JPH11328591A - Following vehicle monitor device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To recognize a following vehicle which travels in the same lane by providing a means which calculates the presence position of a body in the rear by comparing the output of a road shape detecting means with the output of a distance measuring means and judges whether or not the body is a following vehicle from whether or not the presence position of the body at the rear matches the lane of the road. SOLUTION: A control unit 4 begins to operate and starts input from a radar device 1, a vehicle speed detecting means 2, etc. Namely, the distance to the body at the rear which is outputted by the radar device 1, the vehicle speed outputted by the vehicle speed detecting means 2, and a yaw rate signal outputted by a yaw rate detecting means 3 are inputted, thus, the road shape traveling through it is decided. Then it is decided whether or not the body at the rear which is confirmed is a following vehicle. When it is decided that the body at the rear is the following vehicle by reading a RAM 7, the distance to the body at the rear which is detected by the radar device 1 is updated as a vehicle-to-vehicle distance at specific intervals of time. Consequently, the state of the following vehicle can accurately be grasped.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a following vehicle monitoring device for identifying and monitoring a vehicle traveling behind a traveling lane of a host vehicle.

[0002]

2. Description of the Related Art As a conventional device for monitoring the rear of a running vehicle, a device as disclosed in Japanese Patent Application Laid-Open No. 2-287799 is known. This device is a video camera rear monitoring system that recognizes lane division lines to identify driving lanes, sets a monitoring area in the driving lane, recognizes vehicles behind, especially vehicles in adjacent lanes, and changes lanes. Attention is given at the time. Monitoring of the surroundings of the traveling vehicle also requires monitoring of the rear vehicle, but monitoring and warning of obstacles ahead are prioritized. When using a video camera for rear monitoring as described in the above publication, the vehicle must be monitored. In addition, a plurality of in-vehicle video cameras and a plurality of image processing devices are mounted on the vehicle, which imposes a heavy burden on a mounting place and cost.

In order to avoid this, it is conceivable to replace the rearward monitoring device with a radar such as a CW Doppler radar. Such a vehicle may be erroneously detected as a vehicle behind the vehicle, and may not be reliable as compared with an in-vehicle video camera having an image processing device capable of setting a monitoring area. As a means to avoid such radar misidentification and improve reliability,
For example, Patent Registration No. 2596112 is disclosed, which is directed to monitoring of an obstacle in front, but in monitoring an obstacle, checking whether the obstacle is a stationary object, By confirming whether there are a plurality of obstacles or a single obstacle at a predetermined distance, it is possible to recognize whether the obstacle is a roadside obstacle such as a reflector or a traveling vehicle. It is configured so that it can be distinguished from an obstacle on the road shoulder to some extent.

[0004]

A vehicle rear monitoring device monitors the position, distance, and relative speed of a vehicle traveling behind the host vehicle, and determines whether the rear vehicle may cause obstacles to the host vehicle. It is to judge whether or not to issue an alarm and take an avoidance measure.For example, when using the above-mentioned conventional radar device for rearward monitoring, especially on a road having a plurality of traveling lanes. However, it is impossible to discriminate between a running vehicle in an adjacent lane and a vehicle behind the own vehicle, and it is not possible to determine whether or not the vehicle is a vehicle that impairs the own vehicle even if the vehicle can be confirmed.

SUMMARY OF THE INVENTION The present invention has been made to solve such a problem, and it is possible to reliably recognize a following vehicle traveling on the same lane as the own vehicle even on a road having a plurality of lanes. It is another object of the present invention to provide a following vehicle monitoring device capable of appropriately issuing an alarm without erroneously recognizing a vehicle traveling in an adjacent lane or an object on a roadside.

[0006]

A following vehicle monitoring apparatus according to the present invention calculates a trajectory of a host vehicle by inputting a vehicle speed and a yaw rate by inputting a vehicle speed and a yaw rate. The position of the rear object is calculated by comparing the output of the road shape detecting unit with the output of the distance measuring unit, and the position of the rear object is determined by comparing the output of the road shape detecting unit with the output of the distance measuring unit. There is provided a following vehicle determining means for determining whether or not the vehicle is a succeeding vehicle based on whether or not the vehicle is on the lane.

[0007] Further, distance measuring means for measuring the distance to the rear object, road shape detecting means for calculating the trajectory of the vehicle based on the output of the GPS receiver and the map information and specifying the lane shape of the road, The existence position of the rear object is calculated by comparing the output of the road shape detecting means and the output of the distance measuring means,
And a subsequent vehicle determining means for determining whether or not the vehicle is a succeeding vehicle based on whether or not the position of the rear object is on the lane of the road.

[0008] Further, a distance measuring means for measuring a distance to a rear object, and a trajectory and a lane width of the own vehicle are calculated from a video output of an on-board video camera for forward monitoring to specify a lane shape of the road. Detecting means, and calculating the position of the rear object by comparing the output of the road shape detecting means with the output of the distance measuring means, and determining whether or not the position of the rear object coincides with the lane of the road to determine whether the vehicle is a following vehicle. And a following vehicle determining means for determining whether or not the vehicle is a vehicle.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1 FIG. 1 is a block diagram showing a configuration of a following vehicle monitoring device according to a first embodiment of the present invention. FIGS. 2, 3, and 5 are flowcharts for explaining the operation of this embodiment, and FIG. Although the type of the radar device according to the present invention is not particularly limited, a laser radar will be described in the following embodiments. FIG.
1, 1 is a radar device for measuring a distance to a rear object by a laser pulse, 2 is a vehicle speed detecting means for detecting the own vehicle speed, 3 is a yaw rate detecting means for measuring a change in the traveling direction of the vehicle, 4 is an input interface 5 A control unit (hereinafter referred to as CPU) 10 including a microprocessor 6, a RAM 7 for temporarily storing information, a ROM 8 for storing determination conditions and the like, and an output interface 9;
Is a following-vehicle information display means for displaying information such as an inter-vehicle distance to a succeeding vehicle output from the CPU 4 or issuing a warning. The radar device 1 used in this embodiment includes:
A beam having a narrow beam width is used so that an object on the same lane as the own vehicle behind a certain distance is detected.

The operation of the following vehicle monitoring apparatus according to the first embodiment of the present invention will be described with reference to FIGS. The flowchart of FIG. 2 shows the main routine. In FIG.
4 starts operation, the RAM 7 is initialized in step 201, and input from each detecting means such as the radar device 1 and the vehicle speed detecting means 2 is started in step 202. The processing in step 202 can be decomposed into a flowchart in FIG. 3. In step 301 in FIG. 3, the distance to the rear object output by the radar device 1 is input.
2, the vehicle speed output from the vehicle speed detection means 2 is input, and further, in step 303, the yaw rate signal output from the yaw rate detection means 3 is input, and these signal processes are repeated, for example, every 20 msec.

By the above information input, step 2 in FIG.
At 03, the shape of the road on which the own vehicle is passing is determined. That is, it is determined whether the road is a straight road or a curved road. In the case of a curved road, the curvature radius R is calculated using a yaw rate, and R = v / r (1) where v: vehicle speed r: yaw rate And the calculation result is stored in the RAM 7.

After the determination of the road shape is performed, it is determined in step 204 whether the object behind the road identified by the radar device 1 is a following vehicle. In FIG. 4, when the vehicle is traveling at point O on a curved road,
The determination as to whether or not the object S confirmed by the radar device 1 is a following vehicle is made based on whether or not the rear object is on the road as follows. First, assuming that the rear object S is on the road, the rear object S is assumed to be at the point P, and the coordinates of the point P with respect to the own vehicle position O are the radius of curvature R and the object S which is the output of the radar device 1. P = [R− (R ² −U ² ) ^1/2 , U] (2) Then, based on the lane width d of the road, the distance | PQ | from the point P to the point Q which is the road end is stored in the ROM 8, the right triangle TFP in the figure becomes the right triangle PNQ.
| PQ | = d / cosΘ = dR (R ² −U ² ) ^1/2 / (R ² −U ² ) (3)

Further, the coordinate of the point Q in the X-axis direction is
Since there is a distance difference of the straight line | PQ | with respect to the axial coordinate, the X axis coordinate of the point Q with respect to the own vehicle position O is obtained by subtracting the equation (3) from the X axis coordinate of the point P in the equation (2). Is required. That is, Here, if the X coordinate of the point Q is larger than 0, the object S exists outside the lane, so it is determined that the object S is not a following vehicle, and if it is 0 or less, it exists on the lane. The vehicle is determined to be a following vehicle and is stored in the RAM 7 of the CPU 4.

Subsequently, in step 205, an inter-vehicle distance detection process with the following vehicle is performed, and step 205 is processed according to the flow of the flowchart of FIG. FIG.
In step 501, when it is read from the RAM 7 that the rear object S is a following vehicle, the distance U to the rear object S detected by the radar device 1 is stored in the RAM 7 as an inter-vehicle distance in step 502. It is updated every predetermined period. It is not updated when it is determined that the rear object S is not a following vehicle. Finally, in step 206 of FIG. 2, if the distance to the following vehicle or the rate of change of the distance satisfies a certain condition, a situation is output and a warning is issued to the driver. And give instructions for avoidance operations.

The above routine is repeated, for example, every 20 ms, and the distance U to the rear object S is monitored. As described above, in the following vehicle monitoring apparatus according to the first embodiment of the present invention, the lane shape is determined from the distance determination by the radar device 1, the road shape determination based on the yaw rate and the vehicle speed, and the lane width of the road stored in the ROM. Is calculated to determine whether or not the rear object S is on the same lane as the own vehicle. Therefore, it is possible to reliably recognize whether or not the object detected by the radar is a following vehicle, and to give accurate information to the driver. Is possible.

Embodiment 2 FIG. 6 is a block diagram showing a configuration of a following vehicle monitoring apparatus according to Embodiment 2 of the present invention.
8 is a flowchart showing the operation, and FIG. 9 is an explanatory diagram for explaining the contents of the operation. Since the main routine of the operation is the same as that of FIG. 2 shown in the first embodiment, FIG.
This will be described using. This embodiment corresponds to the first embodiment.
Instead of the vehicle speed detecting means 2 and the yaw rate detecting means 3 for detecting the road shape of the GPS receiver 1 as shown in FIG.
1 and receives three or more satellite radio waves, for example, a CPU 4
The road information is read out in comparison with the map information stored in the ROM 8 or the like, the road shape is obtained from the road information, and the succeeding vehicle is detected by the CPU 4.
The functions other than the function 4 are the same as those of the first embodiment.

The operation of the following vehicle monitoring apparatus according to this embodiment will be described with reference to FIGS. 2 and 7 to 9. Step 201 in the flowchart of FIG. 2 is the same as that of the first embodiment. In step 202, as shown in the flowchart of FIG. 7, in step 701, distance information of the rear object S from the radar device 1 is input. In step 702, information from the GPS receiver 11 is input, and the road shape is detected in step 203 in FIG. 2 based on the information. As in the first embodiment, the road shape is used to detect whether the road is straight or curved and, if it is a curve, to know the value of the radius of curvature.
3 operates according to the flowchart of FIG.

In step 801 of FIG. 8, the position of the own vehicle is detected by a known method from three or more satellite radio waves and map information stored in ROM 8 or the like.
Stored in M7. In step 803, the position of the vehicle on the road and the distance U to the rear object S detected by the radar device 1 are determined.
And three points on the road center line including the center point of the road behind the vehicle. As shown in FIG. 9, these three points are points P (coordinates X) that are the same distance as the distance U to the rear object S.
a, Ya) and a position L (coordinates Xb, Y) approaching this.
b) and a position M (coordinates Xc, Yc). Using the coordinates of these positions, in step 804, the curvature radius R of the road and the center coordinates Tx and Ty of the radius with respect to the own vehicle position O are calculated by the following equations. And calculate. (X−Tx) ² + (y−Ty) ² = R ² (5) R and Tx are obtained by substituting the coordinates of the above three points into x and y of the equation (5) and solving a simultaneous equation. And Ty are required,
Thus, when the calculation of the road shape is completed, step 805 is executed.
These values are stored in the RAM 7 and the process returns to step 204 in FIG.

Steps 204 and subsequent steps in FIG. 2 are the same as those in the first embodiment.
From the road width d stored in the vehicle and the distance U to the rear object S, the lane shape is calculated by the above equations (2), (3) and (4), and the following vehicle is determined by comparing the position of the rear object S ( Step 204) and updating and storing the inter-vehicle distance (step 205)
Are performed at predetermined time intervals, and the result is notified to the driver.

Embodiment 3 FIG. 10 is a block diagram showing the configuration of the following vehicle monitoring apparatus according to the third embodiment of the present invention. FIGS. 11, 12, and 15 are flowcharts for explaining the operation, and FIGS. FIG. 2 is an explanatory diagram for explaining the contents, and the main routine of the operation is the same as that of FIG. 2 shown in the first embodiment, and therefore will be described with reference to FIG. In this embodiment, in addition to the GPS receiver 11 for detecting a road shape according to the second embodiment, for example, an image of an in-vehicle video camera used for forward monitoring of a vehicle is stored, and the road shape and the lane shape are determined. The recognition is performed to detect the position of the rear object. In FIG. 10, reference numeral 12 denotes an in-vehicle video camera that detects an obstacle in front of the vehicle, for example. FIG. 10 is the same as Embodiment 2 except for the addition of the on-board camera 12 and the function of the CPU 4.

The operation of the third embodiment configured as described above will be described with reference to the main routine of FIG. 2. First, step 201 is the same as the first embodiment,
In 2, the information is input according to the flow shown in FIG. 11, in step 1101, distance information of the radar 1 is input, and in step 1102, the GPS 11
, And in step 1103, video information of the on-vehicle video camera 12 is input. Following the information input in step 202, step 203
The road shape is detected by the flow shown in the flowchart of FIG.

In FIG. 12, in step 1201, 3
The running locus of the own vehicle is detected by a known method using at least two satellite radio waves, and the running locus of the own vehicle is selected in time series at step 1202 and stored in the RAM 7. Step 1
At 203, the image of the vehicle-mounted video camera 12 is subjected to image processing to detect the traveling locus of the own vehicle in the traveling lane. As shown in FIG. 13, the detection of the traveling locus in the lane includes a point 131 which is the position of the specific point of the own vehicle (the mounting position of the on-board video camera) in the traveling lane, and a distance from the point 131 to the left and right lane ends. dL and dR are detected, and these detections are performed for the three points selected in step 1202. As shown in FIG. 14, each point of the own vehicle position is defined as P0, P1, P2, and The distance from each point to the left lane edge is dL0, dL1, dL2, and the distance from each point to the right lane edge is dR0, dR
1, dR2, and in step 1204, RA
It is stored in M7.

In step 1205, as shown in FIG. 14, the left and right lane end positions L0 and R0 corresponding to the own vehicle position P0 are obtained from the values of the three points detected in step 1203.
Are the left and right lane end positions L1 and R1 with respect to P1.
Are also left and right lane end positions L2 and R with respect to P2.
2 is calculated, and the calculation result is
It is stored in M7. Subsequently, the process returns to step 204 in FIG. 2 of the main routine, and the determination of the following vehicle is made. In step 204, the determination is made according to the flow shown in FIG.

FIG. 1 shows the operation of the flowchart of FIG.
6. First, in step 1501, FIG.
6 with the vehicle position O as the origin and the axis at which the rear object Y is detected as the Y axis, the lane end positions L0, L1, L2, R0, R1 at three points on both sides of the Y axis near both sides of the rear object Y. , R
2 is extracted from the RAM 7. In step 1502, the coordinates of the positions L0, L1, and L2 of the left lane edge are substituted into equation (5) shown in the second embodiment to calculate the trajectory of the left lane edge, and further, the right lane edge position R0, R1 and R2 are similarly calculated to calculate the right lane end locus, and the shape of the traveling lane is detected. In step 1503, based on the lane shape and the distance to the rear object Y, the positions of the coordinates UL and UR of the lane ends on both sides of the rear object Y are calculated by the above equation (5). 1503
It is determined whether the rear object Y exists on the road based on the sign of the UL or UR sign of the calculation result, and the determination result is stored in the RAM 7.

If the position of the rear object Y is determined, FIG.
Returning to step 205, if the rear object Y is on the road, it is determined that it is a following vehicle, and the position calculation and data updating are repeated. If it is outside the road, it is determined that it is not a following vehicle, and the position of the rear object Y is updated. Is not performed, and the confirmation calculation based on the input data is repeated.

[0026]

As described above, according to the following vehicle monitoring device of the present invention, the radar that searches behind the host vehicle detects the rear object, and detects the vehicle speed and the yaw rate or G.
The lane shape of the road is calculated from the data measured using the PS receiver or the on-board camera for shooting ahead, and it is determined whether or not the searched rear object exists on the road to determine whether the object is a following vehicle. Since it was decided that it was off the road,
Particularly on curved roads, etc., it is possible to reliably recognize whether the rear object detected by the radar is a following vehicle, a vehicle in an adjacent lane, or a signboard or reflector outside the road, so that the situation of the following vehicle can be accurately and Information can be provided to the driver in real time, and the information input device therefor is a yaw rate sensor or G used for normal navigation or autonomous driving.
A PS receiver or an in-vehicle camera for forward monitoring may be used, and an excellent following vehicle monitoring device that does not require special additional equipment can be obtained.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a following vehicle monitoring device according to a first embodiment of the present invention.

FIG. 2 is a flowchart illustrating the operation of the first embodiment of the present invention.

FIG. 3 is a flowchart illustrating the operation of the first embodiment of the present invention.

FIG. 4 is an explanatory diagram illustrating an operation of the first embodiment of the present invention.

FIG. 5 is a flowchart illustrating the operation of the first embodiment of the present invention.

FIG. 6 is a block diagram showing a configuration of a following vehicle monitoring device according to a second embodiment of the present invention.

FIG. 7 is a flowchart illustrating an operation of the second embodiment of the present invention.

FIG. 8 is a flowchart illustrating the operation of the second embodiment of the present invention.

FIG. 9 is an operation explanatory diagram of Embodiment 2 of the present invention.

FIG. 10 is a block diagram showing a configuration of a following vehicle monitoring device according to a third embodiment of the present invention.

FIG. 11 is a flowchart illustrating the operation of the third embodiment of the present invention.

FIG. 12 is a flowchart illustrating the operation of the third embodiment of the present invention.

FIG. 13 is an operation explanatory diagram of Embodiment 3 of the present invention.

FIG. 14 is an operation explanatory diagram of Embodiment 3 of the present invention.

FIG. 15 is a flowchart illustrating the operation of the third embodiment of the present invention.

FIG. 16 is an operation explanatory diagram of Embodiment 3 of the present invention.

[Explanation of symbols]

REFERENCE SIGNS LIST 1 radar device, 2 vehicle speed detecting means, 3 yaw rate detecting means, 4 control unit, 5 input interface, 6 microprocessor, 7 RAM, 8
ROM, 9 output interface, 11 GPS receiver, 12 in-vehicle camera

Claims (3)

[Claims] 1. A distance measuring means for measuring a distance to a rear object, a road shape detecting means for calculating a trajectory of a host vehicle by inputting a vehicle speed and a yaw rate, and identifying a lane shape of a road from the trajectory of the host vehicle. By comparing the output of the road shape detecting means with the output of the distance measuring means, the position of the rear object is calculated, and whether or not the position of the rear object coincides with the lane of the road indicates whether the vehicle is a following vehicle or not. And a succeeding vehicle determining means for determining whether the vehicle is a following vehicle. 2. A distance measuring means for measuring a distance to a rear object, a road shape detecting means for calculating a trajectory of the own vehicle based on an output of a GPS receiver and map information and specifying a lane shape of the road. Calculate the position of the rear object by comparing the output of the road shape detection means and the output of the distance measurement means,
A succeeding vehicle monitoring device comprising: a succeeding vehicle determining unit that determines whether the vehicle is a succeeding vehicle based on whether or not the position of the rear object is on the lane of the road. 3. A road shape for determining a lane shape of a road by calculating a trajectory and a lane width of the own vehicle from a video output of an in-vehicle video camera for forward monitoring, and a distance measuring means for measuring a distance to a rear object. Detecting means, and calculating the position of the rear object by comparing the output of the road shape detecting means with the output of the distance measuring means, and determining whether or not the position of the rear object matches the lane of the road. A trailing vehicle monitoring device comprising: a trailing vehicle determining unit configured to determine whether the trailing vehicle is running.