JP2007223505A - Vehicular road surface contact suppressing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vehicular road surface contact suppressing device capable of suppressing the contact of a vehicle body with a road surface. <P>SOLUTION: The vehicular road surface contact suppressing device comprises a gradient information acquisition means for acquiring gradient information of a road surface on a course of a vehicle, a changed position detection means for detecting the gradient change position from the acquired gradient information, a changed point angle detection means for detecting the angular change at the gradient change position detected from the acquired gradient information, a vehicle speed detection means for detecting the vehicle speed, a contact estimation means for estimating the contact of a vehicle with the road surface based on the detected angular change and vehicle speed at the gradient change position, and a contact suppression means for suppressing the contact of the vehicle with the road surface when the contact is estimated. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a road surface contact suppression device for a vehicle, and more particularly to a road surface contact suppression device for a vehicle that suppresses the vehicle from contacting the road surface at a position where the gradient on the road surface changes.

  2. Description of the Related Art Conventionally, there has been known a device that supports driving of a driver by displaying a road surface shape such as a slope or a curve on a head-up display or a predetermined screen using lines or symbols (for example, Patent Document 1). A display alarm device that displays an obstacle on the road and avoids the obstacle is known (for example, Patent Document 2).

JP 2005-145434 A JP 2006-040123 A

  In the apparatus as described above, it is not considered to suppress contact with the “road surface” itself, which is normally not recognized as an obstacle. Here, the vehicle may also contact the road surface. That is, there is a case where the rear side of the vehicle body or the front bumper is rubbed on a slope when entering a parking lot such as a supermarket or on a downhill coming from the back alley to the main street. In the conventional technology described above, even if such an approach slope to the parking lot or the road surface shape of the exit to the main street is temporarily displayed, the driver determines whether or not the vehicle is in contact with the road surface. As a result, the vehicle could come into contact.

  Therefore, the present invention has been made to solve the above-described conventional problems, and an object of the present invention is to provide a vehicle road surface contact suppression device capable of suppressing contact of the vehicle body with the road surface.

In order to achieve the above object, the present invention provides a gradient information acquisition unit that acquires gradient information of a road surface on the course of a vehicle, a change position detection unit that detects a gradient change position from the acquired gradient information, and the acquired gradient Change point angle detection means for detecting the angle change amount at the gradient change position detected from the information, vehicle speed detection means for detecting the vehicle speed of the vehicle, and based on the detected angle change amount and vehicle speed of the gradient change position. A contact prediction unit that predicts contact with a road surface, and a contact suppression unit that suppresses contact of the vehicle with the road surface when contact is predicted, are provided.
In the present invention configured as described above, the contact predicting means predicts contact with the road surface of the vehicle based on the angle change amount and the vehicle speed. Here, the contact between the vehicle and the road surface is likely to occur when the difference in gradient is relatively large and the vehicle speed is relatively large. Accordingly, it is possible to reliably predict the contact of the vehicle with the road surface. And the contact to the road surface of a vehicle can be suppressed by a contact suppression means.

In the present invention, it is preferable that the contact suppressing unit includes a vehicle deceleration unit that decelerates the vehicle.
In this invention comprised in this way, the contact to the road surface of a vehicle can be suppressed more reliably.

In the present invention, it is preferable that the contact suppression unit includes a notification unit that notifies the driver that contact with the road surface of the vehicle is predicted.
In this invention comprised in this way, the driving | operation which suppresses a contact can be encouraged by the notification of contact prediction. As a result, contact with the road surface of the vehicle is suppressed.

In the present invention, it is preferable that the contact suppression unit includes a gradient change position display unit that displays the detected gradient change position so as to be superimposed on the course of the vehicle.
In the present invention configured as described above, since the driver can know the position where the contact is predicted, the contact with the road surface of the vehicle is more reliably suppressed.

In the present invention, it is preferable that the gradient information acquisition unit has a camera mounted on the vehicle and captures the front of the vehicle, and analyzes the image captured by the camera to detect the gradient information on the road surface on the course of the vehicle. To get.
In the present invention configured as described above, the gradient information can be acquired even if the vehicle is not provided with gradient information data in advance.

In the present invention, it is preferable that the vehicle has a navigation device, and the gradient information acquisition unit acquires gradient information on a road surface on the course of the vehicle from the navigation device.
In the present invention configured as described above, gradient information can be obtained with certainty.

In the present invention, it is preferable that the vehicle includes a navigation device, the gradient information acquisition unit includes a camera mounted on the vehicle and photographs the front of the vehicle, and the gradient information acquisition unit is stored in the navigation device. By reading the gradient information and / or analyzing the image taken by the camera, the gradient information of the road surface on the course of the vehicle is acquired.
In the present invention configured as described above, gradient information can be acquired more reliably and gradient information can be enhanced.

In the present invention, it is preferable that the navigation apparatus includes a storage unit that stores a gradient change position at which contact with the road surface of the vehicle is predicted.
In this invention comprised in this way, when passing the same position again, the contact to the road surface of a vehicle can be suppressed more reliably.

In the present invention, it is preferable that the vehicle further includes posture detecting means for detecting a posture change amount with respect to the road surface of the vehicle, and the contact predicting means includes the angle change amount of the gradient change position, the detected vehicle speed, and the posture. Based on the amount of change, the contact of the vehicle with the road surface is predicted.
In this invention comprised in this way, the prediction precision of the contact to the road surface of a vehicle can be improved.

In the present invention, it is preferable that a distance detection unit that detects a distance between the vehicle and the detected gradient change position, an acceleration prediction unit that predicts an acceleration of the vehicle at the detected distance, and a vehicle speed Based on the vehicle speed detected by the detecting means, the distance detected by the distance detecting means, and the acceleration predicted by the acceleration predicting means, the vehicle speed predicting means at arrival time predicts the vehicle speed when the vehicle reaches the gradient change position. The contact prediction means predicts contact with the road surface of the vehicle based on the detected angular change amount of the gradient change position and the predicted vehicle speed at arrival.
In this invention comprised in this way, the prediction precision of the contact to the road surface of a vehicle can be improved.

In the present invention, it is preferable that the vehicle further includes a road surface gradient angle detection unit that detects a road surface gradient angle, and the acceleration prediction unit takes into account the acceleration calculated by the detected gradient angle and gravitational acceleration. Predict vehicle acceleration.
In this invention comprised in this way, the prediction precision of the contact to the road surface of a vehicle can be improved.

In the present invention, preferably, the acceleration predicting means predicts the acceleration of the vehicle in consideration of a required acceleration defined by the accelerator opening of the vehicle.
In this invention comprised in this way, the prediction precision of the contact to the road surface of a vehicle can be improved.

  According to the road surface contact suppression device for a vehicle of the present invention, the contact of the vehicle body with the road surface can be suppressed.

Embodiments of the present invention will be described below with reference to the accompanying drawings.
The road surface contact suppression device for a vehicle according to an embodiment of the present invention suppresses contact between the vehicle and the road surface in a normal travel path, for example, a general road or a supermarket parking lot. For example, as shown in FIG. 5, the lower surface of the body of the vehicle 1 or the front bumper is on the road surface at a gradient change position such as a position E that changes from a downhill to a flat road or a position B that changes from a flat road to an uphill. It suppresses that it contacts. Such contact is unlikely to occur when the vehicle speed is low, and is likely to occur when the vehicle speed is high. In this embodiment, contact between the vehicle and the road surface is basically suppressed according to the vehicle speed and the gradient angle.

  FIG. 1 is a block diagram illustrating a basic configuration of a vehicle road surface contact suppression device according to an embodiment of the present invention. As shown in FIG. 1, the road surface contact suppression device according to the present embodiment includes an ECU 2, which includes image information of an in-vehicle camera 4 that images the front of the vehicle, an output signal of a gyro 6, and a vehicle speed sensor 8. An output signal and an output signal of the accelerator opening sensor 10 are input. Further, of the map data 14 stored in the navigation device 12, road surface gradient information on the course of the vehicle, for example, the gradient change position of the road surface in the forward direction of the vehicle, the gradient angle, and the length of the hill are input. The The ECU 2 has a function of predicting contact with the road surface of the vehicle based on these input signals and outputting a control signal to each device in order to suppress contact. The navigation device 12 includes a display 16 that displays a map and guidance, and a storage device 18 that can store various information.

  The ECU 2 also has a function of analyzing the image obtained by the in-vehicle camera 4 and generating road surface gradient information on the course of the vehicle. Examples of images obtained by the in-vehicle camera 4 are shown in FIGS. FIG. 2 (b) is an image obtained by photographing in the direction shown in FIG. 2 (a) on the downhill, and FIG. 3 (b) is shown in FIG. 3 (a) before the uphill. 4B is an image obtained by photographing in such an orientation as shown in FIG. 4A on a flat road.

As shown in FIG. 4B, on a flat road, the traveling road R extends upward on the screen, and the sky or the like often appears beyond it. On the other hand, as shown in FIG. 2 (b) or FIG. 3 (b), at the end of the downhill or before the uphill, the traveling path R often extends upward on the screen to fill the screen. In many cases, the end E of the downhill and the start end B of the uphill are visible on the screen, and the traveling path R extends on the screen before and after the end E and the start end B ( For example, θ1, θ2) changes.

  The ECU 2 analyzes the image of such a screen and captures the characteristics of the downhill and the uphill. For example, the white line W is extracted by luminance change, and the angle (θ1, θ2, etc.) that the travel path R extends on the screen is detected from the direction in which the extracted white line W extends. From the change point of the angle along which the travel path R extends, the gradient change position (the terminal end E, the start end B, etc.) is extracted. The ECU 2 calculates the relative angle of the gradient before and after the gradient change position from the difference in angle between which the travel path R extends before and after the gradient change position (for example, the difference between θ1 and θ2). The ECU 2 also calculates a distance L (see FIG. 5) from the host vehicle to the gradient change position (for example, E, B) based on the image analysis result.

  Next, the ECU 2 calculates the inclination of the host vehicle from the pitch angle of the gyro 6. The inclination of the host vehicle is used as the slope angle φ of the slope. Further, according to the output signal of the gyro 6, in this embodiment, the posture of the vehicle, that is, the pitch angle and the roll angle with respect to the road surface can be detected. Further, the ECU 2 calculates the vehicle speed V0 of the vehicle 1 from the output signal of the vehicle speed sensor 8, and calculates the required acceleration a from the output signal of the accelerator opening sensor 10.

  Next, as shown in FIG. 1, the display 16 and the storage device 18 of the navigation device 12, the head-up display 20, the indicator / speaker 22, the brake device 24, and the throttle 26 are connected to the ECU 2. As will be described later, each of the displays 16 and 20 and the indicator / speaker 22 notifies the driver of various information by an output signal from the ECU 2. As will be described later, the brake device 24 and the throttle 26 are configured so that the vehicle is decelerated by a signal from the ECU 2.

Next, the contents of processing by the road surface contact suppression device for a vehicle according to the embodiment of the present invention will be described with reference to FIGS.
FIG. 5 is a diagram schematically showing the relationship between the vehicle and the road surface. In this road surface contact suppression device, for example, as shown in FIG. 5, the vehicle 1 is controlled so as not to contact the road surface mainly at the end E of the downhill and the start B of the uphill on the flat road. In the present embodiment, the vehicle 1 is prevented from coming into contact with the road surface on the basis of the relative inclination angle α of the downhill or the uphill with respect to the flat road and the approach speed V1 of the vehicle 1 to the end portion E or the start end portion B. Suppressed. In addition to the road situation as shown in FIG. 5, the present embodiment can detect the relative angle of the gradient and suppress contact even when the downhill is changed to the uphill as it is.

The specific processing details of contact prediction and contact suppression will be described with reference to FIG. FIG. 6 is a flowchart showing the processing contents of the road surface contact suppression device according to the present embodiment.
First, in S1, gradient data such as the road surface gradient angle (φ) of the current location of the vehicle and the gradient change position and gradient angle of the road surface in the traveling direction with respect to the current location are read from the map data 14 of the navigation device 12. The ECU 2 calculates the relative gradient angle (α) of the road surface before and after the gradient change position and the distance (L) from the host vehicle to the gradient change position.

Next, in S2, an image in front of the vehicle is taken by the camera 4, and on the basis of this image, the ECU 2 takes the road surface gradient change position, the distance from the host vehicle to the gradient change position (L), and the gradient change. The relative gradient angle (α) of the road surface before and after the position is calculated.
Next, in S3, the road surface gradient angle (φ) of the current location of the vehicle is calculated from the output signal of the gyro 6.
As a modified example, road gradient data acquisition using the map data 14 of the navigation device 12 (S1), and road surface gradient data acquisition using image information and a gyro by the in-vehicle camera 4 (S2, S3). Only one of them may be performed.

  Next, in S4, it is determined whether or not there is a gradient change position in front of the host vehicle. In this S4, the data obtained from the map data 14 (see S1) is preferentially used for determination. For example, when there is no gradient data in the map data 14 such as a supermarket parking lot, the camera 4 Judgment is made using data obtained from the image (see S2). If it is determined in S4 that there is no gradient change position, the processes of S1 to S4 are repeated again.

If it is determined in S4 that there is a gradient change position, the process proceeds to S5, and the current vehicle speed V0 of the host vehicle is detected from the output signal of the vehicle speed sensor 8.
Next, in S <b> 6, the attitude of the host vehicle with respect to the road surface is detected from the output signal of the gyro 6. In the present embodiment, as shown in FIG. 7, the vehicle pitch is detected as a slope γ.
Next, in S7, the speed V1 when the vehicle reaches the gradient change position is predicted. The contents of the prediction calculation in S7 will be described.

In the present embodiment, the vehicle speed V1 (t) after the predetermined time t has elapsed is calculated using the following equation 1.
V1 (t) = V0 + g × sinφ × t + a × t (Formula 1)
V0 is the vehicle speed detected in S5, g is the gravitational acceleration, and φ indicates the gradient angle of the road surface at the current location of the vehicle. This φ is an absolute angle, unlike α described above, and the downward direction is positive. φ is the value read in S1 or the value detected by the gyro in S3. a is the required acceleration, and this required acceleration a is calculated from the output signal of the opening sensor 10 in S7.

According to Equation 1, the arrival speed V1 can be calculated in consideration of the gravitational acceleration on the downhill and the required acceleration due to the driver's stepping on the accelerator. In this case, the predetermined time t is a time (= T1-T0) until the vehicle reaches the gradient change position. T0 and T1 are vehicle passage times at the respective points shown in FIG. In the present embodiment, the time t until the gradient change position is reached is calculated using the following equation 2.
L (t) = V0 × t + (g × sin φ + a) / 2 × t ² (Formula 2)
L (t) is the distance from the host vehicle, and the other symbols are the same as in Equation 1.

  L (t) includes a distance L (see FIG. 5) from the own vehicle detected in S1 or S2 to the gradient change position, V0 detected in S5, and a road gradient angle φ obtained in S1 or S3. Then, t is calculated by substituting a obtained in S7. If this t is substituted into Equation 1, the arrival speed V1 is calculated as a predicted value. Thus, V1 is calculated based on the vehicle speed V0 obtained by the vehicle speed sensor 8, and further calculated with consideration for acceleration, so that the prediction accuracy is high. As a modification, the arrival speed V1 may be predicted in consideration of only the gravitational acceleration g or only the required acceleration a. As a modification, the length of the hill itself (total distance) is substituted as the value of L (see FIG. 5A), and for example, contact is made in advance before the vehicle enters the downhill. It may be predicted.

  Next, it progresses to S8 and it is determined whether a vehicle contacts a road surface. This determination is made by the ECU 2 based on the maps shown in FIGS. The contents will be described. FIG. 8 is a map showing the relationship between the gradient angle α used for the contact prediction of the road surface contact suppression device according to the present embodiment and the limit vehicle speed, and FIG. 9 is used for the contact prediction of the road surface contact suppression device according to the present embodiment. 3 is a map showing the relationship between the vehicle inclination γ and the limit vehicle speed correction coefficient.

As shown in FIG. 8, for example, if the gradient angle α is 15 °, the limit vehicle speed is 70 km / h, and the limit vehicle speed increases as the gradient angle α becomes smaller than 15 °. Similarly, for example, if the gradient angle α is 21 °, the limit vehicle speed is 50 km / h.
As shown in FIG. 9, when the vehicle posture is tilted by 6 °, the correction coefficient is 0.6. This correction coefficient is multiplied by the limit vehicle speed shown in FIG. That is, in the above-described example, for example, if the gradient angle α is 21 °, the limit vehicle speed is 30 km / h of 50 km / h × 0.6. Here, when the vehicle inclination γ is 16 ° or more, the correction coefficient is larger than that in the case of 11 to 15 °. The correction for the limit vehicle speed defined in FIG. 8 is performed in consideration of the reaction of the submerged suspension. This is to reduce the amount.

In S8, the limit vehicle speed at this gradient change position is specified by the gradient angle α calculated in S1 or S2 and the vehicle inclination γ detected in S6, and the specified limit vehicle speed is predicted in S7. The reached vehicle speed V1 is compared. When V1 is larger than the specified limit vehicle speed, it is determined that the vehicle is in contact with the road surface, and when V1 is smaller, it is determined that the vehicle is not in contact. As a modification, the contact determination may be performed by comparing the vehicle speed V0 obtained from the vehicle speed sensor 8 with the limit vehicle speed. As a modified example, the contact determination may be performed after the limit vehicle speed is specified only by the relationship map between the vehicle speed and the gradient angle α shown in FIG. 8 without detecting the posture of the vehicle in S6.
If it is determined in S8 that no contact is made, the processes of S1 to S7 are repeated again. If it is determined that contact is made, notification to the driver in S9 and deceleration control in S10 are performed in order to suppress contact. Is called.

  In S9, the indicator / speaker 22 (refer to FIG. 1) performs lighting of a warning lamp in the meter panel and notification by sound. Also, as shown in FIG. 10, the head-up display 20 displays a distance display M1 up to the gradient change position where contact is predicted, overlaid on the actually visible road surface. Further, a warning mark M2 is displayed, and the predicted contact position can be clearly understood by this mark M2. Further, as shown in FIG. 11, the predicted display position (gradient change position) M3 and warning mark are superimposed on the map information (in the example of FIG. 11, the map information of the underground parking lot) on the display 16 of the navigation device. M4 is displayed. These notifications (warning lights, voices, M1 to M4) may be any one of them.

Next, at S10, the ECU 2 closes the throttle 26 and activates the brake device 24 to decelerate the vehicle. These deceleration controls are performed until the vehicle speed falls below the limit vehicle speed specified in FIGS. As a modification, only one of S9 and S10 may be performed.
Next, when it is determined in S11 that the driver stores information related to the gradient change position, the process proceeds to S12 by a predetermined button operation, and the position information and gradient angle α of the gradient change position are stored in the storage device 18 of the navigation device 12. Is memorized.

It is a block diagram which shows the basic composition of the road surface contact suppression apparatus of the vehicle by embodiment of this invention. It is a figure which shows an example of the image obtained by a front imaging camera. It is a figure which shows an example of the image obtained by a front imaging camera. It is a figure which shows an example of the image obtained by a front imaging camera. It is a figure which shows typically the relationship between a vehicle and a road surface. It is a flowchart which shows the processing content of the road surface contact suppression apparatus by this embodiment. It is a schematic diagram for demonstrating the inclination of a vehicle. It is a map which shows the relationship between the gradient angle (alpha) used for the contact prediction of the road surface contact suppression apparatus by this embodiment, and a limit vehicle speed. It is a map which shows the relationship between the inclination (gamma) of the vehicle used for the contact prediction of the road surface contact suppression apparatus by this embodiment, and the correction coefficient of a limit vehicle speed. It is an example of the notification screen of the contact prediction displayed on a head-up display. It is an example of the notification screen of the contact prediction displayed on the display display of a navigation apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Vehicle V0 Vehicle speed V1 at the present time of vehicle Predicted vehicle speed α when the vehicle reaches the gradient change position Relative angle φ before and after the gradient change position of the road surface gradient Absolute angle L of the road surface gradient L Change position from the vehicle Distance to (or slope distance)
γ Vehicle posture (tilt (pitch) in the vehicle longitudinal direction)
E, B Gradient change position where contact is expected

Claims (12)

Gradient information acquisition means for acquiring gradient information on the road surface of the vehicle,
Change position detection means for detecting a gradient change position from the acquired gradient information;
Change point angle detecting means for detecting an angle change amount at the detected gradient change position from the acquired gradient information;
Vehicle speed detection means for detecting the vehicle speed of the vehicle;
Contact prediction means for predicting contact with the road surface of the vehicle based on the detected angle change amount and vehicle speed of the gradient change position;
And a contact suppression means for suppressing contact of the vehicle with the road surface when the contact is predicted.   The road surface contact suppression device for a vehicle according to claim 1, wherein the contact suppression means includes vehicle deceleration means for decelerating the vehicle.   3. The road surface contact suppression device for a vehicle according to claim 1, wherein the contact suppression means includes notification means for notifying a driver that contact with the road surface of the vehicle is predicted.   4. The road surface contact suppression device for a vehicle according to claim 1, wherein the contact suppression unit includes a gradient change position display unit that displays the detected gradient change position in a superimposed manner on a vehicle path. 5.   The gradient information acquisition means includes a camera mounted on a vehicle and images the front of the vehicle, and acquires gradient information of a road surface on the course of the vehicle by analyzing an image captured by the camera. The road surface contact suppression device for a vehicle according to any one of 4. The vehicle has a navigation device,
The vehicle road surface contact suppression device according to any one of claims 1 to 5, wherein the gradient information acquisition unit acquires road surface gradient information on a course of the vehicle from the navigation device. The vehicle has a navigation device,
The gradient information acquisition means has a camera mounted on the vehicle and photographs the front of the vehicle,
The gradient information acquisition means acquires gradient information of a road surface on the course of the vehicle by reading gradient information stored in the navigation device and / or analyzing an image taken by the camera. The road surface contact suppression device for a vehicle according to any one of 1 to 5.   8. The road surface contact suppression device for a vehicle according to claim 6, wherein the navigation device has storage means for storing a gradient change position at which contact with the road surface of the vehicle is predicted. Furthermore, it has posture detection means for detecting the amount of posture change with respect to the road surface of the vehicle,
The contact prediction means predicts contact with the road surface of the vehicle based on the angle change amount of the gradient change position, the detected vehicle speed, and the posture change amount. The vehicle road surface contact suppression device according to the description. Further, distance detection means for detecting the distance between the vehicle and the detected gradient change position, acceleration prediction means for predicting acceleration of the vehicle at the detected distance, and vehicle speed detected by the vehicle speed detection means The vehicle speed prediction means at arrival time for predicting the vehicle speed when the vehicle reaches the gradient change position based on the distance detected by the distance detection means and the acceleration predicted by the acceleration prediction means;
10. The contact prediction unit according to claim 1, wherein the contact prediction unit predicts contact with the road surface of the vehicle based on the detected angle change amount of the gradient change position and the predicted vehicle speed at arrival. Vehicle road surface contact suppression device. Furthermore, it has road surface gradient angle detection means for detecting the gradient angle of the road surface,
The vehicle road surface contact suppression device according to claim 10, wherein the acceleration prediction means predicts the acceleration of the vehicle in consideration of the acceleration calculated from the detected gradient angle and gravitational acceleration.   The road surface contact suppression device for a vehicle according to claim 10 or 11, wherein the acceleration prediction means predicts the acceleration of the vehicle in consideration of a required acceleration defined by an accelerator opening of the vehicle.

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