JP2007057527A - Obstruction detection system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an obstruction detection system for a vehicle excellent in an obstruction detection which can aim at the improvement in an obstruction detection capability near a vehicle. <P>SOLUTION: In the obstruction detection system for the vehicle which arranges an ultrasonic sensor 2 into a vehicle body, and performs the obstruction detection of the vehicle 1 circumference, an center axis 22 of a wave transmitting direction of the ultrasonic sensor 2 is established approximately along the surface 12 of the vehicle body. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an obstacle detection system for a vehicle that detects an obstacle around a vehicle by arranging an ultrasonic sensor on a vehicle body.

  Conventionally, as this kind of vehicle obstacle detection system, a plurality of ultrasonic sensors are horizontally arranged on the bumper of the vehicle, and the center axis of the transmission direction of these ultrasonic sensors is set to be horizontal with respect to the vehicle. In some cases, ultrasonic waves are transmitted in the normal direction from the surface of the vehicle to which the ultrasonic sensor is attached. The distance between the ultrasonic sensor and the obstacle is detected by the time until the ultrasonic sensor receives the reflected wave from the ultrasonic obstacle transmitted from the ultrasonic sensor, and the distance is constant. If it is within the range, the driver is informed of the presence of the obstacle.

  The ultrasonic sensor consists of a single ultrasonic sensor that transmits and receives ultrasonic waves to detect obstacles and a pair of ultrasonic sensors, and transmits ultrasonic waves from one of the ultrasonic sensors. There are some which detect an obstacle by receiving a reflected wave with the other ultrasonic sensor. The detection range on the plane including the ultrasonic sensor has a fan shape in the case of the former single ultrasonic sensor, and an elliptical shape in the case of the latter pair of ultrasonic sensors.

  In the vehicle obstacle detection system described above, it is possible to set various obstacle detection ranges by combining the single ultrasonic sensor, the pair of ultrasonic sensors, or both sensors. (For example, patent document 1).

Japanese Patent Laying-Open No. 2001-208843 (paragraph [0010] paragraph and FIG. 1)

  However, the ultrasonic sensors in the above-described obstacle detection system for a vehicle are all set so that the central axis of the ultrasonic wave transmission direction is set in a horizontal direction with respect to the vehicle, and the ultrasonic sensor is attached to the surface of the vehicle. Ultrasonic waves are transmitted in the normal direction. The ultrasonic sensor has a non-detection range in the vicinity of the sensor head due to its property, and an obstacle cannot be detected in this range. Therefore, when the ultrasonic sensor is arranged in the bumper of the vehicle, there is a problem that if the obstacle is too close to the bumper, the obstacle cannot be detected due to the presence of the non-detection range. In addition, since the ultrasonic sensor is arranged on the bumper, if the rear door of the vehicle is opened and a part of the rear door of the vehicle comes out of the obstacle detection range of the ultrasonic sensor, the rear door of the vehicle is opened. There was also a problem that obstacles in the direction could not be detected.

  The present invention has been made paying attention to such problems, and an object thereof is to provide a vehicle obstacle detection system excellent in obstacle detection that can improve the obstacle detection ability in the vicinity of the vehicle. There is.

  The first feature configuration of the vehicle obstacle detection system according to the present invention for achieving the above object is the vehicle obstacle detection system for detecting obstacles around the vehicle by arranging an ultrasonic sensor on the vehicle body. The center axis in the transmission direction of the ultrasonic sensor is set substantially along the surface of the vehicle body.

  As in this configuration, the obstacle detection near the vehicle can be improved by setting the central axis in the transmission direction of the ultrasonic sensor substantially along the surface of the vehicle body. That is, for example, by placing an ultrasonic sensor on the vehicle body above the bumper and tilting the central axis in the transmission direction of the ultrasonic sensor substantially along the surface of the vehicle body so that the vicinity of the bumper is within the detection range, the bumper Occurrence of a non-detection range in the vicinity can be avoided, and an obstacle in the vicinity of the bumper can be detected. Here, the “center axis in the transmission direction” represents the direction axis with the maximum intensity of the ultrasonic wave transmitted from the ultrasonic sensor.

  A second characteristic configuration of the vehicle obstacle detection system according to the present invention is that the surface of the vehicle body is included in a detection range of the ultrasonic sensor.

  As in this configuration, by including the surface of the vehicle body in the detection range of the ultrasonic sensor, ultrasonic waves reflected directly on the surface of the vehicle body are also used for obstacle detection along with the ultrasonic waves directly transmitted from the ultrasonic sensor. can do. In addition, an obstacle that has a shape that is difficult to detect with an ultrasonic wave directly transmitted from an ultrasonic sensor may be easily detected by using an ultrasonic wave reflected on the surface of the vehicle body. Detection is possible.

  A third characteristic configuration of the vehicle obstacle detection system according to the present invention is that the surface of the vehicle body is a surface of a vehicle door that swings.

  As in this configuration, the center axis in the transmission direction of the ultrasonic sensor is set substantially along the surface of the swinging vehicle door, so that even when the swinging vehicle door opens, the ultrasonic sensor together with the door is opened. This makes it possible to detect an obstacle in the opening direction of the vehicle door.

  A fourth characteristic configuration of the vehicle obstacle detection system according to the present invention is that a front end portion of the surface of the swinging vehicle door is included in a detection range of the ultrasonic sensor.

The front end portion of the surface of the swinging vehicle door is a portion that starts most quickly when the vehicle door is opened, that is, a portion that is most likely to hit an obstacle. Like this structure, this front-end | tip part is included in the detection range of an ultrasonic sensor, and the obstruction detection at the time of opening of a vehicle door becomes reliable.
In this configuration, it is preferable to provide the detection range by installing the ultrasonic sensor in a state where the front end portion of the surface of the vehicle door can be directly seen.
However, in general, the outer surface of the vehicle door has various uneven shapes. In this configuration, even if the front end portion of the vehicle door becomes a shadow of other portions of the vehicle door, the front end portion of the vehicle door is set to fall within the detection range. In general, when ultrasonic waves pass near the surface of an object, they are diffracted to some extent along the surface shape. For this reason, with this configuration, even if the tip portion cannot be seen, if the surface shape of the vehicle (vehicle door) is such that the ultrasonic wave is diffracted, an obstacle near the tip portion can be detected.
Furthermore, the vehicle door is generally convex outward, but if the tip of the vehicle door is set to be within the detection range, the outermost edge of the door surface is reliably within the detection range when viewed from the ultrasonic sensor. Will enter. Therefore, the obstacle in the vicinity of the vehicle door can be detected with high accuracy.

  According to a fifth characteristic configuration of the vehicle obstacle detection system according to the present invention, an angle (elevation angle) between a central axis in a transmission direction of the ultrasonic sensor and a vehicle door surface to which the ultrasonic sensor is attached is predetermined. The point is to set the angle.

  The ultrasonic sensor is arranged on the surface of the vehicle door so that the center axis of the transmission direction forms a predetermined elevation angle with respect to the surface of the vehicle door, so that the measurement range of the ultrasonic sensor is adjacent to the vehicle surface. Can be set. This elevation angle arrangement of the ultrasonic sensor can reduce the non-detection area near the vehicle body surface, which could not be avoided by the conventional transmission arrangement in the normal direction, and can widen the obstacle detection range. . Furthermore, by adjusting the elevation angle and including the vehicle body surface in the measurement range of the ultrasonic sensor, a portion of the radially spreading transmission is incident on the vehicle surface at a shallow angle so that the transmission direction side (distant from the ultrasonic sensor) ) To create a detour transmission. As a result, a detour reflected wave that this detour transmission wave hits the obstacle and a direct reflection wave that bounces back when the transmission directly hits the obstacle are generated, and these two reflections are overlapped to output to the ultrasonic sensor side. It becomes possible to reflect, the output of the reflected wave can be increased, and the detection accuracy can be improved.

  A sixth characteristic configuration of the obstacle detection system for a vehicle according to the present invention includes a transmission unit that transmits an ultrasonic signal toward the outside of the vehicle, and the superstructure reflected by the surface of an object at a position away from the vehicle. And receiving means for receiving a sound wave signal in a state of being deviated from the surface of the vehicle to the outside of the vehicle, and virtual receiving means at a position having a mirror image relationship with the receiving means with respect to the surface of the vehicle The ultrasonic signal transmitted from the transmitting means, reflected by the surface of the object and the surface of the vehicle and then received by the receiving means is transmitted from the transmitting means and reflected by the surface of the object. The direct reflected wave signal received by the receiving means after being transmitted from the transmitting means and reflected by the surface of the object after being regarded as a bypass reflected wave signal received by the virtual receiving means, and the bypass reflected wave signal Based on lies in having an arithmetic means for determining the position of the object.

  With this configuration, the direct reflected wave signal received by the receiving means after being reflected by the surface of the object, and the ultrasonic signal transmitted from the transmitting means and received by the receiving means after being reflected by the surface of the object and the surface of the vehicle are transmitted. The position of the object is specified on the basis of the detour reflected wave signal transmitted from the means and received by the virtual receiving means after being reflected by the surface of the object. For this reason, even when the number of receiving means is one, the position of the object can be specified as in the case where there are a plurality of receiving means. As a result, since it is not necessary to provide a plurality of receiving means, the position of the object can be specified with a simple configuration.

  According to a seventh characteristic configuration of the vehicle obstacle detection system according to the present invention, the surface of the vehicle is a surface of an opening / closing body that is driven to open / close with respect to the vehicle, and the position of the object specified by the calculation means However, when it exists in the predetermined area | region previously set with respect to the surface of the said opening-closing body, it is the point provided with the control means which stops the opening drive of the said opening-closing body.

  With this configuration, when the position of the object specified by the calculation means is in a predetermined region set beforehand outside the surface of the opening / closing body, the control means stops the opening / closing body opening drive. For this reason, even when an object exists near the outside of the opening / closing body, the opening / closing body can be prevented from colliding with the object.

  An eighth characteristic configuration of the obstacle detection system for a vehicle according to the present invention is such that the transmission means transmits the ultrasonic signal in pulses, and the reception timing of the two ultrasonic signals received by the reception means is predetermined. When it is within the time, the ultrasonic signal received earlier is the direct reflected wave signal, and the ultrasonic signal received later is the detour reflected wave signal.

  Depending on the state of the surface of the object, the direct reflected wave signal and the detour reflected wave signal based on common ultrasonic waves may not be received. However, since ultrasonic waves are transmitted in pulses, as in this configuration, when the reception timing of the two ultrasonic signals received by the receiving means is within a predetermined time, the previously received ultrasonic signals are directly Even if only one of the direct reflected wave signal and the detour reflected wave signal can be received by calculating the reflected ultrasonic wave as a reflected wave signal, the ultrasonic wave received later is transmitted at a different timing. The position of the object can be approximated and specified by two ultrasonic signals based on the ultrasonic signal.

  A ninth characteristic configuration of the vehicle obstacle detection system according to the present invention includes: a transmission unit that transmits an ultrasonic signal toward the outside of the vehicle; and the superstructure reflected by the surface of an object at a position away from the vehicle. A plurality of receiving means for receiving the sound wave signals at different positions, respectively, and the ultrasonic signals received by the plurality of receiving means based on the respective times received by the receiving means after being transmitted by the transmitting means. If the position of the object is identified and the identified position is determined to be inside the surface of the vehicle, the actual position of the object is mirror-image related to the identified position with respect to the surface of the vehicle. It is in the point provided with the calculating means which sets to the position which becomes.

When a plurality of receiving means are provided as in this configuration, the position of the object can be specified based on the reflected wave received by each receiving means.
For example, when all of the ultrasonic signals transmitted from the transmission means are reflected on the surface of the object and further reflected on the surface of the vehicle and then received by the reception means, the reflected waves return from the inside of the vehicle. The position may be identified as being inside the vehicle.
Therefore, in this configuration, when the position of the specified object is determined to be inside the surface of the vehicle, the calculation means determines the actual position of the object and the mirror image relationship with the specified position with respect to the surface of the vehicle. Set to the position. As a result, the receiving means cannot directly receive the reflected wave signal reflected from the surface of the object, and the receiving means receives the reflected wave signal via the reflection on the surface of the vehicle, thereby identifying the position of the object. Can do.

  In a tenth characteristic configuration of the vehicle obstacle detection system according to the present invention, the surface of the vehicle is a surface of an opening / closing body that is driven to open / close with respect to the vehicle, and the position of the object specified by the calculation means However, when it exists in the predetermined area | region preset inside the surface of the said opening-and-closing body, it exists in the point provided with the control means which stops the opening drive of the said opening-and-closing body.

  With this configuration, when the position of the object specified by the calculation means is in a predetermined region set in advance with respect to the surface of the opening / closing body, the control means stops the opening drive of the opening / closing body. For this reason, even if it is a case where a receiving means cannot receive the reflected wave reflected on the surface of the object directly, the reflected wave on the surface of the opening / closing body can be received and the opening drive of the opening / closing body can be stopped.

  The eleventh characteristic configuration of the vehicle obstacle detection system according to the present invention is that the predetermined area can be changed.

  Depending on the surface shape of the opening and closing body, the ultrasonic signal transmitted from the transmitting means is reflected on the surface of the object, and further reflected on the surface of the vehicle and then received by the receiving means, and thus the specified object The position of also changes. However, according to the present configuration, the region can be changed according to the surface shape of the opening / closing body, so that the present apparatus can be used for various vehicles equipped with various opening / closing bodies.

[Embodiment 1]
An embodiment of a vehicle obstacle detection system according to the present invention will be described with reference to the drawings. FIG. 1 is a view showing a detection range when an ultrasonic sensor is arranged on the rear door 11 of the vehicle 1, and FIG. 2 is a side view of FIG. The rear door 11 is an up-and-down open / close swinging door (open / close body).

  Ultrasonic waves are transmitted from these ultrasonic sensors, the ultrasonic waves hit an obstacle to generate a reflected wave, and the reflected wave is received by the original ultrasonic sensor. The distance between the ultrasonic sensor and the obstacle is detected based on the time from the transmission to the reception. If the distance is within a certain range, the buzzer and warning display in the driver's seat indicate the presence of the obstacle. The driver is informed.

  As shown in FIG. 1, the ultrasonic sensor 2 is disposed in the vicinity of the hinge 13 of the rear door 11 of the vehicle. As shown in FIG. 2, the center axis 22 in the transmission direction of the ultrasonic sensor 2 is inclined downward substantially along the surface 12 </ b> A of the rear door 11 of the vehicle. Since the central axis 22 is “substantially along” the surface 12 A of the rear door 11, specifically, the angle formed by the central axis 22 and the surface of the rear door 11 is preferably within 45 °. A detection range 3 extends in front of the ultrasonic sensor 2, extends in a fan shape on a plane including the ultrasonic sensor, and spatially in a truncated cone shape, and a non-detection range 4 is in the vicinity of the sensor head 21. Existing. For example, if the angle (elevation angle α) formed between the central axis 22 and the surface 12A of the rear door 11 is set to be less than 90 ° and 0 ° or more, the frustoconical detection range of the ultrasonic sensor 2 is set to the rear door 11. Can be set in contact with the front surface 12A, and the obstacle detection range can be expanded by eliminating the non-detection area near the surface. If the elevation angle α is set to 60 ° or less and 0 ° or more, it can be applied even to a low-power ultrasonic sensor. Furthermore, if the elevation angle α is 45 ° or less and 0 ° or more, the detection sensitivity is further improved, and in the rear door 11 that is electrically driven, after the obstacle is detected, the opening / closing operation of the rear door 11 is stopped, It becomes possible to avoid a collision with an obstacle.

  As is apparent from FIG. 2, unlike the conventional case where the ultrasonic sensor is attached to the bumper and the central axis of the transmission direction is directed horizontally, in the present embodiment, the vicinity of the bumper 14 is super It is included in the detection range 3 of the sonic sensor 2. The surface 12A of the convex rear door 11 exists on a straight line connecting the ultrasonic sensor 2 and the bumper 14, but the ultrasonic wave transmitted from the ultrasonic sensor 2 is transmitted to the surface of the convex rear door 11. It can wrap around to bumper 14 along 12A. Therefore, the occurrence of a non-detection range in the vicinity of the bumper as in the prior art can be avoided, and an obstacle in the vicinity of the bumper can be detected.

  As shown in FIG. 2, in this embodiment, the surface 12 of the vehicle body, particularly the surface 12 </ b> A of the rear door 11 is included in the detection range 3 of the ultrasonic sensor 2. In this case, the ultrasonic waves reflected on the surface 12 of the vehicle body can also be used for obstacle detection. That is, as shown in FIG. 4, while there is a normal path (direct reflected wave path) that directly hits the obstacle 5 through the path XX ′ from the ultrasonic sensor 2, an ultrasonic wave transmitted from the ultrasonic sensor 2 is present. A sound wave is reflected at a point P on the surface 12 of the vehicle body, and there is a route (a route for a detour transmission wave) that hits the obstacle 5 through a route YPY '. An ultrasonic wave (a detour reflected wave) reflected by this route is also an obstacle. Can be used for detection. Further, even in the case of an obstacle having a shape that is difficult to detect in the normal route XX ′, for example, an obstacle having a shape substantially parallel to XX ′, the ultrasonic wave by the route YPY ′ reflected on the surface of the vehicle body is XX ′. Therefore, it is easier to detect an obstacle than the ultrasonic wave by the path XX ′. Thus, effective obstacle detection becomes possible by including the surface of the vehicle body in the detection range.

  Further, since the ultrasonic sensor 2 is disposed in the vicinity of the hinge 13 of the rear door 11 of the vehicle, the ultrasonic sensor 2 moves together with the rear door 11 when the rear door 11 is opened and closed. As a result, as shown in FIG. 3, the center axis 22 in the transmission direction of the ultrasonic sensor 2 is always substantially along the surface of the rear door 11 of the vehicle. It will move. Therefore, when an obstacle exists in the opening direction of the rear door 11, this can be easily detected.

  Further, as shown in FIGS. 1 to 3, the detection range 3 of the ultrasonic sensor 2 includes a front end 12 a on the surface of the rear door. The front end portion 12a on the surface of the rear door 11 is a portion that starts most quickly when the rear door 11 is opened, that is, a portion that is most likely to hit an obstacle. Therefore, by including the tip portion 12a in the detection range 3 of the ultrasonic sensor 2, the obstacle detection when the rear door 11 is opened can be made more reliable.

  When the central axis in the transmission direction of the ultrasonic sensor is tilted downward, for example, the detection range may include not only an obstacle but also a part of a vehicle body such as a bumper, a curb, a road, and the like. In such a case, if a normal ultrasonic sensor is used, a part of the vehicle body or a curb is detected as an obstacle, and as a result, the driver is informed of unnecessary information, which is effective. Obstacle detection is not possible. Therefore, in order to distinguish an obstacle and an object other than an obstacle, an ultrasonic sensor that can detect a target obstacle more accurately by removing a predetermined response signal (response time, waveform, etc.) By using it, the obstacle detection system for vehicles excellent in the detection capability can be provided.

  In the present embodiment, as described above, a part of the vehicle body such as the bumper 14 is included in the detection range 3 of the ultrasonic sensor 2. Therefore, a reflected wave is generated from a part of the vehicle body such as the bumper 14, and it is necessary to distinguish this from an obstacle in order to perform effective obstacle detection.

  Therefore, the ultrasonic sensor 2 according to the present embodiment is configured to remove a predetermined response signal in order to distinguish a reflected wave from a part of the vehicle body such as the bumper 14 and a reflected wave from a target obstacle. It is configured. For example, in the case of the bumper 14, since the distance L from the ultrasonic sensor 2 to the bumper 14 is constant when the rear door 11 is closed, the response time T from the transmission of ultrasonic waves to the reception of the bumper 14 is also constant. It becomes. Accordingly, the bumper and the obstacle can be distinguished by removing the response signal returned at the response time T. Similarly, when the rear door 11 is closed, since the shape of the bumper 14 is constant with respect to the ultrasonic sensor 2, the reflected wave is also constant. For this reason, the bumper and the obstacle can be distinguished by removing the signal corresponding to the reflected wave from the response signal.

  Of course, these methods can be applied not only to bumpers but also to other parts of the vehicle body. In addition, by limiting the detection range to a certain distance from the vehicle, for example, by removing what is returned with a response time of a certain time or more, objects near the ground such as curbs and roads can be detected by the ultrasonic sensor. It can be excluded from the detection range.

  As described above, to distinguish between obstacles and non-obstacles, the target obstacle can be detected more accurately by removing the response signal based on the predetermined response time and waveform, etc. It is possible to provide an obstacle detection system for a vehicle excellent in the above.

[Another embodiment 1]
In the above embodiment, the arrangement of the ultrasonic sensor 2 and the direction of the central axis 22 of the transmission direction are set so that the detection range 3 of the ultrasonic sensor 2 includes the surface 12 of the vehicle body. The range may not include the surface of the vehicle body. For example, as shown in FIG. 5, by increasing the angle formed by the central axis 22 in the transmission direction and the surface 12A of the rear door 11, the detection range 3 may be set so as not to include the surface of the vehicle body. it can. In this case, an obstacle can be detected at a location farther away from the vehicle than in the above embodiment.

[Another embodiment 2]
(Outline of obstacle detection system)
Although this obstacle detection system is not particularly limited, for example, as shown in FIG. 6, the obstacle detection system can be applied to a hatchback vehicle including a flip-up type rear door 11.
As shown in FIG. 7, the obstacle detection system includes a transmission unit 24 that transmits an ultrasonic signal toward the outside of the vehicle 1, and the superstructure reflected by the surface of the obstacle 5 that is located away from the vehicle 1. Receiving means 32 for receiving a sound wave signal. A sensor head 21 including the transmission unit 24 and the reception unit 32 is disposed on the surface of the rear door 11.
Moreover, it has the calculating means 51 which pinpoints the position of the said obstruction 5 based on the time required from transmission to reception about the ultrasonic signal received by the receiving means 32.

This vehicle obstacle detection system includes a generation unit 23 that generates an ultrasonic signal. The generation unit 23 outputs an oscillation signal to the transmission unit 24 every time the timing signal from the calculation unit 51 is input, and transmits an ultrasonic signal from the transmission unit 24.
Further, the vehicle obstacle detection system includes a processing unit 31 and a detection unit 41. The processing unit 31 performs processing such as amplification and filtering on the reflected wave signal received by the receiving unit 32. The detection unit 41 performs full-wave rectification on the ultrasonic signal processed by the processing unit 31 and integrates it to obtain an envelope reflected wave signal. Then, the envelope reflected wave is output to the computing means 51. The computing means 51 detects the position of the obstacle 5 based on the envelope reflected wave signal.

  The control means 60 stops the opening / closing body opening drive when the position of the obstacle 5 specified by the calculation means 51 is in a region R1 (see FIG. 8) set in advance outside the surface of the rear door 11. The back door actuator 61 is controlled.

(Identification of obstacle position)
As shown in FIG. 8, the reflected wave signal received by the receiving means 32 is transmitted from the transmitting means 24 and reflected by the receiving means 32 after being reflected by the surface of the obstacle 5 (hereinafter referred to as “directly”). And a reflected wave signal reflected by the surface of the vehicle 1 and then reflected by the surface of the vehicle 1 and received by the receiving means 32.
That is, as shown in FIG. 9, the reflected wave reflected by the obstacle 5 is directly received by the receiving means 32 through the path BO, and the reflected wave reflected by the obstacle 5 is further on the surface of the vehicle body. In some cases, the light is reflected at the point P and received by the receiving means 32 through the path BPO.

The position of the obstacle 5 can be specified based on the reflected wave signal received by the receiving means 32 through the two paths described above.
As shown in FIG. 9, it is assumed that the ultrasonic wave is received at the receiving means 32 via the path BPO, the receiving means 32 and the mirror position with respect to the surface of the vehicle 1 (the surface of the rear door 11). The path length received via the path BO ′ is equal to the virtual virtual receiving means 32 ′.
Therefore, the direct reflected wave signal and the reflected wave signal received by the receiving means 32 through the path BPO are reflected on the reflected wave signal (hereinafter referred to as “bypass reflection”) received by the virtual receiving means 32 ′ through the path BO ′. The position of the obstacle 5 can be determined based on the “wave signal”).
That is, the path length of the path BO obtained from the time until the direct reflected wave signal is received after the ultrasonic signal is transmitted from the transmitting unit 24, and the detour reflected wave signal after the ultrasonic signal is transmitted from the transmitting unit 24 The position of the obstacle 5 can be specified on the basis of the path length of the path BO ′ obtained from the time until it is received and the interval between the receiving means 32 and the virtual receiving means 32 ′.

(Identification processing of obstacle position by calculation means)
Next, the obstacle position specifying process by the calculation means 51 will be described.
When the reception unit 32 receives a direct reflected wave signal and a detour reflected wave signal based on a common ultrasonic signal, the ultrasonic signal is reflected by the surface of the obstacle 5 and then received by the reception unit 32. Have different path lengths. For this reason, as shown in FIG. 10, the computing means 51 obtains an envelope wave signal having two vertices, that is, a vertex P1 based on the direct reflected wave signal and a vertex P2 based on the detour reflected wave signal.
The computing unit 51 identifies the vertices P1 and P2 of the envelope waveform, and uses the voltage counter values in a predetermined range before each vertex to obtain approximate lines L1 and L2 by, for example, the least square method. Then, a timer count value (0 crossing time) at which each approximate line intersects with the voltage counter value 0 is obtained. That is, the estimated rise values T1 and T2 of the envelope wave are specified.
Then, the path length BO and the path length BO ′ are obtained from the estimated start values T1 and T2, and based on the path length BO and the path length BO ′ and the interval OO ′ between the receiving means 32 and the virtual receiving means 32 ′. The position of the obstacle 5 is specified.

On the other hand, as shown in FIG. 11, when the surface of the obstacle 5 is flat, irregular reflection does not occur. Therefore, in order for the receiving means 32 provided close to the transmitting means 24 to directly receive the reflected wave, It is necessary for the ultrasonic waves to be incident on the obstacle 5 substantially perpendicularly. For this reason, even if the obstacle 5 exists in the detection range 3 of the sensor head 21, there may be a case where the direct reflected wave and the detour reflected wave based on the common ultrasonic signal cannot be received. In this case, the position of the obstacle 5 is detected based on the direct reflected wave signal and the detour male reflected wave signal using ultrasonic signals at different timings.
That is, the reflected wave obtained by transmitting the ultrasonic signal a plurality of times is stored in, for example, the memory of the computing means 51, and the reflected wave whose rise estimated value is within a predetermined range is extracted. Here, if the reflected wave signal is from the same obstacle, the positional relationship with the obstacle 5 changes due to the opening operation of the rear door 11, and thus the estimated start value changes. It is determined based on the opening speed and the transmission timing of the ultrasonic signal.
Then, the position of the obstacle 5 is specified based on the focused waveform W1 shown in FIG. 12A and the extracted waveform W2 shown in FIG.
As described above, even when only one of the direct reflected wave signal and the detour reflected wave signal can be received, the position of the obstacle 5 can be specified.

[Another embodiment 3]
(Outline of obstacle detection system)
Similar to the vehicle obstacle detection system according to the above-described embodiment, this obstacle detection system can be applied to a hatchback vehicle provided with a flip-up type rear door 11.

  As shown in FIG. 13, this vehicle obstacle detection system is reflected on the surface of the obstacle 5 located at a position apart from the transmission means 24 that transmits an ultrasonic signal toward the outside of the vehicle 1 and the vehicle 1. And a plurality of receiving means 32 for receiving the ultrasonic signals at different positions. As shown in FIG. 14, for example, the transmission unit 24 and the reception units 32a, 32b, and 32c are provided on the sensor head 21 at positions where the apexes of the square are formed.

  Further, this vehicle obstacle detection system has a calculation means 51. The calculation means 51 uses the time required from transmission to reception for the ultrasonic signals received by the plurality of reception means 32a, 32b, and 32c (by the reception means 32a, 32b, and 32c after being transmitted by the transmission means 24). The position of the obstacle 5 is specified based on each received time). Further, when the position of the specified obstacle 5 is determined to be inside the surface of the vehicle 1, the calculation means 51 determines the actual position of the obstacle 5 as the position specified with respect to the surface of the vehicle 1. Set to a position that will be a mirror image.

  The control means 60 is configured so that the position of the obstacle 5 where the obstacle 5 is specified by the computing means 51 is set in advance in the first region R1 (see FIG. 15) outside the surface of the rear door 11 or the surface of the rear door 11 The back door actuator 61 is controlled so as to stop the opening drive of the rear door 11 when it is in the second region R2 (see FIG. 15) set to the inside.

(Identification of obstacle position)
When a plurality of receiving means 32a, 32b, and 32c are provided as in this configuration, the position of the obstacle 5 can be specified based on the reflected wave signal received by each receiving means 32a, 32b, and 32c.
As shown in FIGS. 15 and 16, when the reflected wave signal is received by the receiving unit 32, when the ultrasonic wave reflected by the obstacle 5 is directly received by the receiving unit 32 (path BO), the obstacle 5 In some cases, the ultrasonic wave reflected at (1) is received by the receiving means 32 after being reflected at a point P on the surface of the vehicle body (path BPO).
When all the ultrasonic signals transmitted from the transmitting means 24 are received by the receiving means 32 through the path BPO, the reflected wave returns from the inside of the vehicle 1, so that the obstacle 5 is on the surface of the vehicle 1 ( May be identified as being inside the vehicle from the rear door surface)

That is, as shown in FIG. 16, the path length of the ultrasonic wave received by each receiving means 32a, 32b, 32c through the path BPO and the obstruction 5 and mirror are in relation to the surface of the rear door 11. When the virtual obstacle 5 ′ is assumed, the path lengths of the ultrasonic waves received by the receiving units 32a, 32b, and 32c through the path B′O are equal.
For this reason, when the ultrasonic wave is received by the receiving unit 32 through the path BPO, the obstacle 5 is specified at a position that is in a mirror image relationship with the position where the obstacle 5 actually exists.

  For this reason, when the position of the obstacle 5 is specified inside the surface of the rear door 11 by the calculation means 51, the actual position of the obstacle 5 is specified as a mirror image with the position specified for the position of the rear door 11. By setting the relevant position, the position of the obstacle 5 can be specified.

Even when the position of the obstacle 5 specified by the calculation means 51 is in the second region R2, the control means 60 stops the opening drive of the rear door 11. For this reason, even if it is a case where only the reflected wave reflected by the rear door 11 can be received after the receiving means 32 is reflected on the surface of the obstacle 5, the opening drive of the rear door 11 can be stopped.
It should be noted that due to the surface shape of the rear door 11, there is a route when the ultrasonic signal transmitted from the transmission unit 24 is reflected by the surface of the obstacle and further reflected by the surface of the vehicle and then received by the reception unit 32. Differently, the position of the specified obstacle 5 also changes. For this reason, it is preferable that the region R can be changed.

(Identification processing of obstacle position by calculation means)
Next, an example of the obstacle obstacle position specifying process will be described.
A process when four reflected waves are received by each receiving means 32a, 32b, 32c at a certain measurement timing will be described. At this time, four envelope waveforms as shown in FIG. 17 are obtained for each receiving means 32a, 32b, and 32c.
First, the computing means 51 specifies the vertices of each envelope waveform for each of the receiving means 32a, 32b, and 32c, and uses the voltage counter values in a predetermined range before the vertices P1, P2, P3, and P4. For example, approximate lines L1, L2, L3, and L4 are obtained by a least square method. Then, timer count values (0 crossing times) T1, T2, T3, and T4 at which the approximate straight lines L1, L2, L3, and L4 intersect with the voltage count value 0 are obtained. That is, the estimated rise value of the envelope wave is specified. This apex specification and rise estimation value specification are performed for the reflected wave signals W1, W2, W3, and W4. The above-described processing is performed for each receiving means 32a, 32b, 32c.
Then, as shown in FIG. 18, the calculation means 51 stores the obtained vertex timer count value, vertex voltage count value, and estimated rise values T1 to T4 in the candidate table 200 for each reception means 32. Store. Here, 200a is a candidate table for the reflected wave signal obtained by the receiving means 32a, 200b is a candidate table for the reflected wave signal obtained by the receiving means 32b, and 200c is a reflection table obtained by the receiving means 32c. It is a candidate table about a wave signal.
In addition, the computing means 51 selects a combination that is a candidate for the same reflected wave reflected by the same obstacle 5 according to the relationship of the estimated rise value in the candidate table.
That is, a candidate set in which the difference in the estimated rise value between the candidate tables 200a and 200b is equal to or less than the predetermined value α is extracted. In addition, a candidate set in which the difference in the estimated start value between the candidate tables 200b-200c is equal to or less than the predetermined value β is extracted. Further, a candidate set in which the difference in the estimated rise value between the candidate tables 200c and 200a is equal to or smaller than the predetermined value γ is extracted. And the union as a whole is selected from each finally extracted combination.
Here, the predetermined values α, β, and γ are indexes indicating whether or not the reflected wave signals received by the receiving units 32a, 32b, and 32c are due to the same obstacle 5. These α, β, and γ are values determined empirically based on the interval between the corresponding receiving means 32, and in this embodiment, α, β, γ = 160.

For all candidate combinations between the candidate tables 200a-200b, the difference between the rise estimation values is obtained, and the set having the obtained difference of 160 or less is extracted. In this case, as shown in FIG. 19A, three sets of candidate 1-candidate 1, candidate 3-candidate 3, and candidate 4-candidate 4 are extracted.
Similarly, as shown in FIG. 19B, four sets of candidate 1-candidate 1, candidate 2-candidate 2, candidate 3-candidate 3, and candidate 4-candidate 4 are extracted between candidate tables 200b-200c. Is done. As shown in FIG. 19C, three sets of candidate 1-candidate 1, candidate 3-candidate 3, and candidate 4-candidate 4 are extracted between candidate tables 200c-200a.
Then, candidate combinations as a whole are selected from these extracted combinations. That is, a combination having a difference in the estimated start value of 160 or less is selected in any of the candidate tables 200a-200b, the candidate tables 200b-200c, and the candidate tables 200c-200a.
That is, for example, when attention is paid to candidate 1 (5587) in candidate table 200a, as shown in FIG. 19 (a), in candidate table 200b, the difference between the estimated start values is 160 or less as candidate 1 (5585). It is. Further, as shown in FIG. 19C, in the candidate table 200c, the candidate 1 (5744) has a difference between the estimated start values of 160 or less. Thus, when attention is paid to candidate 1 of each candidate table 200a, 200b, and 200c, the difference in the estimated start value is 160 or less regardless of which candidate 1 of any candidate table 200 is compared.
Therefore, the union of candidate 1-candidate 1-candidate 1 is selected as union 1. By the same processing, as shown in FIG. 20, three combinations are selected as candidate combinations for the final obstacle 5.

Then, the calculation means corresponds to the selected candidate combination, using the estimated rise value of each waveform as the reception time of the reflected wave, and the position of the obstacle for each combination in FIGS. 14 and 21 by triangulation. It is specified as the (X, Y, Z) coordinates shown.
For example, when the position of the obstacle 5 is specified from the combination 1 in FIG. 20, as shown in FIG. 22A, from the estimated start value (5587) by the receiving means 32a, the receiving means 32a and the obstacle 5 are The distance D2 is obtained, and the distance D1 between the receiving means 32b and the obstacle 5 is obtained from the estimated rise value (5585) by the receiving means 32b. Then, the Y-direction distance y and the Z-direction distance z of the obstacle 5 are obtained from the distance D1 and the distance D2.
Further, as shown in FIG. 22B, the distance D3 is obtained from the estimated start value (5744) by the receiving means 32b. Then, the X-direction distance x and the Z-direction distance z of the obstacle 5 are obtained from the distance D1 and the distance D3.
The above processing is performed for each association, and the positions of the obstacles 1 to 3 are specified as shown in FIG.

[Another embodiment 4]
In the above embodiment, the case where the ultrasonic sensor 2 is arranged on the rear door 11 that swings up and down and opens and closes is shown, but it can of course be arranged on other swinging vehicle doors such as a left and right opening and closing type.

  For example, FIG. 24 shows an embodiment in which the ultrasonic sensor 2 is disposed on a rear door 11 ′ that can be opened and closed on the left and right sides of a truck. As is apparent from FIG. 24, in this case, the ultrasonic sensor 2 is disposed in the vicinity of the hinges 13 of the left and right doors. The center axis 22 in the transmission direction is set substantially along the surface of the rear door 11 ', the left ultrasonic sensor 2 is set to the right, and the right ultrasonic sensor 2 is set to the left. Yes. Further, the detection range 3 includes the surface 12A 'of the rear door 11' and the front end portion 12a 'of the surface of the rear door 11'.

  Accordingly, even when the rear door 11 ′ is opened, the ultrasonic sensor 2 can move together with the rear door 11 ′, and its central axis 22 always follows the surface 12A ′ of the rear door 11 ′ of the vehicle. It becomes a state. That is, since the detection range 3 moves together with the opening of the rear door 11 ′, if there is an obstacle 5 in the opening direction of the rear door 11 ′, this can be easily detected. Further, when the rear door 11 ′ is opened, the front end portion 12 a ′ on the surface of the rear door 11 ′, which is the most likely to hit the obstacle 5, is included in the detection range 3 of the ultrasonic sensor 2. The obstacle 5 can be detected more reliably when the door is opened.

[Another embodiment 5]
In the above-described embodiment, the ultrasonic sensor 2 is disposed in the vicinity of the hinge 13 of the rear door 11 ′. For example, from the viewpoint of design, it can also be arranged on the emblem of the rear door 11 '. In this case, the center axis in the direction of transmission is inclined downward so that the front end of the rear door 11' is desired. can do.

  Further, as shown in FIGS. 25A and 25B, for example, in the case of a truck wing type door 11 ″, even if an ultrasonic sensor is arranged near the hinge as in the above embodiment, the vehicle door The front end 12a ″ of the surface cannot be within the detection range. In such a case, by disposing the ultrasonic sensor 2 at the corner 15 of the wing-type door, the center of the ultrasonic sensor 2 in the transmission direction so as to include the front end portion 12a ″ of the surface of the wing-type door. The shaft 22 can be set substantially along the wing door surface 12A ″. As a result, as shown in FIG. 25 (b), the detection range 3 of the ultrasonic sensor 2 moves together with the opening of the wing-type door 11 ″, and this is easy even when there is an obstacle 5 on the side of the vehicle. Further, since the front end portion 12a "of the surface of the wing type door is included in the detection range 3, the obstacle 5 on the side of the vehicle when the wing type door 11" is opened is detected. Can be made more reliable.

[Another embodiment 6]
In the above embodiment, the ultrasonic sensor is disposed on the vehicle door, but may be disposed on the vehicle body other than the vehicle door. Even in this case, the center axis in the transmission direction of the ultrasonic sensor can be set so as to be substantially along the surface of the vehicle body, and the detection of the obstacle 5 in the vicinity of the vehicle can be improved.

The vehicle rear view which shows the detection range of the ultrasonic sensor of the obstacle detection system for vehicles which concerns on this invention Vehicle side view showing the detection range of FIG. Vehicle side view showing detection range when rear door of vehicle of FIG. 1 is opened Schematic showing the reflection of ultrasonic waves in the car body The vehicle side view which shows the detection range of the ultrasonic sensor in another Embodiment 1 The figure which shows the attachment position of the transmission means in another Embodiment 2, and a receiving means The figure which shows an example of the vehicle obstruction detection system of another Embodiment 2. The figure which shows the vehicle rear part in the case of receiving the reflected wave signal by a common ultrasonic signal The figure which shows the receiving path | route of the reflected wave signal by a receiving means The figure which shows an envelope wave at the time of receiving a reflected wave signal at the same timing The figure which shows the vehicle rear part in the case of receiving the reflected wave signal of a different timing The figure which shows an envelope wave at the time of receiving a reflected wave signal of different timing The figure which shows an example of the obstacle detection system for vehicles of another Embodiment 3. The figure which shows an example of an ultrasonic sensor The figure which shows the receiving path | route of the reflected wave signal by a receiving means The figure which shows the receiving path | route of the reflected wave signal by a receiving means The figure which shows an example of the envelope of a reflected wave The figure which shows an example of a candidate table The figure which shows an example of the process which identifies the reflected wave by an obstruction The figure which shows an example of the process which identifies the reflected wave by an obstruction Diagram showing coordinates for identifying the position of an obstacle Diagram showing how to locate obstacles Diagram showing the location of the identified obstacle Rear view of the vehicle showing the detection range of the ultrasonic sensor in another embodiment 4 Rear view of vehicle showing detection range of ultrasonic sensor in different embodiment 5

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Vehicle 2 Ultrasonic sensor 3 Detection range 5 Obstacle 12 Car body surface 12A-12A "Vehicle door surface 12a-12a" Front end 24 of vehicle door surface Transmitting means 32 Receiving means 32 'Virtual receiving means 51 Calculation means 60 Control means R region

Claims (11)

In the vehicle obstacle detection system for detecting obstacles around the vehicle by placing an ultrasonic sensor on the vehicle body,
A vehicle obstacle detection system in which a center axis of a transmission direction of the ultrasonic sensor is set substantially along a surface of a vehicle body.   The vehicle obstacle detection system according to claim 1, wherein a surface of the vehicle body is included in a detection range of the ultrasonic sensor.   The vehicle obstacle detection system according to claim 1, wherein the surface of the vehicle body is a surface of a vehicle door that swings.   The vehicle obstacle detection system according to claim 3, wherein a front end portion of the surface of the swinging vehicle door is included in a detection range of the ultrasonic sensor. Equipped with an ultrasonic sensor fixed to the surface near the hinge of the vehicle door that opens and closes,
A vehicle obstacle detection system in which a central axis in a transmission direction of the ultrasonic sensor is set to form an angle of 0 degree or more and less than 90 degrees with respect to a surface of the vehicle door. Transmitting means for transmitting an ultrasonic signal toward the outside of the vehicle;
And receiving means for receiving the ultrasonic signal reflected by the surface of an object located away from the vehicle, in a state of being deviated from the surface of the vehicle to the outside of the vehicle,
A virtual receiving means is set at a position that is a mirror image relationship with the receiving means with respect to the surface of the vehicle,
The ultrasonic signal transmitted from the transmitting means and reflected by the receiving means after being reflected by the surface of the object and the surface of the vehicle is transmitted from the transmitting means and reflected by the surface of the object and then received by the virtual reception. As a detour reflected wave signal received by the means,
A vehicle comprising a computing means for obtaining the position of the object based on the direct reflected wave signal transmitted from the transmitting means, reflected by the receiving means and then received by the receiving means, and the detour reflected wave signal Obstacle detection system. The surface of the vehicle is a surface of an opening / closing body that is driven to open / close with respect to the vehicle;
The control unit according to claim 6, further comprising: a control unit that stops opening of the opening / closing body when the position of the object specified by the computing unit is in a predetermined region set in advance outside the surface of the opening / closing body. Vehicle obstacle detection system.   When the transmission unit is configured to pulse-transmit the ultrasonic signal, and the reception timing of the two ultrasonic signals received by the reception unit is within a predetermined time, the ultrasonic signal received first is The vehicle obstacle detection system according to claim 6 or 7, wherein a direct reflected wave signal is used, and the ultrasonic signal received later is the detour reflected wave signal. Transmitting means for transmitting an ultrasonic signal toward the outside of the vehicle;
A plurality of receiving means for receiving the ultrasonic signals reflected by the surface of an object located at a position away from the vehicle, respectively, at different positions;
For the ultrasonic signals received by the plurality of receiving means, the position of the object is specified based on the respective times received by the receiving means after being transmitted by the transmitting means, and the specified position is determined by the vehicle. An obstacle detection system for a vehicle, comprising an arithmetic means for setting an actual position of the object to a position that is in a mirror image relationship with the specified position with respect to the surface of the vehicle when the position is inside the surface. . The surface of the vehicle is a surface of an opening / closing body that is driven to open / close with respect to the vehicle;
10. The control device according to claim 9, further comprising: a control unit that stops the opening and closing of the object when the position of the object specified by the calculating unit is in a predetermined region set in advance with respect to the surface of the opening and closing member. Vehicle obstacle detection system.   The vehicle obstacle detection system according to claim 10, wherein the predetermined area is changeable.

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