JP2001163131A - Warning device for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a warning device for a vehicle for adequately adjusting a vibration as an alarm generated in a steering mechanism according to a vibration transferred to the steering mechanism from an external part. SOLUTION: When a steering actuator(SA) 10 is driven for warning, a vibration control level T0 and a vibration frequency f0 during a normal running are previously stored as references, a vibration level T1pp and a vibration frequency f1 of the steering mechanism of an own vehicle on a road during the running are detected by a steering torque sensor 6. When a calculated value of |T0-T1pp|is smaller than a threshold c for adjusting a control amount, a control amount for the SA 10 is increased. When |f0-f1|is smaller than a threshold b for adjusting vibration frequency, a vibration frequency to be generated is increased or decreased depending on a dimensional relation between f0 and f1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an alarm device for a vehicle, and more particularly, to an alarm device suitable for being mounted on a typical vehicle such as an automobile.

[0002]

2. Description of the Related Art Conventionally, in the case of an automobile, which is a typical vehicle, a device has been proposed which alerts a driver when a predetermined condition to be notified to a driver has occurred. For example, Japanese Patent Laid-Open No. 11-3
No. 4774 discloses an actuator provided on a steering mechanism of an automobile that vibrates the steering mechanism in order to notify the driver of a deviation from the driving lane.
There has been proposed an alarm device for notifying a driver of danger by the vibration of the steering wheel generated by this.

[0003]

However, even in a situation where the vehicle does not deviate from the traveling lane, the driver can obtain a tactile sensation via the steering wheel due to the road surface conditions (unevenness, ruts, etc.) generated during traveling. Depending on the condition of the running road surface, it may be difficult to distinguish between the steering wheel vibration caused by the current running road surface condition and the vibration of the steering mechanism generated as an alarm. is assumed.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a vehicular alarm device that appropriately adjusts vibration generated in a steering mechanism as an alarm in accordance with vibration transmitted from the outside to the steering mechanism.

[0005]

In order to achieve the above object, a vehicular alarm system according to the present invention has the following features.

That is, when the traveling state detected by the traveling state detecting means detects the traveling state of the vehicle (the value relating to the amount of deviation of the vehicle from the traveling lane), the traveling state detected by the traveling state detecting means becomes a predetermined state (the deviation). Alarm means for vibrating the steering mechanism of the vehicle to notify the driver when the value relating to the amount becomes larger than a predetermined value), and vibration of the steering mechanism in a state where the alarm means is not operated. And a vibration mode when the steering mechanism is vibrated by the alarm means corresponds to a value related to the vibration based on the value related to the vibration detected by the steering vibration detecting means. And a control means for correcting the vibration so as to be different from the vibration mode.

[0007] In the above device configuration, for example, the steering vibration detecting means sets the value relating to the vibration as:
In the case where the vibration level of the steering mechanism is detected, the control means, when causing the alarm mechanism to vibrate the steering mechanism, sets a second vibration level larger than the first vibration level detected by the steering vibration detection means. In order to vibrate at the vibration level, a control signal capable of realizing the second vibration level may be set in the alarm means.

Alternatively, for example, in a case where the steering vibration detecting means detects a vibration frequency of the steering mechanism as a value related to the vibration, the control means sets the alarm means to vibrate the steering mechanism. In order to vibrate at a second vibration frequency different from the first vibration frequency detected by the steering vibration detection means, a control signal capable of realizing the second vibration frequency may be set in the alarm means.

[0009] Preferably, the apparatus further comprises obtaining means for obtaining a road surface friction coefficient of the traveling lane of the vehicle, wherein the control means sets the predetermined value to be smaller as the road surface friction coefficient obtained by the obtaining means is smaller. It should be corrected to a value.

[0010]

According to the present invention described above, it is possible to provide a vehicular alarm device that appropriately adjusts a vibration generated in a steering mechanism as an alarm according to vibration transmitted from the outside to the steering mechanism.

That is, according to the first and fifth aspects of the present invention, the vibration generated in the steering mechanism as an alarm is
According to the vibration transmitted from outside to the steering mechanism,
The driver can appropriately adjust the vibration level by changing the vibration level (Claim 2) or the vibration frequency (Claim 3). Thus, it is possible to easily determine the vibration of the steering mechanism as an alarm.

According to the fourth aspect of the present invention, when the traveling lane having a small road friction coefficient μ is slippery, an alarm by vibrating the steering mechanism as compared with when the road friction coefficient μ is large. Is executed early, so that a sudden avoidance operation by the driver can be prevented.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, when a vehicular alarm device according to the present invention is applied to a typical vehicle such as an automobile,
This will be described in detail with reference to the drawings.

FIG. 1 is a diagram showing the overall configuration of an automobile equipped with a vehicle alarm device according to this embodiment.

In FIG. 1, reference numeral 2 denotes a vehicle (vehicle 10).
This is a CCD (Charge Coupled Device) camera that photographs the front of 0). Reference numeral 3 denotes a vehicle speed sensor that detects the vehicle speed V. Reference numeral 4 denotes a wheel speed sensor that individually detects rotation speeds of four wheels of the vehicle 100. Reference numeral 6 denotes a steering torque sensor that detects a steering torque (steering reaction force) of the steering wheel by the driver. Reference numeral 7 denotes a steering angle sensor that detects a steering angle of the vehicle 100. Incidentally, these sensors themselves are common nowadays, and thus detailed description in the present embodiment is omitted.

The control unit 1 drives the steering actuator 10 based on the detection results of these sensors, as described later, to generate vibration in the steering mechanism of the vehicle 100 as one mode of warning to the driver. .

Next, control processing of the steering actuator 10 performed by the control unit 1 using the detection results of the sensors shown in FIG. 1 will be described with reference to FIG.

FIG. 2 is a block diagram for explaining control processing performed by the control unit of the vehicle alarm device according to the present embodiment. A microcomputer (not shown) provided in the control unit 1 is stored in advance. FIG. 4 is a diagram schematically illustrating functions realized by executing a control program.

In FIG. 1, first, a lane marking (for example, a white line) of a currently traveling lane is detected by general image processing based on an image captured by the CCD camera 2, and
The lateral position deviation (ie, course deviation) dy0 and yaw angle φ of the host vehicle with respect to the current target trajectory (for example, a trajectory connecting the center of the traveling lane) TR calculated based on the detected lane markings are detected. The variation ΔY of the target trajectory TR at the gazing point y1 is estimated. Note that the method of obtaining these values is generally common at present, and a detailed description thereof will be omitted.

Then, a predicted value (future lateral deviation) dy1 of the lateral position deviation at the forward fixation point y1 is calculated. For example,
As shown in FIG. 3, the local coordinate system X is located on the trajectory (center of the lane) of the target trajectory TR so that the lateral position deviation dy0 of the host vehicle with respect to the target trajectory TR of the vehicle 100 is on the Y axis.
When −Y is set, the predicted value dy1 can be calculated by the following equation.

Dy1 = ΔY + (dy0 + φ × L), where φ is the yaw angle of the vehicle,
Forward fixation distance L = vehicle speed V × t (t is the time required for the vehicle 100 to reach the front fixation point y1 (headway time).

Next, the distance DL to the lane (white line) that divides the travel lane with the lane width W when the vehicle 100 reaches the forward fixation point y1 can be calculated by the following equation.

DL = W / 2− | dy1 |, and an alarm by driving the steering actuator 10 is issued when the calculated distance DL is smaller than the threshold value A for determining lane departure. This threshold A
Increases the threshold value A when the road friction coefficient μ is small, according to the road friction coefficient μ calculated by a general method based on the difference between the rotational speeds of the wheels detected by the four wheel speed sensors 4. When the road friction coefficient μ is large, the threshold value A is changed to a small value (see FIG. 6).
The warning is stopped when the distance DL exceeds the threshold value A and deviates from the lane departure determination condition, or when the steering is performed in a direction that can avoid the lane departure (the steering angle sensor 7). Is performed when the steering angle detected from the threshold value increases in a direction in which the lane departure can be avoided.

In the present embodiment, when driving the steering actuator 10 as described above, the mode of the vibration control for vibrating the steering mechanism of the vehicle 100 includes control for changing the magnitude of the vibration generated in the steering mechanism, It consists of control for changing the frequency of the vibration. That is, the control for changing the magnitude of the vibration is realized by adjusting the control amount (control torque if the actuator is an electric motor) T for the steering actuator 10, while the control for changing the vibration frequency is The calculated control amount T is applied to the steering actuator 1
It may be realized by changing the pulse rate of the control signal output for 0, adjusting the cycle of changing the control gain, or the like.

As a specific procedure for controlling these vibrations and their frequencies, a vibration control level T0 and a vibration frequency f0 during normal running (during a general paved road) serving as references are stored in advance. Detecting the vibration level T1pp and the vibration frequency f1 of the steering mechanism of the vehicle 100 on the road on which the vehicle is currently traveling by the steering torque sensor 6,
When the calculated value of | T0−T1pp | is smaller than the threshold value c for control amount adjustment, the control amount for the steering actuator 10 is increased and | f0−f1
Is smaller than the threshold value b for adjusting the vibration frequency, the generated vibration frequency is changed to be larger or smaller according to the magnitude relationship between f0 and f1.

By performing such control, the driver can easily discriminate between the vibration generated in the steering mechanism due to the current road surface condition and the vibration of the steering mechanism as an alarm.

Next, a procedure of a control process executed by a microcomputer (not shown) of the control unit 1 to realize the above-described alarm function will be described with reference to FIGS.

FIGS. 4 and 5 are flowcharts showing a control process executed by the control unit of the vehicle alarm device according to the present embodiment. The control process is started by, for example, turning on an ignition key switch of the vehicle 100. You.

In the figure, step S1: The detection result by each sensor shown in FIGS. 1 and 2 is updated.

Steps S2 to S4: In order to use the above-mentioned predicted value dy1 in the calculation, the front gaze distance L is estimated, and the lateral position deviation dy0 and the yaw angle φ are calculated.

Step S5: A lane marking (eg, a white lane) of the currently traveling lane is detected by general image processing based on the image captured by the CCD camera 2, and a target trajectory TR is determined based on the detected lane marking. calculate.

Steps S6 and S7: The future lateral deviation dy1 is calculated by the above-described formula (step S6).
At the same time, the distance DL to the lane (white line) at the time when the vehicle 100 reaches the forward fixation point y1 is calculated (step S7).

Step S8: Based on the difference between the rotational speeds of the wheels detected by the four wheel speed sensors 4, a road friction coefficient μ is calculated by a general procedure.

Step S9: A threshold value A for judging lane departure is set by referring to the look-up table shown in FIG. 10 according to the road friction coefficient μ calculated in step S8.

Step S10: It is determined whether or not the distance DL is smaller than the threshold value A. If the determination is YES (DL ≦ A), the process proceeds to step S11, and if the determination is NO (DL> A), an alarm for notifying the lane departure is issued. Is not necessary and returns.

Steps S11 to S13: Internal flag STR_F indicating whether or not an alarm operation is being performed.
It is determined whether or not G (executing at 0, stopping at 1) is set to "1". If the determination is NO (FL = 0), the alarm operation is already being performed, and the process proceeds to step S1.
Proceed to 4. On the other hand, if the determination in step S11 is YES (FL = 1), the current steering angle θ detected by the steering angle sensor 7 is set as the reference steering angle θ0 for stopping the alarm (step S12), and the FL is set. Is set to “0”.

Steps S14 and S15: Difference | f0−f1 | between steering reaction force noise (vibration frequency) f1 detected by steering torque sensor 6 and vibration frequency f0 during normal running stored in advance in the memory. But,
It is determined whether the threshold value is smaller than the threshold value b for adjusting the vibration frequency. If the determination is NO (| f0-f1 |> b), the process proceeds to step S18, and YES (| f0-f1 | ≦ b)
When f0 and f1, the magnitude relationship between f0 and f1 is compared (step S15). When f0 <f1, the process proceeds to step S16. When f0 ≧ f1, the process proceeds to step S17.
Proceed to.

Step S16: Since the current vibration frequency f1 is higher than the vibration frequency f0, the frequency f
From the current vibration frequency f1 by a predetermined correction amount α (α>
b) Set a lower frequency.

Step S17: Since the current vibration frequency f1 is smaller than the vibration frequency f0, the frequency f
From the current vibration frequency f1 by a predetermined correction amount α (α>
b) Set a higher frequency.

Step S18: Since the difference between the current vibration frequency f1 and the vibration frequency f0 is larger than the threshold value b,
Since it is possible to judge that the driver is unlikely to confuse the vibration frequency of the steering mechanism caused by the road surface condition during the current traveling with the vibration frequency of the steering mechanism as an alarm, the vibration frequency f0 stored in the memory in advance is low.
Is set as the frequency f at the time of alarm execution.

Steps S19 to S21: Difference | T0− between steering vibration noise (vibration level) T1pp detected by steering torque sensor 6 and vibration control level T0 during normal running stored in advance in the memory.
It is determined whether T1pp | is smaller than threshold value c for adjusting the vibration level. Then, in this determination, YES (| T
When 0−T1pp | ≦ c), the control torque T for the steering actuator 10 is set to a value larger than the reference vibration control level T0 by a predetermined correction amount β (step S20), and NO (| T0−T1pp | >
In the case of c), it is possible to judge that the driver is unlikely to confuse the magnitude of the vibration of the steering mechanism caused by the road surface condition during the traveling with the magnitude of the vibration of the steering mechanism as an alarm. The control torque T is set to the vibration control level T0 stored in the memory in advance.

Step S22: It is determined whether or not the vehicle 100 may deviate to the right lane by determining whether the future lateral deviation dy1 calculated in step S6 is greater than zero.

Steps S23 to S26: There is a possibility that the vehicle deviates to the right lane in step S22 (dy
1> 0), step S23 is performed in order to determine whether steering that can avoid the departure to the right lane has been performed.
Then, it is determined whether the difference obtained by subtracting the reference steering angle θ0 set in step S12 from the change amount (steering amount) of the steering angle detected by the steering angle sensor 7 is smaller than a threshold value d (however, right The steering angle in the right direction is positive, and the steering in the left direction is negative). If the determination is YES (θ−θ0 ≦ d), it can be determined that steering that can avoid the departure to the right lane has been performed, so that the alarm operation is stopped and the internal flag STR_FG is set to “1”. Is set (step S24), and the process returns. On the other hand, if the determination in step S23 is NO (θ−θ0 <d), it can be determined that the steering that can avoid the departure to the right lane has not been performed, and therefore, in steps S16 to S18. It is determined that the alarm operation is to be performed with the set vibration frequency f and the control torque T set in step S20 or step S21 (step S25), and the steering actuator 10 is driven by those values (step S26). I do.

Steps S27 to S30: There is a possibility that the vehicle deviates to the left lane in step S22 (dy)
1 ≦ 0), step S27 is performed in order to determine whether steering that can avoid the departure to the left lane has been performed.
Then, it is determined whether or not the difference obtained by subtracting the reference steering angle θ0 set in step S12 from the change amount (steering amount) of the steering angle detected by the steering angle sensor 7 is larger than the threshold value d. If the determination is YES (θ−θ0 ≧ d), it can be determined that steering that can avoid the departure to the left lane has been performed, so the alarm operation is stopped and the internal flag STR_FG is set to “1”. Set (Step S2
8) Return.

On the other hand, if the determination in step S27 is NO (θ
When −θ0> d), it can be determined that the steering that can avoid the departure to the left lane is not being performed. Therefore, the vibration frequency f set in steps S16 to S18, and the step S20 or step S20 S2
It is determined that the alarm operation is to be performed with the control torque T set in Step 1 (Step S29), and the steering actuator 10 is driven by those values (Step S3).
0), return.

As described above, according to the above-described embodiment, the vibration frequency f and / or the magnitude of the control torque T of the vibration generated in the steering mechanism as an alarm are determined according to the vibration transmitted from the outside to the steering mechanism. The steering mechanism can be appropriately adjusted to generate a vibration mode different from the vibration transmitted from the outside. Thus, even if the vibration of the steering mechanism generated due to the road surface condition at the time of traveling is transmitted to the steering wheel, the driver can easily determine the vibration generated by the steering mechanism as an alarm.

Further, in the present embodiment, when the road surface friction coefficient μ is small, the lane departure warning is notified earlier than when the road surface friction coefficient is large. it can.

In the above-described embodiment, the alarm device according to the present embodiment is configured as a device for alarming prevention of departure from the traveling lane. However, the present invention is not limited to this configuration. The warning device may be configured as an alarm device for an obstacle existing in front of the vehicle or an alarm device for another vehicle or the like located on the rear side of the vehicle.

[Brief description of the drawings]

FIG. 1 is a diagram showing an overall configuration of an automobile equipped with a vehicle alarm device according to an embodiment.

FIG. 2 is a block diagram illustrating a control process performed by a control unit of the vehicle alarm device according to the embodiment.

FIG. 3 is a diagram illustrating values to be calculated for an alarm for preventing the vehicle 100 from departing from the lane.

FIG. 4 is a flowchart showing a control process executed by a control unit of the vehicle alarm device according to the embodiment.

FIG. 5 is a flowchart showing a control process executed by a control unit of the vehicle alarm device according to the embodiment.

FIG. 6 is a diagram exemplifying a lookup table used when changing a threshold value A for lane departure determination according to a road friction coefficient μ.

[Explanation of symbols]

 1: control unit, 2: CCD camera, 3: vehicle speed sensor, 4: wheel speed sensor, 6: steering torque sensor, 7: steering angle sensor, 10: steering actuator, 100: vehicle,

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) B62D 113: 00 B62D 119: 00 119: 00 B60R 21/00 624F 624C 626Z F term (Reference) 3D032 CC21 DA01 DA03 DA15 DA23 DA24 DA27 DA32 DA82 DA84 DB01 DC08 DC33 DC38 DE01 EA01 EB11 EC22 GG01 3D037 FA13 FA14 FA16 FA23 FA26 FB11 5H180 AA01 CC04 LL01 LL02 LL08

Claims (5)

[Claims] 1. A driving state detecting means for detecting a value relating to a deviation amount of a vehicle from a traveling lane, and a driver when a value relating to the deviation amount detected by the traveling state detecting means becomes larger than a predetermined value. Alarm means for vibrating the steering mechanism of the vehicle, a steering vibration detecting means for detecting a value relating to the vibration of the steering mechanism when the alarm means is not operated, and the steering mechanism by the alarm means. Control means for correcting, based on a value relating to the vibration detected by the steering vibration detecting means, a vibration mode at the time of causing the vibration to be different from a vibration mode corresponding to the value relating to the vibration. An alarm device for a vehicle, comprising: 2. The steering vibration detecting means detects a vibration level of the steering mechanism as a value related to the vibration. The control means controls the steering vibration when the alarm mechanism vibrates the steering mechanism. A control signal capable of realizing the second vibration level is set to the alarm means so as to vibrate at a second vibration level larger than the first vibration level detected by the detection means. 2. The vehicle alarm device according to 1. 3. The steering vibration detecting means detects a vibration frequency of the steering mechanism as a value related to the vibration. The control means controls the steering vibration when the alarm mechanism vibrates the steering mechanism. A control signal capable of realizing the second vibration frequency is set in the alarm means so as to vibrate at a second vibration frequency different from the first vibration frequency detected by the detection means. Item 4. The vehicle alarm device according to Item 1. 4. The vehicle according to claim 1, further comprising an obtaining unit that obtains a road surface friction coefficient of a traveling lane of the vehicle, wherein the control unit sets the predetermined value to a smaller value as the road surface friction coefficient obtained by the obtaining unit becomes smaller. The vehicular alarm device according to claim 1, wherein the correction is performed. 5. A traveling state detecting means for detecting a traveling state of a vehicle, and the vehicle is adapted to notify a driver when the traveling state detected by the traveling state detecting means becomes a predetermined state. Alarm means for vibrating the steering mechanism of the above, steering vibration detection means for detecting a value relating to vibration of the steering mechanism in a state where the alarm means is not operated, and vibration mode when the steering mechanism is vibrated by the alarm means Control means for correcting, based on a value related to the vibration detected by the steering vibration detecting means, a mode different from a vibration mode corresponding to the value related to the vibration. Alarm device.