JP5434285B2 - Obstacle detection device - Google Patents

Description

  The present invention relates to an obstacle detection device, and more particularly to an obstacle detection device for preventing the bottom surface of a vehicle from coming into contact with the ground or an obstacle.

  For preventing the so-called “bottom rubbing” where the bottom surface of the vehicle is in contact with the ground or an obstacle, various devices have been conventionally used. For example, in Patent Document 1, a feature point of a road surface is measured with a stereo camera, A technique is disclosed in which terrain information of a target point is acquired by combining with map data prepared in advance and compared with the vehicle data prepared in advance, and a warning is issued when bottoming is likely to occur.

  In Patent Document 2, in an apparatus that provides an overhead view around a vehicle, an obstacle is detected, and a warning is issued when the height of the detected obstacle is higher than the bumper of the host vehicle. Is disclosed.

  Patent Document 3 discloses a technique for detecting a vehicle height by a vehicle height sensor when an obstacle is detected by a camera or a radar, and giving a warning when the vehicle is likely to come into contact with the obstacle.

JP 2007-213143 A JP 2007-267343 A JP 2007-112317 A

  In any of the above-mentioned patent documents, since the vehicle posture when the vehicle passes over the obstacle is not taken into account, it is difficult to accurately determine the bottom rubbing, and a portion other than the bottom surface of the vehicle body contacts the obstacle. It is difficult to determine whether or not to do.

  The present invention has been made to solve the above-described problems, and accurately determines bottom rubbing when a vehicle passes over an obstacle, and a portion other than the bottom surface of the vehicle body contacts the obstacle. An object of the present invention is to provide an obstacle detection device capable of determining whether or not to do so.

According to a first aspect of the obstacle detection apparatus of the present invention, an image acquisition unit that acquires at least image data ahead of the host vehicle by a stereo camera, and a road surface shape is measured based on the image data acquired by the image acquisition unit. And when the host vehicle passes an obstacle that obstructs traveling, including road surface irregularities, based on the road surface shape measuring unit, the vehicle data of the host vehicle, and the road surface shape measured by the road surface shape measuring unit. A posture estimation unit that estimates the vehicle posture of the vehicle, and a contact determination unit that receives information on the vehicle posture estimated by the posture estimation unit and determines whether or not the vehicle body of the host vehicle contacts the obstacle And receiving a determination result from the contact determination unit, giving a warning when the vehicle body of the host vehicle comes into contact with the obstacle, and the contact determination unit, based on the host vehicle data, From the bottom of the vehicle Serial to obtain the first height of the stereo camera, based on the height information of the obstacle obtained from the road surface shape measured by the road surface shape measurement unit and said vehicle attitude information, said Calculate the second height from the highest part of the obstacle to the stereo camera, compare the first height and the second height, if the first height is higher, When it is determined that the obstacle is in contact with the bottom of the vehicle body, and the obstacle appears continuously, the obstacle, the bottom of the vehicle body, and the like based on the time change data of the second height Judgment of contact is made.

A second aspect of the obstacle detecting apparatus according to the present invention, the feature points of two images obtained by the scan Tereokamera to correspond with each other, three-dimensional points on the image from the resulting parallax By calculating the position, the three-dimensional image data is acquired, and the road surface shape measurement unit measures the road surface shape based on the three-dimensional image data.

  According to a third aspect of the obstacle detection device of the present invention, the posture estimation unit moves the front wheel of the host vehicle when passing through the obstacle based on the road surface shape measured by the road surface shape measurement unit. Then, the ground contact position of the rear wheel is estimated, and the vehicle posture information including the degree of inclination of the host vehicle is calculated from the position.

  According to a fourth aspect of the obstacle detection device of the present invention, the posture estimation unit determines whether the road surface inclination angle and / or the road surface unevenness is high or low based on the road surface shape measured by the road surface shape measurement unit. Based on the value, it is determined whether or not to perform posture estimation. When it is determined that posture estimation is to be performed, the vehicle posture information is calculated.

According to a fifth aspect of the obstacle detection device of the present invention, the contact determination unit sets a plurality of threshold values for changing the first height in the comparison between the first height and the second height. Setting and determining contact between the obstacle and the bottom of the vehicle body step by step using the plurality of threshold values.

According to the first aspect of the obstacle detection device of the present invention, the vehicle posture when the host vehicle passes over the obstacle is estimated, and the vehicle body of the host vehicle contacts the obstacle based on the vehicle posture. Therefore, it is possible to accurately perform contact determination. Further, it can be relatively easily determined whether or not the obstacle comes into contact with the bottom of the vehicle body. Further, it is possible to determine the contact between the obstacle and the bottom of the vehicle body by removing the influence of the variation due to the time change of the measurement result in the road surface shape measurement unit.

  According to the second aspect of the obstacle detection device according to the present invention, the three-dimensional image data is acquired using the stereo camera, and the road surface shape measurement unit measures the road surface shape based on the three-dimensional image data. In order to acquire the road surface shape, a complicated sensor such as a radar device becomes unnecessary, and the device cost is reduced.

  According to the third aspect of the obstacle detection device of the present invention, the vehicle posture information of the host vehicle can be obtained relatively easily.

  According to the fourth aspect of the obstacle detection apparatus of the present invention, since the posture estimation unit determines whether or not posture estimation is performed, unnecessary estimation processing can be omitted and the processing speed can be improved. be able to.

According to the fifth aspect of the obstacle detection device of the present invention, the contact between the obstacle and the bottom of the vehicle body is determined step by step, so that a more realistic determination can be made.

It is a figure which shows the example of arrangement | positioning of a stereo camera. It is a figure which shows an example of the front image acquired with the stereo camera. It is a block diagram which shows the structure of the obstruction detection apparatus which concerns on this invention. It is a figure which shows an example of the front image acquired with the stereo camera. It is a figure which shows typically the attitude | position estimation operation | movement of the own vehicle in the uneven | corrugated position of a road surface. It is a schematic diagram explaining the determination method of the presence or absence of bottom rubbing. It is a figure which shows the example which sets the determination result in steps. It is a schematic diagram explaining determination of whether parts other than the bottom face of a vehicle body contact an obstruction. It is a bird's-eye view which shows the example which colors and warns the obstruction which requires the warning of bottom rubbing. It is a top view which shows the example which colors and warns the obstruction which requires the warning of bottom rubbing. It is a flowchart explaining the basic detection operation | movement of an obstruction detection apparatus. It is a flowchart explaining the application operation | movement 1 of a detection of an obstruction detection apparatus. It is a block diagram which shows the structure of the obstruction detection apparatus which concerns on this invention. It is a schematic diagram explaining determination of whether the bottom face of a vehicle body contacts an obstruction. It is a graph showing a time variation of H _t. It is a graph showing a time variation of H _t.

<Embodiment>
<Device configuration>
FIG. 1 is a diagram showing an arrangement example of stereo cameras in a vehicle VC equipped with an obstacle detection device according to the present invention.

  In FIG. 1, a vehicle VC is equipped with four stereo cameras that acquire front, left, and right images. That is, a stereo camera SC1 that acquires a front image, a stereo camera SC2 that acquires a left image relative to the front, a stereo camera SC3 that acquires a rear image, and a stereo camera SC4 that acquires a right image relative to the front. Provided, and the respective imaging regions are indicated by regions R1, R2, R3 and R4.

  By using such a system, it is possible to acquire image data around the host vehicle and change the viewpoint to an overhead view viewed from above the host vehicle. A forward image acquired by the camera SC1 is used for detection of an obstacle ahead during traveling.

  The actual arrangement position of each camera differs depending on the vehicle type. For example, the stereo camera SC1 is arranged at the position of the room mirror, and the stereo cameras SC2 and SC4 are arranged at the positions of the left and right side mirrors, respectively. SC3 is arranged at the position of the rear bumper. The above arrangement is an example, and the arrangement of the stereo camera is not limited to this.

  FIG. 2 is a diagram illustrating an example of a front image acquired by the stereo camera SC1, and illustrates a state where the vehicle is traveling on a road surface. FIG. 2 shows a state in which the host vehicle is traveling on the road surface between the center line CL and the roadway outer line OL, and the side wall WL extends outside the roadway outer line OL.

  A bump that becomes an obstacle OB is present in front of the road surface, and the host vehicle travels straight toward the obstacle OB as indicated by an arrow AR. The obstacle OB exists 40 to 50 m away.

  FIG. 3 is a block diagram showing the configuration of the obstacle detection apparatus 100 according to the present invention. As illustrated in FIG. 3, the obstacle detection apparatus 100 includes an image acquisition unit 1 including stereo cameras SC1 to SC4, a road surface shape measurement unit 2 that measures a road surface shape based on image data acquired by the image acquisition unit 1, and Based on the vehicle data of the host vehicle and the road surface shape, the posture estimation unit 3 for estimating the vehicle posture when the host vehicle passes an obstacle, and the information on the estimated posture from the posture estimation unit 3 are received. Based on the determination result from the contact determination unit 4, determination result from the contact determination unit 4, And a host vehicle data holding unit 6 for storing vehicle data of the vehicle. Hereinafter, each part will be described.

<Image acquisition unit 1>
The stereo cameras can simultaneously shoot from different viewpoints with the two cameras, and the image acquisition unit 1 associates the feature points of the two obtained images with each other, and triangulates from the parallax obtained as a result. Based on the principle of surveying, three-dimensional image data can be obtained by calculating the three-dimensional position of each point on the image.

<Road surface shape measuring unit 2>
The road surface shape measuring unit 2 measures the position, height, depth, and shape of obstacles that obstruct traveling such as road surface unevenness based on the three-dimensional image data obtained by the image acquisition unit 1, and the road surface. By measuring the slope of the road, the road surface shape data is obtained.

  When measuring the slope of the road surface, it is possible to use feature points in the image such as the white line indicating the center line and the roadway outside line provided on the road surface and road signs. The measurement accuracy can be improved.

  FIG. 4 is a diagram showing an example of a front image acquired by the stereo camera SC1, and shows a state before the host vehicle is going uphill.

  On the uphill, the center line CL, the roadway outer line OL, the side wall WL, and the like serve as characteristic points representing the inclination, so that the inclination angle and the like can be accurately measured.

  Further, if the road surface shape information is acquired through an external storage medium, for example, by acquiring a topographic map from map data by connecting to a car navigation system, the road surface shape measuring unit 2 has sufficient information on the road surface. If the data cannot be obtained, the external data can be used to supplement the information, and an unexpected situation can be dealt with.

<Attitude estimation unit 3>
The posture estimation unit 3 includes vehicle data of the host vehicle held by the host vehicle data holding unit 6, for example, data relating to the vehicle height, the vehicle length, the vehicle shape, and the height from the vehicle bottom to the stereo camera, and the road surface shape measurement unit 2. Based on the road surface shape measured in step 1, the grounding positions (four points) of the front wheels and the rear wheels when passing through the road surface unevenness are estimated, and the inclination of the host vehicle is estimated from the positions.

  FIG. 5 schematically illustrates the posture estimation operation of the host vehicle at the uneven position on the road surface. FIG. 5 shows the vehicle VC at the current position and the vehicle VC at the future position, and there are a plurality of irregularities on the road surface to which the vehicle VC travels.

  That is, the estimated execution position P1 corresponds to a position (singular point) where the flat road surface once dents and begins to rise again, and in the vicinity of the estimated execution position P1 based on road surface shape information such as the position of the dent and the rising position. The estimation result that the posture of the vehicle VC is inclined forward can be obtained.

  The estimated execution position P2 corresponds to the maximum portion of the road surface bulge. From the road surface shape information such as the slope of the ridge and the size of the top, the posture of the vehicle VC straddles the maximum portion in the vicinity of the estimated execution position P2. The estimation result that it becomes horizontal can be obtained.

  The estimated execution position P3 corresponds to a position (singular point) at which the road surface rises to a road surface depression (singular point). From the road surface shape information such as the position of the depression and the elevation, the vehicle VC is near the estimated execution position P1. It is possible to obtain an estimation result that the posture is inclined forward.

  In FIG. 5, the undulations of the unevenness are extremely shown for the sake of convenience, but actually correspond to the unevenness of the undulations at a level that can be seen from the stereo camera.

<Contact determination unit 4>
The contact determination unit 4 determines the presence or absence of bottom rubbing based on the vehicle posture at the estimated execution position on the obstacle estimated by the posture estimation unit 3.

  FIG. 6 is a schematic diagram for explaining a method for determining the presence or absence of bottom rubbing. In FIG. 6, it is assumed that the bump OB on the road surface is large enough for the vehicle VC to straddle. In the posture estimation unit 3, the front wheel and the rear wheel of the vehicle VC are straddled over the bump OB. If the height position of the ground contact position GC is calculated based on the road surface information measured by the road surface shape measuring unit 2, and the difference in height between the front wheels and the rear wheels can be ignored, the vehicle posture at the estimated execution position is horizontal. Estimated.

  Here, the height position of the ground contact position GC of the front wheel and the rear wheel is assumed to be, for example, a state in which the top of the ridge OB is located in the center in the longitudinal direction of the vehicle body, and the vehicle body data stored in the host vehicle data holding unit 6 By acquiring information on the length from the center in the length direction to the front wheel and the rear wheel, respectively, and specifying the ground contact position GC, it can be easily obtained by associating with the road surface information.

  Hereinafter, as illustrated in FIG. 6, description will be made assuming that the vehicle VC is in a horizontal posture across the ridge OB.

The contact determination unit 4, the vehicle data stored in the vehicle data storage section 6, acquires the height H ₁ from the bottom of the vehicle VC to the stereo camera, raised OB measured by the road surface shape measurement unit 2 The height H ₂ from the top of the ridge OB to the stereo camera is calculated based on the height information.

Then, H ₁ and H ₂ are compared, and if H ₁ is greater than H ₂ (H ₁ > H ₂ ), it is determined that the raised OB is in contact with the bottom surface of the vehicle VC, that is, bottom rubbing occurs. To do.

Here, a margin α is added to the height H ₂ from the top of the ridge OB to the stereo camera in consideration of the vertical movement of the vehicle VC and measurement errors, and the bottom friction is obtained when H ₁ > H ₂ + α. It may be determined that occurrence occurs. The margin α may be a fixed value obtained by a statistical method, or may be a value that is appropriately changed in consideration of parameters such as the vehicle type, road surface shape, loading capacity, and speed.

The determination result may be set in stages. For example, as shown in FIG. 7, two types of threshold values Th ₁ and Th ₂ are set, and as condition 1, a value obtained by subtracting the threshold value Th ₁ from H ₁ is larger than H ₂ (H ₁ −Th ₁ > H ₂ ), A warning indicating danger is displayed on the warning display 5 (FIG. 3). As condition 2, the value obtained by subtracting the threshold Th ₂ from H ₁ is larger than H ₂ (H ₁ −Th ₂ > H _2). ), The warning display unit 5 (FIG. 3) may display a warning indicating that attention is required, and the condition 3 may be set so that no warning is issued in cases other than the condition 1 and the condition 2.

Here, the threshold values Th ₁ and Th ₂ are values representing tolerance, and the magnitude relationship is Th ₁ > Th _{2. In} the condition 1, although the tolerance is set to be large, H ₂ If it is determined that is smaller, a warning indicating a danger is displayed because the degree of danger is higher.

The threshold values Th ₁ and Th ₂ may be fixed values obtained by a statistical method, but may be dynamically changed based on travel data. For example, when a road surface with high undulations is reached during traveling, the threshold values Th ₁ and Th ₂ are both changed to be large based on the result measured by the road surface shape measuring unit 2 so that the undulations are reduced. In this case, a process may be performed in which both the threshold values Th ₁ and Th ₂ are changed to be small.

  Further, the contact determination unit 4 can determine not only the presence or absence of bottom rubbing but also whether or not a portion other than the bottom surface of the vehicle body contacts an obstacle.

  That is, as shown in FIG. 8, on a road surface that repeats sudden ups and downs, for example, the tip of the vehicle body may come into contact with the ascending slope when approaching the ascending slope from the descending slope.

  In that case, the road surface measured by the road surface shape measuring unit 2 in the posture estimation unit 3 in the vicinity of a portion (singular point) where the slope changes from descending to ascending, in the front and rear contact positions GC of the vehicle VC. Based on the information, the vehicle body inclination angle is obtained, and the length L from the ground contact position GC of the front wheel to the vehicle body tip is obtained from the vehicle data stored in the vehicle data holding unit 6 to measure the road surface shape. It is determined whether or not the vehicle body is in contact by matching with the information of the upward inclination obtained from the road surface information measured by the unit 2.

  If it is determined that there is a possibility of contact, the driver should take measures to avoid contact by reducing the speed, etc., by displaying a warning display to alert the warning display unit 5 (FIG. 3). Can do.

  Note that the contact determination can be performed more accurately if information such as the speed of the vehicle VC and the variation in the height of the vehicle body from the road surface due to the load is taken into consideration.

<Warning display unit 5>
The warning display unit 5 uses, for example, an in-vehicle monitor and creates and displays a three-dimensional overhead view as viewed from above the own vehicle based on the image data acquired by the stereo cameras SC1 to SC4. Display warnings such as coloring obstacles that require warning of bottom rubbing. An example is shown in FIG.

  As shown in FIG. 9, the image data captured in the shooting area R1 of the stereo camera SC1 is converted into a bird's-eye view, and the ridges OB ahead of the traveling direction are colored in the portions indicated by hatching. It is displayed as a marking area MK. Since the vehicle is running, only the front stereo camera SC1 is used for obstacle detection, and the imaging areas of the stereo cameras SC2 to SC4 are not displayed.

  The display on the warning display unit 5 is not limited to a bird's-eye view, but a front image acquired by the stereo camera SC1 is displayed, and an obstacle that requires a bottoming warning on the image is colored and warned. You may display such as. An example is shown in FIG.

  As shown in FIG. 10, the front image acquired by the stereo camera SC <b> 1 is shown, and the ridge OB ahead of the traveling direction is colored and displayed as a marking area MK.

  Further, the warning is not limited to the display on the vehicle monitor described above, and may be a warning by voice or a warning by blinking a warning light.

<Own vehicle data holding unit 6>
The own vehicle data holding unit 6 is composed of a storage device such as a hard disk or a non-volatile memory. In addition to dimensional information such as the vehicle length, the vehicle height, and the height from the bottom surface to the stereo camera, the vehicle own weight, the load The weight information acquired by the weight sensor is stored.

<Operation>
<Basic operation>
Next, on the premise of the above description, the detection operation that is the basis of the obstacle detection apparatus 100 will be described using the flowchart shown in FIG.

  When the obstacle detection device 100 starts operating for the first time when the host vehicle travels, image data from the stereo camera of the image acquisition unit 1 starts to be acquired (step S1).

  The road surface shape measurement unit 2 measures the road surface shape as needed based on the image data acquired by the image acquisition unit 1 (step S2).

  First, the posture estimation unit 3 determines whether or not posture estimation is to be performed based on the road surface shape measured by the road surface shape measurement unit 2 (step S3).

  For this determination, the road surface inclination angle and the level of unevenness are used. For example, the detected unevenness does not exceed a predetermined height or depth threshold value, and the road surface inclination angle is a predetermined threshold value. If it does not exceed, it is determined that the vehicle posture is not affected, and posture estimation is not performed.

  This threshold value may be a fixed value obtained by a statistical method, but may be dynamically changed based on traveling data. For example, when an uneven road surface continues, the average value of the undulation may be calculated based on the result measured by the road surface shape measuring unit 2 and used.

  If it is determined in step S3 that the posture estimation is not performed, the operations in step S2 and subsequent steps are repeated. If it is determined that the posture is estimated, the vehicle posture is estimated when the host vehicle passes the target obstacle. Perform (step S4).

  Then, based on the estimated vehicle posture, the contact determination unit 4 determines bottom rubbing and determines whether a vehicle body portion other than the bottom surface is in contact with an obstacle (step S5).

  When the contact determination unit 4 determines that the host vehicle is in contact with the target obstacle, the warning display unit 5 performs a predetermined warning display (step S6).

  When the contact determination unit 4 determines that the host vehicle is in contact with the target obstacle, the warning display is not performed and the operations in step S2 and subsequent steps are repeated.

  After the warning is displayed on the warning display unit 5, the obstacle detection is terminated when it is detected in step S7 that an operation that does not require the obstacle detection is performed, for example, the traveling is stopped. In such a case, the operations after step S2 are repeated. It should be noted that detection of an operation that does not require obstacle detection may be performed by any part of the obstacle detection apparatus 100, or may be configured by a control unit (not shown) of the obstacle detection apparatus 100.

  As described above, according to the obstacle detection apparatus 100, the vehicle posture when the vehicle VC passes over the obstacle is estimated, and the presence or absence of bottom rubbing is determined based on the vehicle posture. It is also possible to determine whether or not a part other than the bottom surface of the vehicle body is in contact with an obstacle.

<Applied operation 1>
The above description is an explanation of the basic operation of the obstacle detection apparatus 100 and has been described on the assumption that the host vehicle goes straight toward the obstacle. However, in reality, the vehicle intentionally changes the course. In some cases, depending on the condition of the road surface, the course may be changed by removing the handle. Therefore, a more realistic applied operation will be described using the flowchart shown in FIG.

  In the flowchart shown in FIG. 12, the operations in steps S11 to S14 are the same as the operations in steps S1 to S4 described with reference to FIG.

  Here, the situation will be described with reference to FIG. 13 showing a front image obtained by acquiring the road surface state with the stereo camera SC1.

  As shown in FIG. 13, there is a bump OB in front of the traveling direction of the host vehicle. However, since the bump OB is on one side of the road, it is possible to avoid passing over the bump OB by changing the course. It is in. The driver changed the course as indicated by an arrow AR before the obstacle detection apparatus 100 performs a series of detection operations.

  In such a case, the posture estimation unit 3 receives information from the steering device, for example, and determines that the course has been changed when the steering wheel is rotated by a predetermined angle or more within a predetermined time, and the steps S12 and after. The operation is repeated. Thereby, a road surface shape is acquired about a new course, and a contact warning will not be performed as a result.

  On the other hand, if the steering wheel operation beyond the predetermined angle is not performed, the process proceeds to step S16, and based on the vehicle posture estimated in step S14, the contact determination unit 4 determines the bottom rubbing or the vehicle body part other than the bottom surface is obstructed. It is determined whether or not the object is touched (step S16).

  When the contact determination unit 4 determines that the vehicle is in contact with the target obstacle, the warning display unit 5 performs a predetermined warning display (step S17).

  Note that if the contact determination unit 4 determines that the host vehicle is in contact with the target obstacle, the warning display is not performed, and the operations in and after step S12 are repeated.

  After the warning is displayed on the warning display unit 5, the obstacle detection is terminated when it is detected in step S18 that an operation that does not require the obstacle detection, such as stopping traveling, is performed. In this case, the operations in step S12 and subsequent steps are repeated.

  As described above, the obstacle detection apparatus 100 obtains course change information, and when there is a course change, the obstacle detection is performed for a new course, thereby realizing more realistic detection. Operation is possible.

  In the above example, the posture estimation unit 3 has been described as determining whether or not there is a course change. However, the determination may be performed by the contact determination unit 4 or may be performed exclusively for determining whether or not there is a course change. A determination unit may be provided.

<Applied operation 2>
When the contact determination unit 4 compares the height H ₁ from the bottom surface of the vehicle VC to the stereo camera with the height H ₂ from the top of the ridge OB to the stereo camera, the height H ₂ includes the vehicle VC. It has been described that the margin α may be added in consideration of the vertical movement of the vehicle and the measurement error. However, there are methods other than this method for dealing with fluctuations in road surface conditions and measurement errors.

  That is, the height value from the top of the obstacle subject to bottom rubbing to the stereo camera is, for example, that the subject vehicle does not move like a raised OB, for example, the host vehicle is on a road surface with undulating undulations. When running, it will constantly change. For this reason, there is a case in which a warning for bottoming is not necessary at a certain timing but a warning is necessary at another timing. In such a case, it is desirable to perform a warning method in consideration of a change in time for the height from the highest part of the target obstacle to the stereo camera. Hereinafter, this method will be described with reference to FIGS.

As shown in FIG. 14, the contact determination unit 4 acquires the height H ₁ from the bottom surface of the vehicle VC to the stereo camera from the host vehicle data stored in the host vehicle data holding unit 6, and the road surface shape measurement unit. Based on the height information of the raised OB that is the target obstacle measured in 2, the height H _t from the top of the raised OB to the stereo camera at a certain time _t is calculated.

  This calculation operation is repeatedly executed at equal intervals until the vehicle VC approaches the approach after detecting the bump OB, and the time t corresponds to the timing for performing the process.

FIG. 15 shows the time change of H _t obtained by this iterative process. In FIG. 15, time is taken on the horizontal axis and the value of H _t is taken on the vertical axis.

As shown in FIG. 15, the value of H _t is varied violently with time, when the value of H _t is large, the position of the stereo camera rises jumped vehicle VC is in the raised road, where it was acquired The height of the raised OB is relatively low, and as a result, it is assumed that the distance from the stereo camera is apparently increased.

On the other hand, when the value of H _t is small, the position of the stereo camera is lowered because the vehicle VC falls into the depression, and the height of the raised OB obtained there becomes relatively high. It is assumed that the distance from the stereo camera is close.

Therefore, the waveform of the time variation of H _t shown in FIG. 15 can be said to be a waveform reflecting the road undulation state, and the reliability of the measurement result is low, but the value of H _t becomes extremely small and the minimum value H _min When there is a high probability that a high bulge OB actually exists, a warning is issued.

Specifically, from the bottom of the minimum value H _min and the vehicle VC is compared with the height H ₁ to the stereo camera, when people of an H ₁ is greater than _{H min (H 1> H min} ) , the ridges It is determined that OB comes into contact with the bottom surface of vehicle VC, that is, bottom rubbing occurs.

Here, in order to specify the minimum value H _min , it is necessary to measure the values before and after the minimum value H _min as shown in FIG. 15, and in extreme cases, unless the measurement is continued until the vehicle VC reaches the raised OB. It may not be understood. However, since the rubbing bottom rides the vehicle VC is the raised OB is meaningless is accidentally occur, determination, the time before the scheduled time t _X which the vehicle VC reaches the raised OB and determine the limit time t _lim, This is executed based on the data of time variation of H _t measured so far.

It should be noted that the scheduled time t _X varies depending on the speed of the vehicle VC, also change determination limit time t _lim if Kaware plan time t _X.

Thus, by giving a warning in consideration of the time change of H _t , the driver can receive a highly reliable warning according to the traveling state.

Here, the determination limit time t _lim may be set anywhere, for example, the time until the stereo camera detects the bulge OB for the first time until it reaches half the distance to the bulge OB, or stops at the current speed. It may be set to the time until the required braking distance is reached.

In addition to setting the determination limit time t _lim as described above and specifying the minimum value H _min based on the data obtained so far, the existence of the minimum value H _min is predicted from the waveform slope. It is possible to adopt the method of determining, based on the slope of the waveform instead of the minimum value _Hmin , or by using other indicators.

Although the time change is shown in FIG. 15, the distance to the ridge OB is taken on the horizontal axis, and the data of the distance change of H _t may be used.

Further, the warning method considering the time change of H _t can be combined with the applied operation 1 described with reference to FIG.

In other words, when the time change of H _t is measured, when the driver changes the course, the minimum value H _min is not measured as a result, and information from the steering device as described above is received. Even if it is not, as a result, course change information can be acquired.

Figure 16 shows a measurement result of the time variation of the similarly H _t and 15, even when running on a violent road of the same relief as in Figure 15, the minimum value H _min by course change An example in which the OB is no longer detected, that is, the bump OB no longer exists on the course is shown.

Since the minimum value H _min is not detected, no warning is issued, and as a result, the contact determination unit 4 detects the course change from the time change data of H _t and performs the contact determination.

In this way, by adopting a warning system in consideration of the time change of H _t , it is not necessary to receive information from the steering device even in an operation considering the course change, and it is determined whether or not there is a course change. There is an effect that the processing is unnecessary and the system can be simplified.

<Modification>
The obstacle detection device 100 described above is described as including the image acquisition unit 1 including the stereo cameras SC1 to SC4. However, instead of obtaining three-dimensional image data by the image acquisition unit 1, the road surface 3 given from the outside is obtained. Obstacle detection may be performed using the dimensional image data.

  For example, when a topographic map is included as 3D image data in the recording medium of the car navigation system, it may be possible to use it.

  In this case, there is an advantage that a change in road surface due to a change in topography can be detected more accurately.

SC1-SC4 Stereo Camera OB Raised VC Vehicle

Claims (5)

An image acquisition unit that acquires at least image data in front of the host vehicle with a stereo camera;
A road surface shape measurement unit for measuring a road surface shape based on the image data acquired by the image acquisition unit;
An attitude for estimating a vehicle attitude when the own vehicle passes an obstacle that obstructs traveling including road surface unevenness based on the vehicle data of the own vehicle and the road surface shape measured by the road surface shape measuring unit. An estimation unit;
A contact determination unit that receives information on the vehicle posture estimated by the posture estimation unit and determines whether or not the vehicle body of the host vehicle is in contact with the obstacle;
Receiving the determination result in the contact determination unit, giving a warning when the vehicle body of the host vehicle contacts the obstacle,
The contact determination unit
Based on the host vehicle data, obtain a first height from the bottom of the host vehicle to the stereo camera,
Based on the obstacle height information obtained from the road surface shape measured by the road surface shape measurement unit and the vehicle posture information, a second height from the highest part of the obstacle to the stereo camera is obtained. The first height is compared with the second height, and when the first height is higher, it is determined that the obstacle is in contact with the bottom of the vehicle body of the host vehicle. An obstacle detection device that determines contact between the obstacle and the bottom of the vehicle body based on time change data of the second height when the obstacle appears continuously. Wherein the image acquiring unit associates feature points of two images obtained by the scan Tereokamera each other, the resulting 3-dimensional image by calculating the three-dimensional position of each point on the image from the parallax Get the data,
The obstacle detection device according to claim 1, wherein the road surface shape measurement unit measures the road surface shape based on the three-dimensional image data. The posture estimation unit
Based on the road surface shape measured by the road surface shape measurement unit, the grounding positions of the front wheels and rear wheels of the host vehicle when passing the obstacle are estimated, and the inclination of the host vehicle is included from the positions. The obstacle detection device according to claim 1, wherein the vehicle posture information is calculated. The posture estimation unit
Based on the road surface shape measured by the road surface shape measuring unit, it is determined whether or not to perform posture estimation based on the inclination angle of the road surface and / or the level of the unevenness of the road surface, and the posture estimation is performed. The obstacle detection device according to claim 3, wherein the vehicle posture information is calculated when it is determined as follows. The contact determination unit
In the comparison between the first height and the second height, a plurality of threshold values for changing the condition of the first height are set, and the obstacles and the steps are stepped using the plurality of threshold values. The obstacle detection device according to claim 1, wherein contact with the bottom of the vehicle body is determined .

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