JPH06206506A - Travel safety device of vehicle - Google Patents

Abstract

PURPOSE:To conduct adequately the conjecture of distance between one's own vehicle and an obstacle and prevent the wrong action of an alarm, automatic brake or the like caused by unnecessary conjecture while safety is being secured. CONSTITUTION:When the information of obstacles ceases to be outputted from a radar device 3, a conjecture means 22, on the basis of information memorized at a memory portion 21 till that time, at least conjectures continuously for a predetermined time the present value of a distance between one's own vehicle and an obstacle, and at the same time a contact possibility judging means 12 judges the contact possibility of one's own vehicle and the obstacle on the basis of information from the conjecture means 22. Also, the pitching quantity of one's own vehicle is detected by means of a sensor 23, and a conjecture method changing means 24 which changes a conjecture method that is by means of the above conjecture means 22, according to its size, is provided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a traveling safety device for avoiding contact with an obstacle such as a preceding vehicle existing in front of a host vehicle, and more particularly, to a vehicle and an obstacle using a radar device. It is related to the improvement of the one that detects the distance and the like.

[0002]

2. Description of the Related Art Conventionally, as a traveling safety device for a vehicle of this type, as disclosed in, for example, Japanese Patent Application Laid-Open No. 53-16230, a radar device is used to provide a space between an own vehicle and an obstacle ahead. The distance and relative speed are continuously detected, and based on the detection results, it is judged whether or not the own vehicle may come into contact with a front obstacle, and the automatic braking device is activated when there is a possibility of contact. It is known that a braking force is applied to each wheel or an alarm device is activated to give an alarm to a driver.

In particular, in the above-mentioned publications, when information on an obstacle is no longer output from a radar device, the information obtained up to that point is used to determine the distance and relative velocity to the obstacle. It is disclosed that the present value is estimated and the possibility of contact is determined based on that value.

[0004]

However, in both cases in which the host vehicle makes a large pitching motion depending on the road condition or the like, and when the host vehicle hardly makes a pitching motion,
There is a problem in uniformly estimating the obstacle when the obstacle disappears (that is, when the information about the obstacle is not output from the radar device). In other words, when the host vehicle makes a large pitching motion, the radar device easily loses sight of the obstacle in front of it, so it is necessary to estimate the distance to the obstacle when the obstacle disappears for a relatively long time. This is because, when the host vehicle hardly makes a pitching motion, it is almost unnecessary to estimate the distance to the obstacle when the obstacle disappears.

The present invention has been made in view of the above points, and an object of the present invention is to change the estimation method when an obstacle disappears in accordance with the pitching state of the host vehicle so as to reduce the possibility of contact. An object of the present invention is to provide a vehicle running safety device capable of appropriately making a judgment and ensuring safety while preventing malfunctions such as an alarm and automatic braking due to unnecessary estimation.

[0006]

In order to achieve the above object, the invention according to claim 1 is provided with a radar device for transmitting a radar wave toward the front of the host vehicle to detect an obstacle existing in the front. A vehicle running safety device that determines the possibility of contact between the vehicle and the obstacle from information on the obstacle detected by the radar device, when the obstacle information is no longer output from the radar device. Based on the information up to at least the estimation means for continuously estimating the current value of the distance between the own vehicle and the obstacle for a predetermined time, and the estimation means when the information on the obstacle is not output from the radar device. The contact possibility determination means for determining the possibility of contact between the own vehicle and the obstacle based on the information from, the pitching amount detection means for detecting the pitching amount of the own vehicle, and the information on the obstacle from the radar device. Depending on the pitching amount of the vehicle when it is no longer a force, a configuration and a speculation method changing means for changing the guess method by the estimating means.

The invention according to claim 2 is dependent on the invention according to claim 1, and shows an example of a change by the estimating method changing means which is one of the components. That is, the estimating method changing means makes an estimation by the estimating means when the pitching amount of the host vehicle when the obstacle information is no longer output from the radar device is larger than a predetermined value, and the pitching amount is larger than the predetermined value. When it is small, it is provided to prohibit the guessing by the guessing means.

[0008]

With the above construction, in the invention according to claim 1,
When the obstacle information is no longer output from the radar device, the estimating means determines at least the current value of the distance between the host vehicle and the obstacle based on the information obtained before the obstacle information was not output. At the same time as the estimation, the contact possibility determination means determines the possibility of contact between the host vehicle and the obstacle based on the information from the estimation means. When there is a possibility of contact, contact avoidance measures such as an alarm and automatic braking are taken to avoid contact between the vehicle and the obstacle.

In this case, the estimating method by the estimating means is changed by the estimating method changing means according to the pitching amount of the host vehicle. For example, when the pitching amount of the host vehicle is large and the radar device easily loses sight of an obstacle on the traveling road as in the invention described in claim 2, safety is ensured by making a guess by the guessing means, while the pitching amount is made. When is smaller than a predetermined value, it is possible to prohibit the estimation by the estimating means and prevent an erroneous operation such as an alarm or automatic braking due to unnecessary estimation.

[0010]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows a block configuration of a vehicle running safety device according to an embodiment of the present invention. In this figure, 1
Is a radar head unit provided in the front part of the vehicle body. The radar head unit 1 emits pulsed laser light as a radar wave toward the front of the host vehicle from the transmitter, and the preceding vehicle and the like existing in the front. The receiving section receives the reflected wave reflected by the obstacle. Further, the radar head unit 1 is of a scan type in which the pulsed laser light emitted from its emission portion is scanned in a horizontal direction at a relatively wide angle. The signal of the radar head unit 1 is input to the calculation unit 2 and the calculation unit 2
In the above, the distance between each obstacle existing within the scanning range and the host vehicle, the direction of the obstacle with respect to the host vehicle, and the like are calculated based on the delay time from the time when the laser received light is emitted. The radar head unit 1 and the computing unit 2 constitute a scanning radar device 3 that detects an obstacle existing in front of the host vehicle.

Reference numeral 4 denotes a steering angle sensor for detecting a steering angle of a steering handle (hereinafter, simply referred to as steering steering angle). Reference numeral 5 denotes a vehicle speed sensor for detecting a vehicle speed of the own vehicle. Both signals are input to the traveling route prediction means 6. The traveling path predicting means 6 predicts the traveling path of the host vehicle based on the steering angle θH and the vehicle speed v0, and specifically calculates the radius of curvature R of the traveling path. Further, the traveling road predicting means 6 also calculates the sideslip angle β of the vehicle. The radius of curvature R and the sideslip angle β are calculated by the following formula 1.

[0013]

[Equation 1] Further, 11 is an obstacle (hereinafter, recently referred to as an obstacle, which is present in the region along the traveling route predicted by the traveling route predicting means 6 and is closest to the own vehicle, among the obstacles detected by the radar device 3. The information of the closest obstacle identified by the identifying means 11 is input to the contact possibility determining means 12, and the determining means 1
At 2, the possibility of contact between the vehicle and the obstacle is judged. When there is a possibility of contact, the actuator 13 of the automatic braking device is actuated based on the control signal output from the determination means 12 to apply the braking force to each wheel,
Further, prior to the braking, the warning device 14 is activated to give a warning to the driver.

In addition, 21 is a storage unit for storing the information of obstacles output from the radar device 3 (calculation unit 2) for a predetermined time, and 22 is an estimating means for receiving the obstacle information from the radar device 3. Then, the estimating means 22 uses the radar device 3
When the obstacle information is no longer output from the vehicle, the present value of the distance between the host vehicle and the obstacle is estimated based on the obstacle information stored in the storage unit 21 up to that point. Is. The contact possibility determination means 12 automatically detects the obstacle based on the information from the estimation means 22 when the obstacle information is not output from the radar device 3 and the closest obstacle cannot be grasped by the identification means 11. It is designed to judge the possibility of contact between the vehicle and obstacles.

Reference numeral 23 is a pitching sensor as a pitching amount detecting means for detecting the pitching amount of the host vehicle. The pitching sensor 23 uses, for example, strut suspension devices on the front and rear wheels. In the case of such a vehicle, the amount of pitching is detected by measuring the amount of expansion and contraction change of the struts in both suspension devices and determining the difference. Reference numeral 24 is an estimation method changing means for receiving the respective signals from the pitching sensor 23 and the radar device 3, and the changing means 24
Is to change the estimation method by the estimation means 22 in accordance with the pitching amount of the host vehicle when the obstacle information is no longer output from the radar device 3.

Next, the identification of the closest obstacle by the identification means 11, the estimation by the estimation means 22 and the change of the estimation method by the change means 24 will be described in detail with reference to the flow charts shown in FIGS.

2 and 3, after the start,
First, in step S11, the data from the traveling road predicting means 6 (that is, the turning radius R and the sideslip angle β of the traveling road) are obtained, and in step S12, the data from the radar device 3 (calculation unit 2) is obtained. The data of this radar device 3 is M
It is composed of individual obstacle data, and as each of the obstacle data, the distance Li (i = 1 to M between the obstacle and the own vehicle).
), The horizontal angle φi of the obstacle from the center line of the radar device 3 (substantially coincident with the center line of the own vehicle) and the no echo counter Ci. It should be noted that the no-echo counter Ci is required between one obstacle (i = n) when scanning the radar device 3 in one direction and an obstacle (i = n -1) adjacent to the leading side in the scanning direction. It indicates the time taken.

Then, in step S13, ln is set to infinity, t
Initial values are set with n being 0 and i being 0. Where ln
Means the distance from the obstacle closest to the host vehicle among the obstacles existing on the traveling path.

After setting the initial value, i is incremented by 1 in step S14, and then it is determined in step S15 whether i is M or less. When this determination is YES, ψ o, ψ min and ψ max are calculated by the following equations in step S16.

Ψo = (Li / 2R) -βψmin = ψo- (W / 2Li) ψmax = ψo + (W / 2Li) Here, as shown in FIG. A straight line a2 connecting the center line CL of the road is an included angle with respect to the center line a1 of the host vehicle A (center line of the radar device 4) a1. W is the road width of the traveling road B and is set to a value slightly larger than the vehicle width of the host vehicle A. ψmin and ψmax are the included angles formed by the straight lines connecting the host vehicle A and the left and right ends of the traveling path B in front of Li with the center line (center line of the radar device 4) a1 of the host vehicle A. However, the sign is positive in the clockwise direction. In FIG. 4, R is the radius of curvature of the traveling road, β is the side slip angle of the host vehicle A, which is the included angle between the traveling direction of the host vehicle A (speed vector vo) and the center line a1.

Then, in step S17, the no echo counter Ci is added to to, and the added value is newly set as to. Then, in step S18, it is determined whether or not the horizontal angle φi of the obstacle is a value between ψmin and ψmax, that is, whether or not the obstacle is on the traveling path B. Subsequently, in step S19, it is determined whether or not the distance Li between the obstacle on the traveling path and the vehicle is smaller than ln. If the determination is YES, the distance Li is set to l in step S20.
Set to n and to to tn, respectively. Then, the process returns to step S14. Also, if the determination in step S18 or S19 is NO, the process returns to step S14.

By repeating the above steps S14 to S20, the obstacle closest to the own vehicle on the traveling path B of the own vehicle A is identified from the M obstacles detected by the radar device 3, and The distance between the closest obstacle and the vehicle is set as ln.

When all the M obstacle data have been checked, the value obtained by subtracting tn from to is newly set as to (= to-tn) in step S21. Here, the previous to is the addition value of the no echo counter of all data from the time when the closest obstacle is detected during the previous frame scanning of the radar device 3, and tn is 1 of the radar device 3 from the replacement in step S20. This is the time required to scan the nearest obstacle during frame scanning. Therefore, the new to is the time from the detection time of the closest obstacle to the detection time of the obstacle detected last, and the latest obstacle is detected when the radar device 3 scans the next one frame with respect to this time to. By adding the no echo counter Ci until the object is detected, the time required to detect the nearest obstacle twice in two frame scanning is measured. This time is used for calculating the relative speed V between the own vehicle and the closest obstacle in step S34 described later.

Subsequently, in step S22, it is determined whether or not ln is infinity, that is, whether the initial value is still set. If the initial value is still set, ln is set to 0 in step S23, and step S31 Move to. When ln is a finite value, the process directly proceeds to step S31.

In step S31, it is determined whether or not there is an obstacle (closest obstacle) in the traveling path. If the determination is YES, the n count is set to 0 in step S32, and the relative speed is set in step S33. After performing various replacements for calculating, the distance (that is, the current value) lo between the current vehicle and the closest obstacle is calculated by an interpolation method such as the least square method in step S34, and The relative velocity V between the current vehicle and the closest obstacle is calculated using the distance l0, and the process returns thereafter.

On the other hand, when the determination in step S31 is NO, the n count is incremented by 1 in step S35, and then it is determined in step S36 whether or not the n count is less than or equal to a predetermined number N. If this determination is YES,
In step S37, it is determined whether or not the pitching amount of the host vehicle is equal to or greater than the predetermined value a, and if this determination is YES, in step S38, the data up to the previous time is used to extrapolate the vehicle to the closest point at the present time Calculate the distance l0 to the obstacle. The current value of this distance lo is estimated by the following equation using the distance ln between the closest obstacle and the obstacle immediately before the closest obstacle disappears and the relative velocity V.

Lo = ln + VT where T is the elapsed time from the time when the closest obstacle disappeared.

The estimation of the distance lo is performed by the estimation means 22.
Done in. It returns after this guess.

When the determination in step S36 is NO, that is, when a predetermined time has elapsed since the closest obstacle disappeared, or when the determination in step S37 is NO, that is, the pitching amount of the vehicle is a predetermined value. When it is smaller than a, the n count is set to 0 in step S39, and lj and tj are both set to 0 in step S40. In step S41, both the distance l0 and the relative speed V between the host vehicle and the closest obstacle are set to 0, and then the process returns. Each determination in steps S36 and S37 is performed by the estimating method changing means 24, and the changing means 24
When the pitching amount of the host vehicle when the information on the obstacle is not output from the radar device 3 is larger than the predetermined value a, the estimation unit 22 continuously makes an estimation for a predetermined time, and the pitching amount is a predetermined value. When it is smaller than the above, the estimation by the estimating means 22 is prohibited.

Next, in order to explain the operation and effect of the above-mentioned embodiment, normally, the identifying means 11 selects the M obstacles detected by the radar device 3 on the traveling path B of the host vehicle A. The obstacle closest to the host vehicle is identified, and information about the closest obstacle (the distance l0 between the host vehicle and the obstacle and the current value of the relative speed V) is output to the contact possibility determination means 12.
Then, the judging means 12 judges the possibility of contact between the host vehicle and the closest obstacle based on the obstacle information from the identifying means 11, and when there is the possibility of contact, the actuator of the automatic braking device 13 is activated to apply a braking force to each wheel to apply a braking force, and the alarm device 14 is activated prior to the braking to issue an alarm to the driver. As a result, it is possible to avoid contact between the own vehicle and the closest obstacle on the traveling road, and ensure safety.

On the other hand, when the obstacle information is no longer output from the radar device 3, the estimation method changing means 24 confirms the elapsed time from the disappearance time of the closest obstacle, and based on the signal from the pitching sensor 23. It is determined whether or not the pitching amount of the host vehicle is equal to or larger than the predetermined value a. Then, when the pitching amount is larger than the predetermined value a, the estimating unit 22 determines the own vehicle and the obstacle based on the information stored in the storage unit 21 before the obstacle information is not output. While keeping the current value of the relative speed V with respect to the previous value, the current value of the distance l0 between the host vehicle and the obstacle is continuously estimated for a predetermined time, and the contact possibility determination means 12 The possibility of contact between the vehicle and the obstacle is determined based on the information from the estimation unit 22. Then, when there is a possibility of contact, the contact possibility determination means 12 issues an alarm and an automatic contact avoidance measure as in the case of the contact possibility determination based on the obstacle information from the identification means 11. Since braking is applied, it is possible to avoid contact between the vehicle and the obstacle.

When the pitching amount is smaller than the predetermined value a, the estimation by the estimating means 22 is prohibited by the estimating method changing means 24. Therefore, the contact possibility determining means 12 also includes information from the estimating means 22. The possibility of contact based on it is not judged. As a result, it is possible to prevent the automatic braking and the alarm from being unnecessarily activated.

In the above embodiment, the estimation method changing means 2
Reference numeral 4 indicates that when the pitching amount of the host vehicle when the obstacle information is no longer output from the radar device 3 is larger than the predetermined value a, the estimation unit 22 continuously makes an estimation for a predetermined time, and the pitching amount is a predetermined value. When it is smaller than a, it is provided so that the estimation by the estimation means 22 is prohibited.
According to the present invention, the estimation method changing means 24 makes the duration of the estimation by the estimating means 22 longer when the pitching amount of the own vehicle is larger than the predetermined value a so that the pitching amount of the own vehicle is larger than the predetermined value a. If the time is small, the duration of the estimation by the estimating means 22 may be shortened.

[0034]

As described above, according to the vehicle traveling safety device of the present invention, the possibility of contact is appropriately determined by changing the estimation method when an obstacle disappears according to the pitching state of the host vehicle. Therefore, it is possible to prevent malfunctions such as alarms and automatic braking due to unnecessary estimation while ensuring safety.

[Brief description of drawings]

FIG. 1 is a block configuration diagram of a vehicle running safety device according to an embodiment of the present invention.

FIG. 2 is a flowchart showing a method for identifying a closest obstacle.

FIG. 3 is a flowchart showing a method of calculating a distance between a host vehicle and a closest obstacle.

FIG. 4 is a schematic diagram showing a positional relationship between a host vehicle and a traveling road.

[Explanation of symbols]

 3 radar device 12 contact possibility judging means 22 estimating means 23 pitching amount detecting means 24 estimating method changing means

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Toru Yoshioka No. 3 Shinchi Fuchu-cho, Aki-gun, Hiroshima Prefecture Mazda Co., Ltd. (72) Inventor Kenichi Okuda No. 3 Shinchi, Fuchu-cho, Aki-gun, Hiroshima Mazda Corporation (72) Inventor Satoshi Morioka, 3-1, Shinchi, Fuchu-cho, Aki-gun, Hiroshima Mazda Co., Ltd. (72) Inventor, Yasunori Yamamoto 3-1-1, Shinchi, Fuchu-cho, Aki-gun, Hiroshima (72) Invention Tomohiko Adachi 3-1, Shinchi, Fuchu-cho, Aki-gun, Hiroshima Prefecture Mazda Motor Corporation

Claims (2)

[Claims] 1. A radar device for transmitting a radar wave to the front of the host vehicle to detect an obstacle existing in front of the host vehicle,
In a vehicle running safety device that determines the possibility of contact between the vehicle and the obstacle from information on the obstacle detected by the radar device, when the obstacle information is no longer output from the radar device until then Estimating means for continuously estimating the present value of the distance between the own vehicle and the obstacle based on the information of, and the estimating means when the information of the obstacle is not output from the radar device. Contact possibility determination means for determining the possibility of contact between the vehicle and the obstacle based on the information of the vehicle, pitching amount detection means for detecting the pitching amount of the vehicle, and information of the obstacle is output from the radar device. A traveling safety device for a vehicle, comprising: an estimating method changing means for changing the estimating method by the estimating means according to the amount of pitching of the host vehicle when the vehicle is no longer driven. 2. The estimating method changing means makes an estimation by the estimating means when the pitching amount of the host vehicle when the obstacle information is no longer output from the radar device is larger than a predetermined value, and the pitching amount is predetermined. The traveling safety device for a vehicle according to claim 1, wherein when the value is smaller than the value, the estimation by the estimating means is prohibited.