JP2019158485A - Object detector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce erroneous detection of partial adhesion of foreign matter such as snow to a front plate provided in front of a radar. SOLUTION: A partial adhesion detection unit 33 averages the detection elevation angles of all the objects detected by the radar sensor 20 for each of the divided areas, which is an area obtained by dividing the horizontal detection area of the radar sensor 20 into a plurality of areas. A value is calculated, and the variation of the average value exceeds the reference level (S13: Yes), and the variation of the average value of the detected elevation angles of the divided areas exceeds the reference level for the moving object (S15: In the case of Yes), it is determined that the attachment is partially attached to the front plate EP (S16). [Selection diagram] FIG.

Description

  The present invention relates to an object detection device that detects an object existing around a vehicle by a radar.

  Conventionally, for example, as proposed in Patent Document 1, an obstacle existing around the own vehicle is detected by a radar, and the own vehicle is prevented from colliding with the obstacle based on the detection information. There is known a driving support device that performs driving support control such as decelerating the vehicle speed. The radar is fixed to the vehicle body so that the radar reference axis is arranged in a preset direction. The radar reference axis is an axis serving as a reference for the detection direction of the radar, and is also called an optical axis or a beam axis. Hereinafter, the radar reference axis is referred to as a radar axis.

  In a state where the radar axis is inclined with respect to the set direction (this state is referred to as an axis deviation), the radar detection accuracy decreases. Thus, for example, as proposed in Patent Document 2 and the like, various techniques for detecting a radar axis misalignment are known.

  Even if the axis deviation of the radar occurs, if the axis deviation amount is recognized, the position of the object can be properly detected by correcting only the axis deviation amount. For this reason, the radar has a function of learning the direction of the radar axis, and is configured to detect the position of the object based on the learned direction of the radar axis.

Japanese Patent Laid-Open No. 2016-210386 JP 2006-47140 A

  Learning the radar axis in the vertical direction, for example, calculates the average value of the vertical detection angles (referred to as detection elevation angles) of all detected objects, and the direction represented by the average value of the detection elevation angles above and below the reference axis of the radar This can be done by setting the direction. By learning the radar axis, the vertical direction of the object can be properly detected even if the vertical axis shift occurs. Hereinafter, an object detected by the radar may be called a target.

  Radar is installed inside the outer plates of bumpers, emblem plates, etc., and transmits radio waves to the outside of the vehicle through the outer plates, and receives the reflected waves reflected by the radio waves hitting objects through the outer plates. The object is detected based on the reflected wave. The radar is provided with a cover plate in front of it. Therefore, even if the radar is not installed inside the outer plate, a certain plate is provided in front of it, so that radio waves are transmitted and received through this plate. Hereinafter, a plate (outer plate or cover plate) provided in front of the radar is referred to as a front plate.

  When foreign objects such as snow adhere to the front plate, it is not possible to properly detect the object by the radar. For example, as shown in FIG. 8, a case is considered in which snow SN partially adheres to the lower side of the front plate EP (in this example, the emblem plate provided on the front grille FG). The radar is fixed to the vehicle body member on the back side of the front plate EP. When snow SN is not attached, the reflected wave reflected by the target in front of the radar is received in the same phase by the upper receiving antenna A1 and the lower receiving antenna A2, as shown in FIG. 9A. Is done.

  On the other hand, as shown in FIG. 9B, when the snow SN exists only in front of the lower receiving antenna A2 (for example, in the state of snow adhering in the section BB in FIG. 8), the lower receiving antenna A2 Since the reflected wave (radio wave) received at 1 propagates through the snow SN having a dielectric constant different from that of air, the wavelength changes. As a result, a phase shift of the received reflected wave occurs between the upper receiving antenna A1 and the lower receiving antenna A2. In the radar, the phase difference between the upper and lower receiving antennas A1 and A2 is a distance difference from the radar to the target, and is used for detecting the direction of the target in the vertical direction (elevation angle detection). For this reason, in the example of FIG. 9B, the vertical position of the target is detected above the actual position. In this case, the radar axis cannot be properly learned.

  Therefore, the applicant of the present application calculates the average value of the detected elevation angles of the targets detected within the most recent predetermined period for each divided area, which is an area obtained by dividing the horizontal detection area of the radar into a plurality of divided areas. Based on the variation in the average value of the detected elevation angle (variation between the average values), a method has been devised to detect that snow is partially attached to the front plate (referred to as partial adhesion).

  For example, as shown in FIG. 8, when the snow SN is partially attached to the front plate EP, the average value of the detected elevation angle is high at the horizontal position corresponding to the attached portion. For this reason, as shown in FIG. 10, variation occurs between the average values of the detected elevation angles for the respective divided areas. Therefore, the partial adhesion can be detected by detecting this variation. FIG. 10 is a diagram illustrating the position of the target viewed from the radar in the horizontal direction and the vertical direction. A horizontal area indicated by gray is an area where partial adhesion occurs.

  For example, a range (θave ± Δθ) that falls within a predetermined width Δθ centering on the average value θave of the detected elevation angles of all detected targets is set as the variation determination region, and the average value of the detected elevation angles for each divided area is When the degree of deviation from the variation determination region is large, it may be determined that “there is variation”, that is, “there is partial adhesion”.

  For example, various determination methods such as “partial adhesion” can be adopted when the number of segment areas where the average value of the detected elevation angle is out of the variation determination region exceeds the reference value.

  However, for example, under a specific situation where the host vehicle is traveling in a tunnel, the average value of the detected elevation angle varies as in the case where the partial adhesion occurs. For this reason, in fact, it may be erroneously determined that partial adhesion has occurred even though partial adhesion has not occurred.

  For example, as shown in FIG. 11A, in the tunnel T, lamps L1 and L2 are provided on the left and right. The left lamp L1 provided on the upper left side of the lane in which the host vehicle travels reflects the radio wave transmitted by the radar to the radar with strong intensity, and the right lamp L2 provided on the upper right side of the adjacent lane transmits the radar. There are cases where the radio waves are not strongly reflected by the radar. In such a case, further, there is no object (for example, a guardrail) that reflects the radio wave transmitted by the radar with high intensity on the left side of the lane in which the host vehicle is traveling (for example, position P1 in FIG. 11 (a)). If there is an object (for example, curbstone) that reflects the radio wave transmitted by the radar with a strong intensity on the right side of the adjacent lane (for example, position P2 in FIG. 11A), FIG. ), The average detected elevation angle of the target detected on the left side of the host vehicle is a high angle, and the average detected elevation angle of the target detected on the right side of the host vehicle is a low angle.

  On the other hand, as shown in FIG. 12A, when partial adhesion occurs on the lower left side of the front plate EP (lower right side as viewed from the front), as shown in FIG. The average value of the detected elevation angle on the left side of the vehicle is a high angle, and the average value of the detected elevation angle on the right side of the host vehicle is a low angle.

  For this reason, under the specific circumstances as described above, it may be erroneously determined that partial adhesion has occurred even though partial adhesion has not occurred.

  The present invention has been made to solve the above-described problems, and an object thereof is to reduce erroneous detection of partial adhesion.

In order to achieve the above object, the feature of the object detection device of the present invention is as follows.
In an object detection device mounted on a vehicle and detecting an object existing around the vehicle by a radar (20, 31),
For each divided area, which is an area obtained by dividing the horizontal detection area of the radar into a plurality of areas, an average value of detected elevation angles that are detected in the vertical direction of the object is calculated, and the detected elevation angle for each divided area And a partial adhesion detecting means (33) for detecting an adhering substance partially adhering to the front plate (EP) provided in front of the radar based on the variation of the average value of
The partial adhesion detection means is
First detection means (S11 to S13) for determining whether or not a variation in an average value of the detected elevation angles for each of the divided areas exceeds a reference level for all detected objects;
Second determination means for determining whether a variation in the average value of the detected elevation angles for each of the divided areas exceeds a reference level for a moving object that is a moving object among all detected objects. (S14 to S15),
The first determination means determines that the variation in the average value of the detected elevation angle for each of the divided areas exceeds the reference level for all detected objects (S13: Yes), and the second On the condition that the variation of the average value of the detected elevation angles for each of the divided areas exceeds the reference level by the determination means (S15: Yes) And partial adhesion determining means (S16) for determining that the adhered substance is attached.

  The object detection device of the present invention is mounted on a vehicle and detects an object existing around the vehicle by a radar. The partial adhesion detection means calculates the average value of the detected elevation angle, which is the detected vertical angle of the object, for each divided area that is an area obtained by dividing the horizontal detection area of the radar into a plurality of areas. Based on the variation in the average value of the detected elevation angle, an adhering matter (foreign matter) partially attached to the front plate provided in front of the radar is detected. This adhering matter is a foreign substance that may detect the detected elevation angle in error, for example, snow. The object for which the average value of the detected elevation angle is calculated is an object detected within the latest preset period, for example, an object detected within the latest fixed time, or the latest The set number of objects detected in the above can be set as appropriate.

  When an adhering matter partially adheres to the front plate, the average value of the detected elevation angle for each divided area varies. Therefore, the partial adhesion detection means detects the adhesion partially adhered to the front plate of the radar by capturing such a phenomenon.

  However, for example, under certain circumstances such as when the host vehicle is traveling in a tunnel, variations in the average value of the detected elevation angle occur in the same way as when the deposits partially adhere to the front plate. Therefore, under certain circumstances, there is a risk of erroneous detection of partial adhesion (incorrectly determining that an adhering substance is partially attached to the front plate).

  Therefore, the partial adhesion detection unit includes a first determination unit, a second determination unit, and a partial adhesion determination unit. A 1st determination means determines whether the variation of the average value of the detection elevation angle for every division area is over the reference level for all the detected objects. The second determination means determines whether or not the variation in the average value of the detected elevation angles for each divided area exceeds a reference level for a moving object that is a moving object among all detected objects. . The reference level is a preset level at which it is possible to detect a situation in which deposits are partially attached to the front plate. The reference level in the first determination unit and the reference level in the second determination unit may be the same or different.

  The second determination means determines whether the variation in the average value of the detected elevation angles for each divided area exceeds the reference level for the moving object. The moving object is mainly a preceding vehicle that travels in front of the host vehicle and an oncoming vehicle that travels in the oncoming lane. Therefore, an object that is detected when the elevation angle is near zero degrees is a target. For this reason, according to the second determination means, even in a specific situation, if the deposit is not partially adhered to the front plate, the variation in the average value of the detected elevation angle for each divided area is set to the reference level. It is determined that it does not exceed.

  In addition, “all detected objects” are objects detected within the latest preset period, for example, objects detected within the latest fixed time period, or detected most recently. A set number of objects can be set as appropriate.

  The partial adhesion determination means is determined by the first determination means that the variation in the average value of the detected elevation angles for each divided area exceeds the reference level for all detected objects, and the second determination means In the case where it is determined that the variation in the average value of the detected elevation angle for each divided area exceeds the reference level for the moving object, it is determined that the adhering material is partially attached to the front plate. .

  Therefore, according to the present invention, partial adhesion is erroneously detected even under a specific situation in which the average value of the detected elevation angle varies in the same manner as the case where deposits partially adhere to the front plate. The possibility of being lost can be reduced.

In the present invention, the following configuration, for example,
“Radar axis learning means for learning a reference axis in the vertical direction of the radar based on the average value of the detected elevation angles of all detected objects;
A learning prohibition that prohibits learning of the reference axis in the vertical direction of the radar by the radar axis learning means when it is determined by the partial adhesion determining means that the deposit is partially attached to the front plate. Means "
It is good to have.
According to this, it is possible to appropriately learn the reference axis in the vertical direction of the radar.
For example, the radar axis learning means may perform a process of setting the direction represented by the average value of the detected elevation angles of all detected objects in the vertical direction of the radar reference axis.

  In the above description, in order to assist the understanding of the invention, the reference numerals used in the embodiments are attached to the constituent elements of the invention corresponding to the embodiments in parentheses. It is not limited to the embodiment defined by.

It is a schematic structure figure of a driving support device provided with an object detection device concerning an embodiment. It is a top view showing the reference axis of a radar, and the detection angle range of the horizontal direction of a radar. It is a side view showing a reference axis of a radar and a detection angle range in the vertical direction of the radar. It is a front view of an emblem plate. It is a flowchart showing a partial adhesion detection routine. It is explanatory drawing showing the average value of the detection elevation angle of all the targets for every division area at the time of tunnel driving | running | working, and the average value of the detection elevation angle of a moving object. It is explanatory drawing showing the average value of the detection elevation angle of all the targets for every division area at the time of generation | occurrence | production of partial adhesion, and the average value of the detection elevation angle of a moving object. It is the front view and sectional drawing of an emblem plate showing a partial adhesion state. It is a figure explaining the principle by which the position of an up-down direction is detected accidentally by partial adhesion. It is explanatory drawing showing that variation arises in the average value of the detection elevation angle of a sampling target by partial adhesion. It is explanatory drawing showing the average value of the detection elevation angle of all the targets for every division area at the time of tunnel driving | running | working. It is explanatory drawing showing the average value of the detection elevation angle of all the targets for every division area at the time of generation | occurrence | production of partial adhesion.

  Hereinafter, a driving support apparatus for a vehicle including an object detection apparatus according to an embodiment of the present invention will be described with reference to the drawings.

  FIG. 1 shows a schematic configuration of a driving support device 1 including an object detection device according to an embodiment of the present invention. The driving assistance device 1 is mounted on a vehicle (hereinafter, sometimes referred to as “own vehicle” in order to be distinguished from other vehicles).

  The driving support device 1 includes a radar device 10, a driving support ECU 40, a camera sensor 50, a meter ECU 60, a brake ECU 70, a buzzer 80, a vehicle state sensor 90, and a driving operation state sensor 100. The radar device 10 corresponds to the object detection device of the present invention.

  Each ECU is an electric control unit (Electric Control Unit) including a microcomputer as a main part. In this specification, the microcomputer includes a CPU, a ROM, a RAM, a nonvolatile memory, an interface I / F, and the like. The CPU implements various functions by executing instructions (programs, routines) stored in the ROM. Some or all of these ECUs may be integrated into one ECU.

  The radar device 10 includes a radar sensor 20 and a target output device 30. The radar device 10 is fixed at the front end of the vehicle body and at the center position in the vehicle width direction. As shown in FIG. 4, the radar apparatus 10 of the present embodiment is fixed to the vehicle body member at a position on the back side of the emblem plate EP provided at the center of the front grille FG. The radar device 10 may be fixed to the vehicle body member, for example, at a position inside the front bumper. Hereinafter, an outer plate (emblem plate, front bumper, or the like) provided on the front surface of the radar apparatus 10 is referred to as a front plate EP.

  As shown in FIGS. 2 and 3, the radar sensor 20 transmits an electric wave to a preset detection area A and receives an reflected wave of the transmitted radio wave, thereby detecting an object existing in the detection area A. Detect. The detection area A is a spatial region that falls within a predetermined angle range set in advance in the horizontal direction (left-right direction) and the vertical direction with the radar axis B as the center. 2 and 3 each show the detection angle range of the radar sensor 20, and do not show the detection distance. The detection distance is appropriately determined according to the application (for example, several tens of meters).

  The radar apparatus 10 is, for example, a millimeter wave radar, and employs an FM-CW (Frequency Modulated-Continuous Wave) system or a pulse compression system (referred to as an FCM (Fast Chirp Modulation) system). The relative position (relative distance and relative angle) of the object with respect to the radar sensor 20 and the relative speed of the object with respect to the radar sensor 20 are detected.

  The radar sensor 20 includes a transmission unit, a reception unit, and a signal processing unit (not shown). The transmitter modulates a reference signal having a preset frequency to generate a signal whose frequency changes with time (referred to as a transmission signal), and the transmission signal (sometimes referred to as a radio wave). Is transmitted from the transmitting antenna to the detection area.

  The receiving unit is an electronic circuit that receives, as a received signal, a signal that propagates through the space in the detection area via the receiving antenna. Therefore, when an object exists in the detection area, a reflected wave of the radio wave radiated to the object is received as a reception signal by the receiving unit.

  The signal processing unit mixes the transmission signal generated by the transmission unit and the reception signal received by the reception unit, and generates a beat signal by taking the difference between the frequency of the transmission signal and the frequency of the reception signal.

  The receiving unit includes a plurality of receiving antennas. The plurality of receiving antennas are arranged so as to be spaced apart from each other by a predetermined distance in the left-right direction and at a predetermined distance in the vertical direction. A beat signal is generated for each channel (for each receiving antenna). The radar sensor 20 transmits a radar detection signal including the generated beat signal to the target output device 30.

  The transmission signal (radio wave) transmitted from the transmission unit and the reception signal (reflected wave) received by the reception unit pass through the front plate EP provided in front of the radar device 10.

  The target output device 30 is an arithmetic circuit having a microcomputer as a main part. As shown in FIG. 1, when focusing on its function, the target information generating unit 31, the radar axis learning unit 32, And a partial adhesion detector 33.

  The target information generation unit 31 performs frequency analysis on the radar detection signal transmitted from the radar sensor 20 by fast Fourier transform or the like, so that the target information generation unit 31 is based on a delay time from transmission of a transmission wave to reception of a reception wave. The distance from the radar sensor 20 to the object is calculated, and the relative speed of the object with respect to the radar sensor 20 is calculated based on the frequency difference between the transmitted wave and the received wave. Further, the target information generation unit 31 calculates the direction of the object (horizontal direction and vertical direction (elevation angle)) with respect to the radar sensor 20 based on the signal phase difference between the channels.

  Hereinafter, information related to the object calculated by the target information generation unit 31, that is, information indicating the relative position (relative distance and relative direction) of the object with respect to the radar sensor 20 and the relative speed of the object with respect to the radar sensor 20 will be described. This is called mark information. Note that an object detected by the radar apparatus 10 may be called a target. The target information generation unit 31 transmits (outputs) target information that is a calculation result to the driving support ECU 40.

  The radar axis learning unit 32 is a functional unit that learns the radar axis of the radar sensor 20. The radar axis learning unit 32 calculates an average value of detection elevation angles (elevation angles calculated by the target information generation unit 31) of all targets detected by the radar sensor 20, and indicates a direction represented by the average value of the detection elevation angles. Set the vertical direction of the radar axis. For example, the detected elevation angle is expressed as a positive value in the upward direction with respect to the radar axis, and is expressed as a negative value in the downward direction with respect to the radar axis.

  For example, when a vehicle is shipped from a factory, radar axis adjustment is performed and a radar reference axis is set. The radar axis learning unit 32 regards the direction represented by the average value of the detected elevation angle as the correct vertical direction of the radar axis, and the direction represented by the average value of the detected elevation angle is deviated from the vertical direction of the radar axis currently set. In this case, the deviation amount (axis deviation amount) is supplied to the target information generation unit 31.

  The target information generation unit 31 stores and updates the axis deviation amount supplied from the radar axis learning unit 32, corrects the direction of the radar axis using the axis deviation amount, and uses the corrected latest radar axis as a reference. Generate target information for.

  The radar axis learning unit 32 repeats the calculation of the axis deviation amount at a predetermined timing, and supplies the axis deviation amount as a calculation result to the target information generation unit 31 each time. For example, the radar axis learning unit 32 sets a sampling period of a certain time, calculates the average value of the detected elevation angles of all targets detected during this sampling period, and shifts the direction represented by the average value of the detected elevation angles. Set to quantity. The amount of axis deviation represents the amount of deviation between the direction represented by the average value of detected elevation angles and the direction of the radar axis that is currently set.

  The radar axis learning unit 32 supplies the calculated axis deviation amount to the target information generation unit 31 every time the axis deviation amount is calculated. The target information generating unit 31 corrects the direction of the radar axis by the amount of axis deviation supplied from the radar axis learning unit 32 (this is a calculation correction).

  Further, the sampling period of the target elevation angle of the target may be a fixed time as described above, or may be a period until the sampling number of the target (number of detected objects) reaches a set number. Each time the sampling period elapses, the radar axis learning unit 32 calculates the average value of the detected elevation angles of all targets detected during the sampling period, and sets the direction represented by the average value of the detected elevation angles as the axis deviation amount. The axis deviation amount is set and supplied to the target information generation unit 31.

  This process is radar axis learning.

  The partial adhesion detection unit 33 detects the adhesion partially attached to the front plate EP based on the target information generated by the target information generation unit 31. That is, it is determined whether or not the deposit is partially attached to the front plate EP. This adhering matter is a foreign substance that may detect the detected elevation angle in error, for example, snow. Hereinafter, the fact that the deposit is partially attached to the front plate EP is referred to as “partial adhesion”.

  As shown in FIG. 9, the radar apparatus 10 detects the elevation angle of the target based on the phase difference between the reflected waves received by the upper receiving antenna A1 and the lower receiving antenna A2 provided in the radar sensor 20. However, as shown in FIG. 9B, when snow SN is present in front of the lower receiving antenna A2, the reflected wave (radio wave) received by the lower receiving antenna A2 is a dielectric that differs from air in the middle. In order to propagate the rate of snow SN, the wavelength changes. Therefore, as shown in FIG. 8, when partial adhesion occurs on the front plate EP, the position of the target in the vertical direction as shown in FIG. Is detected above the actual position. In this case, the radar axis cannot be properly learned.

  When such partial adhesion occurs, as shown in FIG. 10, in the horizontal area corresponding to the part where the foreign matter is attached and the horizontal area corresponding to the part where the foreign matter is not attached, There is a variation in the average value of the detected elevation angle of the target (the average value of the detected elevation angle of the target for each rear section described later). Therefore, by detecting such variation, it can be detected that partial adhesion has occurred.

  However, the average value of the detected elevation angle of the target is not limited to the case where partial adhesion occurs as described above, but under certain circumstances such as when the host vehicle is traveling in the tunnel T. (See FIG. 11).

  Therefore, the partial adhesion detection unit 33 detects the occurrence of partial adhesion so as not to include such a specific situation as much as possible.

  FIG. 5 shows a partial adhesion detection routine executed by the partial adhesion detection unit 33. The partial adhesion detection unit 33 performs a partial adhesion detection routine at a predetermined calculation cycle.

When the partial adhesion detection routine is started, in step S11, the partial adhesion detection unit 33 targets all of the targets detected within the latest preset period, and averages the detected elevation angles of those targets. Calculate the value. The “target detected within the latest preset period” may be, for example, a target detected within a predetermined time set in advance, or a set number of targets detected most recently. It may be a mark. Hereinafter, a target detected within the latest preset period may be referred to as a sampling target.
The calculation in step S11 is performed based on the target information generated by the target information generating unit 31.

  Subsequently, in step S <b> 12, the partial adhesion detection unit 33 calculates the average value of the detected elevation angle of the sampling target for each divided area that is an area obtained by dividing the horizontal detection area of the radar sensor 20 into a plurality of areas. In other words, the partial adhesion detection unit 33 groups all the sampling targets using the divided areas where the respective targets exist, and for each divided area, the average value of the detected elevation angles of the sampling targets belonging to the divided area. Is calculated.

The section area represents each angle range obtained by equally dividing the horizontal detection angle range (detection area A) shown in FIG. For example, if the horizontal detection angle range is 100 deg and the number n of divisions is 10, the horizontal angle range of one division area is 10 deg (100/10).
The calculation in step S12 is performed based on the target information generated by the target information generating unit 31.

  Subsequently, in step S <b> 13, the partial adhesion detection unit 33 determines whether or not the variation in the average value of the detected elevation angles for each divided area exceeds the reference level. For example, the partial adhesion detection unit 33 sets a range (θave ± Δθ) that falls within a predetermined width Δθ around the average value θave of detection elevation angles of all the sampling targets calculated in step S11 as a variation determination region, When the average value of the detected elevation angle exceeds the set number of the divided areas out of the variation determination area, it is determined that the variation in the average value of the detected elevation angle exceeds the reference level.

  The functional unit of the partial adhesion detection unit 33 that performs the processes of steps S11 to S13 corresponds to the first determination unit of the present invention.

  If the variation in the average value of the detected elevation angle does not exceed the reference level (S13: No), it can be determined that partial adhesion has not occurred at this stage. In this case, the partial adhesion detection unit 33 once ends the partial adhesion detection routine.

  On the other hand, if it is determined as “Yes” in step S13, that is, if it is determined that the variation in the average value of the detected elevation angles exceeds the reference level, partial adhesion is suspected, but partial adhesion is not necessarily generated. For example, it is determined as “Yes” even in a specific situation such as when the host vehicle is traveling in a tunnel. In this case, the partial adhesion detection unit 33 advances the process to step S14.

  In step S <b> 14, the partial adhesion detection unit 33 calculates the average value of the detected elevation angle of the moving object belonging to the divided area for each divided area, targeting the moving object among all the sampling targets. For example, the partial adhesion detection unit 33 determines whether the sampling target is a moving object or a stationary object based on the relative speed between the host vehicle and the target and the vehicle speed of the host vehicle. Alternatively, the partial adhesion detection unit 33 may determine whether the sampling target is a moving object or a stationary object based on the movement locus of the position where the sampling target is detected and the movement locus of the host vehicle. . The calculation in step S14 is performed by the target information generated by the target information generation unit 31, the vehicle state sensor 90 (vehicle speed sensor, yaw rate sensor, etc.) and the driving operation state sensor 100 (steering angle sensor, etc.) described later. This is performed based on the detected value.

  The moving object is mainly a preceding vehicle that travels in front of the host vehicle and an oncoming vehicle that travels in the oncoming lane. Therefore, a sampling object that is detected when the elevation angle is near zero degrees is a target. For this reason, even under specific circumstances, if there is no partial adherence to the front plate EP, the variation in the average value of the detected elevation angle of the moving object for each section area should not exceed the reference level. is there.

  For example, when traveling in a tunnel T as shown in FIG. 6 (a), which is in a specific situation, as shown in FIG. 6 (b), detection for each divided area targeting all sampling targets. The average value of the elevation angle has a large variation, but the average value of the detected elevation angle for each divided area for the moving object has a small variation. In the figure, the x mark represents the average value of the detected elevation angle for each divided area for moving objects.

  On the other hand, as shown in FIG. 7 (a), when a deposit is partially adhered to the front plate EP, not only the average value of the detected elevation angle for each divided area targeting all the sampling targets. Also, the average value of the detected elevation angle for each divided area for a moving object also varies greatly.

  The partial adhesion detection unit 33 catches such a phenomenon and prevents the partial adhesion from being erroneously detected under a specific situation.

  In step S14, the partial adhesion detection unit 33 calculates the average value of the detected elevation angle of the moving object for each divided area. Subsequently, in step S15, the variation in the average value of the detected elevation angle of the moving object for each divided area is used as a reference. Determine if the level is exceeded. For example, the partial adhesion detection unit 33 uses the variation determination area (θave ± Δθ) used in the determination in step S13, and the number of the divided areas where the average value of the detected elevation angle of the moving object is out of the variation determination area. When the number exceeds the set number, it is determined that the variation in the average value of the detected elevation angle of the moving object exceeds the reference level.

  The functional unit of the partial adhesion detection unit 33 that performs the processes of steps S14 to S15 corresponds to the second determination unit of the present invention.

  If the variation in the average value of the detected elevation angle of the moving object does not exceed the reference level (S15: No), it can be determined that partial adhesion has not occurred. In this case, the partial adhesion detection unit 33 once ends the partial adhesion detection routine.

  On the other hand, when it is determined that the variation in the average value of the detected elevation angle of the moving object exceeds the reference level (S15: Yes), the partial adhesion detection unit 33 determines the partial adhesion in step S16. That is, it is determined that partial adhesion has occurred. In this case, the partial adhesion detection unit 33 transmits a partial adhesion confirmation signal to the radar axis learning unit 32.

  The partial adhesion detection part 33 once complete | finishes a partial adhesion detection routine, if the process of step S16 is implemented. The partial adhesion detection unit 33 repeatedly executes a partial adhesion detection routine at a predetermined calculation cycle. The partial adhesion confirmation signal is transmitted until the next partial adhesion detection routine is started. Therefore, if it is not determined in the next partial adhesion detection routine that partial adhesion has occurred, transmission of the partial adhesion confirmation signal is stopped at that time.

  Based on the determination results (“Yes”) in steps S13 and S15, the functional unit of the partial adhesion detection unit 33 that performs the process of determining that partial adhesion has occurred in step S16 is the partial adhesion determination of the present invention. Corresponds to means.

  The radar axis learning unit 32 learns the radar axis at a predetermined timing. The radar axis learning unit 32 checks whether or not a partial adhesion confirmation signal is transmitted from the partial adhesion detection unit 33, and the partial adhesion confirmation signal is transmitted. If yes, stop learning the radar axis.

  Therefore, the partial adhesion detection unit 33 not only detects partial adhesion, but also has a function (learning prohibition means) that prohibits the radar axis learning unit 32 from learning the radar axis when partial adhesion is detected. ).

  Next, the driving assistance ECU 40 will be described. The driving support ECU 40 performs driving support control that is control for supporting the driving operation of the driver. The driving assistance ECU 40 of the present embodiment performs pre-crash safety control as driving assistance control. Hereinafter, the pre-crash safety control is referred to as PCS control.

  The driving support ECU 40 is connected to the camera sensor 50, the meter ECU 60, the brake ECU 70, the buzzer 80, the vehicle state sensor 90, and the driving operation state sensor 100 in order to perform various driving support controls including PCS control. .

  The camera sensor 50 includes a camera and an image processing unit (not shown). The camera captures a landscape in front of the host vehicle and acquires image data. The image processing unit detects an obstacle such as a vehicle or a pedestrian existing in front of the host vehicle based on the image data obtained by photographing with the camera, and sends the camera detection information as the detection information to the driving support ECU 40. Send. This camera detection information includes information such as the presence / absence of an obstacle, the position of the obstacle, and the size of the obstacle.

  Meter ECU60 is connected to the indicator 61 provided in the front of the driver's seat. The meter ECU 60 controls the display on the display 61 in accordance with the display command transmitted from the driving support ECU 40.

  The brake ECU 70 is connected to the brake actuator 71. The brake actuator 71 is provided in a hydraulic circuit between a master cylinder (not shown) that pressurizes hydraulic oil by the depression force of the brake pedal and a friction brake mechanism 72 provided on the left and right front and rear wheels. The friction brake mechanism 72 includes a brake disc fixed to the wheel and a brake caliper fixed to the vehicle body. The brake actuator 71 adjusts the hydraulic pressure supplied to the wheel cylinder built in the brake caliper in accordance with an instruction from the brake ECU 70, and presses the brake pad against the brake disc by operating the wheel cylinder with the hydraulic pressure, thereby causing friction braking force. Is generated. Therefore, the brake ECU 70 can control the braking force of the host vehicle by controlling the brake actuator 71.

  For example, when receiving a pressurization assistance command from the driving support ECU 40, the brake ECU 70 controls the brake actuator 71 to generate a friction braking force that is greater than a friction braking force generated by a normal brake pedal operation. That is, the ratio of the friction braking force to the depression stroke of the brake pedal is set to be larger than that at the normal time (when no pressurization assistance command is received). Further, for example, when receiving an automatic brake command from the driving support ECU 40, the brake ECU 70 controls the brake actuator 71 to generate a predetermined friction braking force even when there is no brake pedal operation.

  The buzzer 80 is driven according to the ringing command transmitted from the driving support ECU 40 and generates a buzzer sound in a manner specified by the ringing command. The driver is alerted by this buzzer sound.

  The vehicle state sensor 90 is a plurality of types of sensors that detect the vehicle state. For example, a vehicle speed sensor that detects the traveling speed of the vehicle, a wheel speed sensor that detects the wheel speed, and before and after detecting acceleration in the longitudinal direction of the vehicle. These include a G sensor, a lateral G sensor that detects lateral acceleration of the vehicle, and a yaw rate sensor that detects the yaw rate of the vehicle.

  The driving operation state sensor 100 is a plurality of types of sensors that detect the driving operation state of the driver. For example, an accelerator operation amount sensor that detects the operation amount of the accelerator pedal, and a brake operation amount sensor that detects the operation amount of the brake pedal. A brake switch that detects whether or not the brake pedal is operated, a steering angle sensor that detects the steering angle, a steering torque sensor that detects the steering torque, a winker operation sensor that detects the operation of the winker lever, and a shift position of the transmission For example, a shift position sensor to detect.

  The sensor information of the vehicle state sensor 90 and the driving operation state sensor 100 is also supplied to the radar device 10 as appropriate.

  Here, the PCS control which is the driving support control performed by the driving support ECU 40 will be described. Since PCS control is well known, it will be briefly described here. Based on the target information transmitted from the radar device 10 and the camera detection information transmitted from the camera sensor 50, the driving assistance ECU 40 identifies an obstacle existing in front of the own vehicle, and the own vehicle detects the obstacle. Determine the possibility of a collision with. For example, the driving support ECU 40 is based on the estimated time from the current time until the host vehicle collides with the obstacle based on the relative distance Dr and the relative speed Vr between the host vehicle and the obstacle existing in front of the host vehicle. A certain collision prediction time TTC (= Dr / Vr) is calculated. The predicted collision time TTC is used as an index value representing the high possibility that the host vehicle will collide with an obstacle. It can be determined that the shorter the predicted collision time TTC, the higher the possibility that the host vehicle will collide with an obstacle (the degree of urgency is high).

  When the predicted collision time TTC decreases to the warning level, the driving assistance ECU 40 sounds the buzzer 80 intermittently and displays “Brake!” On the display 61 to warn the driver. Further, the driving assistance ECU 40 transmits a pressurizing assistance command to the brake ECU 70 to assist the pressurization of the brake hydraulic pressure, and enhances the braking effect when the brake pedal is depressed. In addition, when the predicted collision time TTC is further reduced and reaches the automatic brake level, the driving support ECU 40 transmits an automatic brake command to the brake ECU 70, so that a predetermined friction braking force is applied regardless of the driver's brake operation. Is generated.

  By implementing such PCS control, it is possible to support collision avoidance or to reduce damage when a collision occurs.

  In addition to the PCS control, or in place of the PCS control, the driving support ECU 40 may perform other driving support control such as an inter-vehicle distance maintaining travel support control that causes the host vehicle to follow the preceding vehicle with a predetermined inter-vehicle distance. May be implemented. When the inter-vehicle distance maintaining travel support control is performed, the driving support ECU 40 recognizes the inter-vehicle distance between the host vehicle and the preceding vehicle based on the target information transmitted from the radar device 10, and uses this inter-vehicle distance as the target inter-vehicle distance. The target acceleration / deceleration for maintaining the speed is calculated. The driving support ECU 40 transmits an acceleration / deceleration command representing the target acceleration / deceleration to the engine ECU (not shown). Thereby, the own vehicle can be made to follow the preceding vehicle while ensuring an appropriate inter-vehicle distance.

  According to the radar apparatus 10 (object detection apparatus) of the present embodiment described above, it is determined that the variation in the average value of the detected elevation angle of the sampling target for each divided area exceeds the reference level, and the sampling target If the deposit is partially attached to the front plate EP on the condition that the variation of the average value of the detected elevation angle for each divided area exceeds the reference level for moving objects Determined. Therefore, the detection accuracy of partial adhesion can be increased, and erroneous detection of partial adhesion can be reduced. Accordingly, it is possible to appropriately learn the radar axis in the vertical direction.

  Although the object detection device according to the present embodiment has been described above, the present invention is not limited to the above embodiment, and various modifications can be made without departing from the object of the present invention.

  For example, the radar device 10 (object detection device) of the present embodiment is provided at the center in the vehicle width direction at the front end of the vehicle, but the object detection device to which the present invention is applied can be at any position according to the driving support control. Can be provided. For example, the object detection device may be provided in the left and right corner portions in front of the vehicle or in the left and right corner portions in the rear of the vehicle. Further, the object detection device may be provided at the center in the vehicle width direction at the rear end of the vehicle.

  In the present embodiment, the radar device 10 is provided inside the outer plate (emblem plate, front bumper, etc.), but the object detection device to which the present invention is applied is not necessarily located inside the outer plate. There is no need to be provided. For example, a configuration is conceivable in which the radar device 10 itself is provided with a cover plate in the direction of radio wave radiation, and this cover plate is arranged directly on the outer peripheral surface of the vehicle. Even in such a configuration, since snow or the like may adhere to the cover plate, the present invention can be applied effectively.

  DESCRIPTION OF SYMBOLS 10 ... Radar apparatus, 20 ... Radar sensor, 30 ... Target output apparatus, 31 ... Target information generation part, 32 ... Radar axis learning part, 33 ... Partial adhesion detection part, A1 ... Upper receiving antenna, A2 ... Lower receiving antenna , A ... detection area, B ... radar axis, EP ... front plate, SN ... snow.

Claims (1)

In an object detection device that is mounted on a vehicle and detects an object existing around the vehicle by a radar,
For each divided area, which is an area obtained by dividing the horizontal detection area of the radar into a plurality of areas, an average value of detected elevation angles that are detected in the vertical direction of the object is calculated, and the detected elevation angle for each of the divided areas is calculated. Based on the variation of the average value of, comprising a partial adhesion detection means for detecting a deposit partially adhered to the front plate provided in front of the radar,
The partial adhesion detection means is
First determination means for determining whether or not a variation in an average value of the detected elevation angles for each of the divided areas exceeds a reference level for all detected objects;
Second determination means for determining whether a variation in the average value of the detected elevation angles for each of the divided areas exceeds a reference level for a moving object that is a moving object among all detected objects. When,
The first determination means determines that the variation in the average value of the detected elevation angles for each of the divided areas exceeds the reference level for all detected objects, and the second determination means When it is determined that the variation in the average value of the detected elevation angle for each of the divided areas exceeds a reference level for a moving object, the adhering material partially adheres to the front plate. An object detection device comprising: a partial adhesion determination means for determining.

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