JP7675729B2 - Perimeter Monitoring System - Google Patents

Description

The present invention relates to a detection object and surroundings monitoring system.

Conventionally, various perimeter monitoring sensors have been devised to detect and identify objects around a vehicle and provide driving assistance. For example, a perimeter monitoring sensor called LiDAR (Light Detection and Ranging) that uses infrared light is known. In addition, a LiDAR has also been devised that is provided inside a vehicle lamp as one of the suitable locations for detecting objects around the vehicle (see Patent Document 1).

JP 2019-164916 A

However, since the detection accuracy of LiDAR depends on the number and shape of point clouds, the accuracy of object identification decreases when the number of point clouds decreases or when an object with a similar shape is detected. In addition, perimeter monitoring sensors that use infrared light have difficulty distinguishing the color of an object.

The present invention has been made in consideration of these circumstances, and one of its exemplary objectives is to provide a new technology that improves the accuracy of identifying surrounding objects.

In order to solve the above problems, a detectable object in one embodiment of the present invention is a detectable object that is provided on an object to be identified, and is configured so that the detectable object appears to move relative to the object to be identified to a peripheral monitoring sensor that uses infrared light.

According to this aspect, the accuracy of identifying surrounding objects can be improved by utilizing information based on the observed movement of the detected object.

The object to be identified may be a moving object, and the detected object may be configured so that the detected object appears to move differently from the moving object to the perimeter monitoring sensor. In this way, the detected object appears to move differently from the moving object, and characteristic information as to, for example, where the detected object is located on the moving object can be obtained.

The infrared light reflecting area may be configured to change its reflection position or reflection direction. This makes it easier for the detectable object to appear to move differently from the movement of the moving body, making it easier to determine where on the moving body the detectable object is located. In addition, there may be multiple detectable objects located on the moving body. This makes it possible to determine the orientation of the moving body based on the relative positions of multiple detectable objects.

The area from which the infrared light is emitted may be configured to change. This makes it easier for the detected object to appear to move in a way that is different from the movement of the moving object, making it easier to determine where the detected object is located on the moving object.

The moving object may be a vehicle, and the object to be detected may be a vehicle lamp that the vehicle has. This makes it easier to determine the position of the vehicle lamp on the vehicle.

The object to be identified may be a fixed object, and the detectable object may be configured so that it appears to be moving to the perimeter monitoring sensor. This makes it easier to identify the fixed object because the detectable object attached to the fixed object appears to be moving.

The fixed object may be a traffic signal, and the detected object may be configured to appear to move differently depending on the state of the traffic signal. This allows the traffic signal's state to be identified even by a perimeter monitoring sensor that cannot directly detect the color information of the traffic signal.

Another aspect of the present invention is a perimeter monitoring system. This system includes a perimeter monitoring sensor that utilizes infrared light, and a detected object. The perimeter monitoring sensor may identify the state of an identification object on which the detected object is attached based on changes in the infrared light emitted from the detected object. This can improve the accuracy of identifying surrounding objects. Furthermore, when there are multiple detected objects attached to a moving object, the orientation of the moving object can be determined based on the relative positions of the multiple detected detected objects.

In addition, any combination of the above components and conversions of the present invention between methods, devices, systems, etc. are also valid aspects of the present invention.

The present invention improves the accuracy of identifying surrounding objects.

Schematic diagram of a LiDAR unit. Figure 2(a) is a schematic diagram illustrating the position of the detected object when viewed from the front of the vehicle, Figure 2(b) is a schematic diagram illustrating the position of the detected object when viewed from the rear of the vehicle, and Figure 2(c) is a schematic diagram illustrating the position of the detected object when viewed from the side of the vehicle. 3(a) to 3(d) are schematic diagrams for explaining the shape and movement of the detection object. 4(a) to 4(d) are schematic diagrams for explaining combinations of mounting positions of a plurality of detection targets. 5(a) to 5(d) are schematic diagrams showing an example in which a traffic signal is provided with a plurality of detection targets. 6(a) and 6(b) are schematic diagrams showing an example in which a plurality of detection objects are provided on a pedestrian traffic light.

Below, a detailed description of the embodiment of the present invention will be given with reference to the drawings. In the description of the drawings, the same elements are given the same reference numerals, and duplicated descriptions will be omitted as appropriate. In addition, the configurations described below are examples and do not limit the scope of the present invention in any way. In the following, LiDAR will be used as an example of a perimeter monitoring sensor that uses infrared light.

Sensors such as LiDAR use information on the shape of the point cloud and its movement over time to detect and identify objects. Specifically, LiDAR provides information on the detection of surrounding objects, the type of object, the distance to the object, and the location of the object. However, when objects are far away or small, the number of points in the cloud decreases or points are missing, which may reduce the accuracy of object identification.

The inventors of the present application therefore came up with the idea of providing an object to be identified with a detectable object that can provide characteristic information that is different from the point cloud and other information obtained from the entire object. Specifically, they came up with the idea that by providing detectable objects such as reflectors that reflect infrared light and light emitters that emit infrared light on objects to be identified such as vehicles and traffic signals, and adding characteristic information obtained from these detectable objects, it is possible to improve the accuracy of identifying objects to be identified.

(LiDAR unit)
1 is a schematic diagram of a LiDAR unit. The LiDAR unit 10 includes a housing 12, a transmitting portion 14, and a LiDAR 16. The transmitting portion 14 is, for example, an infrared transmitting film.

The LiDAR unit 10 has a LiDAR 16 in a housing 12. The LiDAR 16 is configured to acquire information about the surroundings of the vehicle. The LiDAR 16 is a sensor that generally emits infrared light, which is invisible light, in front of the vehicle, and acquires information such as the distance to an object, the shape of the object, and the material of the object based on the emitted light and the returned light. The LiDAR 16 has a light-emitting element 18 that emits light toward the surroundings of the vehicle (in front of the vehicle) and a light-receiving element 20 that receives light incident from the outside.

(Position of detected object)
The detected object according to the present embodiment is provided on the object to be identified. The detected object according to the present embodiment is a moving object that is a movable object, specifically, a vehicle. The detected object is configured so that the detected object appears to move relative to the object to be identified to a periphery monitoring sensor that uses infrared light. FIG. 2(a) is a schematic diagram illustrating the position of the detected object in a front view of the vehicle, FIG. 2(b) is a schematic diagram illustrating the position of the detected object in a rear view of the vehicle, and FIG. 2(c) is a schematic diagram illustrating the position of the detected object in a side view of the vehicle.

The R1 position shown in Figure 2(a), which is an example of an example of mounting the detectable object, is inside the right headlamp 22R. Similarly, the L1 position shown in Figure 2(a) is inside the left headlamp 22L. A lighting fixture such as a headlamp has a transparent cover or outer lens that can emit visible light, including infrared light, to the outside. Therefore, the detectable object is protected from the environment compared to when the detectable object is mounted outside the vehicle (e.g., on the exterior).

In addition, the distance L [m] between the right headlamp 22R and the left headlamp 22L may be set to a constant value regardless of the vehicle. This allows the LiDAR unit 10 of another vehicle to detect multiple objects whose movements are different from the movement of the vehicle from information about surrounding objects, and if the distance between the objects corresponds to L, it can identify the object as a vehicle.

The f1 position shown in Fig. 2(a) corresponds to the rear side of the rearview mirror inside the vehicle, and is a position where infrared light can be irradiated to the detected object through the front window and emitted from the detected object to the outside of the vehicle. Therefore, the detected object is protected from the environment compared to when the detected object is provided outside the vehicle (for example, on the exterior).

Next, the location of the detected object when viewed from the rear of the vehicle will be described. Position R1' shown in Figure 2(b) is inside the right tail lamp 24R. Similarly, position L1' shown in Figure 2(b) is inside the left tail lamp 24L. Furthermore, the distance L [m] between the right tail lamp 24R and the left tail lamp 24L should preferably be set to a constant value regardless of the vehicle.

As a result, when the LiDAR unit 10 of another vehicle detects multiple objects whose movement differs from the movement of the vehicle from information about surrounding objects, and the distance between these objects corresponds to L, the object can be identified as a vehicle.

The r1 position shown in Fig. 2(b) corresponds to the inside of the upper part of the rear window of the vehicle, and is a position where infrared light can be irradiated to the detected object through the rear window and emitted from the detected object to the outside of the vehicle. Therefore, the detected object is protected from the environment compared to when the detected object is provided outside the vehicle (for example, on the exterior).

2(a) to 2(c) are examples of candidate mounting positions for the object to be detected in a vehicle. Positions A1 to A13 are selected from locations that are easily identifiable as part of a vehicle, such as the roof, bumper, license plate, door handle, roof rail, etc.

(Movement of the detected object)
3(a) to 3(d) are schematic diagrams for explaining the shape and movement of the detected object. The shape of the detected object may be a polygon such as a triangle or a square, a circle, an ellipse, a rectangular parallelepiped, or a curved surface, and may have a large reflecting or self-emitting area and a characteristic movement as a point cloud detected by the LiDAR 16. The detected object may also be a reflecting object, a part in which a reflecting object is embedded, a unit in which a reflecting object is arrayed, or a reflecting surface (such as a mirror). The detected object may also be a self-emitting object, a part in which a self-emitting object is embedded, a unit in which a reflecting object is arrayed, or a self-emitting surface (a light guide or an optical fiber surface).

The detected object 26a shown in FIG. 3(a) is a rectangular light-emitting or reflecting object that moves relative to the vehicle. More specifically, the detected object 26a oscillates at a specific period around the Y axis in the vertical direction of the vehicle. Therefore, when infrared light emitted from the LiDAR 16 of another vehicle is irradiated onto the vehicle on which the detected object 26a is installed, information on the detected object 26a that appears to move differently from the movement of the vehicle is obtained in addition to the point cloud information for the entire object corresponding to the vehicle.

More specifically, in addition to the point cloud information of the entire vehicle obtained by the LiDAR unit 10 of the other vehicle, dynamic information is obtained by the oscillation of the detected object 26a, which is different from the vehicle's movement. As a result, point cloud information of a (characteristic) movement different from the vehicle's movement is obtained in a part of the overall vehicle outline obtained from the point cloud. Then, based on the position of the point cloud of this characteristic movement on the vehicle and the characteristic movement, it is possible to determine not only that the object is a vehicle, but also which direction the vehicle is facing. For example, if the movement of the detected object 26a corresponds to the movement of the detected object provided at position R1 corresponding to the right headlamp 22R, it can be estimated that the vehicle is an oncoming vehicle.

As another example of the movement of the detected object, as shown in Fig. 3(b), the detected object 26a may reciprocate at a specific period along the X-axis in the vehicle width direction. As shown in Fig. 3(c), the circular detected object 26b may reciprocate at a specific period along the Y-axis in the vehicle up-down direction. As shown in Fig. 3(d), the square detected object 26c may reciprocate at a specific period along the Z-axis in the vehicle front-rear direction.

In this way, the detectable objects 26a to 26c according to this embodiment are configured so that the reflection position or reflection direction of the area that reflects infrared light changes. This makes it easier for the detectable object to appear to move in a way that is different from the movement of the vehicle, making it easier to determine where the detectable object is located on the vehicle.

In addition, the detected object itself may not move relative to the vehicle, and the light-emitting state of the detected object may be changed so that the detected object appears to move relative to the vehicle. More specifically, the detected object may not move, and the light-emitting surface of the detected object may flicker or the light-emitting area may change in stages so that the detected object appears to move in a way that is different from the movement of the vehicle. For example, the light-emitting area of the light guide may be changed periodically. This makes it easier to determine where the detected object is located on the vehicle, even if the detected object itself does not move. Furthermore, the reflection or flashing of infrared light does not flicker or obstruct the view of the driver or pedestrians.

In addition, by changing the movement of the detectable object for each mounting position on the vehicle, the accuracy of object identification can be further improved. Figures 4(a) to 4(d) are schematic diagrams for explaining combinations of mounting positions of multiple detectable objects. As shown in Figure 4(a), by mounting detectable objects at positions R1 and L1 on the vehicle, characteristic information that allows the left and right headlamps of the vehicle to be recognized can be added to the point cloud information of the object detected by LiDAR16. In addition, as shown in Figure 4(b), by providing a detectable object at position f1 in addition to positions R1 and L1, the accuracy of object identification can be further improved.

Figure 4(c) shows the case where the detected object is mounted at position L1', position R1', and position A7 shown in Figure 2(b). If a point cloud showing a characteristic movement is present at position L1', position R1', and position A7 among the point cloud showing the outline of the object, the LiDAR unit 10 of the other vehicle identifies the detected object as a vehicle. In addition, if the movement of the detected object mounted at position L1' corresponds to the left tail lamp 24L and the movement of the detected object mounted at position R1' corresponds to the right tail lamp 24R, it can also be identified that the identified vehicle is a leading vehicle (a vehicle traveling ahead in the own lane) as seen from the other vehicle.

Figure 4(d) shows the case where the object to be detected is mounted at positions A8, A9, A10, and A13 shown in Figure 2(c). If a point cloud showing the general shape of the object includes a point cloud exhibiting characteristic movement at positions A8, A9, A10, and A13, the LiDAR unit 10 of the other vehicle will identify the detected object as a vehicle seen from the side.

In this way, by placing multiple detectable objects in different locations on the vehicle and assigning each detectable object a different movement corresponding to its mounting position, the vehicle's orientation can be determined based on the relative positioning of the multiple detectable objects.

As described above, the object to be detected in this embodiment is configured so that the object to be detected appears to move relative to the vehicle (object to be identified) to the LiDAR unit 10 that uses infrared light. According to this aspect, the accuracy of identifying the vehicle can be improved by using information based on the observed movement of the object to be detected.

In addition, the object to be detected according to this embodiment is configured to appear to move differently from the vehicle to the LiDAR unit 10 that uses infrared light. This allows, for example, characteristic information about where the object to be detected is located on the vehicle to be obtained.

(Traffic signal identification)
The object to be identified is not limited to a moving object such as a vehicle, but may be a fixed object that is an object fixed at a predetermined position. Therefore, the object to be detected according to this embodiment may be provided not only to a moving object such as a vehicle, but also to a fixed object such as a traffic signal. Figures 5(a) to 5(d) are schematic diagrams showing an example in which a plurality of objects to be detected are provided on a traffic signal.

A traffic light 30 for vehicles shown in FIG. 5(a), which is a type of traffic light, has detectable objects at position R1 above the green signal light, position C1 above the yellow signal light, and position L1 above the red signal light. These detectable objects are configured so that they appear to move relative to the traffic light to a perimeter monitoring sensor that uses infrared light. More specifically, these detectable objects are configured so that they appear to move to a LiDAR unit 10 equipped in a vehicle. In this way, the three detectable objects that are in a predetermined positional relationship with the three colored signal lights of the traffic light 30 for vehicles appear to move, making it easier to identify the traffic light 30 for vehicles. In addition, by making the movement of the detectable object above the lighted color of the three detectable objects different from the movement of the other two detectable objects, it is possible to determine which color of the signal light of the traffic light 30 for vehicles is on.

The vehicular traffic light 32 shown in Figure 5(b) is the same as the vehicular traffic light 30 shown in Figure 5(a), except that of the three detectable objects in the vehicular traffic light 30 shown in Figure 5(a), the detectable object corresponding to the yellow signal light is located at position C1' below the yellow signal light. This results in the three detectable objects being positioned at the vertices of a triangle, making it easier to recognize the point cloud that exhibits characteristic movement among the point cloud that indicates the general shape of the vehicular traffic light. In other words, even the LiDAR unit 10, which has difficulty directly detecting color information of a traffic light, can identify the lighting state of the traffic light.

The vehicular traffic light 34 shown in Figure 5(c) has detectable objects corresponding to the three colored signal lights provided at three positions R1, C1, and L1 on the support pole. The function of each detectable object is the same as that of the vehicular traffic light 30. The vehicular traffic light 36 shown in Figure 5(d) is the same as the vehicular traffic light 30, except that of the three detectable objects in the vehicular traffic light 34 shown in Figure 5(c), the one corresponding to the yellow signal light is provided at position C1' on the right of the support pole.

Figures 6(a) and 6(b) are schematic diagrams showing an example of a pedestrian traffic light having multiple detectable objects.

The pedestrian traffic light 38 shown in FIG. 6(a), which is a type of traffic light, has detectable objects at position A1 above the red signal light and position A2 below the blue signal light. These detectable objects are configured so that they appear to move to the LiDAR unit 10 equipped in the vehicle. In this way, the two detectable objects, which are in a predetermined positional relationship with the two colored signal lights of the pedestrian traffic light 38, appear to move, making the pedestrian traffic light 38 easier to identify. In addition, by making the movement of the detectable object above or below the signal light of the color that is lit or flashing different from the movement of the other detectable object, it is possible to determine which colored signal light of the pedestrian traffic light 38 is lit.

In the pedestrian traffic light 40 shown in Fig. 6(b), detectable objects corresponding to two colors of signal lights are provided at two positions A1 and A2 on the support pole. The function of each detectable object is the same as that of the vehicle traffic light 30.

The perimeter monitoring system according to this embodiment includes a LiDAR unit 10 that uses infrared light, and a detectable object. The LiDAR unit 10 identifies the state of the object on which the detectable object is located by changes in the infrared light emitted from the detectable object. This improves the accuracy of identifying surrounding objects. In addition, when there are multiple detectable objects on a vehicle, the orientation of the vehicle can be determined by the relative positions of the multiple detected detectable objects.

Although the present invention has been described above with reference to the above-mentioned embodiments, the present invention is not limited to the above-mentioned embodiments, and suitable combinations or substitutions of the configurations of the embodiments are also included in the present invention. Furthermore, it is possible to suitably rearrange the combinations and processing order in the embodiments based on the knowledge of those skilled in the art, and to make modifications to the embodiments such as various design changes, and embodiments to which such modifications have been made are also included in the scope of the present invention.

In the above embodiment, the identification object is mainly a vehicle or a traffic signal. The identification object is not limited to the objects described in the above embodiment, and may be various objects including moving objects and fixed objects. The identification object may be, for example, a device (e.g., a forklift, etc.) that performs various operations (e.g., movement, etc.) in a factory, a worker (e.g., work clothes worn by a worker, etc.), or a fixed object (e.g., a traffic light, etc.) located in a factory. It is also possible to provide a detection object to these identification objects, and monitor the state (e.g., movement, etc.) of each identification object using information based on the observed movement of the detection object.

The present invention can be used in object and perimeter monitoring systems.

10 LiDAR unit, 12 housing, 14 transmitting portion, 16 LiDAR, 18 light emitting element, 20 light receiving element, 22R right side headlamp, 22L left side headlamp, 24R right side tail lamp, 26a, 26b, 26c detected object, 24L left side tail lamp, 30 vehicle traffic light, 38 pedestrian traffic light.

Claims (7)

a first detection object and a second detection object provided on the object to be identified;
A sensor unit including a perimeter monitoring sensor that utilizes infrared light,
the first detection object and the second detection object each have an area that emits or reflects infrared light, and the area is configured to be displaced relative to the identification object;
a distance between the first detection object and the second detection object is determined according to the type of the object to be identified;
A perimeter monitoring system characterized in that the sensor unit identifies the type of the identification object based on the change in the area of each of the first and second detectable objects relative to the identification object, each detected by the perimeter monitoring sensor, and the distance between the first and second detectable objects . the object to be identified is a moving object,
The first detection object is configured so that the first detection object appears to have a movement different from the movement of the moving object to the perimeter monitoring sensor ,
2. The perimeter monitoring system according to claim 1, wherein the second detected object is configured so that its movement appears to the perimeter monitoring sensor to be different from the movement of the moving object. 3. The perimeter monitoring system according to claim 2, wherein the first and second detection objects are each configured such that a reflection position or a reflection direction of an area that reflects infrared light changes. 3. The perimeter monitoring system according to claim 2 , wherein the first detection object and the second detection object are configured so that the area from which the infrared light is emitted varies. the moving object is a vehicle,
5. The surroundings monitoring system according to claim 2, wherein the first detectable object and the second detectable object are provided in vehicle lamps of the vehicle. The object to be identified is a fixed object,
The first detected object is configured so that the first detected object appears to be moving to the perimeter monitoring sensor ,
2. The perimeter monitoring system according to claim 1, wherein the second object is configured to appear to be moving to the perimeter monitoring sensor. the fixed object is a traffic signal,
7. The perimeter monitoring system according to claim 6, wherein the first detectable object and the second detectable object are configured so that their movements appear different depending on the illumination state of the traffic signal.

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