Collision preventing device for vehicle

Description: TECHNICAL FIELD [Detailed description of the invention]

【0001】

[Technical field to which the invention belongs]

The present invention relates to a vehicle collision prevention device that detects an obstacle existing on the traveling path of the own vehicle and determines a collision.

【0002】

[Conventional technology]

Recently, automobiles are equipped with TV cameras, laser radars, etc. to detect vehicles and obstacles in front, determine the risk of collision with them, issue an alarm to the driver, and automatically activate the brakes. The development of technologies related to ASV (Advanced Safety Vehicle), such as stopping the vehicle by letting it stop, or automatically increasing or decreasing the traveling speed so as to keep the distance between the vehicle and the preceding vehicle safe, is being actively promoted. There is.

【0003】

Under normal road conditions, there are multiple vehicles and obstacles in front of the vehicle, and among these, identify the one that is in danger of collision or the preceding vehicle that should be followed. Has become an important issue. For example, Japanese Patent Application Laid-Open No. 6-131596 detects a plurality of vehicles in a predetermined range ahead by a scan-type laser radar, and identifies a vehicle on the traveling path of the own vehicle estimated by a steering angle sensor or a yaw rate sensor. In addition, Japanese Patent Application Laid-Open No. 1-242916 discloses white lines on the left and right of the road from the image of the TV camera, and sets the inside as the driving lane of the own vehicle and is in this lane. A technique for detecting the foremost vehicle as a preceding vehicle with respect to the own vehicle is disclosed.

【0004】

[Problems to be Solved by the Invention]

However, in order to prevent collisions with other vehicles and to follow the preceding vehicle, it is necessary to determine a travel route to a distance of, for example, 40 m to 100 m or more, and the current travel condition of the own vehicle is extended to a distance as it is. In the conventional technology of making a traveling route, for example, if the current traveling state is a straight traveling, the traveling route is estimated assuming that the straight road continues as it is, and even if there is a curve ahead, it is ignored and erroneously. There is a risk that a vehicle or obstacle will be detected.

【0005】

In addition, for example, in order to avoid parked vehicles, pedestrians, motorcycles, etc. at the left end of the own lane, when trying to pass by the side of the own lane by traveling to the right of the own lane, in the conventional technique, pedestrians or Since the motorcycle or the like continues to be recognized as an obstacle in front of the own vehicle, not only the collision warning is continuously output, but also the automatic brake is activated to stop the own vehicle.

【0006】

The present invention has been made in view of the above circumstances, and accurately reflects the driver's steering wheel operation to predict the traveling path of the own vehicle, appropriately detect obstacles and preceding vehicles, and issue an unnecessary warning. It is an object of the present invention to provide a vehicle collision prevention device capable of accurately determining the risk of a collision without any need.

【0007】

[Means for solving problems]

The invention according to claim 1 is based on the assumption that a means for detecting an object existing in the traveling direction of the own vehicle and calculating the position information of the detected object and the current traveling state of the own vehicle continue for a set time. The means for setting the traveling area consisting of the first route section up to after the set time based on the traveling condition of the above and the second route section extending the first route section along the road shape, and the position information of the object. Based on the above, an object hanging in the traveling area is extracted, and the means for determining the possibility of collision with the own vehicle from the position information of the extracted object is provided.

【0008】

The invention according to claim 2 is characterized in that, in the invention according to claim 1, the set time is changed based on the current traveling speed of the own vehicle.

【0009】

The invention according to claim 3 is provided with a means for determining that the lane change is started when the end point of the first route section is outside the white line of the lane in which the own vehicle is traveling in the invention according to claim 1. It is characterized by.

【0010】

The invention according to claim 4 is characterized in that, in the invention according to claim 3, when it is determined that the lane change has started, the traveling area is set to include the entire lane on the side where the lane is changed.

【0011】

That is, in the invention according to claim 1, it is assumed that the current traveling state of the own vehicle continues for the set time, and the first route section until after the set time based on the current traveling state and the first route section are roads. A traveling area consisting of a second route section extended along the shape is set. Then, an object hanging in the traveling area is extracted from the objects detected in the traveling direction of the own vehicle based on the position information, and the possibility of collision with the own vehicle is determined from the position information of the extracted object.

【0012】

At that time, in the invention according to claim 2, the set time is changed based on the current traveling speed of the own vehicle, and in the invention according to claim 3, the end point of the first route section is a white line in the lane in which the own vehicle travels. When it is outside the lane, it is determined that the lane change has started, and further, in the invention according to claim 4, when it is determined that the lane change has started, the traveling area is set to include the entire lane on the side where the lane is changed.

【0013】

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, embodiments of the present invention will be described with reference to the drawings. 1 to 5 relate to the first embodiment of the present invention, FIG. 1 is a configuration diagram of a collision prevention device, FIG. 2 is a circuit block diagram of a collision prevention device, FIG. 3 is a flowchart of a collision determination process, and FIG. 4 is. An explanatory diagram showing the position of the own vehicle after traveling for T0 seconds, and FIG. 5 is an explanatory diagram showing a traveling area.

【0014】

In FIG. 1, reference numeral 1 is a vehicle such as an automobile, and when the vehicle 1 recognizes an obstacle or a preceding vehicle existing in the traveling direction to determine the risk of collision and has a risk of collision. It is equipped with a collision prevention device 2 that issues a collision avoidance warning to ensure safety.

【0015】

The collision prevention device 2 is a stereo optical system 10 for capturing an object outside the vehicle from a different position, and an image processing unit 50 that processes an image captured by the stereo optical system 10 to recognize an obstacle, a preceding vehicle, or the like. The image processing unit 50 and the collision determination unit 60 are composed of a collision determination unit 60 and the like that determine the possibility of a collision from the data of obstacles and preceding vehicles recognized by the image processing unit 50. 4, Sensors for detecting the current running state of the vehicle such as yaw rate sensor 5 and steering angle sensor 6 are connected, and a collision alarm output from the collision determination unit 60 to the display 9 installed in front of the driver. Etc. are displayed.

【0016】

The stereo optical system 10 is composed of a pair of left and right cameras as an imaging system for capturing an object outside the vehicle, and the image processing unit 50 obtains the correlation of a pair of images captured by the stereo optical system 10 and is the same. The distance is calculated from the parallax with respect to the object by the principle of triangulation, the so-called stereo method is used to calculate the three-dimensional distance distribution over the entire image, and from the distance distribution information, the road shape and three-dimensional objects (vehicles, obstacles, etc.) 3 Detects the dimensional position at high speed.

【0017】

The collision determination unit 60 estimates the future travel route of the own vehicle based on the input data from the road shape, the vehicle speed sensor 4, the yaw rate sensor 5, and the steering angle sensor 6 detected by the image processing unit 50. From among the multiple detected vehicles and obstacles, identify the preceding vehicle to follow and the object at risk of collision. Then, based on the data of these vehicles and obstacles, a collision warning is determined, and if it is determined that there is a risk of collision, a warning is issued to the driver by displaying it on the display 9, and a brake operation (not shown) is performed. Or outputs an operation signal to an automatic braking device (not shown).

【0018】

Specifically, the image processing unit 50 and the collision determination unit 60 have the hardware configuration shown in FIG. 2, and the stereo optical system 10 connected to the image processing unit 50 is, for example, a charge-coupled device. It is composed of a pair of left and right CCD cameras 10a and 10b using a solid-state image sensor such as (CCD).

【0019】

The image processing unit 50 and the collision determination unit 60 are an image processor 20 that processes an image captured by the stereo optical system 10 and outputs distance distribution data (distance image) in the form of an image, and the image processor. It is composed of an image processing computer 30 that processes a distance image from 20 to detect a road shape and a plurality of three-dimensional objects, identifies a preceding vehicle, an obstacle, etc., and performs collision warning determination processing.

【0020】

The image processor 20 searches for a portion in which the same object appears in each minute region with respect to two stereo image pairs imaged by the stereo optical system 10, finds the amount of deviation of the corresponding position, and reaches the object. It is composed of a distance detection circuit 20a for calculating the distance of the above and a distance image memory 20b for storing the distance distribution data which is the output of the distance detection circuit 20a.

【0021】

Further, the image processing computer 30 mainly identifies a microprocessor 30a that mainly performs a process of detecting a road shape, a microprocessor 30b that mainly performs a process of detecting an individual three-dimensional object, and a preceding vehicle or an obstacle. The system configuration is a multi-microprocessor in which a microprocessor 30c that performs collision risk determination processing is connected in parallel via a system bus 31.

【0022】

Then, the system bus 31 stores the interface circuit 32 connected to the distance image memory 20b, the ROM 33 for storing the control program, the RAM 34 for storing various parameters during the calculation process, and the parameters of the processing result. Input signals from the output memory 35, the display controller (DISP.CONT.) 36 for controlling the display (DISP) 9, the vehicle speed sensor 4, the yaw rate sensor 5, the steering angle sensor 6, and the like. The I / O interface circuit 37 is connected.

【0023】

In the road detection process by the microprocessor 30a, only the white line on the actual road is separated and extracted by using the three-dimensional position information by the distance image stored in the distance image memory 20b, and the built-in road model is used. Recognize the road shape by modifying / changing the parameters to match the actual road shape.

【0024】

In the above road model, the own lane of the road up to the recognition target range is divided into a plurality of sections according to the set distance, and the left and right white lines are approximated by a three-dimensional straight line for each section and connected in a polygonal line. Therefore, the parameters a and b of this three-dimensional linear equation are obtained, and the linear equation shown in the following equation (1) is obtained. However, the following equation (1) is a horizontal linear equation, and here, the vertical linear equation is omitted. X = a Z + b ... (1) [0025]

Actually, the left and right white lines are approximated by the linear equation of the above equation (1), and the linear parameters aL and bL for the white line on the left side in the traveling direction are obtained for each section, and the white line on the right side in the traveling direction is obtained. Finds the linear parameters aR and bR for, and stores them in the output memory 35.

【0026】

Further, in the object detection process by the microprocessor 30b, the distance image is divided in a grid pattern at predetermined intervals, and only the data of the three-dimensional object that may hinder the traveling is selected for each area, and the data is selected. The detection distance is calculated, and if the difference in the detection distance to the object in the adjacent area is less than or equal to the set value, it is regarded as the same object, while if it is more than the set value, it is regarded as a separate object, and the contour image of the detected object. Regarding the generation of a distance image by the above image processor 20 and the process of detecting a road shape or an object from this distance image, Japanese Patent Application Laid-Open No. 5-265547 submitted earlier by the present applicant It is described in detail in JP-A-6-177236.

【0027】

Next, the collision determination process according to the present invention will be described according to the program of FIG. 3 executed by the microprocessor 30c.

【0028】

In this collision judgment processing program, first, in step S101, the steering angle by the signal from the steering angle sensor 6 and the vehicle speed by the signal from the vehicle speed sensor 4 are read, and it is assumed that the current steering angle and the vehicle speed are maintained. Estimate the travel route of your vehicle. It should be noted that this traveling path may be estimated on the assumption that the current traveling state (vehicle speed and yaw rate) of the vehicle is maintained based on the signal from the yaw rate sensor 5 and the signal from the vehicle speed sensor 4.

【0029】

Next, the process proceeds to step S102, and the position P of the own vehicle is obtained when the vehicle travels for a preset travel time T0 sec (for example, 1 sec) along the travel route obtained in step S101. That is, as shown in FIG. 4, the coordinates (Zp, Xp) of the point P (position P of the center point of the own vehicle) are set to the following using the radius R of the curve of the traveling path calculated from the steering angle or the yaw rate. Obtained by equations (2) and (3). Zp = R sin (V T0 / R) ... (2) Xp = R (1-cos (V T0 / R)) ... (3) However, V: running speed of own vehicle T0: Travel time set value (for example, 1 sec) [0030]

In the following step S103, the X coordinates XL, XR of the left and right white lines at the distance Zp, that is, the positions of the left and right white lines of the own vehicle after traveling for T0sec are obtained, and the process proceeds to step S104. Since the left and right white lines are obtained by the above equation (1), the linear parameters aL, bL, aR, bR of the left and right white lines in the road section including the distance Zp are read from the memory, and the following (4) Calculate the X coordinates XL and XR of the left and right white line positions SL and SR at the distance Zp by Eq. (5). XL = aL × Zp + bL ... (4) XR = aR × Zp + bR ... (5) [0031]

In step S104, as shown by the following equation (6), the distance DL between the point P and the position SL of the left white line is obtained as the relative positional relationship between the point P and the white line. Here, if the white line on the left side is not detected, or if the detection is unstable, the distance DR from the position SR of the white line on the right side is obtained. DL = Xp-XL ... (6) [0032]

After that, the process proceeds from step S104 to step S105, and a traveling area is set in which the traveling route from the present to T0sec is the first route section and the traveling route after T0sec is the second route section. As described above, it is assumed that the current traveling state continues as it is from the present to after T0sec, and as shown in FIG. 5, the own vehicle at each time calculated based on the radius R of the curve of the traveling route. The range obtained by adding 1/2 of the width of the own vehicle and a slight margin α / 2 (for example, 0.2 m to 0.8 m) to the left and right with respect to the center point of the vehicle is obtained, and this range is used as the traveling area of the first route section. And. After T0sec, the relative positional relationship DL between the white line on the left side and the own vehicle (or the relative positional relationship DR between the white line on the right side and the own vehicle) remains the same as the width of the first route section. A constant area is set as the second route section.

【0033】

Next, the process proceeds to step S106, and the position data of a plurality of objects detected by stereo image processing (object detection processing by the microprocessor 30b) and stored in the output memory 35, that is, the left end of the object at the distance Zi from the own vehicle. The position XiL and the right end position XiR of are compared with the left end and the right end at the distance Zi of the traveling area set in step S105, and the object hanging in the traveling area is extracted as an obstacle or a preceding vehicle.

【0034】

Then, in step S107, it is determined whether or not there is a risk of collision from the distance between the object hanging in the traveling area and the own vehicle, the relative speed, and the like, and when it is determined that there is a risk of collision, the process proceeds to step S108. A collision warning is displayed on the display 9 to prompt the driver to operate the brake, and when interlocking with an automatic braking device (not shown), the operation signal is output to exit the routine.

【0035】

On the other hand, when there is no object hanging in the traveling area, or when the relative speed between the object in the traveling area and the own vehicle is positive (the object is moving away), there is no danger of collision. Judging, the process proceeds from step S107 to step 109, and if the collision warning has already been issued and the risk of collision disappears in the subsequent operation, the collision warning is canceled and the automatic braking device is activated. If so, cancel the operation and exit the routine.

【0036】

For example, as shown in Fig. 5, when avoiding an obstacle (parked vehicle A) at the left end of the road, it is common for the driver to drive to the right of the road and pass by the side of the obstacle. If the person operates the steering wheel so as to avoid the parked vehicle A, the parked vehicle A does not enter the traveling area, and it is determined that there is no danger of collision with the parked vehicle A.

【0037】

Further, conventionally, in response to such a steering wheel operation, the traveling path of the own vehicle is extended with the curve radius R, the vehicle B enters the traveling region of the own vehicle, and the relative speed with the vehicle B is negative. In the state (the state where the vehicle B is approaching), it is determined that there is a risk of collision, but in the present invention, since it is assumed that the vehicle travels in parallel with the lane after T0sec, it corresponds to the actual steering wheel operation. Therefore, the vehicle B does not enter the traveling area of the own vehicle, and it is determined that there is no danger of collision with the vehicle B, and unnecessary alarm generation, automatic braking, and the like can be avoided.

【0038】

Furthermore, when the driver avoids the parked vehicle A, if he does not notice the existence of the vehicle B traveling in the lane to the right and operates the steering wheel excessively, the curve radius R becomes smaller and the traveling route is on the right side of FIG. Since the vehicle B moves and hangs in the traveling area, it is determined that there is a risk of collision with the vehicle B, and the driver's excessive steering operation can be accurately detected.

【0039】

That is, in the present invention, the traveling path of the own vehicle can be predicted by accurately reflecting the steering wheel operation of the driver, and an obstacle or a preceding vehicle can be appropriately detected without issuing an unnecessary warning. The risk of collision can be determined.

【0040】

FIG. 6 is a flowchart of a collision determination process according to the second embodiment of the present invention. In the above-mentioned first form, the length of the first route section is set as the mileage during the preset running time T0sec, but in this second form, the running time T is changed according to the running speed V, and the first form is It changes the length of one route section.

【0041】

That is, in general driving, the driver usually tends to operate the steering wheel slowly when the traveling speed V is high, and to operate the steering wheel quickly when the traveling speed V is small. Therefore, in order to reflect such general characteristics of the driver, the length of the first route section is changed according to the traveling speed V.

【0042】

Therefore, in the collision determination processing program of this embodiment, as shown in FIG. 6, only steps S201 and S202 are different from steps S101 and S102 of the collision determination processing program in the first embodiment described above, and steps S203 to S209 are the first. This is the same as steps S103 to S109 of the collision judgment processing program in one form.

【0043】

That is, in the collision determination processing program of this embodiment, the traveling speed V of the own vehicle is read in step S201, and as shown in the following equation (7), the traveling speed V is multiplied by the coefficient K to set the traveling time T. Then, based on the signal from the steering angle sensor 6 or the yaw rate sensor 5, the traveling route of the own vehicle is estimated assuming that the current traveling state of the vehicle is maintained for Tsec. T = K V ... (7) The coefficient K is, for example, a value of about 0.05 to 0.1, and is a lower limit value (for example, 0.8 sec) and an upper limit value (for example, 0.8 sec) with respect to the value of the traveling time T calculated by the above equation (7). , 2.0sec) may be set.

【0044】

Next, in step S202, the coordinates (Zp, Xp) of the position P of the own vehicle when traveling for Tsec along the traveling route obtained in step S201 are set to the above-mentioned equations (2) and (3). The travel time set value T0 is obtained by the following equations (8) and (9) in which the travel time T according to the above equation (7) is replaced, and in step S203 and subsequent steps, the same processing as in step S103 and subsequent steps of the first form described above is performed. Do. Zp = R sin (V T / R) ... (8) Xp = R (1-cos (V T / R)) ... (9) [0045]

In this embodiment, the general characteristics of the driver depending on the traveling speed can be more precisely reflected in the region of the traveling path, and it is possible to determine the collision risk more closely matched to the normal driving.

【0046】

7 to 9 relate to the third embodiment of the present invention, FIG. 7 is a flowchart of a collision determination process, FIG. 8 is an explanatory diagram showing detection of a lane change, and FIG. 9 is an explanatory diagram showing a traveling area.

【0047】

Conventionally, whether or not the own vehicle is changing lanes can be determined by providing a sensor for detecting the operation of the turn signal. However, in actual driving, the driver does not always give a turn signal when changing lanes, and may also give a turn signal for purposes other than changing lanes. Therefore, it is not appropriate to judge whether or not there is a lane change only from the operation state of the turn signal.

【0048】

Therefore, in this embodiment, the implementation of the lane change is detected at an earlier stage based on the information such as the positions of the left and right white lines detected by the stereo image processing, the positional relationship of the own vehicle, and the operation state of the driver's steering wheel, and subsequently. It detects vehicles in front that are suitable for changing lanes and vehicles and obstacles that are at risk of collision.

【0049】

Therefore, in the collision determination processing program of FIG. 7 in the present embodiment, first, in steps S301 and S302, the current traveling state of the vehicle is maintained for T0sec as in steps S101 and S102 in the collision determination processing program of the first embodiment described above. The travel route of the own vehicle is estimated when it is assumed that the vehicle is driven, and the coordinates (Zp, Xp) of the position P of the own vehicle when traveling along this travel route for T0sec are set to the above-mentioned (2) and (3). In step S303, the X coordinates XL and XR of the left and right white line positions SL and SR at the distance Zp are obtained by the above equations (4) and (5) in the same manner as in step S103 in the first embodiment.

【0050】

In steps S301 and S302, the travel route may be estimated with a travel time T that changes according to the travel speed V, as in steps S201 and S202 in the collision determination processing program of the second form described above.

【0051】

Next, the process proceeds to step S304, and the lane change is determined from the positional relationship of the position P of the own vehicle with respect to the left and right white lines after T0sec. After setting, the process proceeds to step S309, and when it is determined that the lane change is made, the process branches to the lane change process according to steps S307 and S308.

【0052】

The judgment of lane change is that if the point P is on the left side of the corresponding point SL of the white line on the left side, it is judged that the lane change has started to the left side, and as shown in Fig. 8, the point P corresponds to the white line on the right side. If it is on the right side of the SR, it is judged that the lane change to the right side has started. In addition, the end of the lane change is determined by analyzing the positional relationship between the detected left and right white lines and the own vehicle, and when it is determined that the own vehicle has all moved to the left or right lane, the traveling area. The setting of is returned to the normal setting according to the above steps S305 and S306.

【0053】

When changing lanes, in step S307, the relative positional relationship between the point P and the white line on the opposite side to the side changing lanes is obtained, and in step S308, the traveling area for changing lanes is set and the process proceeds to step S309. For example, when it is detected that the vehicle has changed lanes to the right lane, as shown in Fig. 9, it is assumed that the current driving condition continues from the present to T0sec, based on the radius R of the curve of the traveling route. To the center point of the own vehicle at each time calculated by adding 1/2 of the width of the own vehicle and a slight margin α / 2 (for example, 0.2 m to 0.8 m), the boundary on the left side of the first route section. Then, the left boundary of the second route section is defined so that the distance DL between the point P and the position SL of the left white line is constant. Further, the boundary on the lane changing side (right side) is set so as to include the entire right adjacent lane from the first route section to the second route section.

【0054】

In this case, the length of the first route section is set as the mileage between T0sec, but when changing lanes, in general, continuous steering is performed in the order of clockwise rotation counterclockwise rotation or counterclockwise rotation clockwise rotation. Therefore, it is not very accurate to assume that the current steering or running condition continues during T0sec. Therefore, in consideration of such uncertain factors in the driver's steering wheel operation, the traveling area is expanded to the entire lane to the right or left of the lane change.

【0055】

Then, in step S309 or later, an object hanging in the traveling area is extracted, the risk of collision is determined, and processing such as collision warning output is performed according to the determination result. The processing of steps S309, S310, S311, and S312 is the same as that of steps S106, S107, S108, and S109 in the collision determination processing program of the first form described above.

【0056】

In this embodiment, in contrast to the lane change for avoiding the parked vehicle A as shown in FIG. 9, the parked vehicle A is excluded from the target as in the first embodiment described above, and the lane change is implemented at an earlier stage. Can be detected. Moreover, since the traveling area is expanded to the entire lane on the lane change side, the vehicle B and other obstacles on the lane on the lane change side can be accurately detected.

【0057】

FIG. 10 is a configuration diagram of a collision prevention device according to a fourth embodiment of the present invention. The collision prevention device 101 mounted on the vehicle 100 of this embodiment emits a monocular CCD camera 102 and a laser beam at regular intervals within a predetermined scanning range instead of stereo image processing by two cameras. In combination with the scanning laser / radar 103 that receives light, it recognizes obstacles outside the vehicle, the preceding vehicle, etc., and determines the collision.

【0058】

Therefore, in the present embodiment, the image processing unit 110 transmits the signal from the monocular CCD camera 102 and the signal from the scanning laser radar 103, which are adopted in place of the stereo optical system 10, with respect to the first embodiment described above. The process is such that a laser beam is projected from the scan-type laser radar 103, and the distance from the object is measured from the time required for the projected laser beam to hit the object and receive the reflected light. By repeating the above steps, the two-dimensional distribution of a plurality of obstacles and vehicles in front is obtained, and the positions of the left and right white lines are detected by analyzing the image captured by the CCD camera 102.

【0059】

Then, based on the information from the image processing unit 110 and the input data from the vehicle speed sensor 4, the yaw rate sensor 5, and the steering angle sensor 6, the collision determination unit 60 will run the own vehicle in the future, as in the first mode described above. The route is estimated, and the collision judgment is made by identifying the preceding vehicle to be followed and the object at risk of collision from among the detected multiple vehicles and obstacles.

【0060】

Also in this embodiment, as in each of the above-described embodiments, it is possible to accurately reflect the driver's steering wheel operation to predict the traveling path of the own vehicle, appropriately detect obstacles and preceding vehicles, and perform unnecessary warnings. It is possible to accurately judge the risk of collision without issuing.

【0061】

[Effect of the invention]

As described above, according to the present invention, it is assumed that the current traveling state of the own vehicle continues for a set time, and the first route section until after the set time based on the current traveling state and this first route section are defined. After setting the traveling area consisting of the second route section extended along the road shape, the objects hanging in the traveling area are extracted from the objects detected in the traveling direction of the own vehicle based on the position information. Since the possibility of collision with the own vehicle is judged from the position information of the extracted object, the course of the own vehicle can be predicted by accurately reflecting the driver's steering wheel operation, and obstacles and preceding vehicles can be appropriately identified. Excellent effects such as being able to accurately determine the risk of collision without detecting and issuing an unnecessary alarm can be obtained.

[Simple explanation of drawings]

[Figure 1]

A block diagram of a collision prevention device according to the first embodiment of the present invention. [Figure 2]

Same as above, circuit block diagram of collision prevention device [Fig. 3]

Same as above, Flow chart of collision judgment processing [Fig. 4]

Same as above, explanatory diagram showing the position of the own vehicle after traveling for T0 seconds [Fig. 5]

Same as above, explanatory diagram showing the traveling area [Fig. 6]

Flow chart of collision determination processing according to the second embodiment of the present invention. [Fig. 7]

Flow chart of collision determination processing according to the third embodiment of the present invention. [Fig. 8]

Same as above, explanatory diagram showing detection of lane change [Fig. 9]

Same as above, explanatory diagram showing the traveling area [Fig. 10]

A block diagram of a collision prevention device according to a fourth embodiment of the present invention. [Explanation of symbols]

1 ... Vehicle (own vehicle) 2 ... Collision prevention device 10 ... Stereo optics 50 ... Image processing unit 60 ... Collision Judgment Department