JPH11213295A - Vehicle interruption detection circuit and rear-end collision alarming device using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To predict the interruption of a vehicle by detecting the interruption of the vehicle when the predicted position of the vehicle is positioned inside a lane. SOLUTION: An image synthesis means 33 doubles, for instance, only the size of the position vector of the vehicle in front calculated in a vehicle position prediction means 32 and overlaps the predicted position coordinate of a preceding vehicle after fixed time on the image of the lane extracted in a lane coordinate detection means 31. In an interruption detection means 34, the tip, that is the coordinate, of the position vector for indicating the predicted position of the vehicle after fixed unit time is extracted based on synthesized images and whether or not it is positioned on the inner side of the lane plotted by using the method of a quadratic approximate curve or the like is judged. Then, in the case of judging that it is positioned on the inner side, it is judged that the possibility that the vehicle in front interrupts after the fixed unit time is large and preliminary alarm signals are outputted to an alarm generation circuit 44.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle interruption detection circuit for detecting a traveling lane and a preceding vehicle, and detecting that the preceding vehicle interrupts the own traveling lane, and a rear-end collision warning device using the same. .

[0002]

2. Description of the Related Art Conventionally, this type of vehicle interrupt detection circuit will be described with reference to Japanese Patent Application Laid-Open No. 7-230600 shown in FIG. The processing ECU 1 includes an A / D converter 2, a RAM 3, and a C
PU 4, ROM 5 and I / Os 6, 7 are connected to each other by a common bus 8 so that they can communicate with each other. Then, the CCD camera 9 is set as a monitoring area in front of the vehicle, captures an image within a predetermined viewing angle, and transfers the captured image signal to the RAM 3 via the A / D converter 2 in the processing ECU 1. It is memorized. The I / O 6 is a port functioning as an input port, to which signals indicating a vehicle running state from the steering angle sensor 10 and the vehicle speed sensor 11 are supplied.
The I / O 7 is a port that functions as an output port, and is connected to an alarm device 12 that issues a desired alarm to the driver and a throttle / brake control actuator 13 that controls the acceleration of the vehicle. Supply signal.

Next, the operation of the processing ECU 1 will be described based on a flowchart shown in FIG. First, step 10
0, the image signal captured by the CCD camera 9 for monitoring the front of the vehicle is taken into the processing ECU 1 and step 1
The lane such as a white line on the road surface is recognized in the image signal input at 02 to detect the traveling lane of the own vehicle. Thereafter, in step 104, the contour of the object that can be estimated as the preceding vehicle is detected in the input image signal, and in the next step 106, the position of the traveling lane of the own vehicle is compared with the position of the preceding vehicle, and the preceding vehicle is compared. The degree of interruption in the traveling lane of the host vehicle is calculated. If the degree of interruption is larger than a predetermined value in step 110, traveling control giving priority to collision avoidance is performed, and if the degree of interruption is smaller than a predetermined value. Executes traveling control giving priority to ride comfort.

[0004]

However, in the above-described vehicle interrupt detection circuit, the fact that a vehicle interrupt has actually occurred is determined on a real-time basis by image processing, so that the vehicle interrupt detection circuit is not used. Cannot be detected in advance.

The present invention has been made in view of the above problems, and has as its object to provide a circuit capable of predicting an interruption of a vehicle in advance and a device for issuing a rear-end collision warning using the circuit.

[0006]

According to a first aspect of the present invention, there is provided a vehicle interrupt detecting circuit for detecting vehicle image data based on an image signal from an image pickup device for capturing an image of a vehicle ahead, and a vehicle image detecting means for detecting the vehicle image data. A vehicle image memory which stores at least the immediately preceding vehicle image data obtained by the image detecting means, the coordinates of the latest vehicle image data obtained by the vehicle image detecting means, and at least the immediately preceding vehicle image data which is stored in the vehicle image memory A vehicle position predicting means for calculating a speed and a moving direction of the vehicle based on the coordinates of the vehicle image data, and calculating a coordinate position of the vehicle after a predetermined time based on the calculated speed and a moving direction; and an image signal from the vehicle image detecting means. Lane coordinate detecting means for detecting the coordinates of the lane drawn on the road on the basis of the lane coordinates, and the vehicle position prediction on the lane coordinates obtained by the lane coordinate detecting means. Superposing the predicted position coordinates of the vehicle after a predetermined time from the unit, the predicted position of the vehicle is characterized by including a interrupt detection means for detecting the interruption of a vehicle when located within the lane.

A rear-end collision warning device according to a second aspect of the present invention is a vehicle collision detection device for detecting vehicle image data based on an image signal from an image pickup device for imaging a vehicle ahead, and a vehicle image detection device obtained by the vehicle image detection device. A vehicle image memory for storing at least the immediately preceding vehicle image data, and a coordinate of the latest vehicle image data obtained by the vehicle image detecting means and a coordinate of at least the immediately preceding vehicle image data stored in the vehicle image memory. A vehicle position estimating means for calculating a speed and a moving direction of the vehicle, and calculating a coordinate position of the vehicle after a predetermined time based thereon, and a lane drawn on a road based on an image signal from the vehicle image detecting means. Lane coordinate detecting means for detecting the coordinates of the vehicle, and the vehicle after a predetermined time from the vehicle position predicting means on the lane coordinates obtained by the lane coordinate detecting means. Interrupt detecting means for superimposing predicted position coordinates and detecting an interrupt of the vehicle when the predicted position of the vehicle is located in the lane; inter-vehicle distance detecting means for calculating the inter-vehicle distance with the preceding vehicle; A rear-end collision warning unit that outputs a warning signal when an inter-vehicle distance from the unit is smaller than a predetermined value and an interruption detection signal is received from the interruption detection unit.

A rear-end collision warning device according to a third aspect of the present invention is characterized in that the inter-vehicle distance detecting means calculates the inter-vehicle distance based on the parallax of the image signals from the two imaging devices.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1 Embodiment 1 of the present invention will be described with reference to FIG. In the figure, 2
Reference numerals 0 and 21 denote first and second CCD cameras (imaging devices).
At the same height in the vehicle interior and with the optical axis parallel to the front of the vehicle, for example, it is fixed to the left and right symmetrical positions with the mounting base of the room mirror sandwiched in between, and is mounted forward, The first CCD camera 20 captures a forward image and outputs an image signal corresponding to the first image.
One screen data is stored in the first memory 24 via the / D converter 22 as one unit. In the second CCD camera 21, one screen data is stored in the second memory 25 via the second A / D converter 23 as one unit. The image data picked up by the first and second CCD cameras 20 and 21 has an image shift due to parallax.

Reference numeral 26 denotes a CPU, and first switching means 27,
The second switching means 28, the distance calculating means 29, the vehicle image detecting means 30, the lane coordinate detecting means 31, the vehicle position predicting means 32, the image synthesizing means 33, and the interrupt detecting means 34 are provided. One of the image signals supplied from both the first and second memories 24 and 25 is preferentially selected and output. The second switching means 28 also preferentially selects one of the image signals supplied from the first and second memories 24 and 25 (the same image signal as that of the first switching means 27) and outputs it. For example, the first and second switching units 27 and 28 are connected to the first CCD camera 20.
Output from the vehicle image detecting means 3
When 0 or a switching signal is supplied from the lane coordinate detecting means 31, an image signal from the second CCD camera 21 is output.

Reference numeral 29 denotes distance calculating means. The distance calculating means 29 is disclosed in JP-A-59-197816 and JP-A-7-197816.
The distance is calculated by using a technique already disclosed in JP 152914, a so-called stereo method, which is a triangulation method. That is, the distance calculation means 2
9 reads the image signal having the parallax stored in the first and second memories 24 and 25, calculates the inter-vehicle distance between the preceding vehicle and the own vehicle from the magnitude of the parallax, and calculates the inter-vehicle distance. Each time it is calculated, it is stored in the following distance memory 35. Further, the distance calculating means 29 compares the calculated latest inter-vehicle distance with the previously calculated inter-vehicle distance stored in the inter-vehicle distance memory 35, and determines whether the calculated inter-vehicle distance suddenly becomes smaller or the calculated latest inter-vehicle distance becomes constant. If it becomes smaller than the value, it is determined that a rear-end collision has occurred, and a preliminary alarm signal is output to prevent rear-end collision.

The vehicle image detecting means 30 detects an image of the preceding vehicle as vehicle position coordinate data using a known method based on the image signal from the first switching means 27, and detects the detected image of the preceding vehicle. Coordinate position (Xi, Y
i) is added and stored in the vehicle image memory 36 described later. As a result, the previous vehicle position coordinates stored in the vehicle image memory 36 are (Xi-1,
Yi-1). Further, the vehicle image detecting means 30 includes:
The previously calculated vehicle position coordinate data (Xi-1, Yi-1) stored in the vehicle image memory 36 in response to a request signal from the vehicle position prediction means 32 described later, and the latest vehicle position calculated this time. The coordinate data (Xi, Yi) is supplied to the vehicle position predicting means 32 described later. When the vehicle image detecting means 30 determines that the vehicle image cannot be detected, the first
The switching unit 27 outputs a switching signal for switching from the first CCD camera 20 to the second CCD camera 21 (or vice versa).

The lane coordinate detecting means 31 extracts a group of coordinates representing a lane such as a white line as a representative coordinate based on the image signal from the second switching means 28 by a known method. As the lane coordinate data, a quadratic approximate curve is obtained by applying the least square method to the lane coordinate data.

The vehicle image detecting means 30 and the lane coordinate detecting means 31 are set so as to process all image data constituting one screen at a fixed unit time.
Therefore, when a certain unit time elapses, both of the detecting means 30 and 31 perform signal processing based on the next new image data. When the lane coordinate detecting unit 31 determines that the white line cannot be detected,
A switching signal for switching from the first CCD camera 20 to the second CCD camera (or vice versa) is output.

The vehicle position predicting means 32 calculates the latest vehicle position coordinate data (Xi, Yi) stored in the vehicle image memory 36 and the vehicle position coordinate data (Xi, calculated a predetermined unit time before). -1, Yi-1) is supplied from the vehicle image detecting means 30 and the amount of movement on the coordinates is {(Xi−Xi−1) ² + (Yi−Yi−1) ² }. The moving direction is detected by tan ^-1 {(Xi-Xi-1) / (Yi-Yi-1)}.

That is, as shown in FIG. 2, for example, when one preceding vehicle moves from the C position to the C 'position and the other preceding vehicle moves from the B position to the B' position, the arrow indicated by the broken line on the coordinates. Thus, the vehicle position predicting means 32 can perform image processing by vector calculation, and can automatically increase the size of this detected dashed arrow vector by doubling its size without rotating it. When the vehicle is at the position A ′, the vehicle position predicting means 32 calculates the predicted positions B ″ and C ″ of the preceding vehicle.

Numeral 33 denotes an image synthesizing means. The position vector of the dashed arrow of the front vehicle calculated by the vehicle position estimating means 32 is multiplied by, for example, twice the predicted position coordinates of the preceding vehicle after a predetermined time. (Xi + 1, Yi + 1) is superimposed on the lane image extracted by the lane coordinate detecting means 31.

Reference numeral 34 denotes an interruption detecting means, based on the image synthesized by the image synthesizing means 33, the tip of a position vector indicating a predicted position of the vehicle after a predetermined unit time, that is, coordinates (Xi + 1, Yi + 1). ) Is extracted, and it is determined whether or not the vehicle is located inside the lane 50 drawn by using a method such as a quadratic approximation curve. Determines that there is a high possibility that the vehicle enters the traveling lane of the own vehicle, that is, the vehicle is interrupted, and outputs a preliminary alarm signal to the alarm generating circuit 44.

Reference numeral 40 denotes a steering angle sensor, which detects the rotation angle of the steering wheel of the vehicle, and supplies a steering angle signal as a detection signal to a warning generation circuit 44 to be described later via a third A / D converter 41. . A vehicle speed sensor 42 supplies a signal proportional to the vehicle speed to an alarm generation circuit 44 via a fourth A / D converter 43.

An alarm generating circuit 44 receives a preliminary alarm signal from both the interrupt detecting means 34 and the distance calculating means 29 and outputs a steering angle signal from the steering angle sensor 40 via the third A / D converter 41. Is supplied, the own vehicle determines that danger avoidance has been performed, prohibits the output of a warning signal for generating a warning, and if the steering angle signal is not supplied, the fourth A / D converter 43 Speed sensor 42 via
In consideration of the magnitude of the vehicle speed signal from the vehicle, an alarm signal having a sound corresponding to the speed is output.

Next, the operation of the above configuration will be described. Image signals picked up by the first and second CCD cameras 20 and 21 are periodically supplied to the corresponding first and second A / D converters 22 and 23 one by one, and the first and second A / D converters 22 and 23 are provided. Each time the / D converters 22 and 23 are supplied, the stored image signal is updated. This image signal is CP
In response to a request from the U26 side, it is supplied to the vehicle image detecting means 30 via the first switching means 27 of the CPU 26, to the lane coordinate detecting means 31 via the second switching means 28, and to the distance calculating means 29. Supplied in parallel.

The vehicle image detecting means 30 and the lane coordinate detecting means 31 are supplied with only the image signals picked up by the first CCD camera 20, for example, by the first and second switching means 27 and 28. I have.
(If the vehicle image detecting means 30 and the lane coordinate detecting means 31 determine that the vehicle cannot be detected or the lane (white line) cannot be detected during the detecting operation for a long time, the first and second switching means are used. A switching signal is supplied to 27 and 28 to switch to an image signal from the second CCD camera 21.)

The distance calculating means 29 to which the image signal having parallax is supplied calculates the inter-vehicle distance to each preceding vehicle by the stereo method, stores and updates it in the inter-vehicle distance memory 35, and updates the inter-vehicle distance below the reference value. When the distance is calculated, a preliminary alarm signal is supplied to the alarm generation circuit 44. If the following distance cannot be calculated, the following distance data stored in the following distance memory 35 is used temporarily. Further, the distance calculating means 29 compares the calculated latest inter-vehicle distance with the inter-vehicle distance stored in the inter-vehicle distance memory 35, and when the distance suddenly decreases, generates a preliminary warning signal for rear-end collision suppression. Output.

The vehicle image detecting means 30 detects the coordinates of the part recognized as a vehicle as vehicle position coordinate data (Xi, Yi), and adds and stores the detected data to the vehicle image memory 36 every time it is detected. When receiving the request signal from the vehicle position predicting means 32, the vehicle image detecting means 30 and the vehicle position coordinate data (Xi-1, Yi-1) calculated last time and the latest vehicle position coordinate data (Xi, Yi). ) Is supplied to the vehicle position prediction means 32. On the other hand, the lane coordinate detecting means 31
A lane such as a white line is extracted, and a secondary approximation curve is obtained based on the extraction result.

The vehicle position predicting means 32 compares the supplied vehicle position coordinate data (Xi, Yi) with the vehicle position coordinate data (Xi-1, Yi-1) to determine the amount of movement on the coordinates. determined by √ determined by ^{{(Xi -Xi-1) 2} + (Yi -Yi-1) 2}, also the direction of movement ^{tan -1 {(Xi -Xi-1} ) / (Yi -Yi-1)} Can be

As a result, the image synthesizing unit 33 doubles only the size of the position vector of the preceding vehicle calculated by the vehicle position estimating unit 32 and converts the position vector to the lane image detecting unit 3.
Superimpose on the image of only the lane image extracted in 1,
If it is determined that the front end of the vector is located inside the extracted lane, it is determined that there is a high possibility that the preceding vehicle will enter the traveling lane of the own vehicle after a predetermined unit time, and the alarm generation circuit A preliminary alarm signal is output to 44.

Distance calculating means 29 and interrupt detecting means 3
4 is supplied with a preliminary alarm signal, and
When the steering signal from the steering angle sensor 40 is supplied via the / D converter 41, the alarm generation circuit 44 determines that the vehicle has avoided danger and suppresses the generation of an alarm. If no signal is supplied, an alarm is generated.

When an alarm is to be generated, a sound alarm signal corresponding to the magnitude of the vehicle speed signal from the vehicle speed sensor 42 is output. In the above embodiment, CC
Although the front of the vehicle is imaged using two D cameras, the position of the front vehicle is detected based on the parallax.
It goes without saying that one CCD camera may be used.

[0029]

As described above, according to the first invention, the interruption of the vehicle can be predicted, and according to the second invention, the interruption warning can be performed by the prediction. The effect of avoidance is exhibited. Further, according to the third aspect of the invention, it is possible to predict the interruption based on the distance detection based on the image.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of a circuit block according to a first embodiment of the present invention.

FIG. 2 is an explanatory diagram for explaining an operation of FIG. 1;

FIG. 3 is a circuit block diagram of a conventional device.

FIG. 4 is a flowchart illustrating the operation of FIG. 3;

[Explanation of symbols]

 20, 21 CCD camera (imaging device) 22, 23, 41, 43 A / D converter 24, 25 memory 26 CPU 27, 28 switching means 29 distance calculation means 30 vehicle image detection means 31 lane coordinate detection means 32 vehicle position prediction Means 33 Image synthesis means 34 Interrupt detection means 35 Inter-vehicle distance memory 36 Vehicle image memory 37 Lane image memory 40 Steering angle sensor 42 Vehicle speed sensor 44 Alarm generation circuit

Claims (3)

[Claims] 1. A vehicle image detecting means for detecting vehicle image data based on an image signal from an image pickup device for imaging a preceding vehicle, and at least the immediately preceding vehicle image data obtained by the vehicle image detecting means. A vehicle image memory, and a speed and a moving direction of the vehicle based on the coordinates of the latest vehicle image data obtained by the vehicle image detecting means and the coordinates of at least the immediately preceding vehicle image data stored in the vehicle image memory. A vehicle position estimating unit that calculates the coordinate position of the vehicle after a predetermined time based on the calculated vehicle position; and a lane coordinate detecting unit that detects the coordinates of the lane drawn on the road based on the image signal from the vehicle image detecting unit. And on the coordinates of the lane obtained by the lane coordinate detecting means,
Interrupt detection means for superimposing the predicted position coordinates of the vehicle after a predetermined time from the vehicle position prediction means, and detecting an interruption of the vehicle when the predicted position of the vehicle is located in the lane. Vehicle interrupt detection circuit. 2. A vehicle image detecting means for detecting vehicle image data based on an image signal from an imaging device for imaging a preceding vehicle, and at least the immediately preceding vehicle image data obtained by the vehicle image detecting means. A vehicle image memory, and a speed and a moving direction of the vehicle based on the coordinates of the latest vehicle image data obtained by the vehicle image detecting means and the coordinates of at least the immediately preceding vehicle image data stored in the vehicle image memory. A vehicle position estimating unit that calculates the coordinate position of the vehicle after a predetermined time based on the calculated vehicle position; and a lane coordinate detecting unit that detects the coordinates of the lane drawn on the road based on the image signal from the vehicle image detecting unit. And on the coordinates of the lane obtained by the lane coordinate detecting means,
Interrupt detecting means for superimposing predicted position coordinates of the vehicle after a predetermined time from the vehicle position predicting means, and detecting an interrupt of the vehicle when the predicted position of the vehicle is located in a lane; and an inter-vehicle distance to the preceding vehicle. And a rear-end collision warning unit that outputs an alarm signal when the inter-vehicle distance from the inter-vehicle distance detection unit becomes smaller than a predetermined value and receives an interruption detection signal from the interruption detection unit. A rear-end collision warning device, comprising: 3. The rear-end collision warning device according to claim 2, wherein said inter-vehicle distance detecting means calculates an inter-vehicle distance based on a parallax of image signals from two imaging devices.