JP3195838B2 - Vehicle safety devices - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a driving safety device for avoiding contact with an obstacle such as a preceding vehicle existing in front of a host vehicle. The present invention relates to an improvement of a device for detecting a distance or the like.

[0002]

2. Description of the Related Art Conventionally, as a driving safety device for a vehicle of this type, for example, as disclosed in Japanese Patent Application Laid-Open No. 53-16230, a radar device is used to connect a host vehicle to an obstacle ahead. The distance and relative speed are continuously detected, and based on the detection results, it is determined whether or not the vehicle may come into contact with an obstacle in front of the vehicle. It is known to apply a braking force to each wheel or to activate a warning device to issue a warning to a driver.

[0003] In particular, when the information of an obstacle is not output from the radar apparatus, the information of the distance and the relative speed to the obstacle are determined by using the information obtained up to that time. It is disclosed that a current value is estimated and a possibility of contact is determined based on the current value.

[0004]

However, when information on an obstacle is no longer output from the radar apparatus, the current value of the distance to the obstacle and the like are always estimated using the information so far to determine the possibility of contact. There is a problem to do. That is, when the driver steers to avoid contact with an obstacle, the obstacle relatively moves out of the detection area of the radar device, so that information on the obstacle is not output from the radar device. Also at this time, if the current value of the distance to the obstacle or the like is estimated using the information obtained up to that time to determine the possibility of contact, it is determined that there is a possibility of contact, and automatic braking, warning, etc. Will operate. As a result, there is a problem that the driver may interfere with steering as a contact avoidance measure, or a warning is frequently issued.

[0005] The present invention has been made in view of such a point, and an object of the present invention is to provide a method for controlling the current value of the distance to an obstacle when the driver steers to avoid contact with the obstacle. By restricting guesswork and judgment on the possibility of contact based on this, it is possible to judge the possibility of contact appropriately and prevent malfunctions such as alarms and automatic braking caused by unnecessary estimations while ensuring safety. It is intended to provide a driving safety device for the obtained vehicle.

[0006]

According to a first aspect of the present invention, there is provided a radar apparatus for transmitting a radar wave toward the front of a host vehicle and detecting an obstacle existing in front of the host vehicle. A driving safety device for a vehicle which determines the possibility of contact between the host vehicle and the obstacle based on information on the obstacle detected by the radar device, when the information on the obstacle is no longer output from the radar device, Estimating means for estimating at least the current value of the distance between the host vehicle and the obstacle based on the information up to and information based on the information from the estimating means when information on the obstacle is no longer output from the radar device. Contact possibility determining means for determining the possibility of contact between the own vehicle and an obstacle, steering time detecting means for detecting the time of steering of the own vehicle, receiving a signal of the detecting means, and Obstruction from radar equipment When the information of the object is no longer output, a configuration and a restricting means for restricting a guess by the estimating means.

[0007] The restricting means is provided when the own vehicle is steered.
Of which, in particular, the distance between the vehicle and the obstacle is less than or equal to a predetermined value
Obstruction information is output from the radar device during steering at
Guessing by the above guessing means only when it is no longer
It is provided so as to regulate.

[0008]

According to the above-mentioned structure, according to the first aspect of the present invention,
When the radar information is no longer output from the radar device, the estimating means usually determines at least the current distance between the host vehicle and the obstacle based on information obtained before the output of the obstacle information. In addition to estimating the value, the contact possibility determining means determines the possibility of contact between the host vehicle and the obstacle based on information from the estimating means. Then, when there is a possibility of contact, contact avoidance measures such as an alarm and automatic braking are taken to avoid contact between the host vehicle and the obstacle.

On the other hand, when information on an obstacle is no longer output from the radar device during steering of the host vehicle, the estimation by the estimation means is restricted or prohibited by the restriction means for receiving a signal from the steering time detection means. The contact possibility judging means does not judge the possibility of contact based on the information from the estimating means. This can prevent unnecessary contact avoidance measures such as alarms and automatic braking. Here, during the steering of the own vehicle, particularly when the distance between the own vehicle and the obstacle is equal to or less than a predetermined value, when the information of the obstacle is not output from the radar device during the steering, that is, when the driver Only when steering is performed to avoid contact with an object, the guess by the estimating means is restricted, so that malfunctions such as alarms and automatic braking caused by unnecessary guess can be reliably prevented.

[0010]

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

FIG. 1 shows a block configuration of a vehicle safety device according to an embodiment of the present invention. In this figure, 1
Is a radar head unit provided at the front of the vehicle body. The radar head unit 1 transmits a pulse laser beam as a radar wave from a transmitting unit toward the front of the own vehicle, and a preceding vehicle or the like existing in front of the vehicle. The receiving unit receives the reflected wave reflected on the obstacle. The radar head unit 1 is of a scanning type that scans a pulse laser beam transmitted from its transmitter at a relatively wide angle in the horizontal direction. The signal from the radar head unit 1 is input to the arithmetic unit 2 and the arithmetic unit 2
In the above, the distance between each obstacle existing in the scanning range and the own vehicle, the direction of the obstacle with respect to the own vehicle, and the like are calculated based on the delay time from the transmission time of the laser reception light. The radar head unit 1 and the arithmetic unit 2 constitute a scan-type 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 a steering angle). Reference numeral 5 denotes a vehicle speed sensor for detecting a vehicle speed of the host vehicle. The signals are both 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. In addition, the traveling route prediction means 6 also calculates the sideslip angle β of the vehicle. The curvature radius R and the sideslip angle β are calculated by the following equation (1).

[0013]

(Equation 1) Further, among obstacles detected by the radar device 3, reference numeral 11 denotes an obstacle existing in an area along the traveling path predicted by the traveling path prediction means 6 and closest to the host vehicle (hereinafter referred to as a recent obstacle). The information on the closest obstacle identified by the identification means 11 is input to the contact possibility determination means 12, and the identification means 1
At 2, the possibility of contact between the host vehicle and the obstacle is determined. Then, when there is a possibility of contact, based on the control signal output from the determination means 12, the actuator 13 of the automatic braking device operates to apply a braking force to each wheel,
Further, prior to the braking, the alarm device 14 is operated to issue an alarm to the driver.

In addition, reference numeral 21 denotes a storage unit for storing obstacle information output from the radar device 3 (arithmetic unit 2) for a predetermined time, and reference numeral 22 denotes estimating means for receiving obstacle information from the radar device 3. Thus, the estimating means 22 includes the radar device 3
Is to estimate the current value of the distance between the host vehicle and the obstacle based on the information on the obstacle stored in the storage unit 21 when the information on the obstacle is no longer output from the storage unit 21 It is. The contact possibility judging means 12 is configured to automatically output information on the obstacle based on the information from the estimating means 22 when the information on the obstacle is not output from the radar device 3 and the closest obstacle cannot be grasped by the identifying means 11. The possibility of contact between the vehicle and an obstacle is determined.

Numeral 23 denotes a regulating means to which signals are inputted from the steering angle sensor 4 and the radar device 3. The regulating means 23 outputs information on obstacles from the radar device 3 when the vehicle is steered. When the guessing means 22 is no longer
Guesses by The steering angle sensor 4
Has a function as a steering time detecting means for detecting the time of steering of the own vehicle.

Next, the identification of the nearest obstacle by the identification means 11, the estimation by the estimation means 22, and the regulation of the estimation by the restriction means 23 will be described in detail with reference to the flowcharts shown in FIGS.

In FIGS. 2 and 3, after starting,
First, in step S11, data from the traveling path predicting means 6 (that is, turning radius R and side slip angle β of the traveling path) is obtained, and in step S12, data from the radar device 3 (arithmetic unit 2) is obtained. The data of the radar device 3 is M
And the distance Li between the obstacle and the vehicle (i = 1 to M).
), The horizontal angle φi of the obstacle from the center line of the radar device 3 (which substantially coincides with the center line of the host vehicle) and the no-echo counter Ci. Note that the no-echo counter Ci is required between one obstacle (i = n) in scanning the radar apparatus 3 in one direction and an obstacle (i = n-1) adjacent to the scanning direction leading side. It shows the time when it was done.

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

After the initial value is set, i is counted up by 1 in step S14, and it is determined in step S15 whether i is equal to or less than M. If the determination is YES, ψo, ψmin, and ψmax 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. 4, ψo is the forward movement of the host vehicle A and Li in front. A straight line a2 connecting the center line CL of the road is an included angle formed by the center line a1 of the vehicle A (center line of the radar device 4). W is the width of the traveling path B, which is set to a value slightly larger than the 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 ahead of Li with respect to the center line a1 of the host vehicle A (center line of the radar device 4). However, the sign is positive in the clockwise direction. In FIG. 4, R is the radius of curvature of the traveling path, β is the side slip angle of the vehicle A, and is the included angle between the traveling direction (velocity vector vo) of the vehicle A and the center line a1.

Subsequently, in step S17, a no-echo counter Ci is added to to, and the added value is newly set as to. Thereafter, 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 road and the host vehicle is smaller than In. If the determination is YES, the distance Li is set to 1 in step S20.
n and to are respectively set to tn. Thereafter, the process returns to step S14. Also, when 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 nearest obstacle and the host vehicle is set to ln.

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

Subsequently, it is determined in step S22 whether or not ln is infinite, that is, whether or not the initial value is set. If the initial value is still set, ln is set to 0 in step S23, and step S31 is performed. 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 (nearest obstacle) in the traveling path. If the determination is YES, n count is set to 0 in step S32, and the relative speed is set in step S33. After performing various substitutions for calculating the distance between the host vehicle and the nearest obstacle (ie, the current value) lo at the present time by an interpolation method such as the least square method in step S34, The relative speed V between the current vehicle and the nearest obstacle is calculated using the distance lo, and then the process returns.

On the other hand, if the determination in step S31 is NO, the n count is incremented by one in step S35, and then it is determined in step S36 whether the n count is equal to or less than a predetermined number N. When this determination is YES,
In step S37, the distance ln between the obstacle and the host vehicle immediately before the nearest obstacle in the traveling path B disappears (that is, immediately before the information on the obstacle is no longer output from the radar device 3) is larger than the predetermined distance La. It is determined whether or not the steering angle θH is too short based on the signal of the steering angle sensor 4 in step S38.
It is determined whether or not the absolute value of is equal to or greater than the predetermined value θa and the vehicle is being steered. One of the two determinations is N
In the case of O, in step S39, the distance l0 between the current vehicle and the nearest obstacle is calculated by extrapolation using the data up to the previous time. The current value of this distance l 0 is the distance l n between the nearest obstacle just before the closest obstacle disappears.
And the relative velocity V, it is estimated by the following equation.

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

The estimation of the distance lo is performed by the estimation means 22.
Done in Return 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 determinations in steps S37 and S38 are both Y.
In the case of ES, that is, when steering is performed in a state where the obstacle before disappearance and the own vehicle are approaching, the n count is set to 0 in step S40, and lj,
Set both tj to 0. In step S42, the distance lo and the relative speed V between the host vehicle and the nearest obstacle are both set to 0, and then the process returns. Step S36 ~
Each of the determinations in S38 is performed by the above-described restricting means 23. The restricting means 23 determines whether a predetermined time has elapsed since the nearest obstacle disappeared, or the obstacle before the disappearance came close to the own vehicle. When the steering is performed in this state, the estimation of the distance lo by the estimating means 22 is prohibited.

Next, the operation and effect of the above embodiment will be described. Normally, the identification means 11 selects one of the M obstacles detected by the radar device 3 on the traveling path B of the vehicle A. The obstacle closest to the own vehicle is identified, and information on the closest obstacle (the current value of the distance lo and the relative speed V between the own vehicle and the obstacle) is output to the contact possibility determining means 12.
The determining means 12 determines the possibility of contact between the host vehicle and the nearest obstacle based on the obstacle information from the identifying means 11, and when there is a possibility of contact, the actuator of the automatic braking device 13 to apply a braking force to each wheel to apply braking, and prior to the braking, activate an alarm device 14 to issue an alarm to the driver. As a result, contact between the vehicle and the nearest obstacle on the traveling path can be avoided, and safety can be ensured.

On the other hand, when the information on the obstacle is no longer output from the radar device 3, the regulating means 23 checks the elapsed time from the disappearance of the nearest obstacle,
It is determined whether or not steering has been performed in a state where the obstacle before disappearance and the own vehicle are approaching. If not, the estimating means 22 calculates the relative speed V between the host vehicle and the obstacle based on the information stored in the storage unit 21 and obtained before the non-output of the obstacle information. While keeping the current value at 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 outputs the information from the estimation means 22. The possibility of contact between the own vehicle and the obstacle is determined based on Then, when there is a possibility of contact, the contact possibility determining means 12 outputs an alarm and an automatic contact avoidance measure as a contact avoidance measure, as in the case of the contact possibility determination based on the obstacle information from the identification means 11 described above. Since braking is applied, contact between the host vehicle and an obstacle can be avoided.

When the host vehicle approaches an obstacle, the driver may steer to avoid contact with the obstacle. In such a case, the radar device 3
When the information on the obstacle is no longer output from, the estimation by the estimating means 22 is prohibited by the restricting means 23, so that the contact possibility judging means 12 also outputs the estimating means 22.
The possibility of contact based on information from is not determined. As a result, the automatic braking is not activated and does not hinder the steering as the contact avoidance measure by the driver himself, and it is also possible to prevent frequent occurrence of alarms.

In the above embodiment, the steering angle θH
, The steering time of the host vehicle is detected from the vehicle. However, instead of the steering angle θH or together with the steering angle θH, the steering angle speed (dθH / d) is detected.
Of course, it may be configured to detect the time of steering of the own vehicle from t).

[0034]

As described above, according to the vehicle driving safety device of the present invention, when the information on the obstacle is not output from the radar device, the information obtained before the non-output of the obstacle information is usually obtained. While the current value of the distance to the obstacle is estimated based on the information and the possibility of the contact is determined, when the obstacle information is not output due to the steering of the own vehicle, the above estimation and the determination of the possibility of the contact are performed. Is regulated or prohibited, so that it is possible to appropriately judge the possibility of contact and prevent malfunctions such as alarms and automatic braking caused by unnecessary guesses while ensuring safety. Can be.

[Brief description of the drawings]

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

FIG. 2 is a flowchart illustrating a method for identifying a nearest obstacle.

FIG. 3 is a flowchart illustrating a method for calculating a distance between a host vehicle and a nearest obstacle;

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

[Explanation of symbols]

 Reference Signs List 3 radar device 4 steering angle sensor (steering detection means) 12 contact possibility determination means 22 estimation means 23 regulating means

Continuing from the front page (72) Inventor Toru Yoshioka 3-1 Shinchi, Fuchu-cho, Aki-gun, Hiroshima Mazda Corporation (72) Inventor Kenichi Okuda 3-1 Shinchi, Fuchu-cho, Aki-gun, Hiroshima Mazda Corporation (72) Inventor Yasunori Yamamoto 3-1 Shinchi, Fuchu-cho, Aki-gun, Hiroshima Mazda Co., Ltd. (72) Inventor Satoshi Morioka 3-1 Shinchi, Fuchu-cho, Aki-gun, Hiroshima Mazda Co., Ltd. (72) Inventor Tomohiko Adachi 3-1, Shinchi, Fuchu-cho, Aki-gun, Hiroshima Prefecture Inside Mazda Co., Ltd. (56) References JP-A-53-16230 (JP, A) JP-A-4-245600 (JP, A) 2-7156 (JP, U) JP-A 4-57474 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) G08G 1/16 B60R 21/00 621 G01S 13/93

Claims (1)

(57) [Claims] A radar device for transmitting a radar wave forward of the host vehicle and detecting an obstacle existing in front of the host vehicle;
A driving safety device for a vehicle that determines the possibility of contact between the host vehicle and the obstacle based on information on the obstacle detected by the radar device, wherein when the information on the obstacle is no longer output from the radar device, Estimating means for estimating at least a current value of the distance between the host vehicle and the obstacle based on the information of the obstacle, based on the information from the estimating means when information on the obstacle is no longer output from the radar device. Contact possibility determining means for determining the possibility of contact between the own vehicle and an obstacle; steering time detecting means for detecting when the own vehicle is being steered; receiving the signal from the detecting means; When the device no longer outputs obstacle information,
And a restricting means for restricting a guess by the estimating means, the regulating means, among during steering of the vehicle, in particular vehicle
When steering when the distance to the obstacle is less than the predetermined value,
When obstacle information is no longer output from the radar device
Only to regulate the guess by the above guess means
Running safety device for a vehicle, characterized in that it is.