steering motor 20 when the wheels are on the lanes 32 and 34. FIG. 4A shows an example of a temporal change of the motor current I (θ) supplied to the steering motor 20 in a normal state. FIG. 4B shows an example of a temporal change of the predetermined value α. FIG. 4C shows an example of a temporal change of the motor current I supplied to the steering motor 20 when the wheels are on the lanes 32 and 34 from the time t1 to the time t2. As shown in FIG. 4C, in this embodiment, when the wheels are on the lanes 32 and 34, the motor current on which the minute vibration component is superimposed is supplied to the steering motor 20.

In the above-mentioned step 106, the wheel is in lane 3
When the vehicle is not on the road 2, 34, the vehicle 10 does not deviate from the traveling path 30, and it is appropriate to supply a motor current corresponding to the steering angle θ of the steering wheel 14 to the steering motor 20. Therefore, when it is determined that the wheels are not on the lanes 32 and 34, the process of step 112 is executed next.

In step 112, a process for turning off the vibration flag Fr is executed. When the process of step 112 is executed, it is determined that the wheels are not on the lanes 32 and 34 thereafter. In step 114, a process is executed in which the motor current I supplied to the steering motor 20 is changed to a current I (θ) corresponding to the steering angle θ of the steering wheel 14.

In step 116, step 110
Alternatively, a process of outputting the motor current I calculated by executing the process of 114 to the steering motor 20 is executed. When the process of step 116 is performed,
Thereafter, the steering motor 20 is driven according to the motor current I. In step 118, it is determined whether or not the vibration flag Fr is on. As a result, if it is determined that the vibration flag Fr is in the ON state, the process proceeds to step 12
0 is executed. On the other hand, when it is determined that the vibration flag Fr is not on, the process of step 122 is executed next.

In step 120, speakers 24, 25
Is executed for outputting an ON signal. When the process of step 120 is performed, the speakers 24 and 25
Is driven, a predetermined sound, specifically, a sound such as a vibration sound generated when the vehicle is traveling on an uneven road is output. In step 122, the speakers 24,
The processing for turning off the signal for 25 is performed.
When the process of step 122 is performed, the speaker 2
The sound from 4, 25 is stopped.

According to the above-described processing, the wheels are moved to the lanes 32, 3
4, the steering torque corresponding to the steering angle θ of the steering wheel 14 can be generated as the assist force. Therefore, according to the present embodiment, the steering torque when the driver operates the steering wheel 14 can be reduced. According to the above-described processing, when the wheel is on the lanes 32 and 34, a minute vibration component can be superimposed on the assist force. For this reason,
According to this embodiment, when the wheels are on the lanes 32 and 34, the steering wheel 14 can be slightly vibrated without turning the wheels. If the steering wheel 14 is slightly vibrated while the driver is operating the steering wheel 14, the driver will experience a feeling that the vehicle is traveling on an uneven road. Therefore, according to the present embodiment, the wheels are in the lanes 32, 34.
When it is above, it is possible for the driver to recognize the situation where the vehicle 10 deviates from the traveling path 30 reliably and promptly.

In this embodiment, the wheels are the lanes 32, 34.
When the vehicle is on the upper side, a sound such as a vibration sound generated when the vehicle is traveling on an uneven road is output from the speakers 24 and 25. For this reason, according to this embodiment, when the wheels are on the lanes 32 and 34, by stimulating the driver's hearing and tactile sensation, the driver feels as if the vehicle is traveling on an uneven road. The driver can feel it.

By the way, in the method in which the driver recognizes the departure of the vehicle from the traveling road 30 by the normal warning sound, the warning sound is always emitted even when the driver intentionally departs from the lanes 32 and 34. However, the driver may feel troublesome. On the other hand, in the present embodiment, as described above, when the wheels are on the lanes 32 and 34, the driver feels that the vehicle is traveling on an uneven road. Then, the driver is made aware of the deviation of the vehicle from the traveling path 30. The sensation that the vehicle is traveling on an uneven road is a sensation that the driver usually experiences frequently. For this reason, according to the present embodiment, the driver can be made to recognize that the vehicle has deviated from the traveling path 30 without feeling uncomfortable. Therefore, according to the present embodiment, the frequency at which the driver feels annoying can be suppressed as compared with the case where the driver recognizes the deviation of the vehicle from the travel path 30 by the normal warning sound.

In the present embodiment, the steering motor 20
By superimposing a minute vibration component on the motor current supplied to the steering wheel 14, the steering wheel 14 minutely vibrates. Normally, the steering motor 20 is driven by the driver on the steering wheel 14.
When the is operated, a driving force corresponding to the steering angle θ is generated as an assist force. For this reason, according to the present embodiment, it is not necessary to separately provide a new actuator for vibrating the steering wheel 14, and the situation in which the vehicle 10 deviates from the traveling path 30 while suppressing an increase in manufacturing cost can be reduced by the driver. Can be recognized.

In the above embodiment, the steering motor 20 corresponds to the "actuator" of the first aspect, and the ECU 12 executes the processing of the step 106 so that the ECU 12 executes the processing of the first step. Departure determination means ''
2. The "driving means" according to claim 1, wherein the processing in step 116 is performed after the processing in step 110.
Have been realized respectively.

By the way, in the above-described embodiment, when the driver operates the steering wheel 14, the steering motor 20 for applying the assist force is driven,
Although the steering wheel 14 is caused to vibrate, the present invention is not limited to this, and a mechanism that vibrates the steering wheel 14 may be provided separately from the steering motor 20 described above. In this case, such a mechanism corresponds to the “actuator” of the first aspect.

Next, a second embodiment of the present invention will be described with reference to FIGS. 5 to 7 together with FIGS. FIG. 5 is a system configuration diagram of a vehicle lane departure warning device according to a second embodiment of the present invention. The lane departure warning device of the present embodiment has a shock absorber for changing the relative position between the wheel and the vehicle body in the configuration shown in FIG. 1, and the ECU 12 executes a routine shown in FIG. 7 instead of the routine shown in FIG. It is realized by making it execute. In FIG. 5, the same components as those shown in FIG. 1 are denoted by the same reference numerals, and description thereof will be omitted.

In the first embodiment described above, the wheels are in the lane 3
By slightly vibrating the steering wheel 14 when the vehicle 10 is on the vehicle 2 or 34, the driver can recognize that the vehicle 10 deviates from the travel path 30. On the other hand, in the present embodiment, when the wheels are on the lanes 32 and 34, the vehicle body is slightly vibrated so that the driver can recognize the situation where the vehicle 10 deviates from the traveling path 30. The lane departure warning device according to the present embodiment is characterized in that the vehicle body is vibrated up and down so that the driver can recognize the situation in which the vehicle 10 deviates from the traveling path 30 reliably and promptly. I have.

As shown in FIG. 5, the vehicle 10 has a front right wheel FR.
, A shock absorber 42 provided on the left front wheel FL, a shock absorber 44 provided on the right rear wheel RR, and a shock absorber 46 provided on the left rear wheel RL. ing. One end of each of the shock absorbers 40 to 46 is connected to a wheel, and the other end is connected to a vehicle body. The shock absorbers 40 to 46 increase the height of the vehicle when the overall length increases, that is, when the relative position between the wheel and the vehicle body largely separates, and when the overall length decreases, When the relative position between the vehicle and the vehicle body is reduced, the vehicle height is reduced. Therefore, the shock absorbers 40 to 4
According to 6, the vehicle height can be adjusted by appropriately changing the overall length. In the present embodiment, each of the shock absorbers 40 to 46 is an absorber having a vehicle height adjusting mechanism whose overall length changes according to the weight of the vehicle.

FIG. 6 shows a hydraulic control circuit 50 used to change the overall length of the shock absorbers 40 to 46. The hydraulic control circuit 50 includes a high-pressure tank 52. The high-pressure tank 52 is filled with high-pressure oil. A high-pressure passage 54 communicates with the high-pressure tank 52. A hydraulic pressure sensor 56 is provided in the high-pressure passage 54. The hydraulic pressure sensor 56 outputs an electric signal corresponding to the internal pressure of the high-pressure passage 54, that is, the hydraulic pressure in the high-pressure tank 52 to the ECU.
12 is output. The ECU 12 includes a hydraulic pressure sensor 56
, The hydraulic pressure P in the high-pressure tank 52 is detected.

The high-pressure passage 54 has a high-pressure cut valve 58
The hydraulic passage 60 communicates with the fluid passage 60 via the. The high-pressure cut valve 58 is a two-position solenoid valve that maintains a closed state in a normal state and is opened when a drive signal is supplied from the ECU 12. A hydraulic passage 64 communicates with the hydraulic passage 60 via a check valve 62. Check valve 62
This is a one-way valve that allows only the flow of oil from the hydraulic passage 64 to the hydraulic passage 60.

In the hydraulic passage 64, a pump 66 is connected.
A hydraulic passage 68 communicating with the reserve tank 68 communicates. The reserve tank 68 can store a predetermined amount of oil inside. According to the above configuration, the pump 66 sucks oil from the reserve tank 68 using the motor as a power source, and discharges the sucked oil toward the hydraulic passage 64 at a predetermined discharge pressure. A fluid pressure passage 70 communicates with the reserve tank 68. Hydraulic passage 70
Is connected to the hydraulic passage 60 via a discharge valve 72. The discharge valve 72 is a two-position solenoid valve that maintains a closed state in a normal state and is opened when a drive signal is supplied from the ECU 12.

In the hydraulic passage 60, a vehicle height adjusting valve 74,
Control hydraulic passages 82 to 88 communicate with each other via 76, 78, 80. The control hydraulic pressure passages 82 to 88 communicate with the shock absorbers 40 to 46. Height adjustment valve 74
Numerals 80 are two-position solenoid valves that maintain a closed state in a normal state and are opened when a drive signal is supplied from the ECU 12.

Next, the operation of the shock absorbers 40 to 46 will be described. The ECU 12 normally turns off all control valves included in the hydraulic pressure control circuit 50.
In this case, the state shown in FIG. 6 is realized in the hydraulic pressure control circuit 50. In the state shown in FIG. 6, the shock absorbers 40 to 46 maintain the vehicle height in a predetermined state.

In this embodiment, the high pressure cut valve 58
Is opened, the oil in the high-pressure passage 54 reaches the hydraulic passage 60. In addition, vehicle height adjusting valves 74 to 8
When 0 is set to the valve open state, the oil in the hydraulic passage 60 reaches the control hydraulic passages 82 to 88. Therefore, when the high-pressure cut valve 58 is opened, the vehicle height adjusting valves 74 to
When the valve 80 is opened, high-pressure oil is guided from the high-pressure tank 52 to the shock absorbers 40 to 46. When high-pressure oil is guided to the shock absorbers 40 to 46, the overall length of the shock absorbers 40 to 46 increases. In this case, the height of the vehicle increases.

In this embodiment, if the high-pressure cut valve 58 is closed while the vehicle height adjusting valves 74 to 80 are open, and the discharge valve 72 is opened, a shock occurs. The oil guided to the absorbers 40 to 46 reaches the hydraulic passage 70 via the hydraulic passage 60. Therefore, when the high-pressure cut valve 58 is closed while the vehicle height adjusting valves 74 to 80 are open and the discharge valve 72 is opened, the reserve tank 68 is released from the shock absorbers 40 to 46. High-pressure oil is discharged toward. When oil is discharged from the shock absorbers 40 to 46, the shock absorbers 40 to 46
Has a shorter overall length, and as a result, a lower vehicle height.

As described above, according to the present embodiment, the vehicle height can be adjusted according to the hydraulic pressure of the oil flowing through the shock absorbers 40-46. In order to vibrate the vehicle body in the vertical direction, it is necessary to control the control valve in a short time. In this embodiment, the shock absorber 40
The vehicle body is vibrated in the up-down direction by changing the total length of .about.46 in a short time. According to such a method, it is possible to make the driver recognize the situation in which the vehicle 10 deviates from the travel path 30 quickly and reliably without any uncomfortable feeling.

FIG. 7 shows an example of an ECU for realizing the above functions.
12 shows a flowchart of an example of a control routine executed by the control routine 12. The routine shown in FIG. 7 is a routine that is repeatedly started each time the processing ends. In FIG. 7, steps that execute the same processing as the steps shown in FIG. 3 are denoted by the same reference numerals, and description thereof will be omitted or simplified. That is, in the routine shown in FIG. 7, after it is determined in step 106 that the wheel is on the lane, the process of step 140 is executed next.

In step 140, it is determined whether or not the timer T1 is equal to or greater than a first predetermined value Tsh1. Incidentally, the timer T1 is a counter for counting the duration after starting the process of increasing the total length of the shock absorbers 40 to 46 in order to cause the vehicle body to slightly vibrate. Further, the first predetermined value Tsh1 is a continuation time from the start of the process of increasing the total length of the shock absorbers 40 to 46 in order to cause the vehicle body to vibrate minutely, and is set to a minute value. As a result of the processing in step 140, T1 ≧ Tsh1
Does not hold, it can be determined that the time for stopping the process of increasing the total length of the shock absorbers 40 to 46 has not elapsed. Therefore, when such a determination is made, the process of step 142 is executed next.

In step 142, the exhaust valve 72 is closed, the high-pressure cut valve 58 is opened, and the vehicle height adjusting valve 7 of the wheel which is determined to be on the lane.
The process of opening the valves 4 to 80 is executed. When the processing of step 142 is executed, the high-pressure oil stored in the high-pressure tank 52 is released from the shock absorbers 40 to 4.
It is led to 6.

In step 144, a process for incrementing the timer T1 is executed. According to such processing,
The timer T1 counts the time after the execution of the processing of step 142, that is, the continuation time after starting the processing for increasing the total length of the shock absorbers 40 to 46 so as to slightly vibrate the vehicle body. Step 140 above
If T1.gtoreq.Tsh1 holds, it can be determined that the time for stopping the process of increasing the total length of the shock absorbers 40 to 46 has elapsed. In this case, it is necessary to stop such processing and then start processing to reduce the overall length. Therefore, if such a determination is made in step 140, the process of step 146 is performed next.

At step 146, it is determined whether or not the timer T2 is equal to or greater than a second predetermined value Tsh2. Incidentally, the timer T2 is a counter for counting the duration after starting the process of reducing the total length of the shock absorbers 40 to 46 in order to cause the vehicle body to slightly vibrate. Further, the second predetermined value Tsh2 is a continuation time from the start of the process of reducing the overall length of the shock absorbers 40 to 46 in order to cause the vehicle body to slightly vibrate, and is set to a minute value. As a result of the processing in step 146, T2 ≧ Tsh2
Does not hold, it can be determined that the time for stopping the process of reducing the overall length of the shock absorbers 40 to 46 has not elapsed. Therefore, when such a determination is made, the process of step 148 is executed next.

At step 148, the high pressure cut valve 5
8 is closed, the exhaust valve 72 is opened, and the vehicle height adjustment valve 7 of the wheel determined to be on the lane
The process of opening the valves 4 to 80 is executed. When the processing of step 148 is executed, the shock absorber 4
The oil guided to 0 to 46 is discharged to the reserve tank 68.

In step 150, a process for incrementing the timer T2 is executed. According to such processing,
The timer T2 counts the time after the execution of the processing in step 148, that is, the continuation time after starting the processing for reducing the total length of the shock absorbers 40 to 46 so as to cause the vehicle body to slightly vibrate. Step 146 above
If T2≥Tsh2 is satisfied, it can be determined that the time for stopping the process of reducing the overall length of the shock absorbers 40 to 46 has elapsed. In this case, it is necessary to stop such processing and then start processing to increase the overall length again. Therefore, if such a determination is made in step 146, the process of step 152 is executed next.

In step 152, a process for resetting the timers T1 and T2 to "0" is executed. According to this process, the process of step 142 can be performed after the process of step 140, and the process of step 148 can be performed after step 146. Steps 144 and 15 above
When the processes of 0 and 152 are completed, the process of step 120 is executed, and predetermined sounds are output from the speakers 24 and 25.

When the processing of steps 140 to 152 is repeatedly executed, the shock absorber 4
The total length of 0 to 46 expands and contracts. First predetermined value Tsh
When the first and second predetermined values Tsh2 are set to appropriate times, it is possible to shorten the cycle in which the shock absorbers 40 to 46 expand and contract. If it is determined in step 106 that the wheel is not on the lane, the process of step 154 is executed next.

In step 154, the hydraulic pressure P in the high-pressure tank 52 detected based on the output signal of the pressure sensor 56
Is greater than or equal to a predetermined value P0. P ≧ P0
Does not hold, it can be determined that high-pressure oil is not stored in the high-pressure tank 52. If high-pressure oil is not stored in the high-pressure tank 52, even if the high-pressure cut valve 58 is opened in order to change the total length of the shock absorbers 40 to 46, high-pressure oil can be guided to the shock absorbers 40 to 46. Can not. Therefore, it is necessary to always store high-pressure oil in the high-pressure tank 52. Therefore, if it is determined in this step 154 that P ≧ P0 is not satisfied, the process of step 156 is executed next.

In step 156, a process is executed in which the pump 66 is operated and the high-pressure cut valve 58 is opened. After the processing of step 156 is performed, the oil is sucked from the reserve tank 68 by the pump 66, and the sucked oil is discharged toward the high-pressure tank 52 at a predetermined discharge pressure. Thereby, the liquid pressure in the high-pressure tank 52 is increased.

In step 158, a process is executed in which the discharge valve 72 is closed and the vehicle height adjusting valves 74 to 80 are closed. When the process of step 158 is performed, the oil pressurized by the pump 66 is prevented from being guided to the shock absorbers 40 to 46. When the process of step 158 is completed, the process of step 122 is executed, and the sound output from the speakers 24 and 25 is stopped.

If P ≧ P0 is satisfied in step 154, it can be determined that high-pressure oil is stored in the high-pressure tank 52. In this case, the high pressure tank 52
There is no need to guide high pressure oil to Therefore, if it is determined that P ≧ P0 holds, the process of step 160 is executed next. In step 160, a process of stopping the pump 66 and closing the high-pressure cut valve 58 is executed. When the process of step 160 is completed, the process of step 158 is executed.

According to the above-described processing, the wheels are moved to the lanes 32, 3
4, the shock absorber 4 of the corresponding wheel
The total length of 0 to 46 can be slightly changed. When the total length of the shock absorbers 40 to 46 slightly changes, the relative position between the wheels and the vehicle body changes. Therefore, according to the present embodiment, when the wheels are on the lanes 32 and 34, the vehicle body can be slightly vibrated in the vertical direction with respect to the wheels. When the vehicle body vibrates slightly in the vertical direction, the driver experiences a feeling that the vehicle is traveling on an uneven road. Therefore, according to the present embodiment, similarly to the case of the first embodiment, when the wheels are on the lanes 32 and 34, the situation in which the vehicle 10 deviates from the traveling path 30 can be reliably and promptly determined. It is possible to make the driver recognize without discomfort.

In this embodiment, as described above, when the wheels are on the lanes 32 and 34, the vehicle body slightly vibrates. Therefore, according to the present embodiment, unlike the first embodiment, it is possible to make a passenger other than the driver recognize the situation where the vehicle 10 deviates from the traveling path 30. Therefore, according to the present embodiment, even when the driver cannot recognize such a situation, the passenger can recognize the situation, thereby improving the safety of the vehicle.

When the hydraulic pressure in the high-pressure tank 52 is small, the responsiveness when changing the total length of the shock absorbers 40 to 46 is reduced. On the other hand, in the present embodiment, when the hydraulic pressure in the high-pressure tank 52 is small in a situation where the wheels are not on the lanes 32 and 34, the hydraulic pressure in the high-pressure tank 52 is increased. For this reason, according to the present embodiment, the responsiveness of the shock absorbers 40 to 46 is prevented from lowering because the hydraulic pressure in the high-pressure tank 52 is constantly maintained at a high pressure.

In the present embodiment, the wheels are in the lane 3
2 and 34, the speakers 24 and 25
A sound such as a vibration sound generated when the vehicle is traveling on an uneven road is output. Therefore, according to the present embodiment, the same effect as that of the first embodiment can be obtained.
Furthermore, in this embodiment, the vehicle body vibrates in the vertical direction by adjusting the total length of the shock absorbers 40 to 46 for adjusting the vehicle height. The overall length of the shock absorbers 40 to 46 usually changes according to the vehicle weight. Therefore, according to the present embodiment, it is not necessary to separately provide a new actuator for vibrating the vehicle body, and the driver recognizes the situation where the vehicle 10 deviates from the traveling path 30 while suppressing an increase in manufacturing cost. Can be done.

In the above embodiment, the shock absorbers 40-46 correspond to the "actuator" of the first aspect, and the ECU 12 repeatedly executes the processing of the steps 140-152. The "driving means" described in Item 2 is realized. By the way, in the above embodiment, the shock absorber 40
Although the total length of .about.46 is normally changed in accordance with the weight of the vehicle, it may be changed in accordance with the state of a predetermined switch.

[0063]

As described above, according to the first aspect of the present invention, by vibrating the steering wheel, it is possible to surely and promptly recognize the situation in which the vehicle deviates from the traveling road. Can be. According to the second aspect of the present invention, by vibrating the vehicle body up and down, the driver can reliably and promptly recognize the situation in which the vehicle deviates from the traveling road.

[Brief description of the drawings]

FIG. 1 is a system configuration diagram of a lane departure warning device for a vehicle according to a first embodiment of the present invention.

FIG. 2 is a diagram schematically illustrating a situation realized when a vehicle travels on a traveling road.

FIG. 3 is a flowchart of an example of a control routine executed in the lane departure warning device of the embodiment.

FIG. 4 is a diagram for explaining a change in motor current supplied to a steering motor when a wheel is on a lane.

FIG. 5 is a system configuration diagram of a vehicle lane departure warning device according to a second embodiment of the present invention.

FIG. 6 is a hydraulic pressure control circuit used to change the overall length of the shock absorbers 40 to 46.

FIG. 7 is a flowchart illustrating an example of a control routine executed in the lane departure warning device according to the present embodiment.

[Explanation of symbols]

 12 Electronic control unit (ECU) 20 Steering motor 40-46 Shock absorber

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Claims (2)

[Claims] A lane departure warning device for a vehicle, comprising: a steering mechanism for turning a wheel based on an operation of a steering wheel; and an actuator for applying a driving force to the steering mechanism. A departure discriminating means for discriminating whether or not the vehicle deviates from the traveling road; and a driving means for driving the actuator so that the steering wheel vibrates when it is determined that the vehicle deviates from the traveling road. Lane departure warning device. 2. A lane departure warning device for a vehicle having an actuator for changing a relative position between a wheel and a vehicle body, comprising: a departure determining unit configured to determine whether the vehicle deviates from a traveling road; And a driving means for driving the actuator so that the vehicle body vibrates in the up-down direction when it is determined that the vehicle has a lane departure warning device.