JP2010038706A - Signal processing apparatus and radar system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an anterolateral monitoring radar system of a vehicle which precisely detects a position of a target object. <P>SOLUTION: A signal processing apparatus of a radar transceiver which is mounted to the vehicle and scans a scan area containing a lateral area of the vehicle includes: a position detecting means for detecting X and Y coordinates of the target object position in the scan area wherein Y-axis is along the anterolateral direction of the vehicle, and X-axis intersects with the Y-axis; a position predicting means for predicting the X and Y coordinates of the target object position based on X-coordinate difference values and Y-coordinate difference values at respective detection cycles for the target object position detected in past detection cycles; and a position determining means for determining the detected position when the detected X and Y coordinates are within allowable ranges of the predicted X and Y coordinates, respectively. Therefore, the target object position having a large X-coordinate difference value can be predicted precisely, and position detection can be improved with accuracy. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a signal processing apparatus and signal processing method for a radar transceiver that is mounted on a vehicle and scans a scanning region including a region on the side of the vehicle, and more particularly, detects a position of a target object in the scanning region. The present invention relates to a signal processing apparatus and a signal processing method.

  There is known a vehicle control system that detects the position of a preceding vehicle that travels in front of the host vehicle using an in-vehicle radar device and travels following the detected position. Patent Document 1 describes an example of an on-vehicle radar device for follow-up traveling control.

  A radar apparatus in such a vehicle control system is mounted such that the center (radar axis) of the scanning area faces the front of the host vehicle, and scans the scanning area in front of the host vehicle. Then, the radar apparatus detects the position coordinates of the target object (preceding vehicle) on the XY coordinate plane with the radar axis as the Y axis and the direction perpendicular to the Y axis, that is, the left and right direction of the host vehicle as the X axis.

  Then, the radar apparatus predicts the Y coordinate of the target object in the new detection cycle from the difference value of the Y coordinate of the target object detected in the previous detection cycle. The position (detection position) detected in the new detection cycle is within the prediction area, with the X coordinate range corresponding to the lane width centered on the host vehicle and the predetermined allowable range for the predicted Y coordinate as the prediction area. The position is determined as a detection position. By doing so, the accuracy of the detection result for every detection cycle is ensured. This is because the position of the target object to be controlled in the follow-up traveling control moves in the direction along the Y axis in a state where the X coordinate is within the range corresponding to the lane width.

  The relationship between the prediction region for each detection cycle and the detected position is illustrated in FIG. FIG. 1A is a plan view showing a scanning region of the forward monitoring radar device mounted on the vehicle 1, and n (n = 1, 2, 3) on the XY coordinate plane with the radar device as the origin O. ...) Shows a detection position P (n) and a prediction area A (n) (illustrated by hatching) for each detection cycle.

Here, as an example of the case where the target object gradually approaches, it is shown that the prediction area A (n) in each detection cycle is set in an area within the lane width (prediction target area) along the Y-axis direction. . Then, when the detected position P (n) is within the prediction area A (n), the position P (n) is determined.
JP 2001-319299 A

  By the way, in recent years, radar devices are used as object recognition means for collision avoidance control for avoiding collision with other vehicles and collision response control for protecting an occupant in the event of a collision, in addition to vehicle follow-up control. It is done. In such collision avoidance control and collision response control, the target object to be controlled is an oncoming vehicle or another vehicle that encounters an encounter (hereinafter referred to as an encounter vehicle). Therefore, the radar apparatus is a vehicle so that these target objects can be easily detected. The radar shaft is directed to the front side of the vehicle (for example, the direction of 45 degrees side when the front is 0 degree).

  The position of the target object detected by the front side monitoring radar apparatus is shown in FIG. FIG. 1B is a plan view showing a scanning region of the front side monitoring radar apparatus. FIG. 1B shows an XY coordinate plane in which the Y-axis is set to 45 degrees ahead of the vehicle 1 and the radar apparatus is the origin O.

  Here, it is shown that the positions of the oncoming vehicle and the meeting vehicle move along a trajectory that crosses the scanning region. That is, these positions have large X-coordinate difference values for each detection cycle. Then, if the prediction area is set in the prediction target area as shown in FIG. 1A, there is a high probability that the position cannot be determined when the detection position of the target object deviates from the prediction area.

  If the position cannot be determined, an estimation process for estimating the detection position in the prediction area is possible. However, since the estimated position is set in the prediction target area based on the difference value of the Y coordinate, the target The position of the object moves in the direction along the Y axis within the prediction target area. Therefore, there is a possibility that the position of an oncoming vehicle that normally moves by passing or the position of another vehicle that crosses the front is misrecognized so as to approach along the Y axis as indicated by the dotted arrow.

  Further, in the case of the front side monitoring radar apparatus, the frequency at which the detection position of the roadside installation object (hereinafter referred to as a stationary object) moves across the scanning region increases as the host vehicle travels along the road. Since such a stationary object does not originally move toward the host vehicle, it is preferable to exclude it from the control target of the collision avoiding operation and the collision handling operation. However, when the position is predicted as described above, the position of the stationary object may deviate from the prediction region and may be erroneously recognized so as to approach the host vehicle as indicated by the dotted line by the estimation process.

  If an oncoming vehicle, another vehicle, or the position of a stationary object is misrecognized in this way, erroneous vehicle control, such as collision avoidance or collision handling, is performed even if there is no target object that is originally approaching. It may lead to

  SUMMARY OF THE INVENTION An object of the present invention is to provide a signal processing device that accurately detects the position of a target object in a radar device for front side monitoring of a vehicle and does not cause a malfunction of a collision avoiding operation or a collision handling operation.

  In order to achieve the above object, according to a first aspect of the present invention, there is provided a signal processing apparatus for a radar transceiver that is mounted on a vehicle and scans a scanning area including a side area of the vehicle. A position detection means for detecting the X and Y coordinates of the position of the target object in the scanning area when the front side of the vehicle is the Y axis and the direction intersecting the Y axis is the X axis; Position predicting means for predicting the X and Y coordinates of the position of the target object based on the X coordinate difference value and the Y coordinate difference value per detection cycle of the position of the detected target object; and the detected position When the X and Y coordinates are included in the respective allowable ranges of the predicted predicted X and Y coordinates, there is provided a signal processing device having position determining means for determining the detected position.

  According to the above aspect, the position predicting means is configured to determine X of the position of the target object based on the X coordinate difference value and the Y coordinate difference value per detection cycle of the position of the target object detected in the past detection cycle. Since the Y coordinate is predicted, the position of the target object having a large X coordinate difference value can be accurately predicted. Therefore, the probability that the detected position is within the prediction region is increased, and the position detection accuracy is improved.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. However, the technical scope of the present invention is not limited to these embodiments, but extends to the matters described in the claims and equivalents thereof.

  FIG. 2 is a diagram for explaining a usage situation of a radar apparatus to which the present invention is applied. The radar apparatus 10 is installed in the front side portion of the vehicle 1, for example, in the vicinity of the fog lamp in the front bumper. The radar apparatus 10 transmits a radar signal (electromagnetic wave) to a scanning region centered on the radar axis by aligning the radar axis in the direction of 45 degrees to the front side of the vehicle 1, that is, the front side (0 degree). The reflected signal from the scanning area is received and the received signal is processed to detect the position of the target object. Based on the detection result, the vehicle control device 100 configured by a microcomputer or the like avoids a collision with an oncoming vehicle or an encounter vehicle, or predicts the collision to protect the occupant. Control various actuators. It is possible to install a radar apparatus not only on the right front side as shown, but also on the left front side. In any case, the angle of the radar axis with respect to the vehicle 1 shown in the figure is an example, and can be set in a range from 0 degrees forward to 90 degrees lateral.

  FIG. 3 is a diagram for explaining the position of the target object detected by the radar apparatus 10 in the present embodiment. The radar apparatus 10 detects XY coordinates as the position of the target object on an XY coordinate plane with the radar axis direction as the Y axis, the orthogonal direction as the X axis, and the radar apparatus 10 as the origin O. At this time, the radar apparatus obtains the azimuth angle θ of the target object and the relative distance R of the target object when the Y-axis is set to 0 degrees by a procedure described later, and the X coordinate: x is determined from the azimuth angle θ and the relative distance R. = R · sin θ, Y coordinate: y = R · cos θ is calculated.

  FIG. 4 is a diagram illustrating the configuration of the radar apparatus according to this embodiment. In FIG. 4A showing the configuration of the entire radar apparatus, the radar apparatus 10 is an FM-CW (Frequency Modulated-Continuous Wave) radar apparatus as an example, and is a millimeter-wave continuous wave (electromagnetic wave) subjected to frequency modulation. ) As a transmission signal, the reflection signal is received, a beat signal of a frequency corresponding to the frequency difference between the transmission and reception signals is generated, and a signal processing for processing the beat signal generated by the radar transmission and reception 30 Device 14.

  The radar transceiver 30 transmits a transmission signal that is frequency-modulated with a triangular wave toward the scanning region, and receives a reflection signal of the transmission signal. When the transmission / reception signals are mixed and a beat signal having a beat frequency corresponding to the frequency difference between the transmission / reception signals is generated, the beat signal is A / D converted and the digital data is output to the signal processing device 14.

  Here, FIG. 4B shows the configuration of the radar transceiver 30 in the case of the mechanical scan method. In the radar transmitter / receiver 30, when the frequency modulation instruction unit 16 generates a triangular wave-shaped frequency modulation signal, the voltage controlled oscillator (VCO) 18 has a linear frequency in the rising section of the triangular wave according to the signal generated by the frequency modulation instruction unit 16. And a transmission signal whose frequency falls linearly in the falling section of the triangular wave is output. This transmission signal is power-distributed by the distributor 20 and a part thereof is transmitted from the transmission antenna 11. Then, the reflected signal is received by the receiving antenna 12, and the received signal is input to the mixer 22. The mixer 22 mixes a part of the power-distributed transmission signal and the reception signal, and generates a beat signal having a frequency corresponding to the frequency difference between the two. The beat signal is converted to digital data by an AD converter and output to the signal processing device 14.

  Further, the radar transceiver 30 includes a rotating unit 26 including a mechanism for reciprocally rotating the antenna unit 11a including the transmitting antenna 11 and the receiving antenna 12, and an encoder for detecting the rotation angle of the antenna unit 11a. . An angle signal indicating the rotation angle of the antenna unit 11 a is output from the encoder of the rotation unit 26 to the signal processing device 14. The signal processing device 14 detects the angle of the antenna unit 11a when receiving the reception signal based on the angle signal, and detects the azimuth angle of the target object. Further, in this case, the signal processing device 14 detects the target object with a period in which the antenna unit 11 rotates once in the angle range corresponding to the scanning region and scans the scanning region once as one detection cycle.

  Next, FIG. 4C shows a configuration of the radar transceiver 30 in the case of the electronic scan method. The radar transmitter / receiver 30 includes a plurality of receiving antennas 12_1, 12_2,... That receive reflected signals, spaced apart from each other by a predetermined interval, and a switch that inputs the received signals from the receiving antennas 12_1, 12_2,. Circuit 28. The mixer 22 mixes each of the receiving antennas 12_1, 12_2,... With the transmission signal to generate a beat signal.

  In this case, the signal processing device 14 changes the directivity of the entire antenna by controlling the phase difference of the received signal between the antennas. Then, by determining the directivity when the gain of the received signal is maximized, the azimuth angle of the target object corresponding to the directivity is detected. Alternatively, in the phase monopulse method that is one form of the electronic scan method, the signal processing device 14 directly detects the azimuth angle of the target object that is the arrival direction of the received signal from the reception phase difference between the antennas. In such an electronic scanning method, the signal processing device 14 performs target object detection processing with a frequency increase period and a frequency decrease period of the transmission signal as one detection cycle.

  Returning to FIG. 4A, the configuration of the signal processing device 14 will be described. The signal processing device 14 is an arithmetic processing device such as a DSP (Digital Signal Processor) that performs FFT (Fast Fourier Transform) processing on the digitized beat signal, and processes the frequency spectrum of the beat signal to obtain the target object. It has a microcomputer for positioning. This microcomputer includes a CPU (Central Processing Unit), a ROM (Read Only Memory) in which various processing programs and control programs executed by the CPU are stored, and a RAM (Random Access Memory) in which the CPU temporarily stores various data. ).

  Therefore, distance / speed detecting means 14a for detecting the relative distance and relative speed of the target object by analyzing the frequency of the beat signal, and the azimuth angle detecting means for detecting the azimuth angle of the target object by the mechanical scan method or the electronic scan method. 14b, position detection means 14c for obtaining a position on the XY coordinate plane from the relative distance and azimuth of the target object, and a position for predicting the position of the target object in the new detection cycle from the position of the target object detected in the past detection cycle The predicting unit 14d, the position determining unit 14e for determining the detected position when the detected position is within the allowable range of the predicted position, and the stationary object determining unit 14f for determining whether the target object is a stationary object, It comprises a program that defines each processing procedure and a CPU that executes the program.

  In addition, a vehicle speed signal indicating the speed of the vehicle 1 is input to the signal processing device 14 from a vehicle speed sensor of the vehicle 1. Further, a yaw rate signal indicating the yaw rate of the vehicle is input to the signal processing device 14 from the yaw rate sensor of the vehicle 1. The position predicting means 14d detects the vehicle speed from the vehicle speed signal, detects the turning radius from the yaw rate signal and the vehicle speed, and uses it for position prediction described later.

  Here, when a configuration example of the control system of the vehicle 1 to which the radar apparatus 10 is applied is shown in FIG. 5, the stationary object determination unit 14f described above is a signal of the radar apparatus 10 as in the configuration example of FIG. The processing apparatus 14 may have this. At this time, the signal processing device 14 of the radar device 10 corresponds to the “signal processing device” in the present embodiment. Or the vehicle control apparatus 100 of the vehicle 1 may have this like the structural example of FIG.5 (B). At this time, the signal processing device 14 of the radar device 10 and the control device 100 on the vehicle side correspond to the “signal processing device” in the present embodiment.

  FIG. 6 is a flowchart for explaining the operation procedure of the signal processing device 14. The procedure shown in FIG. 6 is executed every detection cycle.

  First, the signal processing device 14 performs FFT processing on the beat signal for each frequency increase period and frequency decrease period of the transmission signal and detects its frequency spectrum (S10). Then, the distance / velocity detecting means 14a pairs (associates) the peak signals that form the maximum value in the frequency increase period and the frequency decrease period with each other, and uses the respective frequencies to determine the relative distance and relative of the target object. The speed is calculated (S12). Further, the azimuth angle detection means 14b calculates the azimuth angle of the target object for each pairing result (S14).

  Then, the position detection unit 14c calculates the position of the target object from the azimuth angle and relative distance of the target object (S16). The calculated position is stored in the RAM in the signal processing device 14. Then, the position predicting unit 14d predicts the position in the new detection cycle from the detection position in the past detection cycle stored in the RAM (S18). Then, the position determination unit 14e confirms that the detection position in the new detection cycle is included in the allowable range (prediction region) of the predicted position, and determines the position as a detection result (S20).

  The stationary object determination unit 14f determines a stationary object among the target objects and excludes it from the output target (S22). Then, the signal processing device 14 uses the position, relative speed, and the like of the target object whose number of detection cycles at which the detected position has been determined has reached a predetermined number of times as data used for controlling the vehicle 1. Or it outputs to the other module of the vehicle control apparatus 100 (S24).

  Next, a position prediction method and a determination method in the present embodiment will be described.

  FIG. 7A is a plan view showing a scanning area of the radar apparatus 10, and every n (n = 1, 2, 3,...) Detection cycle on the XY coordinate plane with the radar apparatus as the origin O. Shows the detection position P_n and the prediction area A_n for each detection cycle.

  The position predicting unit 14d uses the X coordinate of the positions P1 and P2 as a locus from the detection position P_1 (x1, y1) to the second detection cycle detection position P_2 (x2, y2) in the first detection cycle of the same target object. And the position of the end point is predicted as a position fP_3 (x3 ′, y3 ′) in the third detection cycle. Here, the detection position is indicated by a black circle, and the predicted position is indicated by a white circle. Then, the allowable range ± xR of the predicted X coordinate “x3 ′” and the allowable range ± yR of the predicted Y coordinate “y3 ′” are set as a prediction region A_3 (illustrated by hatching). Here, the allowable ranges xR and yR are positive numbers that can be arbitrarily set.

  When the detection position in the third detection cycle is P3 (x3, y3), if the X and Y coordinates are within the prediction region A_3, the position P_3 (x3, y3) is detected in the third detection cycle. Confirm as

  Similarly, the radar apparatus determines the X coordinate difference value Δx23 and the Y coordinate difference value Δy23 from the detection position P_2 (x2, y2) in the second detection cycle and the detection position P_3 (x3, y3) in the third detection cycle. And the position fP_4 (x4 ′, y4 ′) in the fourth scan is predicted based on these. If the X and Y coordinate coordinates of the detection position P_4 (x4, y4) in the fourth scan are within the prediction area A_4, the position P_4 (x4, y4) is determined as the detection position in the fourth scan. Thereafter, the same processing is repeated.

  As described above, in this embodiment, not only the Y coordinate of the new position is predicted based on the difference value of the Y coordinate between the previous detection position and the previous detection position, but also the new position of the new position is determined based on the difference value of the X coordinate. Predict X coordinate. Then, a prediction area is set for the predicted X coordinate and Y coordinate, and the detected position is determined when the X and Y coordinates of the newly detected position are within the prediction area. By doing so, when scanning the scanning area on the front side of the vehicle, it is possible to accurately predict the position of the target object that moves along a trajectory that crosses the scanning area, in other words, the target object having a large X coordinate difference value. It can be carried out. That is, since the probability that the detection position is within the prediction region increases for each detection cycle, the position detection accuracy is improved.

  Further, even if the detection position deviates from the prediction area and estimation processing for estimating the predicted position (prediction position) as the detection position is performed, the trajectory crosses the scanning area in the X-axis direction. Therefore, in actuality, it is not erroneously detected that the target object crossing the scanning area approaches the host vehicle. Therefore, erroneous control of the vehicle due to erroneous detection can be prevented.

  In this embodiment, the difference between the X and Y coordinates per detection cycle of the target object is used as the moving speed in the X-axis direction and Y-axis direction of the position of the target object. When the object is decelerated, a target object that increases or decreases more than a certain degree of movement speed in the X-axis direction and the Y-axis direction is subjected to a stationary object determination process for determining a stationary object that is not a control target, such as a roadside installation. This is because the stationary object does not move by itself, and the change in the moving speed and the change in the speed of the own vehicle have a certain correlation.

  As a specific determination method, when a reference value is set for the amount of change in the movement speed in the X-axis direction and the Y-axis direction, and either change amount (or both change amounts may be set as the reference value) is greater than or equal to the reference value. In addition, the target object can be determined as a stationary object. In this case, as the reference value, an arbitrary value that can be regarded as a change in the moving speed of the target object due to a change in the speed of the host vehicle is used. For example, the reference value may be a uniform fixed value, or may be a value that dynamically changes in response to a change in the speed of the host vehicle, for example, a value that increases as the speed change of the host vehicle increases. Or, conversely, by setting the reference value to a very small value, it may be determined that the object is a stationary object when the amount of change occurs even a little.

  Further, the reference value may be a different value for each of the X-axis direction and the Y-axis direction, or may be the same value. When different values are used for the X-axis direction and the Y-axis direction, the difference value of the X coordinate is relative when scanning the front scanning area of the vehicle compared to scanning the scanning area ahead of the vehicle. Considering that the moving speed in the X-axis direction is relatively large, the reference value in the X-axis direction may be set to a value larger than the reference value in the Y-axis direction.

  By determining the stationary object in this way, the stationary object determination unit 14f can exclude a stationary object that does not originally move toward itself from being controlled. Therefore, the process of selecting the detection results output to the vehicle control device 100 can be made efficient. In particular, the throughput can be improved when a large number of target objects are detected.

  Furthermore, in order to improve the accuracy of the stationary object determination process, the following procedure may be used. That is, the stationary object determination unit 14f calculates the movement amount per detection cycle of the target object on the XY coordinate plane (for example, the movement amount from the position P_1 to P_2 in FIG. 7A) from the difference value between the X and Y coordinates. Ask. Then, using the movement amount of the target object as the movement speed, a movement amount change amount (for example, a change amount between the movement amount from the position P_1 to P_2 and the movement amount from the position P_2 to P_3) is obtained. Then, the target object in which the amount of change in the moving speed on the XY coordinate plane thus obtained matches the amount of change in the vehicle speed within a certain error range is determined as a stationary object, and the other objects are determined as moving objects. . This is because a stationary object such as a roadside object is observed to move relatively in parallel with the path of the host vehicle, so the amount of change in the movement speed in the direction of movement matches the amount of change in the host vehicle speed. By doing.

  Furthermore, in any of the above-described stationary object determination processes, a difference between the movement speed detected in the immediately preceding detection cycle and the movement speed detected in the new detection cycle may be detected as the movement speed change amount. Alternatively, the movement speed detected in a plurality of past detection cycles may be stored in time series, and the amount of change in movement speed may be obtained based on this. For example, a deviation from the average of a plurality of past movement speeds may be obtained as the amount of change, and a weighted average obtained by assigning a large weight to new movement speed data may be used as the average in that case.

  By the way, especially when the target object is a stationary object, the position prediction method described above obtains the prediction area based on the difference values of the X coordinate and Y coordinate in the previous detection cycle from the previous time, so that the host vehicle accelerates and decelerates. Thus, when the amount of movement on the XY coordinate plane changes, the possibility that the detection position of the target object deviates from the prediction region increases. Then, the opportunity to detect the amount of change in the moving speed of the target object is lost, and it cannot be determined as a stationary object.

  Therefore, in the present embodiment, the position predicting unit 14d corrects the predicted position of the target object when the host vehicle accelerates or decelerates so that the detected position falls within the predicted region. By doing so, the position of the stationary object can be detected with high accuracy. By doing so, the stationary object can be determined, and the stationary object can be excluded from the control target.

  Here, the correction of the predicted position will be described with reference to FIG. For example, when the host vehicle accelerates or decelerates when the position of the target object moves from position P_1 to P_4, the difference value Δx12 (X, Y coordinate difference from position P_1 (x1, y1) to position P_2 (x2, y2) = x2-x1), Δy12 (= y2-y1), and X, Y coordinate difference values Δx23 (= x3-x2), Δy23 (= From y3−y2), the change amount Δxd (= Δx12−Δx23) of the X coordinate difference value and the change amount Δyd (= Δy12−Δy23) of the Y coordinate difference value are obtained. When the X-coordinate difference value Δxd and the Y-coordinate difference value Δyd are each equal to or greater than a reference amount (a value that can be regarded as a change in the moving speed of the target object due to acceleration / deceleration of the vehicle speed), the position fP_4. Predict (x4 ′, y4 ′) as follows:

x4 ′ = x3 + Δx23 + Δxd
y4 ′ = y3 + Δy23 + Δyd
The position predicting unit 14d can reliably detect a stationary object whose movement speed changes with the acceleration / deceleration of the host vehicle speed by executing the above-described process for each detection cycle, and further determines that the stationary object is a stationary object. , Can be excluded from the control target. By doing so, the processing load of the vehicle control apparatus 100 of the vehicle 1 can be reduced.

  Furthermore, as a modification of the present embodiment, the position predicting unit 14d corrects the predicted position when the host vehicle turns. FIG. 8 shows the locus of the position of the stationary object and the X coordinate difference value when the vehicle 1 goes straight and turns left. When the vehicle 1 turns left, the difference value of the X coordinate of the stationary object is Since it becomes large, prediction can be performed more accurately by making the difference value of the X coordinate from the detection position to the prediction position larger than usual.

  Specifically, when the position predicting unit 14d detects that the own vehicle 1 turns with the change in the yaw rate exceeding a certain value, the position predicting unit 14d calculates the turning radius from the yaw rate and the own vehicle speed according to the following equation.

ω = V · T / C
Here, yaw rate: ω (radian / second), yaw rate detection cycle: T (second), and C: turning radius (meter).

  Then, the X and Y coordinates of the predicted position are corrected according to the turning radius. As an example, correction by multiplying the above Δxd by a coefficient obtained from a map as shown in FIG. 9 is possible.

  When the radar apparatus 10 scans the left front side region of the vehicle 1, the above procedure in which the left and right are reversed can be applied.

  FIG. 10 is a flowchart for explaining the operation procedure of the position predicting unit 14d that performs the above-described processing. This corresponds to the subroutine of step S18 shown in FIG.

  The position predicting unit 14d reads the previous detected position from the RAM (S32), and calculates the X and Y coordinate difference values two times before.

  When the change amount of the vehicle speed is equal to or greater than a reference value (an arbitrarily set value that can be regarded as a change in the vehicle speed) (YES in S36), the change amount of the difference value between the X and Y coordinates is also the reference value. If it is equal to or greater than the value (YES in S38), the position is predicted based on the amount of change in the difference value between the X and Y coordinates (S40), and the predicted position is stored in the RAM (S42). On the other hand, when the change amount of the vehicle speed is less than the reference value (NO in S36), or even when the change amount of the vehicle speed is greater than or equal to the reference value, the change amount of the difference value between the X and Y coordinates is less than the reference value (S38). NO), the position is predicted based on the difference value between the X and Y coordinates (S44), and the predicted position is stored in the RAM (S42).

  FIG. 11 is a flowchart for explaining the operation procedure of the position determining means 14e that performs the above-described processing. This corresponds to the subroutine of step S20 shown in FIG.

  The position determining unit 14e reads the predicted position from the RAM (S32), and calculates a predicted area having a predetermined allowable range (S52).

  When the detected position is within the prediction region (YES in S54), the detected position is determined (S56), and the detected position is stored in the RAM (S58). On the other hand, when the detected position is not within the predicted region (NO in S54), the predicted position is estimated as the detected position (S56), and the estimated detected position is stored in the RAM (S58).

  FIG. 12 is a flowchart showing an operation procedure of the stationary object determination unit 14f that performs the above-described processing. This corresponds to the procedure of the subroutine of step S22 shown in FIG. The stationary object determination unit 14f is when the change amount of the vehicle speed is equal to or greater than the reference value (YES in S70), and further, when the change amount of the difference value between the X and Y coordinates is equal to or greater than the reference value (YES in S72). Determines that the target object is a stationary object (S74). On the other hand, when the change amount of the vehicle speed is less than the reference value (NO in S70), or even when the change amount of the vehicle speed is greater than or equal to the reference value, the change amount of the difference value between the X and Y coordinates is less than the reference value (S72). NO)), the target object is determined as a moving object (S76).

  In the above description, an example of the radar apparatus 10 that scans the scanning area on the front side of the vehicle is shown. However, in the present embodiment, the radar apparatus that scans the scanning area on the rear side (including both the left and right sides) of the vehicle. It can also be applied to. In this case, the moving object corresponds to the following vehicle or a pedestrian, and the stationary object corresponds to the roadside installation object or the installation object behind when moving backward in the parking lot. The radar device is a succeeding vehicle that follows the host vehicle when the host vehicle moves forward, a vehicle that travels in an adjacent lane, or a person (pedestrian) that is located rearward when the host vehicle moves backward in a parking lot or the like. And the installation object are detected and output to the vehicle control device 100. The vehicle control device 100 executes collision response / avoidance control when the probability of collision or collision of these target objects is large.

  As described above, according to the present embodiment, when the radar apparatus scans the scanning area including the area on the side of the vehicle, the difference between the X-coordinate and the Y-coordinate between the previous detection position and the previous detection position is set. Since the X and Y coordinates of the new position are predicted based on this, the position of the target object having a large X coordinate difference value can be accurately predicted. That is, since the probability that the detection position is within the prediction region increases for each detection cycle, the position detection accuracy is improved.

  Further, when the host vehicle accelerates or decelerates, the predicted position of the target object is corrected so that the detected position falls within the predicted area. By doing so, the position of the stationary object can be detected with high accuracy. Therefore, the stationary object can be determined, and the stationary object can be excluded from the control target.

It is a figure which shows the relationship between the prediction area | region for every detection cycle of the radar apparatus for front monitoring, and the detected position. It is a figure explaining the use condition of the radar apparatus with which this invention is applied. It is a figure explaining the position of the target object which radar device 10 detects. It is a figure explaining the structure of the radar apparatus in this embodiment. It is a figure which shows the structural example of the control system of the vehicle 1 to which the radar apparatus 10 is applied. FIG. 5 is a flowchart for explaining an operation procedure of the signal processing device 14. It is a figure which shows the relationship between the prediction area | region for every detection cycle of the radar apparatus for front side monitoring, and the detected position. It is a figure which shows the difference value of the X coordinate of a stationary object when a vehicle turns. It is a figure which shows the example of the coefficient which multiplies (DELTA) xd according to a turning radius. It is a flowchart figure explaining the operation | movement procedure of the position estimation means 14d. It is a flowchart explaining the operation | movement procedure of the position determination means 14e. It is a flowchart figure which shows the operation | movement procedure of the stationary-object determination means 14f.

Explanation of symbols

  10: radar device, 14: signal processing device, 14c: position detection means, 14d: position prediction means, 14e: position determination means, 30: radar transceiver

Claims (5)

A signal processing device for a radar transceiver that is mounted on a vehicle and scans a scanning region including a region on the side of the vehicle,
Position detecting means for detecting the X and Y coordinates of the position of the target object in the scanning region when the front side of the vehicle is the Y axis and the direction intersecting the Y axis is the X axis;
Position prediction means for predicting the X and Y coordinates of the position of the target object based on the X coordinate difference value and the Y coordinate difference value per detection cycle of the position of the target object detected in the past detection cycle;
A signal processing apparatus comprising: position determining means for determining the detected position when the X and Y coordinates of the detected position are included in an allowable range of each of the predicted predicted X and Y coordinates. In claim 1,
The position prediction means predicts the position of the target object based on the amount of change in the X coordinate difference value and the Y coordinate difference value when the speed of the vehicle changes. In claim 2,
When the speed of the vehicle changes, when one or both of the X coordinate difference value and the Y coordinate difference value of the target object change by a reference value corresponding to the amount of change in the speed of the vehicle, the target object is A signal processing apparatus, further comprising a stationary object determination unit configured to determine a stationary object. In claim 1,
The signal processing apparatus according to claim 1, wherein the position predicting unit corrects the predicted position based on a turning radius of the vehicle. A radar apparatus comprising the radar transceiver according to any one of claims 1 to 4 and a signal processing apparatus.

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