Vehicle blind spot monitoring system and vehicle blind spot monitoring method

Abstract

Provided is a host vehicle blind spot monitoring system provided with a function for identifying targets in host vehicle blind spots, in order to comply with regulations (UN R151 and UN R159). A host vehicle blind spot monitoring system transmits transmission waves to a predetermined probe region, and identifies the type of an object on the basis of sensing results of a plurality of radar devices that sense the object by using reflected waves received from the object that reflects the transmission waves, wherein: the plurality of radar devices are arranged so that the probe regions of the respective radar devices have a different vertical height from the road surface; a sensing point where the object was sensed is acquired for each of the probe regions, as well as distance information from the radar device to the sensing point; and an identification processing unit is included for identifying the type of the object on the basis of the distance information and the size of a sensing region constituted of the sensing points.

Description

[Technical field]

[0001] The present embodiment relates to a vehicle blind spot monitoring system and a vehicle blind spot monitoring method for detecting vulnerable road users such as pedestrians and cyclists in the front blind spot or side blind spot of a large commercial vehicle. [Background technology]

[0002] 2. Description of the Related Art Recent vehicles are equipped with various systems to ensure the safety of drivers, pedestrians, etc., such as vehicle distance warning systems and collision damage mitigation brake systems.

[0003] In the above safety assurance system, the automotive millimeter-wave radar is one of the sensors that detects the situation around the vehicle in real time. It emits radio waves (millimeter waves) into the space around the vehicle and performs signal processing on the waves reflected from surrounding objects (vehicles ahead, vulnerable road users such as pedestrians and cyclists, obstacles such as guardrails and utility poles, etc.) to estimate target information such as the distance to the target, the target's speed, the target's angle, and the reflection intensity from the target.

[0004] Here, Patent Document 1 is a known document that discloses a radar-equipped vehicle. The abstract of this document states that the problem is to "accurately detect the direction and ground vehicle speed of the vehicle's movement and reliably avoid approaching the object," and as a solution, it states that "stationary objects are identified using multiple side monitoring radar devices 21, 22. Objects that exist in a spatially dense manner are determined to be stationary objects RM1, RM2 based on the detection values ​​of the direction and relative speed of the stationary objects RM1, RM2, and the probability of approaching the object is determined based on information on the direction and relative speed of objects T11, T21 that are located closest to the vehicle among the objects (reflection points) that constitute the determined stationary objects, and a signal for reducing this probability is supplied to the vehicle control device 50." [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2010-43960 A Summary of the Invention [Problem to be solved by the invention]

[0006] In large commercial vehicles (large trucks, etc.) where the driver's seat is located high, the driver's line of sight is higher, as shown in Figure 1, so the close-up blind spot in front of the vehicle tends to be larger. In addition, since the vehicle overall length is generally long, the close-up blind spot to the sides of the vehicle also tends to be larger, as shown in Figure 1.

[0007] In order to prevent collisions with vulnerable road users such as pedestrians and cyclists in the vehicle's blind spot when such large commercial vehicles start moving, regulations have been enacted that require the system to detect and provide an alert for vulnerable road users (pedestrians and cyclists) in the front blind spot and to detect and provide an alert for vulnerable road users (cyclists) in the side blind spot (URN151). Large commercial vehicles weighing 3.5 tons or more are required to be equipped with systems to comply with these regulations.

[0008] The vehicle movement status detection device of the above-mentioned Patent Document 1 is intended to be installed in so-called standard vehicles (see FIG. 1 in the document, etc.), and is not intended to be installed in large commercial vehicles, which have significantly different vehicle body shapes. In addition, the device is intended to detect stationary objects, and is not intended to detect moving objects such as pedestrians and cyclists. In other words, Patent Document 1 does not specifically disclose a system that is intended to be installed in large commercial vehicles and detects vulnerable road users in the blind spot of the vehicle and issues an alarm, etc.

[0009] Therefore, an object of the present invention is to provide a vehicle blind spot monitoring system and vehicle blind spot monitoring method that, in a large commercial vehicle where the driver's seat is positioned high, identifies the type of object in the vehicle's blind spot, and if the object is a vulnerable road user such as a pedestrian or cyclist, warns the driver and executes vehicle control such as automatic braking or automatic steering to avoid contact accidents. [Means for solving the problem]

[0010] In order to solve the above problems, the blind spot monitoring system of the present invention is a vehicle blind spot monitoring system that identifies the type of object based on the detection results of a plurality of radar devices that transmit transmission waves to a specified search area and detect the object using reflected waves received from an object that reflects the transmission waves, wherein the plurality of radar devices are arranged so that the search area of ​​each radar device is at a different vertical height from the road surface, and the vehicle blind spot monitoring system has an identification processing unit that obtains, for each search area, a detection point at which the object is detected and distance information from the radar device to the detection point, and identifies the type of object based on the size of the detection area composed of the detection points and the distance information. Effect of the Invention

[0011] According to the vehicle blind spot monitoring system and vehicle blind spot monitoring method of the present invention, in a large commercial vehicle in which the driver's seat is positioned high, it is possible to identify the type of object in the vehicle's blind spot, and if the object is a vulnerable road user such as a pedestrian or cyclist, it is possible to issue a warning to the driver and execute vehicle control such as automatic braking or automatic steering to avoid contact accidents. [Brief description of the drawings]

[0012] [Figure 1] An illustration of the blind spot near a large commercial vehicle. [Diagram 2] FIG. 2 is an explanatory diagram of an installation position of the radar device according to the first embodiment. [Diagram 3] FIG. 2 is a functional block diagram of the radar device according to the first embodiment. [Figure 4] 3 is a functional block diagram of an ECU according to the first embodiment; [Diagram 5] FIG. 2 is an explanatory diagram of a method for distinguishing between object and sign using the host vehicle blind spot monitoring system according to the first embodiment. [Figure 6] 4 is a flowchart of a process for each object sign performed by the host vehicle blind spot monitoring system of the first embodiment. [Figure 7] FIG. 11 is an explanatory diagram of an installation position of a radar device according to a second embodiment. [Figure 8] FIG. 11 is an explanatory diagram of a method for distinguishing between object and sign using the host vehicle blind spot monitoring system according to the second embodiment. [Figure 9]11 is a flowchart of a process for each object sign performed by the host vehicle blind spot monitoring system according to the second embodiment. [Figure 10] FIG. 11 is an explanatory diagram of a method for distinguishing between object and sign using the host vehicle blind spot monitoring system according to the third embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of a vehicle blind spot monitoring system according to the present invention will be described in detail with reference to the drawings. EXAMPLES

[0014] First, with reference to Figs. 2 to 6, a detailed description will be given of a vehicle blind spot monitoring system 100 according to a first embodiment of the present invention, which is intended to comply with the regulation (UNR159) for protecting vulnerable road users (pedestrians P, cyclists C) in the blind spot area ahead of large commercial vehicles.

[0015] <Outline of the host vehicle V0 and the host vehicle blind spot monitoring system 100> The host vehicle V0 in this embodiment is a large commercial vehicle with a high driver's seat, for example, a large freight vehicle such as a truck or a dump truck, or a large passenger transport vehicle such as a bus. In the following, an example in which the host vehicle V0 is a truck will be described.

[0016] As shown in Fig. 2, in order to detect vulnerable road users in a blind spot area ahead of the vehicle V0 in this embodiment, the radar device 1A is installed at a high position (e.g., at a height of 1.5 m) in front of the vehicle V0, and the radar device 1B is installed at a low position (e.g., at a height of 0.5 m) in front of the vehicle V0. Note that in Fig. 2, the radar devices 1A and 1B of the same specifications are arranged in a substantially vertical direction to make the monitoring directions of the radar devices approximately coincident, but as long as the monitoring directions of the radar devices overlap to a certain extent or more, the radar devices 1A and 1B may be arranged with a lateral shift or the specifications of the field of view of the radar devices 1A and 1B may be different.

[0017] The host vehicle blind spot monitoring system 100 mounted on the host vehicle V0 is a system that uses radar devices 1A and 1B arranged above and below in combination to identify the type of target in the blind spot area ahead, and if the target is a vulnerable road user, issues a warning to the driver and executes vehicle control to avoid contact accidents, such as automatic braking and automatic steering, and has, in addition to the above-mentioned radar devices 1 (1A, 1B), an Electronic Control Unit (hereinafter referred to as "ECU 2"), a Controller Area Network bus (hereinafter referred to as "CAN bus 3"), a user interface 4, and a vehicle control device 5. Each of these will be described in detail below.

[0018] <Radar device 1> The radar device 1 (1A, 1B) of this embodiment is an on-vehicle millimeter-wave radar that emits radio waves (transmission waves) into a search area in front of the vehicle and performs signal processing on the reflected waves that bounce back from targets in the search area (preceding vehicles, vulnerable road users such as pedestrians and cyclists, obstacles such as guardrails and utility poles, etc.) to estimate target information D for each target, such as the distance to the target, the target speed, the target angle, and the reflection intensity at the target, and outputs the estimated target information D to the ECU 2.

[0019] 3, the radar device 1 includes a transmission / reception control unit 11, a transmission unit (a modulation processing unit 12 and a transmission antenna 13), a reception unit (a reception antenna 14 and a modulation processing unit 15), and a signal processing unit (a frequency analysis unit 16 and a target detection unit 17). The target detection unit 17 includes a target tracking processing unit 17a and a target information calculation unit 17b.

[0020] In this radar device 1, first, the transmission / reception control unit 11 determines the timing of emitting radio waves and commands the modulation processing unit 12 to emit radio waves. Upon receiving the command, the modulation processing unit 12 raises the carrier frequency of the radio waves that have been phase-modulated or frequency-modulated according to the method to a specific frequency band such as the 77 GHz band, and then radiates the radio waves via the transmission antenna 13 into the space in front of the host vehicle V0.

[0021] If there is any target in the direction of radio wave emission (in front of the vehicle), the radio waves reflected from the target are received by the receiving antenna 14, and in the demodulation processing unit 15, the transmitted radio waves are used to downgrade the frequency to a baseband signal that can be analyzed by signal processing, and the signal is then converted into digital data through signal amplification, filtering, and AD conversion.

[0022] The converted digital data is then input to a frequency analysis unit 16, which performs threshold processing based on the frequency spectrum after Fourier transform in the distance, speed, and angle directions to extract data points to be passed to the downstream target detection unit 17. Within the target detection unit 17, first, a target tracking processing unit 17a performs filter processing in the time series direction using target information from the past. Based on the processed data, a target information calculation unit 17b estimates and outputs target information D. In the following, the output of the upper radar device 1A is referred to as target information D. A The output of the lower radar device 1B is called target information D B This will be referred to as the "

[0023] <CANバス3> The CAN bus 3 is a bus that communicatively connects various devices within the vehicle V0 to each other, and specifically, it communicatively connects the radar device 1 and the ECU 2, the ECU 2 and the user interface 4, and the ECU 2 and the vehicle control device 5.

[0024] <User Interface 4> The user interface 4 is an interface for alerting the driver to the presence of a vulnerable road user when the vulnerable road user is in the near blind spot of the vehicle V0, and is specifically a display or lamp that visually alerts the driver to the presence of the vulnerable road user, or a speaker that audibly alerts the driver to the presence of the vulnerable road user.

[0025] <Vehicle control device 5> The vehicle control device 5 is a control device that controls the braking system, steering system, etc. of the host vehicle V0, and when a vulnerable road user is in the proximity blind spot area of ​​the host vehicle V0, the vehicle control device 5 automatically brakes the host vehicle V0 to bring the host vehicle V0 to an emergency stop before contact with the vulnerable road user, or automatically steers the host vehicle V0 to avoid the vulnerable road user. Although not shown, the ECU 2 receives speed information and steering information of the host vehicle V0 from the vehicle control unit 5, so that the ECU 2 can grasp the host vehicle speed and traveling direction.

[0026] <ecu2> Next, referring to FIG. 4, the target information D from the radar devices 1A and 1B A , D B The ECU 2 of this embodiment, which processes the above, will be described in detail. Specifically, the ECU 2 is a computer equipped with a calculation device such as a CPU, a storage device such as a semiconductor memory, and hardware such as a communication device. The calculation device executes a predetermined program to realize each function described below. In the following, the details of each part of the ECU 2 will be described while appropriately omitting such well-known techniques in the computer field.

[0027] First, the information integration unit 21 receives target information D A , D B After integrating the information, the target type is identified based on the integrated information, and the identification result is sent to the collision risk prediction unit 22. The details of the object sign-specific processing in the information integration unit 21 will be described later.

[0028] The collision risk prediction unit 22 predicts a collision with the target based on the output information of the information integration unit 21 (the position, speed, and type of the target ahead of the vehicle) and predicts the risk of collision. Then, if the target is a vulnerable road user and the risk of collision is low, a warning is issued to the driver via the user interface 4 of the risk of collision with the vulnerable road user. This allows the driver to perform vehicle operations to avoid contact with the vulnerable road user. On the other hand, if the target is a vulnerable road user and the risk of collision is high, a command is sent to the vehicle control device 5 to bring the vehicle V0 to an emergency stop with automatic braking or to avoid the vulnerable road user with automatic steering.

[0029] <Details of processing in information integration unit 21> As described above, the information integration unit 21 integrates the target information D, which is the output of the radar devices 1A and 1B installed at different heights in front of the vehicle V0. A , D B By using this in combination, the target type can be identified. A , D B This section explains the principle of identifying target types using the above.

[0030] As shown in FIG. 2, the two radar devices 1A and 1B are mounted at different heights. Therefore, if a target in front of the vehicle has a wide range in height, the radar devices 1A and 1B will receive reflected waves from different parts of the target.

[0031] FIG. 5 shows target information D from radar devices 1A and 1B when the targets ahead of the vehicle are (1) a pedestrian P, (2) a cyclist C, and (3) a leading vehicle V1. A , D B FIG.

[0032] For example, as shown in FIG. 5(2), when the target in front of the vehicle is a cyclist C, the upper radar device 1A detects the rear (back, etc.) of the cyclist C (in the figure, the detection point of the radar device 1A is illustrated by a circle), and the lower radar device 1B detects the rear end (tire, etc.) of the bicycle (in the figure, the detection point of the radar device 1B is illustrated by a cross). In this case, the target information D from both radar devices A , D B When comparing the two, the radar device 1A that detects humans has a characteristic that the reflection intensity is relatively small compared to the reflection intensity of the radar device 1B that detects metal, rubber, etc. When comparing the distance in the depth direction (the traveling direction of the host vehicle V0), the radar device 1A that detects the back of the cyclist C has a characteristic that the detection distance is longer than the detection distance of the radar device 1B that detects the rear end of the bicycle.

[0033] Therefore, the target information D A , D B If the relative relationship indicated by the above indicates a large difference in depth (specifically, the detection distance of the radar device 1A is longer than the detection distance of the radar device 1B by approximately 70 cm or more, which corresponds to the length of the rear tire of the bicycle) and the difference in reflection intensity is large (specifically, if the difference in reflection intensity between the radar device 1A and the radar device 1B is approximately 5 dB or more, which corresponds to the difference in size of the detection area (RCS, Radar Cross Section) between a person and a bicycle), the target type can be identified as cyclist C.

[0034] On the other hand, as shown in Fig. 5(1)(3), when the target in front of the vehicle is a pedestrian P or a preceding vehicle V1, the target information D A , D B In some cases, the relative relationship between the depth difference and the reflection intensity is less than 10 cm, which is the radar resolution, and the reflection intensity difference is less than -2 dB, making it difficult to distinguish between the pedestrian P and the preceding vehicle V1 from the relative difference in depth or reflection intensity. In this embodiment, the pedestrian P and the preceding vehicle V1 are distinguished from each other by considering the absolute value of the reflection intensity in addition to the depth difference and reflection intensity. Specifically, the absolute value of the RCS value for the pedestrian P, whose area is small when viewed from the host vehicle V0, is usually about -5 dB, and the absolute value of the RCS value for the preceding vehicle V1, whose area is large when viewed from the host vehicle V0, is usually about 10 dB. Therefore, by using the absolute value of the RCS value, the pedestrian P and the preceding vehicle V1 can be clearly distinguished from each other.

[0035] <Processing flow of the information integration unit 21> Next, the details of the process for each object sign in the information integration unit 21 of this embodiment, which utilizes the principle of identifying object types explained in FIG. 5, will be explained with reference to the flow chart of FIG.

[0036] First, in step S1, the information integration unit 21 judges whether the following conditions for starting processing by object sign (conditions 1 to 3) are satisfied. If the conditions are satisfied, the process proceeds to step S2, and if not, the process ends. Note that since the present embodiment is aimed at complying with UNR159 (protection of vulnerable road users in blind spots ahead of the vehicle when starting the vehicle), the following conditions are those stipulated by UNR159. (Condition 1) The target is close to the vehicle V0 (travel direction: within 0.8m to 3.7m, lateral direction: within 0.8m to 3.7m) (within 0.5m of the side) (Condition 2) The target speed is between 0km / h and 10km / h. (Condition 3) Vehicle V0 is moving straight and at a speed of 10 km / h or less.

[0037] In step S2, the same target determination unit 21a determines whether the targets detected by the respective radar devices are the same target or not, and if they are the same target, the process proceeds to step S3, and if not, the process ends.

[0038] Specifically, the judgment in this step is to evaluate whether the following (Equation 1) and (Equation 2) are satisfied based on the position and speed information of the target detected by each radar device.

[0039]

number

[0040]

number

[0041] In (Equation 1) and (Equation 2), X and Y indicate the target detection positions of each radar device when the center of the front of the host vehicle V0 is set as the origin, the front-rear direction of the host vehicle V0 is set as the X axis (forward direction is positive), and the left-right direction is set as the Y axis (left direction is positive). A , Y A The radar device 1B is X B , Y B In addition, VX and VY indicate the X-direction component and the Y-direction component of the target velocity, and VX is the velocity of the radar device 1A. A , V.Y. A The radar device 1B is VX B , V.Y. B It states that:

[0042] Using these two equations, the magnitude of the distance and velocity between the detection points of each radar device is calculated based on the threshold value R TH , V TH If the left side of both equations is less than the threshold of the right side, the targets detected by each radar device are regarded as the same target. Th For example, the length of the bicycle is 1.9m, V Th For example, the radar velocity resolution is set to 1.8 km / h.

[0043] In step S3, the object identification unit 21b evaluates the difference in depth and the difference in reflection intensity between the targets detected by each radar device. If both differences are large, the process proceeds to step S4, and if not, the process proceeds to step S5. Note that since step S3 is a process for determining whether or not the person is cyclist C, in step S3, "large depth difference" indicates that there is a distance difference of approximately 70 cm or more, which is roughly equivalent to the length of the rear tire of the bicycle, and "large reflection intensity difference" indicates that there is a reflection intensity difference of approximately 5 dB or more, which is the RCS difference between a person and a bicycle.

[0044] In step S4, the object identification unit 21b identifies the object ahead of the vehicle as the cyclist C.

[0045] In step S5, the object identification unit 21b evaluates the absolute value of the reflection intensity. If the absolute value is large (the RCS value is equivalent to that of an automobile (approximately 10 dB)), the process proceeds to step S6, where the object ahead of the host vehicle is identified as a preceding vehicle V1. On the other hand, if the absolute value is not large (the RCS value is equivalent to that of a pedestrian (approximately -5 dB)), the process proceeds to step S7, where the object ahead of the host vehicle is identified as a pedestrian P. Note that in FIG. 5, "depth difference = small" indicates, for example, a distance difference of 10 cm or less, which is the distance resolution of the radar, and "reflection intensity difference = small" indicates, for example, a reflection intensity difference of -1 dB or less.

[0046] After executing the above processing, information on each target (position, speed, and target type) is transmitted to the downstream collision risk prediction unit 22. Thereafter, the collision risk prediction unit 22 generates a command according to the target type and the magnitude of the collision risk, and transmits it to the user interface 4 and the vehicle control device 5.

[0047] <Effects of this embodiment> As described above, according to the vehicle blind spot monitoring system of this embodiment, in a large commercial vehicle in which the driver's seat is positioned high, the type of object in the blind spot area in front of the vehicle can be identified, and if the object is a vulnerable road user such as a pedestrian or cyclist, a warning can be issued to the driver and vehicle control such as automatic braking or automatic steering can be executed to avoid contact accidents. EXAMPLES

[0048] Next, a vehicle blind spot monitoring system 100 according to a second embodiment of the present invention, which aims to comply with the regulation (UNR151) for protecting vulnerable road users (cyclists C) in the side blind spots of large commercial vehicles, will be described in detail with reference to Figures 7 to 9. Note that, in the following, overlapping explanations of points common to the first embodiment will be omitted.

[0049] In the first embodiment, a method for identifying targets in a blind spot area ahead of the vehicle is described using the radar device 1A on the upper front side and the radar device 1B on the lower front side. In contrast, in the present embodiment, a method for identifying targets in blind spots to the side of the vehicle is described using the radar device 1A on the upper side and the radar device 1B on the lower side. From the viewpoint of utilizing the difference in detection information between a pair of radar devices with different mounting heights, the object marker identification method of the first embodiment and the object marker identification method of the present embodiment have the same basic processing content.

[0050] As shown in FIG. 7, in this embodiment, in order to detect a vulnerable road hazard (cyclist C) in the lateral blind spot area of ​​the host vehicle V0, a ​​radar device 1A is installed at a high position on the side of the host vehicle V0 (for example, at a height of 1.0 m), and a radar device 1B is installed at a low position on the side of the host vehicle V0 (for example, at a height of 0.4 m).

[0051] When the blind spot areas on the sides of the vehicle V0 are sensed by both radar devices, detection results are obtained that appear to be spread out in the front-rear direction from targets that have a size toward the traveling direction of the vehicle V0, such as the cyclist C, a wall, or a guard rail. In this embodiment, the lower radar device 1B is mounted under the body of a commercial vehicle, and target sensing is performed at a lower position than the lower radar device 1B in embodiment 1. Therefore, if there are no targets on the sides of the vehicle, there is a high possibility that ground reflections will be picked up.

[0052] In this embodiment, the target information D of the two radar devices 1A and 1B, which are mounted at different heights as described above, is A , D B The target type is identified based on the principle shown in Figure 8.

[0053] FIG. 8 shows target information D from the radar devices 1A and 1B when the targets on the side of the vehicle are (1) a cyclist C, (2) structures such as walls and guardrails, and (3) only the ground. A , D B FIG.

[0054] For example, as shown in FIG. 8(1), when the target to the side of the vehicle is a cyclist C, the upper radar device 1A detects only the upper body of the cyclist C and therefore has a small detection range (e.g., a front-to-back length of 70 cm or less), whereas the lower radar device 1B detects the entire bicycle and therefore has a large detection range (e.g., a front-to-back length of 190 cm or more).

[0055] In contrast, when the target on the side of the vehicle is a structure such as a wall or a guardrail as shown in Fig. 8(2), the detection ranges of both the upper radar device 1A and the lower radar device 1B are large, and when only the ground exists on the side of the vehicle as shown in Fig. 8(3), the upper radar device 1A does not detect anything. In this way, the type of target on the side of the vehicle can be identified by combining the sizes of the detection ranges of the upper and lower radar devices 1.

[0056] <Processing flow of the information integration unit 21> Next, the details of the process for each object sign in the information integration unit 21 of this embodiment, which utilizes the principle of identifying object types explained in FIG. 8, will be explained with reference to the flow chart of FIG.

[0057] First, in step S11, the information integration unit 21 determines whether the following conditions for starting processing by object sign (conditions 1 to 3) are satisfied. If the conditions are satisfied, the process proceeds to step S12, and if not, the process ends. Note that since the purpose of this embodiment is to comply with UNR151 (protection of cyclists in side blind spots when the host vehicle starts), the following conditions are those stipulated by UNR151. (Condition 1) The target is located within 0.9 m to 4.25 m from the side of the host vehicle V0. (Condition 2) The target speed is between 0km / h and 20km / h. (Condition 3) The vehicle V0 is moving straight and its speed is within the range of 0km / h to 30km / h.

[0058] In step S12, the same target determination unit 21a determines whether the targets detected by the respective radar devices are the same target or not, and if they are the same target, the process proceeds to step S13, and if not, the process ends.

[0059] In step S13, the object identification unit 21b evaluates the detection spread of the target detected by each radar device. If the detection spread of the lower radar device 1B is large and there is no detection by the upper radar device 1A, the process proceeds to step S14 and identifies it as a ground reflection (no target). On the other hand, if not, the process proceeds to step S15.

[0060] In step S15, the object identification unit 21b evaluates the detection spread of the upper radar device 1A, and if it is large, proceeds to step S16 and identifies the object as a structure, and if it is small, proceeds to step S17 and identifies the object as cyclist C. Here, "small detection spread" refers to the size of cyclist C being approximately 60 cm, and "large detection spread" refers to the size of the bicycle being greater than approximately 1.9 m.

[0061] <Effects of this embodiment> As described above, the vehicle blind spot monitoring system of this embodiment can identify the type of object in the blind spot area to the side of the vehicle in a large commercial vehicle in which the driver's seat is located high, and if the object is a cyclist, it can issue a warning to the driver and execute vehicle control such as automatic braking and automatic steering to avoid contact accidents. EXAMPLES

[0062] Third Embodiment Next, a vehicle blind spot monitoring system 100 according to a third embodiment of the present invention will be described in detail with reference to Fig. 10. Note that, in the following, overlapping descriptions of points common to the above-mentioned embodiments will be omitted.

[0063] FIG. 10 shows a conceptual diagram of detection points for cyclist C when using the radar device 1 of embodiment 1, which does not have height resolution, and when using the radar device of this embodiment (hereinafter referred to as imaging radar 10), which has height resolution.

[0064] In FIG. 10(1), even if the radar device 1 does not have height resolution, by integrating the detection information of the two radar devices 1A and 1B, it is possible to have an effect equivalent to sampling two points in the height direction of the target, thereby effectively providing height resolution.

[0065] On the other hand, in Fig. 10(2), when the upper and lower imaging radars 10A and 10B are used, the number of sampling points in the height direction increases compared to Fig. 10(1) because of the resolution in the height direction. Therefore, in this embodiment in which the imaging radar 10 is used, the accuracy of each object sign is expected to improve due to the increase in the detection points in the height direction.

[0066] 10(3) assumes a test case of UNR159 in which the imaging radar 10 is employed and the distance to the target is close (0.9m to 3.7m). In this case, the distance is too close and it is not possible to gain detection points in the height direction of the target with only one imaging radar 10, making it difficult to distinguish between targets using only one imaging radar. However, accurate distinction between targets can be made by using the outputs of both imaging radars 10 in combination.

[0067] As described above, the host vehicle blind spot monitoring system of this embodiment, in which the radar device 1 of Examples 1 and 2 is replaced with the imaging radar 10, can identify target types more accurately than the host vehicle blind spot monitoring systems of Examples 1 and 2. [Explanation of symbols]

[0068] 100: vehicle blind spot monitoring system, 1, 1A, 1B: radar device, 11: transmission / reception control unit, 12: modulation processing unit, 13: transmission antenna, 14: reception antenna, 15: demodulation processing unit, 16: frequency analysis unit, 17: target detection unit, 17a: target tracking processing unit, 17b: target information calculation unit, 10, 10A, 10B: imaging radar, 2: ECU, 21: information integration unit, 21a: same target determination unit, 21b: object sign classification unit, 22: collision risk prediction unit, 3: CAN bus, 4: user interface, 5: vehicle control device, D: target information, V0: vehicle, V1: preceding vehicle, P: pedestrian, C: cyclist

Claims

1. A blind spot monitoring system for a vehicle, comprising: a plurality of radar devices that transmit a transmission wave into a predetermined search area and detect the object using a reflected wave received from the object that reflects the transmission wave, and based on the detection results of the detection, identify the type of the object; the plurality of radar devices are arranged such that the search areas of the respective radar devices are at different vertical heights from a road surface; an identification processing unit that acquires detection points that detect the object for each of the search areas and distance information from the radar device to the detection points, and identifies the type of the object based on the size of the detection area formed by the detection points and the distance information; the identification processing unit is configured to identify the object based on the presence or absence of the detection area for each of the search areas and the horizontal length of the detection area, If the horizontal extent of the detection area of ​​the upper radar device disposed on the side of the vehicle is small and the horizontal extent of the detection area of ​​the lower radar device disposed on the side of the vehicle is large, the type of the object is identified as a cyclist; If the horizontal extent of the detection area of ​​the upper radar device is large and the horizontal extent of the detection area of ​​the lower radar device is large, the type of the object is identified as a structure; a blind spot monitoring system for a host vehicle, the blind spot monitoring system determining that the object is not present when the detection area of ​​the upper radar device is absent and the horizontal extent of the detection area of ​​the lower radar device is large;

2. 2. The vehicle blind spot monitoring system according to claim 1, A blind spot monitoring system for a host vehicle, characterized in that the identification processing unit starts object identification processing when the following conditions are satisfied. (Condition 1) The object must be located within 0.9m to 4.25m of the side of the vehicle. (Condition 2) The object speed is between 0 km / h and 20 km / h. (Condition 3) The vehicle is moving straight and the speed is between 0 km / h and 30 km / h.

3. A vehicle blind spot monitoring system that identifies a type of object based on detection results of a plurality of radar devices that transmit a transmission wave into a predetermined search area and detect the object using a reflected wave received from the object that reflects the transmission wave, the plurality of radar devices are arranged such that the search areas of the respective radar devices are at different vertical heights from a road surface; an identification processing unit that acquires detection points that detect the object for each of the search areas and distance information from the radar device to the detection points, and identifies the type of the object based on the size of the detection area formed by the detection points and the distance information; The identification processing unit is A depth length of the object is calculated from the distance information, and the object is identified based on the depth length of each of the search areas; acquiring a reflection intensity of the detection point, and identifying the object based on the reflection intensity for each of the search areas; This vehicle blind spot monitoring system is characterized in that when there is a large difference in depth length of the object detected by an upper radar device and a lower radar device arranged in front of the vehicle, and when there is a large difference in the reflection intensities detected by both radar devices, the type of the object is identified as a cyclist.

4. 4. The vehicle blind spot monitoring system according to claim 3, the identification processing unit identifies the type of the object as a preceding vehicle when the absolute value of the reflection intensities detected by both radar devices is large, and identifies the type of the object as a pedestrian when the absolute value of the reflection intensities detected by both radar devices is small.

5. 4. The vehicle blind spot monitoring system according to claim 3, A blind spot monitoring system for a host vehicle, characterized in that the identification processing unit starts object identification processing when the following conditions are satisfied. (Condition 1) The object is present within 0.8 m to 3.7 m in the direction of travel of the vehicle. (Condition 2) The object speed is between 0 km / h and 10 km / h. (Condition 3) The vehicle is moving straight and the speed is 10 km / h or less.

6. A blind spot monitoring method for a vehicle, comprising: transmitting a transmission wave to a predetermined search area; detecting the object using a reflected wave received from the object that reflects the transmission wave; and based on detection results of a plurality of radar devices, identifying a type of the object; the plurality of radar devices are arranged such that the search areas of the respective radar devices are at different vertical heights from a road surface; a detection point that detects the object and distance information from the radar device to the detection point are acquired for each of the search areas, and a type of the object is identified based on a size of the detection area formed by the detection points and the distance information; The identification process identifies the object based on the presence or absence of the detection area for each of the search areas and the horizontal length of the detection area, If the horizontal extent of the detection area of ​​the upper radar device disposed on the side of the vehicle is small and the horizontal extent of the detection area of ​​the lower radar device disposed on the side of the vehicle is large, the type of the object is identified as a cyclist; If the horizontal extent of the detection area of ​​the upper radar device is large and the horizontal extent of the detection area of ​​the lower radar device is large, the type of the object is identified as a structure; a detection area for detecting an object from the upper radar device and a detection area for detecting an object from the lower radar device, the detection area being detected by the lower radar device being expanded in a horizontal direction;

7. A blind spot monitoring method for a vehicle, comprising: transmitting a transmission wave to a predetermined search area; detecting the object using a reflected wave received from the object that reflects the transmission wave; and based on detection results of a plurality of radar devices, identifying a type of the object; the plurality of radar devices are arranged such that the search areas of the respective radar devices are at different vertical heights from a road surface; a detection point that detects the object and distance information from the radar device to the detection point are acquired for each of the search areas, and a type of the object is identified based on a size of the detection area formed by the detection points and the distance information; The identification process calculates a depth length of the object from the distance information, and identifies the object based on the depth length for each of the search regions, acquiring a reflection intensity of the detection point, and identifying the object based on the reflection intensity for each of the search areas; a blind spot monitoring method for a vehicle, characterized in that if there is a large difference in depth length of the object detected by an upper radar device and a lower radar device arranged in front of the vehicle, and if there is a large difference in the reflection intensities detected by both radar devices, the type of the object is identified as a cyclist.

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