JP4730832B2 - In-vehicle radar system - Google Patents

Description

  The present invention relates to an on-vehicle radar device that detects an object around a host vehicle.

Conventionally, an in-vehicle radar device that detects an object around the host vehicle is known (for example, Patent Document 1).
JP 2005-9881 A

Now, in a vehicle-mounted radar device that detects an object around the host vehicle, when using a wide-angle radar device with relatively low detection accuracy in the angular direction, the object position detection accuracy should be improved as follows. Can be considered.
That is, as shown in FIG. 5a, two radar devices A and B are mounted on a vehicle. When the object position PA that is a distance DA away from the radar apparatus A is detected by the radar apparatus A, and the object position PB that is a distance DB away from the radar apparatus B is detected by the radar apparatus B in the vicinity of the position PA. Then, the intersection point Q between the arc having the radius DA centered on the radar device A and the arc having the radius DB centered on the radar device B is detected as the true position of the object.

However, when this is done, as shown in FIG. 5b, for other vehicles that exist in front of the two radar devices A and B and whose direction of the line connecting the two radar devices A and B is parallel to the front-rear direction, In some cases, the correct position cannot be detected.
That is, the direction of the line connecting the two radar devices A and B is the x direction, the direction perpendicular to the x direction is the y direction, and the x direction of the radar device A or the radar device B is within the x direction existence range of the other vehicle. When the position is included, the positions PA and PB on the side surface of the other vehicle closest to the radar apparatus are detected by the radar apparatuses A and B. Therefore, according to the calculation method shown in FIG. As the position of the other vehicle, a position Q having a y-direction position shifted by a distance dE from the true y-direction position of the other vehicle is calculated.

Therefore, the detection accuracy of the object position cannot be improved sufficiently only by the method as shown in FIG. 5a.
Therefore, an object of the present invention is to further improve the accuracy of object position detection in an in-vehicle radar device that detects an object around the host vehicle using two radar devices.

  In order to achieve the above object, the present invention provides an on-vehicle radar device mounted on an automobile, wherein a first radar antenna and a first radar that repeatedly performs radar positioning of an object around the vehicle using the first radar antenna. Measurement means, a second radar antenna, second radar measurement means for repeatedly positioning an object around the vehicle using the second radar antenna, and the first radar measurement means measured by the radar positioning. A position calculation unit configured to repeatedly perform a position calculation process for calculating the position of the object based on the measurement value and the measurement value measured by the second radar measurement unit by the radar positioning; In each of the position calculation processes, a first relative distance that is a relative distance of the object measured by the radar positioning by the first radar measurement means, and a second laser When at least one of the second relative distance, which is the relative distance of the object measured by the radar positioning by the measuring means, has not changed with the passage of time, the relative position of the object at the horizontal and first radar As the coordinate in the direction perpendicular to the line connecting the antenna and the second radar antenna, the same coordinate as the coordinate in the perpendicular direction of the relative position of the object calculated previously is calculated.

  Here, when the relative distance measured by the radar positioning using a certain radar antenna does not change, the radar positioning is translated in a direction parallel to the line connecting the first radar antenna and the second radar antenna. It is considered that the position on the side of the object to be captured is captured. Therefore, in such a case, the same coordinates as the coordinates of the relative direction of the object calculated in the previous time are set as the coordinates of the object in the vertical direction. Thus, it is possible to detect an appropriate relative position without causing an error as shown in FIG.

  By the way, in such an on-vehicle radar device, when only the first relative distance does not change with the passage of time in each time of the position calculation processing in the position calculation means, the relative position of the object is As a coordinate in a direction parallel to a line connecting the first radar antenna and the second radar antenna, a coordinate in the vertical direction on an arc centered on the second antenna having a radius of the second relative distance is It is also preferable to calculate the coordinate in the parallel direction at a position that is the same as the coordinate in the vertical direction of the relative position of the object calculated last time.

  By doing in this way, the position that also matches the second relative distance measured by the second radar measurement means by the radar positioning can be calculated as the relative position of the object. Thus, the relative position of the object can be calculated more appropriately.

  Further, in each of the above-described in-vehicle radar devices, when both the first relative distance and the second relative distance change with the passage of time, both the radar measurement means and the first radar antenna It is considered that the side surface of the object moving in parallel with the line connecting the second radar antennas is not captured. Therefore, in such a case, in the position calculating means, as shown in FIG. 5a, the arc having the radius of the first relative distance centered on the first radar antenna, and the second It is preferable to calculate an intersection point with an arc whose radius is the second relative distance centered on the radar antenna as the relative position of the object.

  Each of the above-described on-vehicle radar devices has the above-described position calculation means in which each of the first relative distance and the second relative distance does not change with time in each time of the position calculation processing. The relative position of the object measured by the first radar measurement means by the radar positioning as the coordinate in the direction parallel to the line connecting the first radar antenna and the second radar antenna. You may make it calculate the coordinate of the said parallel direction of the midpoint of a 1st relative position and the 2nd relative position which is a relative position of the said object which the 2nd radar measurement means measured by the said radar positioning.

  As described above, according to the present invention, the accuracy of object position detection can be further improved in an in-vehicle radar device that detects an object around the host vehicle using two radar devices.

Hereinafter, embodiments of the present invention will be described.
FIG. 1 a shows the configuration of the in-vehicle radar device according to the present embodiment.
This in-vehicle radar device is a device mounted on an automobile. As shown in the figure, a right radar positioning unit 11, a left radar positioning unit 12, a rear radar positioning unit 13, a right target position calculating unit 21, a left side The target position calculating unit 22, the rear target position calculating unit 23, the surrounding situation display unit 3, and the display device 4 are configured. Further, the right radar positioning unit 11, the left radar positioning unit 12, and the rear radar positioning unit 13 have the same configuration, and each include two radar positioning units 100.

  Each radar positioning unit 100 drives the antenna 101 via the antenna 101, the transmitter / receiver 102, and the transmitter / receiver 102, and periodically scans a target (such as another vehicle) existing in the scan range. The radar measurement signal processing unit 103 outputs the relative distance, the relative direction, and the relative velocity of each target detected by the scan as measurement data for each scan.

  Here, as shown in FIG. 1b, the antennas A and B of the two radar positioning units 100 of the two radar positioning units 100 of the right radar positioning unit 11 are arranged side by side on the right side of the vehicle. The two radar positioning units 100 of the right-side radar positioning unit 11 output the relative distance, the relative direction, and the relative speed of an object existing in the scan range as measurement data with the right side of the own vehicle as the scan range. The antennas C and D of the two radar positioning units 100 of the two radar positioning units 100 of the left radar positioning unit 12 are arranged side by side on the left side of the vehicle. The two radar positioning units 100 output the relative distance, the relative direction, and the relative speed of an object existing in the scan range as measurement data, with the left side of the vehicle as the scan range. The antennas C and D of the two radar positioning units 100 of the two radar positioning units 100 of the rear radar positioning unit 13 are arranged side by side on the rear surface of the vehicle, and the two radars of the rear radar positioning unit 13 are arranged. The positioning unit 100 outputs the relative distance, relative direction, and relative speed of an object existing in the scan range as measurement data, with the rear of the host vehicle as the scan range.

  Next, the right target position calculation unit 21 calculates the position of the object on the right side of the vehicle based on the measurement data output from the two radar positioning units 100 of the right radar positioning unit 11, and the left side. The target position calculation unit 22 calculates the position of the object on the left side of the host vehicle based on the measurement data output from the two radar positioning units 100 of the left radar positioning unit 12, and the rear target position calculation unit 23. Calculates the position of the object behind the host vehicle based on the measurement data output from the two radar positioning units 100 of the rear radar positioning unit 13.

  And the surrounding situation display part 3 is based on the position of the object on the left and right of the own vehicle calculated by the right target position calculating part 21, the left target position calculating part 22, and the rear target position calculating part 23. The display device 4 performs processing for displaying information indicating the presence of other vehicles around the host vehicle and other various situations around the host vehicle.

Hereinafter, in such a configuration, the right target position calculation unit 21, the left target position calculation unit 22, and the rear target position calculation unit 23 calculate the above-described object position by the same target position calculation operation. I do.
Hereinafter, this target position calculation operation will be described by taking the target position calculation operation of the right target position calculation unit 21 as an example.
In the following, for the sake of convenience, of the two radar positioning units 100 of the right radar positioning unit 11, the radar positioning unit 100 having the antenna A of FIG. The positioning unit B will be described.
The right target position calculation unit 21 performs target tracking processing and target position calculation processing.
First, in the target tracking processing, measurement data (relative distance, relative direction, and relative speed) for each object within the scan range output by the radar positioning unit A at each scan, and the radar positioning unit B output at each scan. The measurement data for each object within the scan range to be processed is processed for each object. That is, for example, one measurement data GA (n) output by the radar positioning unit A at a certain scan time n, and measurement data GA (n) output by the radar positioning unit A at the next scan time n + 1. One measurement data GA (n + 1) whose contents approximate to n) is measurement data measured for the same object, and the measurement data GA (n + 1) belongs to the measurement data GA (n). The measurement data is the (n + 1) th measurement data in the series. Similarly, one measurement data GB (n) output from the radar positioning unit B at a certain scan time n and measurement data GB output from the radar positioning unit B at the next scan time n + 1. One measurement data GB (n + 1) whose content approximates to (n) is measurement data measured for the same object, and the measurement data GB (n + 1) is the measurement data GB (n). The measurement data is the (n + 1) th measurement data in the affiliated series.

  Further, in this target tracking processing, one series of measurement data generated as described above and output from the radar positioning unit A, and a measurement output from the radar positioning unit B whose contents are approximate to the one series. A process for managing one series of data as a series of measurement data of the same object is also performed. That is, in the target tracking process, measurement data output from the radar positioning unit A and the radar positioning unit B in each scan for each object is managed.

Next, the target position calculation process performed by the right target position calculation unit 21 will be described.
In the target position calculation process, the position calculation process shown in FIG. 2 is performed for each scan with each object whose series is managed in the target tracking process as the target.
However, in the following, the direction of the line connecting the antenna A of the radar positioning unit A and the antenna B of the radar positioning unit B is the x direction, and the direction perpendicular to the x direction is the y direction.
As shown in FIG. 2, in this position calculation process, first, the relative distance DA of the target measured by the radar positioning unit A and the relative measurement of the target measured by the radar positioning unit B in the current scan. The distance DA is acquired (step 202).
Then, the acquired relative distance DA of the target measured by the radar positioning unit A changes by a predetermined level or more from the relative distance of the target measured by the radar positioning unit A in the previous scan. Whether the acquired relative distance DB of the target measured by the radar positioning unit B has changed by a predetermined level or more from the relative distance of the target measured by the radar positioning unit B during the previous scan. A check is made (step 204). Here, the predetermined level is a level at which the relative distance can be regarded as substantially unchanged if the change is within the predetermined level.

  If both the acquired relative distances DA and DB have changed from the previous time (step 204), as shown in FIG. 5a, the radar positioning unit A is centered on the antenna A of the radar positioning unit A. The relative distance DB of the target measured by the radar positioning unit B in this scan is centered on the arc having the radius of the relative distance DA of the target measured in the current scan and the antenna B of the radar positioning unit B. The intersection with the arc as the radius is calculated as the relative position of the target (step 214), and the current position calculation process for the target is terminated.

On the other hand, if any of the acquired relative distances has changed from the previous time (step 204), the y-direction relative coordinate y (-1) of the relative position calculated for the target is obtained in the previous scan. This time, it calculates as the y direction relative coordinate of the target object (step 206).
Next, the relative distance DA of the target measured by the radar positioning unit A acquired in step 202 is greater than or equal to a predetermined level from the relative distance of the target measured by the radar positioning unit A in the previous scan. The relative distance DB of the target measured by the radar positioning unit B that has not been changed is greater than or equal to a predetermined level from the relative distance of the target measured by the radar positioning unit B during the previous scan. It is checked whether or not it has changed (step 208).

  If both of the acquired relative distances DA and DB have not changed from the previous time, the x-direction coordinate of the relative position PA of the target measured by the radar positioning unit A this time and the target measured by the current radar positioning unit B The x-direction coordinate of the position corresponding to the midpoint of the relative position PB of the target relative to the x-direction coordinate is calculated as the current target x-direction relative coordinate (step 216). And the position calculation process about this target object this time is complete | finished. The relative position PA is obtained from the relative distance and relative direction indicated by the measurement data of the target measured by the radar positioning unit A this time, and the relative position PB is the target measured by the radar positioning unit B this time. It is obtained from the relative distance and relative direction indicated by the measurement data.

  On the other hand, if it is determined in step 208 that either of the acquired relative distances DA and DB has changed from the previous time, the relative distance DA of the target measured by the radar positioning unit A acquired in step 202 is determined. In the previous scan, it is checked whether or not the relative distance of the target measured by the radar positioning unit A has changed by a predetermined level or more (step 210). If it has changed, y = y (- The x-direction coordinate of the intersection of the straight line satisfying 1) and the arc whose radius is the relative distance DA acquired in step 202 centered on the antenna A is calculated as the x-direction relative coordinate of the target object this time ( Step 212). However, y (−1) is a relative coordinate in the y direction of the relative position calculated for the target in the previous scan as described above. When there are two intersections, the x direction closer to the x direction coordinate of the relative position PB of the target measured by the radar positioning unit B in the current scan among the x direction coordinates of the two intersections. The coordinates are calculated as relative coordinates in the x direction of the target object this time. And the position calculation process about this target object this time is complete | finished.

  In step 210, the relative distance of the target measured by the radar positioning unit A acquired in step 202 changes by a predetermined level or more from the relative distance of the target measured by the radar positioning unit A in the previous scan. In other words, the relative distance DB of the target measured by the radar positioning unit B acquired in step 202 is the relative distance of the target measured by the radar positioning unit B during the previous scan. When the distance has changed by a predetermined level or more, x at the intersection of a straight line satisfying y = y (−1) and an arc whose radius is the relative distance DB acquired in step 202 centered on the antenna B. The direction coordinates are calculated as the x-direction relative coordinates of the target object this time (step 218). However, y (-1) is the y-direction relative coordinate of the relative position calculated for the target in the previous scan. If there are two intersections, the x-direction coordinate closer to the x-direction coordinate of the relative position PA of the target measured by the radar positioning unit A in the current scan among the x-direction coordinates of the two intersections. The coordinates are calculated as relative coordinates in the x direction of the target object this time. And the position calculation process about this target object this time is complete | finished.

The target position calculation process performed by the right target position calculation unit 21 has been described above.
Here, a processing example of the target position calculation processing as described above will be shown.
Now, as shown in FIG. 3a, the direction of the line connecting the antenna A of the radar positioning unit A and the antenna B of the radar positioning unit B is the x direction, and the direction perpendicular to the x direction is the y direction. As shown by broken lines in the figure, the leading positions of other vehicles at times T1, T2, T3, T4, and T5 are translated with respect to the antenna A and the antenna B with the x direction in the −x direction and the front and rear direction. Shall.

  In this case, the radar positioning unit B including the antenna B measures the measurement data of the position of the left front end of the other vehicle from time T1 to T2, and the position closest to the antenna B on the left side surface of the other vehicle from time T2 to T4. The measurement data of the left rear end of the other vehicle is measured from time T4 to T5. Here, time T2 is the time when the left front end of the other vehicle has reached a position straight ahead in the y direction from the antenna B, and time T4 is the time when the left rear end of the other vehicle goes straight from the antenna B in the y direction. It is the time when it reached the position.

  In the figure, P1 is a relative position measured by the radar positioning unit B at time T1, P2-4 is a relative position measured by the radar positioning unit B from time T1 to T4, and P5 is measured by the radar positioning unit B at time T5. Relative position. In the figure, D1 is a relative distance measured by the radar positioning unit B at time T1, D2-4 is a relative distance measured by the radar positioning unit B from time T1 to T4, and D5 is measured by the radar positioning unit B at time T5. Relative distance.

Therefore, the relative distance of the other vehicle measured by the radar positioning unit B including the antenna B decreases between the times T1 and T2 and does not change between the times T2 and T4 as shown in FIG. It increases between T4 and T5.
As shown in FIG. 3b, the relative position of the other vehicle measured by the radar positioning unit B including the antenna B is in a period in which an arbitrary position on the side surface of the other vehicle is in a position straight from the antenna B in the y direction. The distance and relative position do not change.
The same applies to the relative distance and relative position of the other vehicle measured by the radar positioning unit A including the antenna A at a position shifted from the antenna B in the x direction. The relative distance and the relative position of the other vehicle measured by the radar positioning unit A including the antenna A do not change during the period in which the vehicle is in a position straight ahead in the y direction.

Therefore, according to the position calculation process described above, the relative position Q of the other vehicle that translates in the -x direction with the x direction as the front-rear direction is calculated as shown in FIG.
That is, as shown in FIG. 4a, when the x direction range of the other vehicle is on the + x direction side of both the antenna A and the antenna B, the radar positioning B also measures the relative distance DA measured by the radar positioning unit A. Since the relative distance DB also changes with time (step 204), in step 214, the arc centered on the antenna A having the radius of the relative distance DA measured by the radar positioning unit A and the relative measured by the radar positioning unit B. The intersection point with the arc centered on the antenna B having the distance DB as the radius is calculated as the relative position Q of the other vehicle.

  Also, as shown in FIG. 4b, the x direction range of the other vehicle is on the + x direction side of the antenna A, but when the x direction position of the antenna B is included in the x direction range of the other vehicle, Although the relative distance DA measured by the radar positioning unit A changes with time, the relative distance DB measured by the radar positioning B does not change with time (steps 204 and 210). The direction coordinate y (-1) is calculated as the y-direction coordinate of the relative position Q of the other vehicle (step 206). The relative position measured by the radar positioning unit B at the intersection of the straight line y = y (-1) and the arc centered on the antenna A having the radius of the relative distance DA measured by the radar positioning unit A. The x direction coordinate of the intersection closer to PB is calculated as the x direction coordinate of the relative position Q of the other vehicle (step 212).

  Next, as shown in FIG. 4c, when the x direction position of the antenna A and the x direction position of the antenna B are included in the x direction range of the other vehicle, the relative distance DA measured by the radar positioning A is also measured by the radar positioning. Since the relative distance DB measured by the part B also does not change with time (steps 206 and 208), the y-direction coordinate y (-1) of the relative position previously calculated for the other vehicle is the y-direction coordinate of the relative position Q of the other vehicle. (Step 206). Further, the x-direction coordinate of the midpoint between the x-direction coordinate of the relative position PA measured by the radar positioning unit A and the x-direction coordinate of the relative position PB measured by the radar positioning unit B is the x-direction coordinate of the relative position Q of the other vehicle. (Step 216).

  In addition, as shown in FIG. 4d, the x direction range of the other vehicle is on the −x direction side of the antenna B, but when the x direction position of the antenna A is included in the x direction range of the other vehicle, Although the relative distance DB measured by the radar positioning unit B changes with time, the relative distance DA measured by the radar positioning A does not change with time (steps 204 and 210). The coordinate y (-1) is calculated as the y-direction coordinate of the relative position Q of the other vehicle (step 206). The relative position measured by the radar positioning unit A among the intersections of the straight line y = y (-1) and the arc centered on the antenna B having the radius of the relative distance DB measured by the radar positioning unit B. The x-direction coordinate of the intersection closer to PA is calculated as the x-direction coordinate of the relative position Q of the other vehicle (step 218).

  As shown in FIG. 4e, when the x direction range of the other vehicle is on the −x direction side of both the antenna A and the antenna B, the radar positioning B also measures the relative distance DA measured by the radar positioning unit A. Since the relative distance DB also changes with time (step 204), in step 214, the arc centered on the antenna A having the radius of the relative distance DA measured by the radar positioning unit A and the relative measured by the radar positioning unit B. The intersection point with the arc centered on the antenna B having the distance DB as the radius is calculated as the relative position Q of the other vehicle.

  As described above, as shown in FIG. 4, according to the present embodiment, the other vehicle that exists in front of the two antennas A and B and in which the direction of the line connecting the two antennas A and B is parallel to the front-rear direction is also used. The position in the direction perpendicular to the direction of the line connecting the two antennas A and B can be detected correctly.

It is a block diagram which shows the structure of the vehicle-mounted radar apparatus which concerns on embodiment of this invention. It is a flowchart which shows the position calculation process which concerns on embodiment of this invention. It is a figure which shows the process example of the position calculation process which concerns on embodiment of this invention. It is a figure which shows the process example of the position calculation process which concerns on embodiment of this invention. It is a figure which shows the example of calculation of the object position using two radar apparatuses.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 3 ... Peripheral condition display part, 4 ... Display apparatus, 11 ... Right radar positioning unit, 12 ... Left radar positioning unit, 13 ... Back radar positioning unit, 21 ... Right target position calculation part, 22 ... Left object A target position calculation unit, 23 ... a rear target position calculation unit, 100 ... a radar positioning unit, 101 ... an antenna, 102 ... a transceiver, 103 ... a radar measurement signal processing unit.

Claims (4)

An on-vehicle radar device mounted on an automobile,
A first radar antenna;
First radar measurement means for repeatedly positioning an object around the host vehicle using the first radar antenna;
A second radar antenna;
Second radar measuring means for repeatedly positioning an object around the vehicle using the second radar antenna;
The first radar measuring means is the radar measurement value measured by the positioning and the second radar measuring means based on a measured value measured by the radar positioning, position calculation performed repeatedly position calculation processing to calculate the position of the object Means,
The position calculating means, at each time of the position calculating process ,
A first relative distance that is a relative distance of the object measured by the first radar measurement means by the radar positioning; and a second relative distance that is a relative distance of the object measured by the second radar measurement means by the radar positioning; When at least one of the above has not changed over time, the previous position is calculated as a coordinate of the relative position of the object in the direction perpendicular to the horizontal line connecting the first radar antenna and the second radar antenna. Calculate the same coordinates as the vertical direction coordinates of the relative position of the object ,
When both the first relative distance and the second relative distance change over time, an arc whose radius is the first relative distance centered on the first radar antenna; An in-vehicle radar device characterized in that an intersection point with an arc having a radius of the second relative distance centered on a second radar antenna is calculated as a relative position of the object . The on-vehicle radar device according to claim 1,
The position calculating means is configured to detect the first radar antenna and the second radar of the relative position of the object when only the first relative distance does not change with time in each position calculation process. As the coordinates in the direction parallel to the line connecting the antennas, the coordinates in the vertical direction on the arc centered on the second antenna with the second relative distance as the radius are the relative positions of the objects previously calculated. An in-vehicle radar device characterized by calculating coordinates in the parallel direction at a position that is the same as a coordinate in a vertical direction. The on-vehicle radar device according to claim 1 or 2,
The position calculation means is configured to determine the first position of the relative position of the object when both the first relative distance and the second relative distance have not changed with time in each of the position calculation processes. A first relative position, which is a relative position of the object measured by the first radar measurement means by the radar positioning, as coordinates in a direction parallel to a line connecting the radar antenna and the second radar antenna, and a second radar measurement An in-vehicle radar device characterized in that the means calculates a coordinate in the parallel direction of a midpoint with respect to a second relative position which is a relative position of the object measured by the radar positioning. In an in-vehicle radar device mounted on an automobile, an object position calculation method for calculating the position of an object around the own vehicle,
A positioning step of repeatedly positioning an object around the vehicle using the first radar antenna and repeatedly positioning an object around the vehicle using the second radar antenna;
The position calculation process is repeatedly performed, and at each time of the position calculation process, based on the measurement value measured by the radar positioning using the first radar antenna and the measurement value measured by the radar positioning using the second radar antenna. And a position calculating step for calculating the position of the object,
In each time of the position calculation process performed in the position calculation step,
A first relative distance that is a relative distance of the object measured by radar positioning using the first radar antenna and a second relative distance that is a relative distance of the object measured by radar positioning using the second radar antenna. When at least one of the above has not changed with the passage of time, the previous calculation is performed as the coordinate of the relative position of the object in the direction perpendicular to the horizontal line connecting the first radar antenna and the second radar antenna. Calculating the same coordinate as the coordinate in the vertical direction of the relative position of the object,
When both the first relative distance and the second relative distance change over time, an arc whose radius is the first relative distance centered on the first radar antenna; An object position calculating method in an in-vehicle radar device, wherein an intersection point with an arc having a radius of the second relative distance centered on a second radar antenna is calculated as a relative position of the object.