Object detection device

Abstract

To provide an object detection device capable of improving abnormal detection accuracy.SOLUTION: An object detection device includes: two distance sensors 11 and 12 installed on the same side surface of a vehicle 100, outputting a detection signal when an object within a predetermined range is detected, and outputting a non-detection signal when the object within the predetermined range is not detected; and a determination unit 30 that determines whether or not the distance sensors 11 and 12 are abnormal, in which the determination unit 30 determines that one of the distance sensors is abnormal when the two distance sensors 11 and 12 pass through the same determination range, one distance sensor outputs the detection signal over the entire of the determination range, and the other distance sensor outputs the non-detection signal on at least one detection range.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to an object detection device. [Background technology]

[0002] An object detection device mounted on a vehicle detects objects around the vehicle using a distance sensor such as an ultrasonic sensor. In such an object detection device, the detection performance decreases when an abnormality occurs in the distance sensor, such as snow or water droplets adhering to the distance sensor. Therefore, it is desirable to be able to know whether an abnormality occurs in the distance sensor.

[0003] For example, Patent Document 1 proposes a technology in which, in a distance sensor that detects objects at close range, if the time the object is detected exceeds a threshold, the detected object is determined to be attached to the distance sensor. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 6149616 Summary of the Invention [Problem to be solved by the invention]

[0005] While a vehicle is moving, there are few objects that continue to exist in the vicinity in the traveling direction of the vehicle. Therefore, the technology described in Patent Document 1 is considered to be useful in determining an abnormality in a distance sensor that detects an object in the traveling direction of the vehicle. For example, the above technology is considered to be useful in determining an abnormality in a distance sensor at the front of the vehicle while the vehicle is moving forward, in determining an abnormality in a distance sensor at the rear of the vehicle while the vehicle is moving backward, or in determining an abnormality in a distance sensor on the side of the vehicle while the vehicle is being steered.

[0006] However, when the vehicle moves along an object such as a wall, the object continues to be present at a close distance from the distance sensor on the side of the vehicle. Therefore, the distance sensor continues to detect the object at a close distance, which results in a detection result similar to that when an abnormality such as an attachment occurs, thereby reducing the accuracy of the abnormality determination.

[0007] In view of the above, an object of the present disclosure is to provide an object detection device capable of improving the accuracy of abnormality determination. [Means for solving the problem]

[0008] In order to achieve the above-mentioned object, according to one aspect of the present disclosure, an object detection device includes two distance sensors (10, 11, 12) installed on the same side of a vehicle, which output a detection signal when an object within a specified range is detected and output a non-detection signal when an object within the specified range is not detected, and a judgment unit (30) that judges whether or not there is an abnormality in the distance sensors, and when the two distance sensors pass through the same judgment section, and one distance sensor outputs a detection signal throughout the entire judgment section and the other distance sensor outputs a non-detection signal in at least a part of the judgment section, the judgment unit judges that there is an abnormality in one of the distance sensors.

[0009] If two distance sensors are installed on the same side of the vehicle, the combination of the detection results of the two distance sensors will be different when the vehicle is traveling along a wall or when an abnormality occurs in one of the distance sensors. Therefore, by performing abnormality judgment using the combination of the detection results of the two distance sensors, the accuracy of abnormality judgment is improved.

[0010] Note that the reference symbols in parentheses attached to each component indicate an example of the correspondence between the component and specific components described in the embodiments described below. [Brief description of the drawings]

[0011] [Figure 1]1 is a diagram showing a configuration of an object detection device according to a first embodiment. [Diagram 2] FIG. 11 is a diagram for explaining an abnormality determination process. [Diagram 3] FIG. 13 is a diagram showing a state in which a vehicle runs along a wall in a comparative example. [Figure 4] FIG. 2 is a diagram showing a state in which a vehicle runs along a wall in the first embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. In the following embodiments, parts that are the same or equivalent to each other will be denoted by the same reference numerals.

[0013] (First embodiment) The first embodiment will be described. The object detection device of the present embodiment shown in Fig. 1 is mounted on a vehicle 100 and configured to detect objects around the vehicle 100. The object detection device includes a distance sensor 10, a vehicle state detection unit 20, and a determination unit 30.

[0014] The distance sensor 10 detects a surrounding object and measures the distance to the object. The distance sensor 10 is, for example, an ultrasonic sensor that detects an object by transmitting and receiving ultrasonic waves and measures the distance to the object, but the distance sensor 10 may be composed of a millimeter wave radar, a camera, a laser radar, or the like.

[0015] The object detection device includes two distance sensors 10 installed on the same side of a vehicle 100. The two distance sensors 10 are referred to as distance sensors 11 and 12. Distance sensor 11 is installed at the front of the left side of the vehicle 100, and distance sensor 12 is installed at the rear of the left side of the vehicle 100.

[0016] The distance sensors 11 and 12 are installed in components made of different materials. For example, the distance sensor 11 is installed in a part of the body of the vehicle 100 that is made of resin, and the distance sensor 12 is installed in a part of the body of the vehicle 100 that is made of metal.

[0017] The distance sensor 10 is configured to detect an object within a predetermined range. For example, the distance sensor 10 is set to detect an object at a short distance of 50 cm or less. When an object is detected, the distance sensor 10 outputs a detection signal which is a signal indicating that an object is present within the detection range. On the other hand, when an object is not detected, the distance sensor 10 outputs a non-detection signal which is a signal indicating that an object is not present within the detection range. The output signal of the distance sensor 10 is transmitted to the determination unit 30.

[0018] The vehicle state detection unit 20 detects the driving state of the vehicle 100. The vehicle state detection unit 20 is composed of a vehicle speed sensor, a steering angle sensor, a shift position sensor, etc. The detection results of the vehicle state detection unit 20, such as the vehicle speed, steering angle, and shift position, are transmitted to the determination unit 30.

[0019] The determination unit 30 determines whether or not there is an abnormality in the distance sensor 10. The determination unit 30 is configured with an ECU (Electronic Control Unit). As shown in Fig. 2, the determination unit 30 sets a predetermined determination section R while the vehicle 100 is traveling. The determination section R is an area formed along the traveling direction of the vehicle 100 indicated by a white arrow, and is set as a rectangular area on the predicted path of the left front tire, for example.

[0020] The length of the determination section R along the traveling direction of the vehicle 100 is set to L. The length L is set to be equal to or greater than a predetermined value. For example, the length L is set to be equal to or greater than the length of the vehicle 100 in the front-rear direction. In addition, for example, the length L is set to be equal to or greater than the distance between the distance sensors 11 and 12.

[0021] The judgment unit 30 judges whether the distance sensors 11, 12 have passed through the judgment section R based on the detection results of the vehicle speed and shift position transmitted from the vehicle condition detection unit 20 and the time, and when it is determined that the distance sensors 11, 12 have passed through the judgment section R, it performs an abnormality judgment of the distance sensors 11, 12.

[0022] Assume that two distance sensors 10 pass through the same judgment section R, and one distance sensor 10 outputs a detection signal throughout the entire judgment section R, while the other distance sensor 10 outputs a non-detection signal in at least a part of the judgment section R. In this case, the judgment unit 30 judges that one of the distance sensors 10 has an abnormality.

[0023] In this embodiment, the determination unit 30 determines whether or not there is an object attached to the distance sensor 10. That is, when two distance sensors 10 pass through the same determination section R, and one distance sensor 10 outputs a detection signal as described above and the other distance sensor 10 outputs a non-detection signal, the determination unit 30 determines that one distance sensor 10 has an object attached.

[0024] For example, the judgment unit 30 outputs a detection signal throughout the time the distance sensor 11 passes through the judgment section R, and if the distance sensor 12 outputs a non-detection signal when passing through at least a portion of the same judgment section R, it judges that there is an object attached to the distance sensor 11.

[0025] In addition, the judgment unit 30 outputs a non-detection signal when the distance sensor 11 passes through at least a part of the judgment section R, and if the distance sensor 12 outputs a detection signal throughout the entire time it passes through the same judgment section R, it judges that there is an object attached to the distance sensor 12.

[0026] In cases other than those mentioned above, the determination unit 30 determines that no object is attached to the distance sensors 11 and 12. That is, the determination unit 30 determines that no object is attached to the distance sensors 11 and 12 when the distance sensors 11 and 12 output detection signals in only a part of the determination section R. The determination unit 30 also determines that no object is attached to the distance sensors 11 and 12 when the distance sensors 11 and 12 both output detection signals throughout the entire determination section R and when the distance sensors 11 and 12 both output non-detection signals throughout the entire determination section R.

[0027] When it is determined that there is no object attached to the distance sensors 11 and 12, the determination unit 30 further performs object detection determination. That is, the determination unit 30 determines whether or not there is an object that may come into contact with the vehicle 100 on the left side of the vehicle 100, based on the output signals of the distance sensors 11 and 12.

[0028] Since the judgment becomes complicated when the inner wheel difference is large, the judgment unit 30 judges the presence or absence of an object attached to the distance sensor 10 when the steering angle of the vehicle 100 transmitted from the vehicle state detection unit 20 is within a predetermined range. For example, the judgment unit 30 performs the object judgment when the steering angle is -20 degrees or more and 20 degrees or less, or -10 degrees or more and 10 degrees or less.

[0029] Regarding the judgment section R, it is not necessary for the distance sensors 11 and 12 to pass through exactly the same route, and the object judgment may be performed when the distance sensors 11 and 12 pass through approximately the same judgment section R. In other words, the object judgment may be performed when the passing routes of the distance sensors 11 and 12 are shifted due to steering of the vehicle 100.

[0030] The determination unit 30 also performs a determination when the attached matter has been removed. Specifically, after it has been determined that there is an attached matter on the distance sensor 11 or the distance sensor 12, when both the distance sensors 11 and 12 output a non-detection signal, the determination unit 30 changes the determination result that there is an attached matter and determines that there is no attached matter on the distance sensors 11 and 12. For example, when both the distance sensors 11 and 12 output a non-detection signal over the entire section that is equal to or longer than a predetermined length, the determination unit 30 determines that there is no attached matter on the distance sensors 11 and 12. This section may be the determination section R or may be a section different from the determination section R.

[0031] The determination unit 30 repeatedly executes such an object determination process at a predetermined cycle, and the determination section R is newly set each time the object determination process is executed. The object detection device is also provided with two distance sensors 10 on the right side of the vehicle 100, and the determination unit 30 performs object determination for these two distance sensors 10 in the same manner as for the distance sensors 11 and 12.

[0032] The effect of this embodiment will be described. In a comparative example shown in Fig. 3, the object detection device has only one distance sensor 10 on the side of the vehicle 100. In such a configuration, when the vehicle 100 is running along a wall as shown in Fig. 3, the distance sensor 10 outputs a detection signal. Even if there is no object on the side of the vehicle 100, if there is an object attached to the distance sensor 10, the distance sensor 10 outputs a detection signal as in the scene shown in Fig. 3. Therefore, it is not possible to distinguish between a wall and an object attached to the wall, which may result in an erroneous determination.

[0033] 4, when the vehicle 100 is traveling along a wall, both the distance sensors 11 and 12 output detection signals in the judgment section R because the wall is nearby, and the judgment unit 30 judges that there is no object on the distance sensors 11 and 12. The judgment unit 30 also judges that there is an object nearby on the left side of the vehicle 100.

[0034] Furthermore, when no object is present to the side of the vehicle 100, if there is no object on the distance sensors 11, 12, both of the distance sensors 11, 12 output non-detection signals in the judgment section R, and the judgment unit 30 judges that there is no object on the distance sensors 11, 12. The judgment unit 30 also judges that there is no object in the short distance on the left side of the vehicle 100. In this way, when the detection results of the distance sensors 11, 12 match, it is judged that there is no object on the distance sensors 11, 12.

[0035] On the other hand, if there is no object on the side of the vehicle 100 but there is an object attached to either of the distance sensors 11, 12, the detection results of the distance sensors 11, 12 will not match, and the judgment unit 30 will determine that there is an object attached.

[0036] That is, when there is an object on the distance sensor 11, a detection signal is output from the distance sensor 11 throughout the entire judgment section R, and a non-detection signal is output from the distance sensor 12, so it is determined that there is an object on the distance sensor 11. When there is an object on the distance sensor 12, a non-detection signal is output from the distance sensor 11 throughout the entire judgment section R, and a detection signal is output from the distance sensor 12, so it is determined that there is an object on the distance sensor 12.

[0037] In this manner, in this embodiment, it is possible to distinguish between the case where an object such as a wall is present in the vicinity and the case where there is something adhering to either of the distance sensors 11 and 12.

[0038] As described above, in this embodiment, the abnormality determination is performed using a combination of the detection results of the two distance sensors 10, thereby improving the accuracy of the abnormality determination and increasing the number of scenes in which an abnormality can be determined.

[0039] Furthermore, according to the above embodiment, the following effects can be obtained.

[0040] (1) The length L is set to a predetermined value or more. If the length L is too short, there is a risk of erroneous determination in a scene where another vehicle passes by. However, by setting the length L to a predetermined length, such as the length of the vehicle 100 in the front-rear direction or the distance between the distance sensors 11 and 12, or the like, erroneous determination can be suppressed.

[0041] (2) When the distance sensors 11, 12 output a non-detection signal, the determination unit 30 determines that there is no abnormality in the distance sensors 11, 12. This allows for correct determination even when the abnormality in the distance sensors 11, 12 is resolved.

[0042] (3) The distance sensors 11 and 12 are installed on members made of different materials. If the materials on which the distance sensors 11 and 12 are installed are different, the ease with which foreign matter such as water droplets adhere to the distance sensors 11 and 12 will differ, making it easier to determine that an abnormality has occurred.

[0043] (Other embodiments) It should be noted that the present disclosure is not limited to the above-described embodiment, and can be modified as appropriate. In addition, in the above-described embodiment, it goes without saying that the elements constituting the embodiment are not necessarily essential, except when they are specifically stated as essential or when they are clearly considered essential in principle. In addition, in the above-described embodiment, when the numbers, values, amounts, ranges, etc. of the components of the embodiment are mentioned, they are not limited to the specific numbers, except when they are specifically stated as essential or when they are clearly limited to a specific number in principle. In addition, in the above-described embodiment, when the shapes, positional relationships, etc. of the components are mentioned, they are not limited to the shapes, positional relationships, etc., except when they are specifically stated or when they are limited to a specific shape, positional relationship, etc. in principle.

[0044] At least two distance sensors 10 may be installed on the side of the vehicle 100 on the same side, and three or more distance sensors 10 may be installed on the side of the vehicle 100 on the same side. When three or more distance sensors 10 are installed, the determination unit 30 determines that there is an abnormality when the object detection results of all the distance sensors 10 are not consistent. In this case, the determination unit 30 performs a determination for all combinations in which two of the three or more distance sensors 10 are selected, in the same manner as the determination performed for the distance sensors 11 and 12 in the first embodiment. For example, assume that three distance sensors 10 are installed. In this case, when one or two distance sensors 10 output a detection signal throughout the entire determination section R and the remaining distance sensor 10 outputs a non-detection signal in at least a part of the determination section R, the determination unit 30 determines that there is an abnormality in the distance sensor 10 that output the detection signal. Note that, among the three or more distance sensors 10, an abnormality determination may be performed only for some distance sensors 10, including two distance sensors 10.

[0045] In the first embodiment, the case where the adhering matter determination is performed as an example of the abnormality determination has been described, but the abnormality determination may be performed for an abnormality other than an adhering matter.

[0046] The distance sensors 11, 12 may be mounted on a member of the same material. [Explanation of symbols]

[0047] 10, 11, 12 Distance sensor 30 Judgment section

Claims

1. An object detection device, Two distance sensors (10, 11, 12) are installed on the side of the same side of the vehicle, and output a detection signal when an object within a predetermined range is detected, and output a non-detection signal when an object within the predetermined range is not detected; A determination unit (30) that determines whether or not there is an abnormality in the distance sensor, The determination unit is The two distance sensors pass through the same judgment section, one of the distance sensors outputs the detection signal throughout the entire determination section; When the other distance sensor outputs the non-detection signal in at least a part of the determination section, The object detection device determines that one of the distance sensors has an abnormality.

2. The object detection device according to claim 1 , wherein the determination unit determines whether or not there is an object attached to the distance sensor.

3. The object detection device according to claim 1 , wherein the distance sensor detects an object at a distance of 50 cm or less.

4. The object detection device according to claim 1 , wherein the determination unit determines whether or not the distance sensor is abnormal when a steering angle of the vehicle is within a predetermined range.

5. The object detection device according to claim 1 , wherein the length of the determination section is set to be equal to or greater than a predetermined value.

6. 6. The object detection device according to claim 5, wherein the length of the determination section is equal to or greater than the length of the vehicle.

7. The object detection device according to claim 5 , wherein the length of the determination section is set to be equal to or greater than the distance between the two distance sensors.

8. The object detection device according to claim 1 , wherein the determination unit determines that there is no abnormality in the two distance sensors when the two distance sensors output the non-detection signal.

9. The object detection device according to claim 8 , wherein the determination unit determines that there is no abnormality in the two distance sensors when the two distance sensors output the non-detection signal over an entire section having a predetermined length or more.

10. The object detection device according to claim 1 , wherein the two distance sensors are installed on members made of different materials.

11. The object detection device according to claim 1 , wherein the distance sensor is an ultrasonic sensor.

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