JP2008242795A - Obstacle detector - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an obstacle detector, for preventing contact of a vehicle with a corner or a column of a building when passing through a narrow passage or the like at low speed. <P>SOLUTION: When a television camera 12 provided on a side surface of a vehicle images an object present in a first area R1 including at least an area from the side of the vehicle to the diagonally forward direction, and a sonar 14 provided on the front side surface of the vehicle V measures the distance of the object present in a second area R2 that is a part of the first area R1, a relative position calculation means M1 calculates the relative position of an edge of the object to the vehicle from the direction of the object imaged by the television camera 12 and the distance of the object detected by the sonar 14, and a relative position trace means M2 traces the relative position of a characteristic part of the object according to a moving track of the vehicle calculated by a moving track calculation means M2. Therefore, a driver can successively recognize the position of the characteristic part of the object likely to be brought into contact with the vehicle and avoid the contact therewith. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an obstacle detection device for avoiding contact with an obstacle when a vehicle moves in a narrow passage or the like at a low speed.

The radar mounted on the vehicle detects the distance and relative speed between the host vehicle and the monitored vehicle, and the imaging means mounted on the vehicle detects the degree of approach of the monitored vehicle in the direction orthogonal to the traveling direction of the host vehicle. The following patent document describes the current or future positional relationship between the own vehicle and the monitored vehicle from the detection results, and predicts the risk of collision between the two vehicles to notify the driver. 1 is known.
JP 2001-334896 A

  However, the above-mentioned conventional ones are effective in preventing contact with other vehicles during traveling at medium and high speeds, but prevent contact with corners and pillars of buildings when passing through narrow passages at low speeds. In order to do this, there has been a problem that the detection accuracy of the position of the obstacle is not always sufficient.

  In such a case, if many sonars and radars are arranged along the side of the vehicle body, the position of the obstacle can be detected with high accuracy, but this is difficult to realize due to cost and design restrictions. .

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an obstacle detection device that reliably prevents contact with corners or pillars of a building when passing through a narrow passage or the like at a low speed.

  In order to achieve the above object, according to the first aspect of the present invention, there is provided imaging means for imaging an object that is provided on a side surface of the vehicle and that is present in a first region including at least a diagonally front side of the vehicle. A distance measuring means for measuring a distance of an object existing in a second area which is a part of the first area and provided on a front side surface of the vehicle; a direction of the object imaged by the imaging means; and the distance measuring means Relative position calculation means for calculating the relative position of the characteristic part of the object with respect to the vehicle from the distance of the object detected in step 1, movement locus calculation means for calculating the movement locus of the vehicle, and vehicle calculated by the movement locus calculation means There is proposed an obstacle detection device comprising a relative position tracing means for tracing the relative position of the characteristic portion of the object that changes in accordance with the movement trajectory of the object.

  According to the invention described in claim 2, in addition to the configuration of claim 1, an obstacle detection device is proposed in which the characteristic portion is an edge of the object.

  According to the invention described in claim 3, in addition to the configuration of claim 1 or claim 2, the relative position calculating means is set to the smallest distance among the plurality of distances measured by the distance measuring means. An obstacle detection device is proposed that calculates a relative position of the object based on the above.

  According to a fourth aspect of the present invention, in addition to the configuration of any one of the first to third aspects, the movement trajectory calculating means is configured to detect the movement trajectory of the vehicle based on the vehicle speed and the steering angle. An obstacle detection device is proposed which is characterized in that

  According to the invention described in claim 5, in addition to the configuration of any one of claims 1 to 4, the distance between the characteristic portion traced by the relative position tracing means and the vehicle is predetermined. Provided with at least one of a steering assist device that assists steering in a direction that avoids contact with the feature portion, a deceleration control device that automatically decelerates the vehicle, and an alarm device that issues a warning to the driver when the threshold value is below the threshold An obstacle detection apparatus characterized by the above is proposed.

  The television camera 12 of the embodiment corresponds to the image pickup means of the present invention, the sonar 14 of the embodiment corresponds to the distance measuring means of the present invention, and the edge Oa of the embodiment corresponds to the characteristic part of the present invention. To do.

  According to the configuration of the first aspect, the imaging means provided on the side surface of the vehicle images at least an object existing in the first region including the diagonally front side of the vehicle, and the measurement unit provided on the front side surface of the vehicle. When the distance unit measures the distance of the object existing in the second region that is a part of the first region, the relative position calculation unit calculates from the direction of the object imaged by the imaging unit and the distance of the object detected by the distance measuring unit. The relative position of the feature portion of the object with respect to the vehicle is calculated, and the relative position tracing means traces the relative position of the feature portion of the object according to the movement locus of the vehicle calculated by the movement locus calculation means. It is possible to avoid the contact by sequentially recognizing the position of the feature portion of the object that becomes an obstacle that may be touched. Moreover, since it is only necessary to provide one image pickup means and one distance measuring means on each side of the vehicle body, the cost is low, and the influence on the design of the vehicle body side surface that is conspicuous in appearance can be minimized.

  According to the second aspect of the present invention, since the relative position calculating means calculates the relative position of the object edge, it is possible to recognize the relative position of the object edge that the vehicle is most likely to contact and reliably avoid contact. it can.

  According to the third aspect of the present invention, the relative position calculating means calculates the relative position of the object based on the smallest distance among the plurality of distances measured by the distance measuring means. It is possible to calculate with high accuracy.

  According to the fourth aspect of the present invention, since the movement trajectory calculating means calculates the vehicle trajectory based on the vehicle speed and the steering angle, the vehicle movement trajectory can be accurately calculated by a simple calculation.

  According to the fifth aspect of the present invention, when the distance between the feature portion of the object traced by the relative position tracing means and the vehicle is equal to or less than the predetermined threshold value, the steering assist device moves in a direction to avoid contact with the feature portion. Since the steering is supported and the deceleration control device automatically decelerates the vehicle or the alarm device issues an alarm to the driver, it is possible to reliably avoid the vehicle from coming into contact with the obstacle.

  Embodiments of the present invention will be described below with reference to the accompanying drawings.

  1 to 6 show an embodiment of the present invention. FIG. 1 is a view of a vehicle and an obstacle as viewed from above. FIG. 2 is a block diagram of an obstacle detection device. FIG. FIG. 4 is an explanatory diagram of object detection using a combination of a TV camera and sonar, FIG. 5 is a diagram showing a map for searching the coordinates of the object feature, and FIG. 6 is a coordinate trace of the object feature. It is explanatory drawing.

  As shown in FIG. 1, the vehicle V includes left and right television cameras 12 and 12 provided on the left and right door mirrors 11 and 11 and left and right sonars (acoustic wave detectors) 14 and 14 provided on both left and right ends of the front bumper 13. With. Each television camera 12 captures an image of the object O present in the first wide-angle region R1 from the side surface of the vehicle V to the diagonally forward direction, and detects a feature such as the edge Oa. In addition, each sonar 14 can measure the distance of the object O existing in the relatively narrow second region R2 included in the first region R1 that is directed obliquely forward from the side surface of the vehicle V. The television camera 12 can recognize the direction of the object O from the position of the object O on the captured image, but cannot recognize the distance of the object O. The sonar 14 can measure the shortest distance of the object O existing in the second region R2, but cannot recognize the direction of the object O.

  As shown in FIG. 2, the electronic control unit U includes a relative position calculation unit M1, a movement trajectory calculation unit M2, and a relative position trace unit M3. The relative position calculation means M1 is connected to the television cameras 12 and 12 and the sonars 14 and 14, and the movement trajectory calculation means M2 is a vehicle speed sensor 15 that detects the traveling speed of the vehicle V, and the steering wheel of the vehicle V. A steering angle sensor 16 for detecting the steering angle is connected. The relative position tracing means M3 includes a steering assist device 17 that assists the steering operation of the driver by applying steering torque to the steering wheel by an actuator, and a deceleration control device 18 that automatically operates the brake to decelerate the vehicle V. And an alarm device 19 that issues an alarm to the driver with a monitor image, sound, buzzer, chime or the like.

  FIG. 3C shows an image on the right side of the vehicle body imaged by the television camera 12. Assume that an object O is detected at a predetermined position A with respect to the vehicle body on the image of the television camera 12. However, since the image of the television camera 12 cannot detect the depth of the object O (the distance from the television camera 12), the image of the point A is A1 on the road surface as shown in FIGS. Whether the image is a point image or an A2 point image that is higher than the road surface cannot be identified.

  Therefore, even if it is attempted to specify the coordinates of the point A in the XY coordinate system fixed to the vehicle body, the coordinates when the object O is at the point A1 are (X1, Y1), and the coordinates when the object O is at the point A2 Becomes (X2, Y2), and the actual position of the object O cannot be specified.

  In the present embodiment, the XY coordinate system is provided separately for the object O on the right side of the vehicle V and for the object O on the left side of the vehicle V, and the origins thereof are respectively the left and right door mirrors. 11, 11 coincide with the positions of the television cameras 12, 12, the positive direction of the X axis faces the front of the vehicle body, and the positive direction of the Y axis faces the outside in the vehicle width direction. Of course, the setting of the XY coordinate system is not limited to that described above, and can be arbitrarily set.

  On the other hand, when the direction of the object O detected by the image of the television camera 12 and the distance of the object O detected by the sonar 14 are used together as shown in FIGS. Can be identified. That is, if the distance from the sonar 14 to the object O is D, it is the intersection of a line L indicating the direction of the object O detected from the image of the television camera 12 and a spherical surface having a radius D centered on the sonar 14. The point A2 can be identified as the position of the object O that is higher than the road surface, and the coordinates (X2, Y2) of the object O can be known.

  The above is the principle of the obstacle detection method of the present embodiment, and the obstacle detection method will be specifically described below based on the block diagram of FIG.

  First, the image data captured by the television camera 12 and the distance of the object O detected by the sonar 14 are input to the relative position calculation means M1 of the electronic control unit U. Although the detectable distance of the sonar 14 is relatively small, it is sufficient if the object O that can come into contact with the vehicle V (hereinafter referred to as the host vehicle) running at a low speed can be detected. When the sonar 14 detects the distance of the object O, the relative position calculation unit M1 extracts the edge Oa of the object O existing in the detection region R2 of the sonar 14 from the image data picked up by the television camera 12 as a feature portion. . The edge Oa of the object O is, for example, a corner of a building or a corner of a building, and is a portion that is highly likely to come into contact with the side surface of the vehicle body due to an inner ring difference when the vehicle tries to go around the periphery. . Since there are usually a plurality of edges Oa that are characteristic portions, the one having the shortest distance is selected.

  Thus, based on the direction of the edge Oa of the object O detected by the television camera 12 and the distance of the edge Oa, the coordinates of the edge Oa of the object O with respect to the XY coordinates fixed to the own vehicle (that is, with respect to the own vehicle). Relative position) can be specified.

  The specification of the coordinates of the object O is performed using a map search in order to shorten the calculation time. That is, a map storing the coordinates of the object O corresponding to each detection direction of the TV camera 12 is prepared, and the coordinates of the object O are obtained from the map using the distance of the object O measured by the sonar 14 as a parameter. You can search. For example, as shown in FIG. 4A, when the object O is detected in the direction of the point A1 on the road surface, as shown in FIG. 5, the sonar 14 is displayed on the map for the object O existing in the direction of the point A1. If the distances D1 to D4 to the object O, which are the parameters measured in (1), are applied and searched, the coordinates of the positions A1 to A4 of the object O corresponding to the distances D1 to D4 can be known.

  The movement trajectory calculation means M2 calculates the movement trajectory of the host vehicle every predetermined time Δt from the vehicle speed detected by the vehicle speed sensor 15 and the steering angle detected by the steering angle sensor 16. The movement trajectory of the own vehicle includes the movement trajectory of the origin of the XY coordinate system and the directions of the X axis and the Y axis.

  The relative position tracing means M3 calculates the object O for each time Δt from the coordinates of the edge Oa of the object O calculated by the relative position calculating means M1 and the movement trajectory of the own vehicle calculated for each time Δt by the movement trajectory calculating means M2. Trace the coordinates of the edge Oa. As a result, as shown in FIG. 6, it is possible to know how the edge Oa of the object O moves relative to the vehicle every time Δt. When it is determined that the distance between the side surface of the vehicle body (its coordinates are known) and the edge Oa of the object O is equal to or less than the threshold value after the time Δt, the steering assist device 17 avoids contact with the edge Oa of the object O. Is generated, the deceleration control device 18 activates the automatic brake, and the alarm device 19 informs the driver that there is a possibility of contact, so that the vehicle contacts the edge Oa of the object O. Can be avoided reliably.

  In addition, since one TV camera 12 and one sonar 14 need only be provided on each side of the vehicle V, not only the cost is low, but also the influence on the design of the side of the vehicle body that is conspicuous in appearance can be minimized.

  The embodiments of the present invention have been described above, but various design changes can be made without departing from the scope of the present invention.

  For example, in the embodiment, the steering assist device 17, the deceleration control device 18, and the alarm device 19 are provided to avoid the vehicle V coming into contact with an obstacle, but at least one of them may be provided. Alternatively, the alarm device 19 may be activated first, the steering assist device 17 may be activated when the driver does not respond, and the deceleration control device 18 may be activated when there is still a possibility of contact.

View of vehicle and obstacles from above Block diagram of obstacle detection device Illustration of object detection using only a TV camera Illustration of object detection using TV camera and sonar together The figure which shows the map which searches the coordinate of the feature part of the object Illustration of the trace of the coordinates of the feature part of the object

Explanation of symbols

12 TV camera (imaging means)
14 Sonar (ranging means)
17 Steering support device 18 Deceleration control device 19 Alarm device M1 Relative position calculation means M2 Movement trajectory calculation means M3 Relative position tracing means O Object Oa Edge (characteristic part)
R1 1st field R2 2nd field V Vehicle

Claims (5)

An imaging means (12) provided on a side surface of the vehicle (V) for imaging an object (O) existing in a first area (R1) including at least an oblique front from a side of the vehicle (V);
Ranging means (14) for measuring the distance of an object (O) present in a second region (R2) that is provided on a front side surface of the vehicle (V) and is a part of the first region (R1);
From the direction of the object (O) imaged by the imaging means (12) and the distance of the object (O) detected by the distance measuring means (14), the characteristic part (Oa) of the object (O) with respect to the vehicle (V) ) Relative position calculating means (M1) for calculating the relative position of
A movement locus calculating means (M2) for calculating a movement locus of the vehicle (V);
Relative position tracing means (M3) for tracing the relative position of the characteristic portion (Oa) of the object (O) that changes according to the movement locus of the vehicle (V) calculated by the movement locus calculation means (M2);
An obstacle detection device comprising:   The obstacle detection device according to claim 1, wherein the feature (Oa) is an edge of the object (O).   The relative position calculating means (M1) calculates the relative position of the object (O) based on the smallest distance among a plurality of distances measured by the distance measuring means (14). The obstacle detection device according to claim 1 or 2.   The said movement locus | trajectory calculation means (M2) calculates the movement locus | trajectory of a vehicle (V) based on the speed and steering angle of a vehicle (V), Any one of Claims 1-3 characterized by the above-mentioned. The obstacle detection device described.   When the distance between the characteristic portion (Oa) traced by the relative position tracing means (M3) and the vehicle (V) is equal to or less than a predetermined threshold, the direction in which the contact with the characteristic portion (Oa) is avoided. It is provided with at least one of a steering assist device (17) that assists steering, a deceleration control device (18) that automatically decelerates the vehicle (V), and an alarm device (19) that issues an alarm to the driver, The obstacle detection device according to any one of claims 1 to 4.

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