JP6945776B2 - Obstacle detector - Google Patents

Description

The present invention relates to an obstacle detection device.

A conventional obstacle detection device uses a single ultrasonic sensor installed in a vehicle, and the ultrasonic waves transmitted from the ultrasonic sensor to the side of the vehicle are reflected by the parked vehicle while the vehicle is running. The distance from the time required to be received by an ultrasonic sensor to a parked vehicle is detected, and the position of the ultrasonic sensor when the distance of the parked vehicle is detected and the detected distance are used according to the principle of triangular surveying. Guess the reflection point. Then, the conventional obstacle detection device obtains the shape and corners (corners) of the parked vehicle by using the point sequence data of the reflection points, and discriminates the parking zone (see, for example, Patent Document 1).

Japanese Patent No. 5965276

The conventional obstacle detection device has a configuration in which the corners of obstacles existing on the side of the own vehicle can be obtained only when the own vehicle passes by the side of the parked vehicle which is an obstacle. Further, in the conventional obstacle detection device, when the obstacle is tilted more than a certain angle with respect to the own vehicle, it is difficult to accurately determine the corner portion of the obstacle. As described above, the conventional obstacle detection device has a problem that it cannot detect an inclined obstacle existing in front of or behind the own vehicle.

The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to detect an inclined obstacle existing in front of or behind the own vehicle.

The obstacle detection device according to the present invention includes a transmission / reception unit that transmits and receives a direct wave and an indirect wave to a plurality of distance measuring sensors installed on the front surface or the rear surface of the vehicle, and an indirect wave in the plurality of distance measuring sensors. An inclined obstacle detection unit that detects the existence of an inclined obstacle having an inclined surface inclined with respect to the installation direction of a plurality of distance measuring sensors based on the reception status of When it is detected that an obstacle is present, two circles are drawn using the result of the same distance measuring sensor transmitting and receiving direct waves twice at different times while the vehicle is running. Based on the intersection processing unit that calculates the position of the intersection group from the transmission / reception results of direct waves by multiple ranging sensors by performing the 2-circle intersection processing to find the intersection, and the position of the intersection group calculated by the intersection processing unit. Based on the shape estimation unit that estimates the shape of the tilt obstacle and the shape of the tilt obstacle estimated by the shape estimation unit, the position of the part of the tilt obstacle that is closest to the vehicle is estimated and the contact position information. It is provided with a contact position estimation unit that outputs as.

According to the present invention, it is possible to detect an inclined obstacle existing in front of or behind the own vehicle.

It is a block diagram which shows the structural example of the obstacle detection apparatus which concerns on Embodiment 1. FIG. 2A and 2B are diagrams showing the reflection path of ultrasonic waves in a tilted obstacle. It is a figure explaining 2 circle intersection processing by an intersection processing part. It is a figure explaining how the position of an intersection shifts to a distant side as a vehicle approaches an inclined obstacle. 5A, 5B, and 5C are diagrams illustrating a method of estimating the shape of an inclined obstacle by the shape estimation unit and a method of estimating the contact position by the contact position estimation unit. It is a flowchart which shows the operation example of the obstacle detection apparatus which concerns on Embodiment 1. FIG. It is a block diagram which shows the structural example of the obstacle detection apparatus which concerns on Embodiment 2. FIG. 8A to 8F are diagrams illustrating a method of selecting a distance measuring sensor by the sensor selection unit. It is a flowchart which shows the operation example of the obstacle detection apparatus which concerns on Embodiment 2. It is a figure which shows the continuation of the flowchart of FIG. It is a figure which shows an example of the hardware configuration of the obstacle detection apparatus which concerns on each embodiment. It is a figure which shows another example of the hardware composition of the obstacle detection apparatus which concerns on each embodiment.

Hereinafter, in order to explain the present invention in more detail, a mode for carrying out the present invention will be described with reference to the accompanying drawings.
Embodiment 1.
FIG. 1 is a block diagram showing a configuration example of the obstacle detection device 10 according to the first embodiment. The obstacle detection device 10 is mounted on the vehicle and detects obstacles around the vehicle. The obstacle detection device 10 includes a transmission / reception unit 11, an inclination obstacle detection unit 12, an intersection processing unit 13, a shape estimation unit 14, and a contact position estimation unit 15. Further, the obstacle detection device 10 is connected to a plurality of distance measuring sensors 1 to 4 installed in the vehicle and a collision determination unit 20.

In FIG. 1, four distance measuring sensors 1 to 4 are connected to the obstacle detection device 10, but the number of distance measuring sensors is not limited to four, and may be two or more.
The ranging sensors 1 to 4 transmit ultrasonic waves or radio waves as exploration waves, and receive the reflected waves that are the exploration waves reflected by obstacles around the vehicle. In the following, it is assumed that the distance measuring sensors 1 to 4 are ultrasonic sensors.

The transmission / reception unit 11 causes the distance measurement sensors 1 to 4 to transmit / receive direct waves and indirect waves at a predetermined drive interval (for example, 50 ms) while the vehicle is traveling. For example, the transmission / reception unit 11 causes the distance measurement sensors 1 to transmit ultrasonic waves, and then causes the distance measurement sensors 1 to 4 to receive reflected waves. In this case, the reflected wave received by the distance measuring sensor 1 itself that transmitted the ultrasonic wave is a direct wave, and the reflected wave received by the distance measuring sensors 2 to 4 is an indirect wave. The transmission / reception unit 11 causes the distance measurement sensor 2 to transmit the ultrasonic wave 50 ms after the time when the distance measurement sensor 1 transmits the ultrasonic wave, and then causes the distance measurement sensors 1 to 4 to receive the reflected wave. In this case, the reflected wave received by the distance measuring sensor 2 itself that transmitted the ultrasonic wave is a direct wave, and the reflected wave received by the distance measuring sensors 1, 3 and 4 is an indirect wave. Similarly to the above, the transmission / reception unit 11 causes the distance measurement sensor 3 to transmit the ultrasonic waves 50 ms after the time when the ultrasonic waves are transmitted from the distance measurement sensor 2, and 50 ms from the time when the distance measurement sensor 3 transmits the ultrasonic waves. Later, ultrasonic waves are transmitted from the distance measuring sensor 4, and 50 ms after the time when the ultrasonic waves are transmitted from the distance measuring sensor 4, the ultrasonic waves are transmitted from the distance measuring sensor 1 again. In this way, the transmission / reception unit 11 causes the distance measuring sensors 1 to 4 to transmit / receive direct waves and indirect waves in a drive cycle of 200 ms. The transmission / reception unit 11 outputs information indicating the distance measuring sensor that transmits / receives the direct wave and information indicating the distance to the reflection point where the direct wave is reflected to the tilt obstacle detection unit 12 as the transmission / reception result of the direct wave. Further, the transmission / reception unit 11 transmits and receives the indirect wave transmission / reception result of the information indicating the distance measuring sensor that transmitted the direct wave and the distance measuring sensor that received the indirect wave and the information indicating the distance to the reflection point where the indirect wave was reflected. Is output to the tilt obstacle detection unit 12.

The tilt obstacle detection unit 12 receives the transmission / reception result of the direct wave and the transmission / reception result of the indirect wave from the transmission / reception unit 11. The tilt obstacle detection unit 12 detects the presence of a tilt obstacle based on the reception status of the indirect wave in the distance measuring sensors 1 to 4. The "tilted obstacle" is an obstacle having an inclined surface inclined with respect to the installation direction of the distance measuring sensors 1 to 4. On the other hand, an obstacle having no inclined surface inclined with respect to the installation direction of the distance measuring sensors 1 to 4, that is, an obstacle having a surface substantially parallel to the installing direction of the distance measuring sensors 1 to 4 is "non-tilted". It is called an "obstacle". When the inclined obstacle detection unit 12 detects that an inclined obstacle is present, the inclination obstacle detection unit 12 outputs the transmission / reception result of the direct wave to the intersection processing unit 13. The installation direction of the distance measuring sensors 1 to 4 is a direction parallel to the front surface of the vehicle when the distance measuring sensors 1 to 4 are installed on the front surface of the vehicle, and the distance measuring sensors 1 to 4 are installed on the rear surface of the vehicle. If installed, the direction is parallel to the rear surface.

2A and 2B are diagrams showing the reflection path of ultrasonic waves at the inclined obstacles 61 and 62. In the illustrated example, the distance measuring sensors 1 and 2 are installed side by side in a row on the rear surface 51 of the vehicle 50. Here, the inclined obstacles 61 and 62 are obstacles having an inclined surface inclined with respect to the installation direction of the distance measuring sensors 1 and 2, that is, the rear surface 51.

In the case of an inclined obstacle 61 having a corner portion 61a and having a shape like a prism as shown in FIG. 2A, when the ultrasonic wave transmitted by the distance measuring sensor 1 is reflected by the inclined surface of the inclined obstacle 61. Spread to. Therefore, the distance measuring sensor 1 can receive the direct wave, but the distance measuring sensor 2 cannot receive the indirect wave. Similarly, since the ultrasonic waves transmitted by the distance measuring sensor 2 are also diffused when reflected on the inclined surface of the inclined obstacle 61, the distance measuring sensor 2 can receive the direct wave, but the distance measuring sensor 1 receives the indirect wave. I can't receive it. Since the area where the ultrasonic wave is reflected is small in the corner portion 61a, neither the direct wave nor the indirect wave is returned to the distance measuring sensors 1 and 2.

In the case of the inclined obstacle 62 having no corner and shaped like an inclined wall as shown in FIG. 2B, as in the case of the inclined obstacle 61, the ultrasonic waves transmitted by the distance measuring sensors 1 and 2 are transmitted. The sound wave is diffused when it is reflected on the inclined surface of the inclined obstacle 62. Therefore, the ranging sensors 1 and 2 can receive the direct wave, but cannot receive the indirect wave.

Therefore, in the tilt obstacle detection unit 12, for example, when the distance measuring sensor 1 transmits an ultrasonic wave, the distance measuring sensor 1 receives a direct wave, and the distance measuring sensor 2 does not receive an indirect wave, the vehicle 50 It is detected that the inclined obstacle 61 or the inclined obstacle 62 is present behind the.
On the other hand, the tilt obstacle detection unit 12 determines that a non-tilt obstacle exists behind the vehicle 50 when the distance measurement sensor 1 receives the direct wave and the distance measurement sensor 2 receives the indirect wave. To detect. Further, when the distance measuring sensor 1 does not receive the direct wave and the distance measuring sensor 2 does not receive the indirect wave, the inclined obstacle detection unit 12 is behind the vehicle 50 with an inclined obstacle and a non-inclined obstacle. Detects that does not exist.

When the inclination obstacle detection unit 12 detects that the inclination obstacle exists, the intersection processing unit 13 receives the transmission / reception result of the direct wave from the inclination obstacle detection unit 12. The intersection processing unit 13 draws two circles using the result of the distance measuring sensor 1 transmitting and receiving a direct wave twice at different times while the vehicle is traveling, and performs two-circle intersection processing to obtain the intersection of the two circles. By doing so, the position of the intersection is calculated. Similarly, the intersection processing unit 13 calculates the position of the intersection for each of the distance measurement sensor 2, the distance measurement sensor 3, and the distance measurement sensor 4 by using the transmission / reception results of the two direct waves. The intersection processing unit 13 outputs information indicating the position of the intersection group calculated from the transmission / reception results of the direct waves by the distance measuring sensors 1 to 4 to the shape estimation unit 14.

FIG. 3 is a diagram for explaining the 2-circle intersection processing by the intersection processing unit 13. In the example of FIG. 3, the vehicle 50 is moving backward, and the distance measuring sensor 1 moves from the position of the distance measuring sensor 1 to the position of the distance measuring sensor 1a as the vehicle 50 moves backward. While the vehicle 50 is reversing, the intersection processing unit 13 uses the transmission / reception result of the direct wave transmitted / received at the position of the distance measuring sensor 1 from the time when the distance measuring sensor 1 transmits ultrasonic waves to the time when the direct wave is received. Based on the time required, the distance to the reflection point 70 where the ultrasonic wave is reflected is calculated by the TOF (Time Of Flight) method, centered on the position of the distance measuring sensor 1, and the distance to the reflection point 70 is defined as the radius. Draw a circle. Similarly, the intersection processing unit 13 uses the transmission / reception result of the direct wave transmitted / received at the position of the distance measuring sensor 1a, and the time required from the distance measuring sensor 1a transmitting the ultrasonic wave to receiving the direct wave. Based on the above, the distance to the reflection point 71 where the ultrasonic wave is reflected is calculated by the TOF method, and a circle is drawn with the position of the distance measuring sensor 1a as the center and the distance to the reflection point 71 as the radius. Then, the intersection processing unit 13 calculates the position of the intersection 72 of the two circles.

The intersection processing unit 13 acquires various information such as vehicle speed, yaw rate, and steering angle from the vehicle 50, and uses the acquired various information to measure the distance measurement sensor 1 for each time when the vehicle 50 is traveling. The positions of ~ 4 may be calculated. Further, although FIG. 3 shows an example in which the vehicle 50 is traveling straight, the vehicle 50 may be curved.
The position where the distance measuring sensors 1 to 4 transmit the ultrasonic wave while the vehicle 50 is traveling is different from the position where the distance measuring sensors 1 to 4 receive the direct wave reflected by the inclined obstacle. The intersection processing unit 13 is located at the position where the distance measuring sensors 1 to 4 transmit ultrasonic waves, the position where the distance measuring sensors 1 to 4 directly receive the wave, or the position where the distance measuring sensors 1 to 4 receive the direct wave, or the position where the distance measuring sensors 1 to 4 receive the ultrasonic wave during the two-circle intersection processing. A circle centered on any one of the intermediate positions may be drawn.

FIG. 4 is a diagram illustrating how the positions of the intersections 76 and 77 shift to the far side as the vehicle 50 approaches the inclined obstacle 62. While the vehicle 50 is moving backward, the ultrasonic wave transmitted at the position of the distance measuring sensor 1 is reflected at the position of the reflection point 73, and the reflected wave transmitted at the position of the distance measuring sensor 1a is reflected at the position of the reflection point 74. The reflected wave transmitted at the position of the distance measuring sensor 1b is reflected at the position of the reflection point 75. In this way, as the vehicle 50 approaches the inclined obstacle 62, the positions of the reflection points 73, 74, and 75 shift to positions farther from the vehicle 50. Therefore, compared to the position of the intersection 76 calculated by the two-circle intersection processing using the reflection point 73 and the reflection point 74, the intersection 77 calculated by the two-circle intersection processing using the reflection point 74 and the reflection point 75 The position is shifted to the side farther from the vehicle 50.

It is preferable that the intersection processing unit 13 performs the above-mentioned two-circle intersection processing by using the reflected wave first received by the distance measuring sensor 1 after the distance measuring sensor 1 transmits ultrasonic waves as a direct wave. Since the reflected wave first received by the ranging sensor 1 corresponds to the shortest distance from the ranging sensor 1 to the tilting obstacle 62, the positions of the intersections 76 and 77 become tilting obstacles as the vehicle 50 approaches the tilting obstacle 62. It will shift along the inclined surface of the object 62. Therefore, it is possible to obtain an approximate straight line with respect to the intersection group in the shape estimation unit 14 described later.

The shape estimation unit 14 receives information indicating the position of the intersection group calculated by the intersection processing unit 13 from the intersection processing unit 13 while the vehicle 50 is reversing. The shape estimation unit 14 estimates the shape of the inclined obstacle based on the position of the intersection group calculated by the intersection processing unit 13. The shape estimation unit 14 outputs information indicating the shape of the inclined obstacle to the contact position estimation unit 15.

The contact position estimation unit 15 receives information indicating the shape of the inclined obstacle from the shape estimation unit 14. The contact position estimation unit 15 estimates the position of the portion of the tilt obstacle closest to the vehicle 50 based on the shape of the tilt obstacle estimated by the shape estimation unit 14, and provides information indicating the position of the estimated portion. Is output to the collision determination unit 20 as contact position information indicating a position that is likely to come into contact with the vehicle 50.

5A, 5B, and 5C are diagrams for explaining the shape estimation method of the inclined obstacles 61 and 62 by the shape estimation unit 14 and the estimation method of the contact positions 82, 84, 87, 90 by the contact position estimation unit 15. Is. In the illustrated example, the intersections calculated by the intersection processing unit 13 are indicated by black circles (●). Further, the distance measuring sensors 1 to 4 are installed side by side in a row on the rear surface 51 of the vehicle 50.

The shape estimation unit 14 obtains approximate straight lines 80, 81, 83, 85, 86, 88, 89 of the intersection group based on the position of the intersection group calculated by the intersection processing unit 13. The shape estimation unit 14 estimates that the inclined obstacle 61 has a corner portion 61a when the approximate straight line of the intersection group is divided into two or more (FIGS. 5A and 5C). Further, the shape estimation unit 14 estimates that the intersection position of the plurality of approximate straight lines is the position of the corner portion 61a of the inclined obstacle 61. The contact position estimation unit 15 estimates the position of the corner portion 61a estimated by the shape estimation unit 14 as the contact position 82. As shown in FIG. 5C, when two inclination obstacles 61 are arranged side by side, three intersections can be obtained from the four approximate straight lines 85, 86, 88, 89, so that the shape estimation unit 14 has an inclination obstacle. It is presumed that the object has a shape having three corners 61a. In this case, the contact position estimation unit 15 may set the positions of the two corners 61a existing closer to the vehicle 50 from the three corners 61a as the contact positions 87 and 90.

On the other hand, the shape estimation unit 14 estimates that the inclined obstacle 62 has a shape having no corner portion 61a when the approximate straight line of the intersection group is one (FIG. 5B). In this case, the contact position estimation unit 15 estimates the position of the intersection of the approximate straight line 83 of the intersection group and the virtual vehicle side line 53 extending the side surface of the vehicle 50 as the contact position 84. At this time, the contact position estimation unit 15 is located closer to the vehicle 50 than the position of the intersection of the approximate straight line 83 and the vehicle side line 52 and the position of the intersection of the approximate straight line 83 and the vehicle side line 53. May be the contact position 84.

The shape estimation unit 14 estimates whether or not a convex corner portion 61a exists on the vehicle 50 side in a range facing the distance measuring sensors 1 to 4 behind the vehicle 50. Therefore, the inclined obstacle 62 shown in FIG. 8F, which will be described later, has a shape like a prism having a corner portion 61a, but the corner portion 61a exists outside the range facing the distance measuring sensors 1 to 4. The shape estimation unit 14 estimates that the inclined obstacle 62 has a shape like an inclined wall having no corners.

The collision determination unit 20 receives the contact position information from the contact position estimation unit 15. For example, the collision determination unit 20 determines that the possibility of a collision is high when the distance between the rear surface 51 of the vehicle 50 and the contact position 82 of the inclined obstacle 61 shown in FIG. 5A is equal to or less than a predetermined distance. do. When the collision determination unit 20 determines that the vehicle 50 has a high possibility of collision, the vehicle 50 has a function of operating the brake of the vehicle 50 to reduce the impact at the time of a collision (so-called collision damage mitigation brake) in order to avoid a collision. Or, a function of issuing an alarm to the driver (so-called collision prevention warning system) or the like is executed in order to prevent a collision.

FIG. 6 is a flowchart showing an operation example of the obstacle detection device 10 according to the first embodiment. The obstacle detection device 10 repeatedly executes the operation shown in the flowchart of FIG. 6 while the vehicle 50 is traveling.

In step ST1, the transmission / reception unit 11 causes the distance measuring sensors 1 to 4 to transmit / receive direct waves and indirect waves at predetermined drive intervals, and outputs the transmission / reception result to the tilt obstacle detection unit 12.

In step ST2, the tilt obstacle detection unit 12 detects the presence of a non-tilt obstacle when a direct wave or an indirect wave is received by any of the distance measuring sensors 1 to 4 (step ST2 ". YES ”). In this case, the tilt obstacle detection unit 12 outputs the transmission / reception result of the direct wave and the transmission / reception result of the indirect wave to the intersection processing unit 13.
On the other hand, when the indirect wave is not received by all of the distance measuring sensors 1 to 4 and the direct wave is received by any of the distance measuring sensors 1 to 4, the tilt obstacle detection unit 12 has a tilt obstacle. Detects the existence of an object (step ST2 “NO”). In this case, the tilt obstacle detection unit 12 outputs the transmission / reception result of the direct wave to the intersection processing unit 13.

In step ST3, the intersection processing unit 13 performs 2-circle intersection processing using the transmission / reception result of the direct wave and the transmission / reception result of the indirect wave received from the inclination obstacle detection unit 12, and corresponds to the shape of the non-inclination obstacle. Calculate the position of the intersection group. For example, assume that the ranging sensor 1 transmits ultrasonic waves, the ranging sensor 1 receives a direct wave, and the ranging sensor 2 receives an indirect wave.
In this case, the intersection processing unit 13 uses the transmission / reception result of the direct wave, and based on the time required from the distance measuring sensor 1 transmitting the ultrasonic wave to receiving the direct wave, the ultrasonic wave is subjected to the TOF method. Calculate the distance to the non-tilted obstacle reflected by. Then, the intersection processing unit 13 draws a circle centered on the position of the distance measuring sensor 1 and having the distance to the non-tilted obstacle calculated based on the direct wave as the radius. Further, the intersection processing unit 13 uses the transmission / reception result of the indirect wave, and based on the time required from the distance measuring sensor 1 transmitting the ultrasonic wave to the distance measuring sensor 2 receiving the indirect wave, the TOF method is used. The distance to the non-tilted obstacle to which the ultrasonic wave is reflected is calculated by. Then, the intersection processing unit 13 focuses on the position of the distance measuring sensor 1 and the position of the distance measuring sensor 2, and draws an ellipse using the distance to the non-tilted obstacle calculated based on the indirect wave. Then, the intersection processing unit 13 calculates the position of the intersection between the circle and the ellipse.

In step ST4, the contact position estimation unit 15 receives the position of the intersection group calculated by the intersection processing unit 13 from the intersection processing unit 13 via the shape estimation unit 14. The contact position estimation unit 15 estimates the position of the intersection group calculated by the intersection processing unit 13 as the position of the non-tilted obstacle, and outputs the position as contact position information to the collision determination unit 20.

In step ST5, the collision determination unit 20 determines the possibility of a collision between the inclined obstacle or the non-inclined obstacle and the vehicle 50 by using the contact position information received from the contact position estimation unit 15. When the collision determination unit 20 determines that the possibility of a collision is high (step ST5 “YES”), the collision determination unit 20 instructs the vehicle 50 to avoid the collision in step ST6. When the possibility of collision is low (step ST5 “NO”), the operation of the obstacle detection device 10 returns to step ST1.

In step ST7, the intersection processing unit 13 performs 2-circle intersection processing as shown in FIGS. 3 and 4 using the transmission / reception result of the direct wave received from the inclined obstacle detection unit 12, and forms the shape of the inclined obstacle. Calculate the position of the corresponding intersection group.

In step ST8, the shape estimation unit 14 obtains an approximate straight line with respect to the intersection group calculated by the intersection processing unit 13. In step ST9, the shape estimation unit 14 determines whether or not there are a plurality of obtained approximate straight lines.

When there are a plurality of approximate straight lines (step ST9 “YES”), in step ST10, the shape estimation unit 14 estimates that the inclined obstacle has a shape having a prism-like corner. In step ST11, the contact position estimation unit 15 estimates the position of the corner portion estimated by the shape estimation unit 14 as the contact position, and outputs the position as contact position information to the collision determination unit 20.

When the approximate straight line is singular (step ST9 “NO”), in step ST12, the shape estimation unit 14 estimates that the inclined obstacle has a shape having no corner such as an inclined wall. In step ST13, the contact position estimation unit 15 estimates the position of the intersection of the approximate straight line obtained by the shape estimation unit 14 with the vehicle side line 52 or the vehicle side line 53 as the contact position, and uses that position as the contact position information. Output to the collision determination unit 20.

As described above, the obstacle detection device 10 according to the first embodiment includes a transmission / reception unit 11, an inclination obstacle detection unit 12, an intersection processing unit 13, a shape estimation unit 14, and a contact position estimation unit 15. The transmission / reception unit 11 causes a plurality of distance measuring sensors 1 to 4 installed on the rear surface 51 of the vehicle 50 to transmit / receive direct waves and indirect waves. The inclined obstacle detection unit 12 has an inclined obstacle having an inclined surface inclined with respect to the installation direction of the plurality of distance measuring sensors 1 to 4 based on the reception status of the indirect wave by the plurality of distance measuring sensors 1 to 4. Detect that it exists. When the intersection processing unit 13 detects that an inclined obstacle exists by the inclined obstacle detecting unit 12, the same ranging sensor transmits and receives a direct wave twice at different times while the vehicle 50 is traveling. By drawing two circles using the results and performing a two-circle intersection process for finding the intersections of the two circles, the position of the intersection group is calculated from the transmission / reception results of direct waves by the plurality of distance measuring sensors 1 to 4. The shape estimation unit 14 estimates the shape of the inclined obstacle based on the position of the intersection group calculated by the intersection processing unit 13. The contact position estimation unit 15 estimates the position of the portion of the inclination obstacle closest to the vehicle 50 based on the shape of the inclination obstacle estimated by the shape estimation unit 14, and outputs it as contact position information. As a result, the obstacle detection device 10 can detect an inclined obstacle existing behind the vehicle 50.

Further, the intersection processing unit 13 of the first embodiment performs 2-circle intersection processing using the reflected wave first received by the distance measuring sensor as a direct wave after the distance measuring sensor transmits ultrasonic waves. As a result, as the vehicle 50 approaches the inclined obstacle, the position of the intersection shifts along the inclined surface of the inclined obstacle, so that the shape estimation unit 14 can obtain an approximate straight line with respect to the intersection group. Become.

Further, the shape estimation unit 14 of the first embodiment obtains an approximate straight line of the intersection group, estimates that the inclined obstacle has a corner portion when there are a plurality of the approximate straight lines, and the approximate straight line is a single number. If this is the case, it is presumed that the inclined obstacle has a shape without corners. Thereby, the shape estimation unit 14 can determine whether the inclined obstacle has a shape like a prism or an inclined wall. Since the portion of the prism and the inclined wall that come into contact with the rear surface 51 of the vehicle 50 is different, the shape estimation unit 14 discriminates between the prism and the inclined wall, so that the collision possibility determination accuracy by the collision determination unit 20 is improved.

Further, when there are a plurality of approximate straight lines of the intersection group, the shape estimation unit 14 of the first embodiment estimates that the intersection position of the approximate straight line is the position of the corner portion of the inclined obstacle. The contact position estimation unit 15 outputs the position of the corner portion estimated by the shape estimation unit 14 as contact position information. As a result, the contact position estimation unit 15 can accurately estimate the position of the portion closest to the rear surface 51 of the vehicle 50 with respect to the inclined obstacle shaped like a prism.

Further, when the approximate straight line of the intersection group is a single number, the shape estimation unit 14 of the first embodiment uses the position of the intersection between the approximate straight line and the vehicle side lines 52 and 53 extending from the side surface of the vehicle 50 as contact position information. Output. As a result, the contact position estimation unit 15 can accurately estimate the position of the portion closest to the rear surface 51 of the vehicle 50 with respect to the inclined obstacle shaped like an inclined wall.

Embodiment 2.
FIG. 7 is a block diagram showing a configuration example of the obstacle detection device 10 according to the second embodiment. The obstacle detection device 10 according to the second embodiment has a configuration in which a sensor selection unit 16 is added to the obstacle detection device 10 of the first embodiment shown in FIG. In FIG. 7, the same or corresponding parts as those in FIG. 1 are designated by the same reference numerals, and the description thereof will be omitted.

The sensor selection unit 16 transmits and receives direct waves from the distance measuring sensors 1 to 4 based on the position of the portion of the tilt obstacle estimated by the contact position estimation unit 15 that is closest to the vehicle, that is, the contact position. Select one or more ranging sensors to perform. The sensor selection unit 16 outputs information indicating the selected ranging sensor to the transmission / reception unit 11. When the distance measuring sensor is selected by the sensor selection unit 16, the transmission / reception unit 11 causes two or more selected distance measurement sensors to directly transmit / receive waves.

8A to 8F are diagrams illustrating a method of selecting a distance measuring sensor by the sensor selection unit 16. In FIGS. 8A to 8F, the same or corresponding parts as those in FIGS. 1 to 5 are designated by the same reference numerals, and the description thereof will be omitted. In this example, the sensor selection unit 16 causes two ranging sensors close to the contact position of the tilted obstacle to directly transmit and receive waves, and stops transmission and reception by the remaining ranging sensors.

Hereinafter, the distance measuring sensor that transmits and receives the direct wave is referred to as a "drive sensor", and the distance measuring sensor that stops the transmission and reception of the direct wave is referred to as a "non-drive sensor".

In the case of FIG. 8A, the sensor selection unit 16 selects the distance measuring sensor 2 and the distance measuring sensor 3 close to the contact position 91 of the inclined obstacle 61 as the drive sensor. In the case of FIG. 8B, the sensor selection unit 16 selects the distance measuring sensor 1 and the distance measuring sensor 2 close to the contact position 92 of the inclined obstacle 61 as drive sensors.

As an exception, when the corner portion of the tilt obstacle 61 is present in front of the distance measuring sensor, it is difficult for the ranging sensor in front of the corner portion to receive the wave directly, so that the sensor selection unit 16 is in front of the distance measuring sensor. From the remaining distance measuring sensors excluding the distance measuring sensor, two distance measuring sensors close to the contact position are selected. In the case of FIG. 8C, the sensor selection unit 16 uses the distance measuring sensor 2 located in front of the contact position 93, which is the corner of the inclined obstacle 61, as a non-driving sensor, and the distance measuring sensor 1 adjacent to the distance measuring sensor 2. The ranging sensor 3 is selected as the drive sensor. In the case of FIG. 8D, the sensor selection unit 16 uses the distance measuring sensor 1 located in front of the contact position 94, which is the corner of the inclined obstacle 61, as a non-driving sensor, and the distance measuring sensor 2 adjacent to the distance measuring sensor 1. The ranging sensor 3 is selected as the drive sensor.

Further, in the case of an inclined obstacle 62 shaped like an inclined wall, the sensor selection unit 16 selects two distance measuring sensors close to the contact position. In the case of FIG. 8E, the sensor selection unit 16 selects the distance measuring sensor 1 and the distance measuring sensor 2 near the contact position 95, which is the intersection of the approximate straight line of the intersection group (not shown) and the vehicle side line 52, as the drive sensor. In the case of FIG. 8F, the inclination obstacle 62 exists outside the distance measuring sensor 1. The inclined obstacle 62 is shaped like a prism having corners, but since there is only one approximate straight line (not shown), it is like an inclined wall having no corners in the shape estimation unit 14. It is presumed to be an inclined obstacle 62 having a shape, and the contact position 96, which is the intersection of the approximate straight line and the vehicle side line 52, is estimated by the contact position estimation unit 15. Therefore, the sensor selection unit 16 selects the distance measuring sensor 1 and the distance measuring sensor 2 close to the contact position 96 as the drive sensor in the case of FIG. 8F as in the case of FIG. 8E.

9 and 10 are flowcharts showing an operation example of the obstacle detection device 10 according to the second embodiment. The obstacle detection device 10 repeatedly executes the operations shown in the flowcharts of FIGS. 9 and 10 while the vehicle 50 is traveling.

In step ST21, the transmission / reception unit 11 confirms whether or not the drive sensor is selected from the distance measurement sensors 1 to 4 by the sensor selection unit 16. When the drive sensor is selected (step ST21 “YES”), the transmission / reception unit 11 performs the operations after step ST31 shown in FIG. On the other hand, when the drive sensor is not selected (step ST21 “NO”), the transmission / reception unit 11 performs the operations after step ST1. Since the operations of steps ST1 to ST13 in the flowcharts of FIGS. 9 and 10 are the same as the operations of steps ST1 to ST13 in the flowchart of FIG. 6, the description thereof will be omitted.

In step ST22, the sensor selection unit 16 receives the contact position information indicating the contact position of the inclined obstacle estimated by the contact position estimation unit 15 in step ST11 or step ST13 from the contact position estimation unit 15. The sensor selection unit 16 compares the contact position based on the contact position information with the positions of the distance measuring sensors 1 to 4, and drives at least two distance measuring sensors close to the contact position among the distance measuring sensors 1 to 4. It is selected as a sensor, and information indicating the selected drive sensor is output to the transmission / reception unit 11.

In step ST31, the transmission / reception unit 11 causes each of at least two drive sensors selected by the sensor selection unit 16 to directly transmit / receive waves at a predetermined drive interval (for example, 50 ms), resulting in transmission / reception. Is output to the tilt obstacle detection unit 12. For example, when the distance measuring sensor 2 and the distance measuring sensor 3 are selected as drive sensors as shown in FIG. 8A, the transmission / reception unit 11 first causes the distance measuring sensor 2 to transmit ultrasonic waves, and then causes the distance measuring sensor 2 to transmit ultrasonic waves. Receive the reflected wave (that is, the direct wave). The transmission / reception unit 11 causes the distance measurement sensor 3 to transmit ultrasonic waves 50 ms after the time when the distance measurement sensor 2 transmits ultrasonic waves, and then causes the distance measurement sensor 3 to transmit a reflected wave (that is, a direct wave). Receive. Since there are only two drive sensors, the distance measurement sensor 2 and the distance measurement sensor 3, the transmission / reception unit 11 causes the distance measurement sensor 2 to transmit the ultrasonic waves again 50 ms after the ultrasonic waves are transmitted from the distance measurement sensor 3. .. In this way, the transmission / reception unit 11 causes the distance measurement sensor 2 and the distance measurement sensor 3, which are drive sensors, to directly transmit / receive waves in a drive cycle of 100 ms. In step ST1, the transmission / reception unit 11 drives the four ranging sensors 1 to 4 with a driving cycle of 200 ms, but in step ST31, the two ranging sensors 2 and 3 are driven with a drive cycle of 100 ms. .. Therefore, the obstacle detection device 10 can obtain more information on the contact position in a short time, and the collision determination unit 20 can determine the possibility of collision more accurately.

In step ST32, the intersection processing unit 13 receives the transmission / reception result of the direct wave by the drive sensor from the transmission / reception unit 11 via the tilt obstacle detection unit 12. The intersection processing unit 13 performs 2-circle intersection processing using the transmission / reception result of the direct wave, and calculates the position of the intersection group corresponding to the shape of the inclined obstacle.

Since the operations of steps ST33 to ST39 in the flowchart of FIG. 10 are the same as the operations of steps ST8 to ST13 and ST5 in the flowcharts of FIGS. 6 and 9, the description thereof will be omitted.

In the example of FIGS. 8A to 8F, the sensor selection unit 16 drives the distance measurement sensors 1 to 4 with the drive sensor based on the contact position of the tilting obstacle and the installation position of the distance measurement sensors 1 to 4. It is classified as a sensor, and the transmission and reception of direct waves of the non-driving sensor is stopped, but the present invention is not limited to this.
For example, when the tilt obstacle 61 is present at the position shown in FIG. 8A, the ultrasonic waves transmitted from the distance measuring sensors 1 and 2 do not reach the distance measuring sensors 3 and 4 as shown in FIG. 2A. Similarly, the ultrasonic waves transmitted from the distance measuring sensors 3 and 4 do not reach the distance measuring sensors 1 and 2. Therefore, in the case of FIG. 8A, the distance measuring sensors 1 and 2 and the distance measuring sensors 3 and 4 can directly transmit and receive waves without interfering with each other with the contact position 91 which is the corner portion 61a sandwiched between them.

Therefore, for example, the transmission / reception unit 11 may drive the distance measurement sensor 2 and the distance measurement sensor 3 selected as the drive sensor in FIG. 8A at the same time instead of alternately driving them at intervals of 50 ms. In this case, the transmission / reception unit 11 can drive the two ranging sensors 2 and 3 with a drive cycle of 50 ms.
Alternatively, the transmission / reception unit 11 shortens the drive interval between the distance measurement sensor 2 and the distance measurement sensor 3 selected as the drive sensor in FIG. 8A, and reduces the drive interval between the distance measurement sensor 1 and the distance measurement sensor 4, which are non-drive sensors. It may be lengthened. In this case, the transmission / reception unit 11 drives, for example, the drive sensor every drive cycle, and drives the non-drive sensor once every two drive cycles.

As described above, the obstacle detection device 10 according to the second embodiment is a plurality of distance measuring sensors based on the position of the portion of the inclined obstacle estimated by the contact position estimation unit 15 that is closest to the vehicle 50. The sensor selection unit 16 is provided to select a distance measuring sensor that directly transmits and receives waves from 1 to 4. The transmission / reception unit 11 causes the distance measuring sensor selected by the sensor selection unit 16 to directly transmit / receive waves. As a result, the obstacle detection device 10 can transmit and receive more direct waves in a short time to obtain more contact position information, and the collision determination unit 20 can collide more accurately. Can be determined.

In the first and second embodiments, the distance measuring sensors 1 to 4 are installed on the rear surface 51 of the vehicle 50, but they may be installed on the front surface of the vehicle 50. In this case, the obstacle detection device 10 detects an inclined obstacle existing in front of the vehicle 50 by using the distance measuring sensors 1 to 4 installed on the front surface of the vehicle 50.

Finally, the hardware configuration of the obstacle detection device 10 according to each embodiment will be described.
11 and 12 are diagrams showing a hardware configuration example of the obstacle detection device 10 according to each embodiment. The functions of the transmission / reception unit 11, the tilt obstacle detection unit 12, the intersection processing unit 13, the shape estimation unit 14, the contact position estimation unit 15, and the sensor selection unit 16 in the obstacle detection device 10 are realized by the processing circuit. That is, the obstacle detection device 10 includes a processing circuit for realizing the above functions. The processing circuit may be a processing circuit 100 as dedicated hardware, or a processor 101 that executes a program stored in the memory 102.

As shown in FIG. 11, when the processing circuit is dedicated hardware, the processing circuit 100 may be, for example, a single circuit, a composite circuit, a programmed processor, a parallel programmed processor, or an ASIC (Application Specific Integrated Circuit). ), FPGA (Field Processor Metal Gate Array), or a combination thereof. The functions of the transmission / reception unit 11, the tilt obstacle detection unit 12, the intersection processing unit 13, the shape estimation unit 14, the contact position estimation unit 15, and the sensor selection unit 16 may be realized by a plurality of processing circuits 100, or the functions of each unit may be realized. The functions may be collectively realized by one processing circuit 100.

As shown in FIG. 12, when the processing circuit is the processor 101, the transmission / reception unit 11, the tilt obstacle detection unit 12, the intersection processing unit 13, the shape estimation unit 14, the contact position estimation unit 15, and the sensor selection unit 16 The function is realized by software, firmware, or a combination of software and firmware. The software or firmware is described as a program and stored in the memory 102. The processor 101 realizes the functions of each part by reading and executing the program stored in the memory 102. That is, the obstacle detection device 10 includes a memory 102 for storing a program in which the step shown in the flowchart of FIG. 6 or the like is eventually executed when executed by the processor 101. Further, this program causes a computer to execute the procedure or method of the transmission / reception unit 11, the tilt obstacle detection unit 12, the intersection processing unit 13, the shape estimation unit 14, the contact position estimation unit 15, and the sensor selection unit 16. It can be said that.

Here, the processor 101 is a CPU (Central Processing Unit), a processing device, an arithmetic unit, a microprocessor, or the like.
The memory 102 may be a non-volatile or volatile semiconductor memory such as a RAM (Random Access Memory), a ROM (Read Only Memory), an EPROM (Erasable Programmable ROM), or a flash memory, and may be a non-volatile or volatile semiconductor memory such as a hard disk or a flexible disk. It may be a magnetic disk of the above, or an optical disk such as a CD (Compact Disc) or a DVD (Digital Versaille Disc).

Some of the functions of the transmission / reception unit 11, the tilt obstacle detection unit 12, the intersection processing unit 13, the shape estimation unit 14, the contact position estimation unit 15, and the sensor selection unit 16 are realized by dedicated hardware. The part may be realized by software or firmware. As described above, the processing circuit in the obstacle detection device 10 can realize the above-mentioned functions by hardware, software, firmware, or a combination thereof.

The present invention allows any combination of embodiments, modifications of any component of each embodiment, or omission of any component of each embodiment within the scope of the invention.

Since the obstacle detection device according to the present invention detects inclined obstacles existing in front of and behind the vehicle, it is suitable for use in an obstacle detection device used in a collision damage mitigation brake, a collision prevention warning system, or the like. There is.

1,1a, 1b, 2,3,4 Distance measuring sensor, 10 Obstacle detection device, 11 Transmission / reception unit, 12 Tilt obstacle detection unit, 13 Intersection processing unit, 14 Shape estimation unit, 15 Contact position estimation unit, 16 Sensors Selection part, 20 collision detection part, 50 vehicle, 51 rear surface, 52,53 vehicle side line, 61,62 tilt obstacle, 61a corner part, 70,71,73,74,75 reflection point, 72,76,77 intersection, 80,81,83,85,86,88,89 Approximate straight line, 82,84,87,90,91,92,93,94,95,96 Contact position, 100 processing circuit, 101 processor, 102 memory.

Claims (6)

A transmitter / receiver that transmits and receives direct and indirect waves to multiple ranging sensors installed on the front or rear of the vehicle.
Inclined obstacle detection that detects the existence of an inclined obstacle having an inclined surface inclined with respect to the installation direction of the plurality of distance measuring sensors based on the reception status of the indirect wave in the plurality of distance measuring sensors. Department and
When it is detected by the tilt obstacle detection unit that the tilt obstacle is present, the same ranging sensor transmits and receives a direct wave twice at different times while the vehicle is running. An intersection processing unit that calculates the position of the intersection group from the transmission / reception results of direct waves by the plurality of distance measuring sensors by performing a two-circle intersection processing that draws one circle and finds the intersection of the two circles.
A shape estimation unit that estimates the shape of the inclined obstacle based on the position of the intersection group calculated by the intersection processing unit, and a shape estimation unit.
A contact position estimation unit that estimates the position of the portion of the inclination obstacle closest to the vehicle based on the shape of the inclination obstacle estimated by the shape estimation unit and outputs it as contact position information is provided. Obstacle detector. The two-circle intersection processing is performed by using the reflected wave first received by the distance measuring sensor as the direct wave after the distance measuring sensor transmits the exploration wave. Obstacle detector. The shape estimation unit obtains an approximate straight line of the intersection group, estimates that the inclined obstacle has a corner portion when there are a plurality of the approximate straight lines, and when the approximate straight line is a single number, the shape is estimated. The obstacle detection device according to claim 1, wherein the inclined obstacle is presumed to have a shape having no corners. When there are a plurality of approximate straight lines of the intersection group, the shape estimation unit estimates that the intersection position of the approximate straight line is the position of the corner portion of the inclination obstacle.
The obstacle detection device according to claim 3, wherein the contact position estimation unit outputs the position of the corner portion estimated by the shape estimation unit as the contact position information. The contact position estimation unit is characterized in that, when the approximate straight line of the intersection group is a single number, the position of the intersection between the approximate straight line and the vehicle side line extending the side surface of the vehicle is output as the contact position information. The obstacle detection device according to claim 3. Based on the position of the portion of the tilt obstacle estimated by the contact position estimation unit that is closest to the vehicle, a distance measuring sensor that directly transmits and receives waves is selected from the plurality of distance measuring sensors. Equipped with a sensor selection unit
The obstacle detection device according to claim 1, wherein the transmission / reception unit directly transmits / receives waves to the distance measuring sensor selected by the sensor selection unit.

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