Axis offset determination device and axis offset determination method

Abstract

The purpose of the present invention is to provide an axial shift determination device capable of determining whether the axis of a radar has shifted off axis, even when the angle of shift of a radar built into a door mirror is large and the lateral surface of the vehicle itself does not fit within the radar detection range. This axial shift determination device has: an object detection unit which is attached to a vehicle, transmits a transmission wave toward the surrounding area and detects a detection point on an object which reflects the transmission wave on the basis of a reflected wave which was reflected by said object; and a determination unit which sets a prescribed region in the detection range of the object detection unit as a self-vehicle region in which said vehicle itself is present, and determines whether the object detection unit has shifted off axis on the basis of detection results at the detection point in the self-vehicle region when the detection point is detected inside the self-vehicle region.

Description

[Technical field]

[0001] The present invention relates to an axis deviation determination device and an axis deviation determination method for determining an axis deviation of a door mirror built-in radar that monitors the sides and rear of a vehicle. [Background technology]

[0002] In recent years, an increasing number of automobiles are being equipped with advanced driver assistance systems (ADAS) and autonomous driving (AD) systems. Advanced driver assistance systems are systems that alert the driver and assist operation according to the conditions of obstacles and moving objects around the vehicle, while autonomous driving systems are systems that automatically control the acceleration / deceleration and steering of the vehicle according to the conditions of obstacles and moving objects around the vehicle. Both systems are equipped with sensors, such as cameras, LiDAR, and radar, to detect the environment around the vehicle.

[0003] A vehicle radar device disclosed in Patent Document 1 is known as a conventional technology for monitoring the left and right rear of a vehicle using a radar. For example, the abstract of the document states that "to provide a vehicle radar device with improved detection accuracy of a door mirror built-in radar sensor" as an object, and states that the solution is that "a vehicle radar device mounted on a vehicle and detecting objects around the vehicle has a radar sensor attached to the vehicle so that at least a part of the vehicle body is within a detection range, sets a position where at least a part of the vehicle body detected by the radar sensor extends as a reference position, and when an object around the vehicle is detected by the radar sensor, detects the direction of the object as a deviation angle from the reference position."

[0004] That is, as explained in FIG. 3, FIG. 4, etc. in the patent document, the vehicle radar device of Patent Document 1 can detect the deviation angle from the reference position of the radar sensor under the condition that at least a part of the vehicle body is within the detection range of the radar sensor and that objects around the vehicle are also within the detection range of the radar sensor. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2009-20076 A Summary of the Invention [Problem to be solved by the invention]

[0006] However, the vehicle radar device of Patent Document 1 has a problem in that the radar deviation angle cannot be detected when the radar deviation angle becomes large and the host vehicle body is no longer within the detection range, or conversely, when objects around the host vehicle are no longer within the detection range. In other words, the radar deviation angle can be detected only in an environment where both the host vehicle body and objects around the host vehicle are within the detection range.

[0007] Therefore, an object of the present invention is to provide an axis deviation determination device and an axis deviation determination method that can determine the axis deviation of a radar even when the deviation angle of the door mirror built-in radar becomes large and the side of the vehicle is no longer within the radar's detection range. [Means for solving the problem]

[0008] In order to solve the above problems, the axis misalignment judgment device of the present invention is an axis misalignment judgment device that has an object detection unit that is attached to a vehicle and transmits a transmission wave to the surrounding area and detects a detection point on an object that reflects the transmission wave based on the reflected wave reflected by the object, and a judgment unit that sets a predetermined area within the detection range of the object detection unit as a host vehicle area in which the vehicle is present, and when the detection point is detected within the host vehicle area, judges the axis misalignment of the object detection unit based on the detection result of the detection point within the host vehicle area. Effect of the Invention

[0009] According to the axis deviation determination device or axis deviation determination method of the present invention, the axis deviation of the radar can be determined even when the deviation angle of the door mirror built-in radar becomes large and the side of the vehicle is no longer within the radar's detection range. [Brief description of the drawings]

[0010] [Figure 1] FIG. 2 is a top view of the vehicle with the radar of the embodiment deployed. [Diagram 2] 1 is a schematic configuration diagram of a vehicle system according to an embodiment; [Diagram 3] FIG. 2 is a top view of the vehicle with the radar of the embodiment stored in the rear. [Figure 4] FIG. 2 is a top view of the vehicle with the radar of the embodiment stored in the front. [Diagram 5] A plot of detection points detected by the deployed left radar while the vehicle was stopped. [Figure 6] A plot of detection points where the left radar in the forward stowed state detected something incorrectly while the vehicle was stopped. [Figure 7] FIG. 13 is a top view of the detection points detected by the deployed left radar while the vehicle was moving slowly. [Figure 8A] FIG. 13 is a top view of the detection points detected by the left radar in the forward-stored state while the vehicle was moving slowly. [Figure 8B] Top view of the detection point erroneously detected by the left radar in Figure 8A. [Figure 9] FIG. 2 is a functional block diagram of the axis deviation determination device according to the embodiment; [Figure 10] 4 is a process flowchart of the axis deviation determination device according to the embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] An embodiment of an axis deviation determination device 10 according to the present invention will now be described with reference to the drawings.

[0012] 1 is a top view of a vehicle V with a door mirror built-in radar (hereinafter, simply referred to as "radar 1") of this embodiment deployed. The radar 1 is a sensor that transmits a transmission wave to the surroundings and detects a detection point on an object that reflects the transmission wave based on the reflected wave reflected by the object. In the vehicle V of this embodiment, a left radar 1 that detects a range from the left side to the left rear is mounted on the left door mirror. L The right door mirror is equipped with a right radar 1 that detects the area from the right to the rear right. R In the following, the left radar 1 shown by the dashed line is L The detection range of the left detection range S L The right radar 1 is shown by the dashed line. R The detection range of the right detection range S R It is called.

[0013] FIG. 2 is a schematic diagram of a vehicle system for implementing the above-mentioned ADAS and AD in a host vehicle V. As shown in FIG. L or right radar 1 R The detection points, which are the outputs of the radar, are input to an ECU2 (Electronic Control Unit). The ECU2 detects obstacles and moving objects around the vehicle based on the detection point information (information on the position of each detection point and line-of-sight velocity) input from each radar, and determines the possibility of contact between the detected obstacles and the vehicle V. When an obstacle or the like is detected, the ECU2 notifies the driver of the presence of the obstacle or the like via an alarm device 3, and when it determines that there is a possibility of contact, it controls a vehicle control system 4 to automatically brake and automatically steer the vehicle V in order to avoid contact.

[0014] Many recent vehicles are equipped with a function to automatically fold door mirrors in order to make the vehicle width as narrow as possible when parking or passing through a narrow passage. Known methods for folding door mirrors include a rearward folding method that is often used in small vehicles such as passenger cars, and a forward folding method that is often used in large vehicles such as trucks. In the following, the present invention will be described in detail assuming that both door mirror folding methods are installed in a passenger car.

[0015] FIG. 3 is a top view illustrating a radar storage state of a host vehicle V that employs rearward-folding door mirrors. In this case, the left radar 1 L Fold counterclockwise to make the right radar 1 R As a result of folding the left and right radars clockwise, the detection ranges of both the left and right radars are covered by the sides of the vehicle, making it impossible to detect objects around the vehicle. Therefore, the radar deviation angle can only be detected in an environment where both the vehicle body and objects around the vehicle are within the detection range. The technology disclosed in Patent Document 1 cannot detect radar axis deviation.

[0016] On the other hand, FIG. 4 is a top view illustrating a radar storage state of a host vehicle V that employs forward storage door mirrors. In this case, the left radar 1 L Fold clockwise to right radar 1 R As a result of folding the left and right radars counterclockwise, the detection ranges of both the left and right radars face toward the outside of the vehicle, making it impossible to detect the vehicle itself. Therefore, the technology disclosed in Patent Document 1 cannot detect the axis misalignment of the radar.

[0017] However, by using the axis deviation determination method of the present invention, it is possible to determine a large axis deviation of each radar even in the radar storage state as shown in Fig. 4. The axis deviation determination method of the present invention will be described in detail below.

[0018] <Example of detection points detected by Radar 1 while stopped> First, using Figs. 5 and 6, while the host vehicle V is stopped, the left radar 1 in the deployed state L The detection points detected by the left radar 1 in the forward stowed position L We will explain the differences in the detection points detected by the

[0019] FIG. 5 shows the left radar 1 in a deployed state when the host vehicle V is stopped in a certain environment. L FIG. 1 is a plot diagram showing a specific example of detection points detected by the left radar 1 (see FIG. 1). In this plot diagram, the center of the front of the vehicle V is the origin of the XY coordinate system, the forward direction of the vehicle V is the positive direction of the X axis, and the left direction of the vehicle V is the positive direction of the Y axis. L , Left Radar 1 L The detection points are placed around the vehicle on the assumption that the left radar 1 is deployed. L The actual attitude (deployed state) of the left radar 1 matches the above assumption (deployed state). L is the left detection range S in the deployed state L Therefore, an abnormality such as a detection point being located within the area in which the host vehicle V exists (hereinafter referred to as "host vehicle area R") does not occur.

[0020] On the other hand, FIG. 6 shows the left radar 1 in the forward storage state when the host vehicle V is stopped in a different environment. L FIG. 5 is a plot diagram showing a specific example of detection points detected by the left radar 1 of the present embodiment. L , Left Radar 1 L The detection points are placed around the vehicle on the assumption that the left radar 1 is deployed. L The actual attitude (forward stored state) of the left radar does not match the above assumption (deployed state). In this case, L The left detection range S corresponds to the position where it should be (the forward storage state) L (inside) but the left detection range S equivalent to the deployed state LV Therefore, an abnormality occurs in which detection points are placed within the host vehicle region R where no detection points should actually exist.

[0021] <Example of detection points detected by Radar 1 while moving forward slowly> Next, using FIG. 7 and FIGS. 8A and 8B, while the host vehicle V is moving forward slowly, the left radar 1 in the deployed state L The detection points detected by the left radar 1 in the forward stowed position LWe will explain the differences in the detection points detected by the

[0022] FIG. 7 shows the left radar 1 in a deployed state in an environment in which the host vehicle V is moving slowly forward along the left wall W. L FIG. 1 is a top view illustrating detection points detected on a left wall W and the left side of the vehicle V. In this case, the left radar 1 L The detection points in the direction away from the radar (marked with - in the figure) and the left radar 1 L There are two types of detection points (marked with o in the figure) whose distance is constant when viewed from the left radar 1. L ECU2, which receives the output of the above, can distinguish between detection points caused by an object to the left of the vehicle (wall W) and detection points caused by the side of the vehicle, based on the distance and direction of each detection point and the line-of-sight velocity of each detection point.

[0023] On the other hand, FIG. 8A shows the left radar 1 in the forward storage state in an environment in which the host vehicle V is moving slowly forward along the left wall W. L FIG. 4 is a top view showing an example of the original arrangement of detection points detected on the left wall W. In this case, the left radar 1 L The detection points in the approaching direction (marked with + in the figure) and the left radar 1 L The detection points whose distance is constant as seen from the left radar (marked with o in the figure) and the left radar 1 L There are three types of detection points in the direction away from the left radar (marked with - in the figure). L Assuming that the left radar is in the forward stowed position, L The ECU 2 that receives the output of should be able to determine that each detection point is caused by an object (wall W) to the left of the vehicle, based on the distance and direction of each detection point and the line-of-sight velocity of each detection point.

[0024] However, as explained in FIG. 6, the left radar 1 of this embodiment L , Left Radar 1 L In order to process the detection points on the assumption that the left radar 1 is in a deployed state, L The left radar 1 mistakenly believes that the detection points, which should actually be at the positions shown in FIG. 8A, are at the positions shown in FIG. 8B. LThe ECU2, which has received the output of (the erroneous detection point cloud shown in FIG. 8B), detects an object (a virtual wall W V ) will be falsely detected.

[0025] Here, left radar 1 L As is obvious from FIG. 8B, the detection point group that is positioned in an incorrect position when the left radar 1 is in the forward stored state has the following characteristics. That is, first, a part of the detection point group is present inside the host vehicle region R. Second, the detection point group within the host vehicle region R is located in the left radar 1. L When viewed from the direction of the radar 1, the radar 1 has a radial velocity in the direction away from the vehicle V (radial velocity<0 m / s). Therefore, when a detection point group satisfying these two conditions is detected while the vehicle V is moving forward slowly, it can be determined that a large axis deviation of the radar 1 has occurred, which cannot be detected by the technology disclosed in Patent Document 1. On the other hand, when there are no detection points satisfying these two conditions, it can be determined that a large axis deviation of the radar 1 has not occurred.

[0026] <Details of the axis deviation determination device 10> Next, the axis deviation judgment device 10 of this embodiment will be described in detail with reference to the functional block diagram of Fig. 9 and the processing flowchart of Fig. 10. Note that the axis deviation judgment device 10 of this embodiment is named after the axis deviation judgment function of the radar 1, and the radar 1 and the axis deviation judgment device 10 are actually the same device.

[0027] As shown in FIG. 9, the axis deviation judgment device 10 of this embodiment has an object detection unit 11 and a judgment unit 12, and outputs a group of detection points detected by the object detection unit 11 to the ECU 2. The object detection unit 11 has a transmission unit 11a, a reception unit 11b, and a detection point calculation unit 11c, and the judgment unit 12 has a host vehicle area storage unit 12a and an axis deviation judgment unit 12b. The components of the axis deviation judgment device 10, except for the transmission unit 11a and the reception unit 11b, are specifically a computer equipped with hardware such as a calculation device such as a CPU, a storage device such as a semiconductor memory, and a communication device. The calculation device executes a predetermined program to realize each function of the detection point calculation unit 11c and the like. In the following, the details of each unit will be described in order while appropriately omitting such well-known techniques in the computer field.

[0028] The transmitter 11a is a transmitting antenna that transmits a transmission wave to the surroundings of the vehicle, and the receiver 11b is a receiving antenna that receives a reflected wave reflected by an object. Note that the detailed configurations of these antennas and the control methods for transmission and reception are well known, and therefore detailed explanations will be omitted.

[0029] The detection point calculation unit 11c arranges detection points due to objects within the detection range of the radar 1 based on the reflected waves received by the receiving unit 11b, and calculates the radial velocity of each detection point as seen from the radar 1. As a result, various detection point groups (indicated by -, o, and + marks in the figures) as shown in Fig. 7 and Fig. 8B are arranged within the detection range on the assumption that the radar 1 is in a deployed state.

[0030] The host vehicle area storage unit 12a is a storage unit that stores the shape of the host vehicle area R exemplified in Fig. 5 and Fig. 6 and the mounting positions of the left and right radars in the host vehicle area R. The host vehicle area R and the like stored here may be the shape of the host vehicle V registered in advance, or may be the host vehicle shape estimated from the side shape of the host vehicle V measured by the radar 1 and registered afterwards.

[0031] The axis deviation judgment unit 12b judges that a large axis deviation that cannot be detected by the technology disclosed in Patent Document 1 has occurred when the detection points placed by the detection point calculation unit 11c and the vehicle area R stored in the vehicle area memory unit 12a satisfy the two conditions described above.

[0032] Here, the axis deviation judgment process performed by the axis deviation judgment device 10 (particularly the judgment unit 12) of this embodiment will be described in detail with reference to the processing flowchart of FIG.

[0033] First, in step S1, the object detection unit 11 receives reflected waves from an object within the detection range of the radar 1 via the transmission unit 11a and the reception unit 11b, and then, via the detection point calculation unit 11c, places a detection point due to the object within the detection range on the assumption that the radar 1 is in a deployed state.

[0034] Next, in step S2, the determination unit 12 determines whether a detection point is located within the host vehicle region R stored in the host vehicle region storage unit 12a. If a detection point is located within the host vehicle region R, the process proceeds to step S3, and if not, the process returns to step S1.

[0035] In step S3, the determination unit 12 sets the detection points within the host vehicle region R as extraction points.

[0036] In step S4, the determination unit 12 determines whether there is an extraction point with a line-of-sight speed of less than 0 m / s, that is, whether there is a detection point in the direction away from the radar 1 within the vehicle region R. If there is an extraction point that satisfies the condition, it is determined that a large axis deviation that cannot be detected by the technology disclosed in Patent Document 1 has occurred. In this case, the ECU 2 may use the output of the radar 1 on the premise that there is a large axis deviation. On the other hand, if there is no extraction point that satisfies the condition, the process proceeds to step S5.

[0037] Here, the reason for performing the judgment in step S4 in addition to the judgment in step S2 in the axis deviation judgment method of the present invention will be explained. Comparing Fig. 8A with Fig. 8B, it seems that the presence or absence of a large axis deviation can be judged simply by judging whether or not there is a detection point in the host vehicle region R, that is, by performing the judgment in step S2. However, when the left radar 1 is observed on the left side of the host vehicle in the situation in Fig. 7 where no large axis deviation occurs, L Theoretically, the group of detection points (marked with o in the figure) whose distance is constant when viewed from the left side should be arranged along the left side of the vehicle region R, but in reality, some of the detection points may be arranged within the vehicle region R due to the influence of measurement errors and the like. In this case, the determination in step S2 alone may lead to a misunderstanding that a large axis misalignment has occurred, even though a large axis misalignment has not actually occurred. In this way, since the determination in step S2 alone cannot accurately determine whether or not a large axis misalignment has occurred, in this embodiment, in addition to the determination in step S2, a determination in step S4 focusing on the line-of-sight speed of the detection points in the vehicle region R is performed, thereby making it possible to accurately determine whether or not a large axis misalignment has occurred.

[0038] The processes from step S5 to step S7 are useful processes when the host vehicle region R is not registered in the host vehicle region storage unit 12a, for example. First, in step S5, the detection point calculation unit 11c identifies an extraction point (see o in FIG. 7) with a line-of-sight velocity of 0 m / s from the extraction point. Next, in step S6, the detection point calculation unit 11c re-extracts an extraction point near the side reference position from the identified extraction point. Finally, in step S7, the detection point calculation unit 11c sets the outermost side of the re-extraction point as the side of the vehicle, and registers this as the host vehicle region R in the host vehicle region storage unit 12a. By these processes, even if the host vehicle region R is not registered in the host vehicle region storage unit 12a or the host vehicle region R registered in the host vehicle region storage unit 12a is incorrect, an appropriate host vehicle region R that conforms to the actual situation can be registered in the host vehicle region storage unit 12a based on the measurement results of the radar 1. Note that, since the line-of-sight velocity at the detection point on the side of the vehicle may not be 0 m / s due to the influence of measurement errors, etc., in step S5, an extraction point with a line-of-sight velocity within ±0.1 m / s, for example, may be selected.

[0039] <Effects of this embodiment> According to the axis deviation determination device or axis deviation determination method of the present embodiment described above, even if the deviation angle of the radar sensor becomes large and the side of the vehicle is no longer within the detection range of the radar, the axis deviation of the radar can be determined based on the radial velocity of the detection point within the area of ​​the vehicle. [Explanation of symbols]

[0040] V…Vehicle, 1…Radar, 1 L …Left radar, S L …Left detection range, 1 R …Right radar, S R ...right detection range, 2...ECU, 3...alarm device, 4...vehicle control system, 10...axis deviation determination device, 11...object detection unit, 11a...transmission unit, 11b...reception unit, 11c...detection point calculation unit, 12...determination unit, 12a...own vehicle area storage unit, 12b...axis deviation determination unit, W...wall, W V …Virtual wall

Claims

1. an object detection unit that is attached to the vehicle and transmits a transmission wave to the surroundings and detects a detection point on the object that reflects the transmission wave based on the reflected wave reflected by the object; a determination unit that sets a predetermined area within the detection range of the object detection unit as a host vehicle area in which the vehicle is present, and, when the detection point is detected within the host vehicle area, determines an axis misalignment of the object detection unit based on the detection result of the detection point within the host vehicle area.

2. 2. The axis deviation determination device according to claim 1, The axis deviation determination device according to the present invention is characterized in that the determination unit stores the vehicle area in advance.

3. 2. The axis deviation determination device according to claim 1, The axis deviation determination device is characterized in that the determination unit sets the vehicle area within the detection range in accordance with a detection result of the side of the vehicle detected by the object detection unit.

4. 2. The axis deviation determination device according to claim 1, The object detection unit calculates a line-of-sight velocity of the detection point with respect to the object detection unit, The axis misalignment determination device according to the present invention is characterized in that the determination unit determines the axis misalignment of the object detection unit based on the line-of-sight velocity of the detection point within the vehicle area.

5. using an object detection unit attached to the vehicle to transmit a transmission wave to the surroundings and detect a detection point on the object that reflects the transmission wave based on the reflected wave reflected by the object; a step of setting a predetermined area as a host vehicle area in which the vehicle is present, and when the detection point is detected within the host vehicle area, determining the axis misalignment of the object detection unit based on the detection result of the detection point within the host vehicle area.

Images