JP2007333616A - Radar measurement system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a "radar measurement system" that accurately calculates relative velocity vector of a moving body by using a radar device. <P>SOLUTION: When a relative position PL measured by a left radar device 1 and a relative position PR measured by a right radar device 2 come close to a predetermined level or more, both of the relative positions are regarded as measured relative positions of a same point. A near and far direction relative vector of PL is defined as uL, and a near and far direction relative vector of PR is defined as uR (a) here. Straight line LBL vertical to uL and passing through a position proceeding from PL by uL and straight line LBR vertical to uR and passing through a position proceeding from PR by uR are obtained. Point QL on the straight line LBL and point QR on the straight line LBR are obtained to make position vector of the point QR in a view from the point QL and position vector ΔP of PR in a view from PL equal. Velocity vector u proceeding from PL to QL in a unit time is defined as relative velocity vector of a point where PL and PR are measured. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a technique for measuring a moving body using a radar apparatus.

  According to the measurement using the radar apparatus, the velocity component of the object in the direction closer to the radar apparatus can be obtained by measuring the Doppler shift amount generated in the reflected wave of the object. However, in the measurement using the radar device, the velocity component of the object in the direction perpendicular to the straight line connecting the object and the radar device cannot be measured, and therefore the relative velocity vector of the object with respect to the radar device cannot be obtained.

Therefore, conventionally, a relative velocity vector of the moving body is calculated from changes in a plurality of position vectors estimated at the different time points using the radar device and measured for the same moving body ( For example, Patent Document 1).
JP 2000-147107 A

  According to the technique of Patent Literature 1, which position vector measured by the radar apparatus at a certain time point and which position vector among position vectors measured by the radar apparatus in the past are the positions of the same moving object at different time points. However, it is relatively difficult to perform such estimation with few errors at least between position vectors measured at a time that is greatly separated by at least one scanning period of the radar apparatus. .

  Further, according to the technique of Patent Document 1, the calculated relative velocity vector represents an average of the relative velocity vectors during a period in which a plurality of position vectors used for calculating the relative velocity vector are measured. It does not directly represent the relative velocity vector at the time.

Therefore, according to the technique of Patent Document 1, the relative velocity vector cannot be calculated with sufficient accuracy.
Therefore, an object of the present invention is to accurately calculate a relative velocity vector of a moving object using a radar apparatus.

   In order to achieve the above object, the present invention detects a radar measurement system that measures the relative velocity vector of an object using a radar by detecting a point on the object existing within a set scanning range as a detection point. A first radar device that measures a position vector of a detection point and a perspective relative velocity vector that represents the magnitude and direction of the relative velocity in the perspective direction with respect to itself; and the first radar device that is spaced apart from the first radar device, A point on an object existing within the set scanning range in which a scanning range that overlaps the scanning range of the first radar apparatus is detected as a detection point, and the position vector of the detected detection point and the perspective direction with respect to itself A second radar device that measures a perspective relative velocity vector representing the magnitude and direction of the relative velocity, and a position indicated by the measured position vector are close to each other by a predetermined level or more. The first detection point detected by the first radar device and the second detection point detected by the second radar device are extracted as two detection points corresponding to a single point on the object, A component in the direction equal to the direction of the perspective relative velocity vector measured by the first radar device having the same magnitude as the perspective relative velocity vector measured by the first radar device at the first detection point. And the direction of the perspective relative velocity vector measured by the second radar device is equal to the magnitude of the perspective relative velocity vector measured by the second radar device at the second detection point. A relative velocity vector for calculating a relative velocity vector having a direction component as a relative velocity vector of a single point on the object corresponding to the first detection point and the second detection point. Including calculating means and the relative velocity vector calculating means is obtained by configuration.

  As described above, in the radar measurement system according to the present invention, the two radar devices are used to measure the overlapping scanning ranges, and among the detection points measured by the two radar devices, the position vector is If the indicated position is closer than a predetermined level, these detection points are considered to correspond to the same single point on the same object. And about these detection points, each long-distance direction relative velocity vector measured by each radar apparatus represents the component of the same direction as the long-distance direction relative velocity vector of the relative velocity vector of the said point. Then, a single relative velocity vector on the object corresponding to these detection points is obtained.

  That is, according to the radar measurement system of the present invention, the measurement required for calculating the relative velocity vector at a certain point is a measurement for each of the points of the two radar devices. And such a measurement can be completed in a short time rather than measuring the said point in multiple times with a single radar apparatus. Therefore, detection points detected for the same point by the two radar apparatuses can be extracted with few errors, and a more instantaneous relative velocity vector can be measured. Therefore, according to the present radar measurement system, the relative velocity vector of the moving object can be calculated with higher accuracy using the radar device.

  Here, such a radar measurement system may be mounted on an automobile. In this case, the first radar apparatus and the second radar apparatus calculate a horizontal relative velocity vector with respect to the own vehicle. In order to be able to do so, it is arranged at least horizontally on the vehicle.

  As described above, according to the present invention, it is possible to accurately calculate the relative velocity vector of the moving object using the radar apparatus.

Hereinafter, an embodiment of the present invention will be described taking application to an on-vehicle periphery monitoring system mounted on an automobile as an example.
FIG. 1 a shows the configuration of an on-vehicle periphery monitoring system according to this embodiment.
As shown in the figure, the on-vehicle periphery monitoring system includes a left radar device 1, a right radar device 2, a target measurement unit 3, a target tracking unit 4, a peripheral object characteristic detection unit 5, a peripheral state presentation unit 6, a display device 7, A warning output device 8 is included.
Further, the left radar device 1 and the right radar device 2 have the same configuration, and are configured by an antenna 11, a transceiver 12, and a radar measurement signal processing unit 13, respectively. Then, the radar measurement signal processing unit 13 drives the antenna 11 via the transmitter / receiver 12 to detect an object existing within a predetermined scan range, and a relative position indicating a relative position of each detected object with respect to the antenna 11. A scan of a vector and a perspective relative velocity vector representing the magnitude and direction of the relative velocity in the perspective direction of each detected object with respect to the antenna 11 is measured and output to the target measurement unit 3 as measurement data is repeatedly performed.

  Here, as shown in FIG. 1b, the left radar device 1 and the right radar device 2 are arranged at the rear of the vehicle so as to be separated in the left-right direction. That is, the left radar device 1 is disposed on the left side of the rear part of the vehicle, and detects an object within the scan range with the rear of the vehicle as the scan range. The right radar apparatus 2 is disposed on the right side of the rear part of the vehicle, and detects an object within the scan range with the rear of the vehicle as the scan range. Note that the scanning periods of the left radar device 1 and the right radar device 2 are the same.

  Next, the target measurement unit 3 performs a target measurement process described later each time one scan of the right radar device 2 is completed, and converts the measurement data output from the left radar device 1 and the right radar device 2 into measurement data. Based on this, the position vector, perspective direction relative speed vector, and relative speed vector of the object existing behind the host vehicle are calculated. Then, for each object existing behind the host vehicle, target measurement data including the position vector calculated for the object, the perspective relative velocity vector, and the relative velocity vector is generated and output to the target tracking unit 4. .

  And the target tracking part 4 tracks each object which exists behind the own vehicle based on each target measurement data output from the target measurement part 3, and for each tracking object which is an object being tracked In addition, the target tracking process for generating and managing tracking information is repeated. Here, tracking of an object is a process of grouping target measurement data calculated at each time point as time-series measurement data of the object for each object for which the target measurement data is calculated. Further, the tracking information of a certain tracking object refers to the time-series target measurement data of the tracking object that are serialized in this way.

In the target tracking process, for example, an object is tracked as follows.
That is, among the target measurement data, the current position vector of the tracking target object estimated from the past target measurement data of the tracking target object, the perspective direction relative velocity vector, the position vector approximate to the relative velocity vector, When target measurement data indicating a perspective relative velocity vector or a relative velocity vector exists, the target measurement data is added to the tracking information of the tracking target object as the target measurement data of the tracking target object. . In addition, the estimation of the current position vector from the past target measurement data of a certain object is performed, for example, when the past recent target measurement data includes a relative velocity vector, for example, the past recent target measurement data. From the relative position indicated by the position vector to the current direction from the latest measurement data of the object in the direction of movement indicated by the relative speed vector at the relative speed indicated by the relative speed vector of the most recent target measurement data. This is performed by estimating a position vector indicating the position moved by time as the current position vector of the object.

  In addition, if there is target measurement data that could not be used as target measurement data for the object being tracked, the object for which the target measurement data was measured is replaced with a new one. Tracking information is generated as the tracking object, and the existing target measurement data is added to the tracking information of the new tracking object. Further, in the target tracking process, tracking is terminated for a tracking object for which the corresponding target measurement data has not been measured for a predetermined period or longer, and the tracking information for the tracking object is deleted.

  Next, the peripheral object characteristic detection unit 5 performs processing for estimating the characteristics of each object being tracked by the target tracking unit. That is, the peripheral object characteristic detection unit 5 estimates the vehicle / motorcycle / human / fixed object from the characteristics of the movement of the vehicle in the direction perpendicular to the traveling direction indicated by the relative velocity vector of the tracking information. Processing to estimate the characteristics of the object by estimating the characteristics of the type or by estimating whether the object is another vehicle that is being overtaken or overtaken from the relative speed vector of the tracking information And so on.

  Then, based on the tracking information of each tracking object and the characteristics of each tracking object estimated by the peripheral object characteristic detection unit 5, the surrounding situation presentation unit 6 determines the relative position and relative of the object behind the vehicle to the vehicle. Processing for displaying the moving direction and type on the display device 7 is performed. Further, based on the tracking information of each tracking object and the characteristics of each tracking object estimated by the surrounding peripheral object characteristic detection unit 5, the route is changed when the other vehicle behind the host vehicle is passing / passing. The warning output device 8 outputs a warning that warns that there is no warning or a warning that warns that there is a possibility of collision with an object being tracked from the warning output device 8.

Hereinafter, the target measurement process performed by the target measurement unit 3 as described above will be described.
Here, as described above, this target measurement process is performed each time one scan of the right radar apparatus 2 is completed.
FIG. 2 shows the procedure of the target measurement process.
As shown in the drawing, in this target measurement process, first, each measurement data output in the latest scan of the left radar device 1 is sequentially set as measurement data (i-th measurement data) to be processed. (Steps 202, 210, and 216) and Steps 204, 206, 208, and 214 are performed.

  That is, in the processing of steps 204, 206, 208, and 214, the same points as the measurement target measurement data output from the left radar device 1 are selected from the measurement data output in the recent scan of the right radar device 2. The measurement data estimated to have been measured is searched (step 204). Here, in this search, for example, relative to the reference point that is close to a relative position with respect to the predetermined reference point on the vehicle indicated by the position vector of the measurement data to be processed output from the left radar device 1 by a predetermined level or more. It is estimated that the measurement data having the strongest degree of proximity among the measurement data output by the right lator device including the position vector indicating the position is measured at the same point as the measurement data to be processed output from the left radar device 1. Search as measured data.

If the search in step 204 fails (step 206), the measurement target measurement data output from the left radar apparatus 1 is output as target measurement data as it is (step 214), and the measurement target measurement is performed. Finish processing the data.
On the other hand, when the search in step 204 is successful (step 206), the measurement data output from the left radar device 1 and the measurement data output from the searched right radar device 2 are grouped, and this group is grouped. On the other hand, one position vector, one perspective direction relative vector and one relative velocity vector are calculated, and target measurement data including the calculated position vector, perspective direction relative velocity vector and relative velocity vector is output (step 208) Then, the processing for the measurement data to be processed is finished. Here, the calculation method of one position vector, one perspective direction relative vector, and one relative velocity vector for the group performed in step 208 will be described in detail later.

  Now, if the processing of steps 204, 206, 208, and 214 is performed for each of the measurement data output in the recent scan of the left radar apparatus 1 in this way, in the recent scan of the right radar apparatus 2 Of the output measurement data, any of the measurement data output in the recent scan of the left radar device 1 and not grouped in Step 208 is output as target measurement data as it is (Step 212). Then, the current target measurement process is terminated.

Note that the target measurement data output in steps 212 and 214 in the above target measurement process includes only the position vector and the perspective direction relative velocity vector, and does not include the relative velocity vector.
Hereinafter, one position vector and one position group for one measurement data output from the left radar device 1 and one measurement data output from the right radar device 2 in step 208 of such target measurement processing are described. Details of the method of calculating the perspective direction relative vector and one relative velocity vector will be described.

  Now, as shown in FIG. 3a, the relative position indicated by the position vector of the measurement data output by the left radar device 1 in the group is PL, the perspective relative vector is uL, and the measurement output by the right radar device 2 in the group. Assuming that the relative position indicated by the data position vector is PR, and the perspective relative vector is uR, the component in the uL direction of the relative velocity vector obtained by the perspective relative vector uL, the relative velocity vector obtained by the perspective relative vector uR Calculate the relative velocity vector as a component in the uR direction

  More specifically, in this case, first, a straight line LBL passing through a position advanced from PL in unit time uL and perpendicular to the straight line LAL connecting PL and the antenna 11 of the left radar device 1, and advanced from PR in unit time uR. A straight line LBR perpendicular to the straight line LAR connecting PR and the antenna 11 of the right radar device 2 passing through the position is obtained. Then, the point QL on the straight line LBL and the point QR on the straight line LBR are obtained so that the position vector of the point QR viewed from the point QL is equal to the PR position vector ΔP viewed from PL. Then, a velocity vector u that travels from PL to QL (same as PR to QR) per unit time is set as a relative velocity vector calculated for this group. The position vector calculated for this group is the position vector indicated by the measurement data representing the more recent measurement result of the two measurement data in the group, and the perspective relative velocity vector calculated for this group is: Of the two measurement data in the group, the relative relative velocity vector indicated by the measurement data representing the more recent measurement result is used. Alternatively, the position vector calculated for this group is the average of the position vectors indicated by the two measurement data in the group, and the perspective relative velocity vector calculated for this group is the near-point indicated by the two measurement data in the group. It is good also as an average of a direction relative velocity vector.

  As shown in FIG. 3b, the relative velocity vector u is a unit time uL from PL, where RD is a position obtained by moving the position of the antenna 11 of the right radar device 2 by the position vector ΔD of the point PL viewed from the point PR. A straight line LBL perpendicular to a straight line LAL that connects PL and the antenna 11 of the left radar device 1 and a straight line that passes a position advanced from PL in unit time uR and that is perpendicular to a straight line LARD that connects PL and RD. The intersection Q with the LBRD can be obtained, and the velocity vector u traveling from PL to Q per unit time can be obtained as a relative velocity vector calculated for this group.

  Further, if the relative position indicated by the position vector of the measurement data output from the left radar device 1 in the group and the relative position indicated by the position vector of the measurement data output from the right radar device 2 are equal P, As shown in 3c, it passes through a position advanced from P by a unit time uL, passes a line LBL perpendicular to the straight line LAL connecting P and the antenna 11 of the left radar device 1, and passes a position advanced from P by a unit time uR. The intersection point Q between the straight line LBR perpendicular to the straight line LAR connecting P and the antenna 11 of the right radar apparatus 2 is obtained, and the velocity vector u that advances from P to Q per unit time is set as the relative velocity vector calculated for this group. Can be obtained.

The embodiment of the present invention has been described above.
As described above, according to the present embodiment, the relative velocity vector of the object around the own vehicle is directly obtained from the perspective direction relative velocity vector measured by the two radar devices, so that the surrounding of the own vehicle can be accurately and promptly obtained. The relative velocity vector of the object can be measured.

It is a block diagram which shows the structure of the vehicle-mounted periphery monitoring system which concerns on embodiment of this invention. It is a flowchart which shows the object measurement process which concerns on embodiment of this invention. It is a figure which shows the process example of the object measurement process which concerns on embodiment of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Left radar apparatus, 2 ... Right radar apparatus, 3 ... Target measurement part, 4 ... Target tracking part, 5 ... Peripheral object characteristic detection part, 6 ... Peripheral condition presentation part, 7 ... Display apparatus, 8 ... Warning output Device: 11 ... Antenna, 12 ... Transceiver, 13 ... Radar measurement signal processing unit.

Claims (3)

A radar measurement system for measuring a relative velocity vector of an object using a radar,
A point on the object existing within the set scanning range is detected as a detection point, and a position vector of the detected detection point and a perspective relative velocity vector representing the magnitude and direction of the relative velocity in the perspective direction with respect to itself are measured. A first radar device;
A point on the object that is located within the set scanning range and is set apart from the scanning range of the first radar device, which is spaced apart from the first radar device, is set as a detection point. A second radar device that detects and measures a position vector of the detected detection point and a perspective relative velocity vector representing a magnitude and direction of a relative velocity in the perspective direction with respect to itself;
A first detection point detected by the first radar device and a second detection point detected by the second radar device, where the positions indicated by the measured position vectors are close to each other by a predetermined level or more, Two detection points corresponding to a single point on the object are extracted, and the first detection point has a magnitude equal to the magnitude of the perspective relative velocity vector measured by the first radar device for the first detection point. A component in a direction equal to the direction of the perspective relative velocity vector measured by the radar device, and a magnitude equal to the magnitude of the perspective relative velocity vector measured by the second radar device for the second detection point, The first detection point and the second detection point correspond to a relative velocity vector having a component in the same direction as the direction of the perspective relative velocity vector measured by the second radar device. Radar measurement system characterized by having a relative velocity vector calculating means for calculating a relative velocity vector of a single point on the object that. The radar measurement system according to claim 1,
The radar measurement system is installed in an automobile,
The radar measurement system according to claim 1, wherein the first radar device and the second radar device are arranged on the automobile at least horizontally apart from each other. A relative velocity vector measurement method for measuring a relative velocity vector of an object using a radar,
The first radar device detects a point on the object existing within the scanning range set in the first radar device as a detection point, and the position vector of the detected detection point and the relative velocity in the perspective direction with respect to itself are detected. Measuring a perspective relative velocity vector representing magnitude and orientation;
On an object existing within a set scanning range by a second radar device which is disposed apart from the first radar device and has a scanning range which overlaps the scanning range of the first radar device. Detecting a point as a detection point, and measuring a position vector of the detected detection point and a perspective direction relative velocity vector representing the magnitude and direction of the relative velocity in the perspective direction with respect to itself,
A first detection point detected by the first radar device and a second detection point detected by the second radar device, where the positions indicated by the measured position vectors are close to each other by a predetermined level or more, Extracting as two detection points corresponding to a single point on the object;
A component in the direction equal to the direction of the perspective relative velocity vector measured by the first radar device having the same magnitude as the perspective relative velocity vector measured by the first radar device at the first detection point. And the direction of the perspective relative velocity vector measured by the second radar device is equal to the magnitude of the perspective relative velocity vector measured by the second radar device at the second detection point. Calculating a relative velocity vector having a directional component as a relative velocity vector of a single point on an object corresponding to the first detection point and the second detection point. Speed vector measurement method.