JP3167992B2 - Curve approach control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To set an allowable curve approach speed as a value suitable for the actual curve curvature radius even when the curve is a tight corner having a curve curvature radius set based on a node transmitted from a navigation device equal to or less than a prescribed ratio to road width. SOLUTION: When a curve curvature radius calculated by a front road attribute calculating part 25 based on node data transmitted from a navigation device 7 is a prescribed ratio or less to the road width of the curve, an allowable approach speed setting part 27 sets an allowable approach speed based on an allowable acceleration set by an allowable acceleration setting part 26 and the prescribed ratio to the road width. In this case, the prescribed ratio to the road width is set so as to be larger in an outer curve than that in an inner curve.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention sets an allowable approach speed for a forward curve on the basis of a road width and an allowable lateral acceleration in a tight corner in which a curvature radius of a curve ahead of a traveling road is equal to or less than a set ratio with respect to a road width. To a curve approach control device.

[0002]

2. Description of the Related Art Conventionally, an allowable approach speed for a forward curve detected by using road map data of a navigation device or a visual recognition device (a stereo camera or the like) is calculated, and a speed higher than the allowable approach speed, that is, a forward curve is calculated. Japanese Patent Application Laid-Open No. 4-23 discloses a vehicle traveling system which detects an overspeed state of the own vehicle with respect to the vehicle and performs an alarm or deceleration control.
No. 6699, for example.

[0003]

However, in a tight corner where the radius of curvature is close to the road width, as in the case of a vehicle running line indicated by a solid line in FIG. In many cases, the vehicle travels (so-called out-in-out) with a turning radius slightly larger than the actual curve radius of curvature by effectively using the road width.

[0004] In this case, the allowable approach speed for the curve is set according to the radius of curvature of the curve, so that the allowable approach speed is set to a value that is too low for the actual running (out-in-out). . As a result, the warning and the deceleration control become too sensitive contrary to the actual running, and the driver feels strange. This tendency is more pronounced when traveling on an outside curve (right curve in a country traveling on the left, left curve in a country traveling on the right).

In view of the above circumstances, the present invention makes it possible to set the allowable approach speed for a curve to an appropriate value according to the curve curvature of the actual running locus, and to provide a troublesome alarm or deceleration control that is contrary to the actual running. It is an object of the present invention to provide a curve entry control device that eliminates the problem and reduces the uncomfortable feeling given to a driver.

[0006]

In order to achieve the above object, a first curve approach control device according to the present invention calculates an allowable approach speed to a curve based on at least a radius of curvature of a forward curve, and calculates the allowable approach speed to the curve. In a curve approach control device that performs warning or deceleration control based on speed, when the radius of curvature is equal to or less than a set ratio with respect to the road width of the curve, the allowable approach speed for the curve is increased and corrected. In such a configuration, when the radius of curvature of the front curve of the vehicle is a tight corner that is equal to or smaller than the set ratio with respect to the curve road width, the allowable approach speed calculated based on the radius of curvature of the curve is increased and corrected to increase the allowable approach speed. The driver's discomfort caused by the approach speed being too low with respect to the actual running state is reduced.

A second curve entry control device is the first curve entry control device, wherein the set ratio is set to a larger value when the vehicle travels on an outer curve than when the vehicle travels on an inner curve. 2. The curve approach control device according to claim 1, wherein:

In such a configuration, by setting the set ratio of the curve to the road width to a value larger for the outer curve than for the inner curve, the allowable approach speed of the outer curve is set to an appropriate value corresponding to the actual running. It can be.

A third curve approach control measure is characterized in that, in the first curve approach control device, the set ratio is variably set according to a road type of the curve. In such a configuration, the allowable approach speed according to the road environment can be set by setting the setting ratio of the curve to the road width according to the road type.

The fourth curve entry control device calculates a permissible approach speed to the curve based on at least a radius of curvature of a forward curve, and performs a warning or deceleration control based on the permissible entry speed. Comparing at least the allowable approach speed set based on the radius of curvature with at least a predetermined value set according to the road width of the curve, and selecting a larger one as the allowable approach speed. Features. In such a configuration, by comparing the allowable approach speed, the allowable approach speed set based on the curvature radius of the curve, and a predetermined value <br/> to be set according to the road width of at least curves, the allowable approach By selecting the larger of the speed and the guard value as the actual allowable approach speed, it is possible to set an appropriate allowable approach speed along the actual traveling turning radius.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. FIG. 1 shows a functional block diagram of a control unit provided in the curve entry control device.

On the input side of the control unit 1, the yaw rate τ detected by the yaw rate sensor 2, the steering angle δf detected by the steering wheel angle sensor 3, and the lateral acceleration G detected by the lateral acceleration sensor 4 are provided.
y, the vehicle speed V detected by the vehicle speed sensor 5, the longitudinal acceleration detected by the longitudinal acceleration sensor 6, the brake pressure detected by the brake pressure sensor 9, and other data are input, and the navigation device 7 and the road shape detecting device 10 are input. Various signals output from are input.

As shown in FIG. 3, the navigation device 7
From, the number n of nodes transmitted on the own vehicle traveling route, the east longitude of the own vehicle, the north latitude of the own vehicle position, data on the node immediately after the own vehicle, data on the node immediately before the own vehicle, the second point in front of the own vehicle Data about nodes, ...
Information such as data relating to the node at the (n-1) th point in front of the vehicle is output periodically (for example, every 500 ms).

Further, the road shape detecting device 10 uses a CCD camera or the like to determine the state of the curve (the direction of the curve,
The degree of curvature and the like are detected, and the information is output to the control unit 1.

In the control unit 1, based on information detected by the sensors 2 to 6, 9, the navigation device 7, the road shape detection device 10 and the like, the vehicle is stable even when entering a curve ahead of the traveling road at the current speed. Calculate whether or not you can turn in the state where
The alarm device 11 including a buzzer, an audio alarm, a warning light, and the like is driven as necessary to notify the driver.

When it is necessary to forcibly decelerate, a deceleration command is output to the deceleration device 12. Reduction gear 1
In 2, the deceleration control is performed by downshifting the transmission, reducing the engine torque, operating the brakes, etc. in accordance with the deceleration command from the control unit 1.

In the control section 1 shown in FIG. 1, the road surface friction coefficient estimating section 21 first calculates the road surface friction coefficient based on parameters such as the yaw rate τ, the steering angle δf, the lateral acceleration Gy, and the vehicle speed V. μ is estimated using, for example, the calculation method described in Japanese Patent Application Laid-Open No. H8-2274 previously submitted by the present applicant. In the road gradient estimating unit 22,
The road gradient SL is estimated based on the rate of change of the vehicle speed V at each set time and the longitudinal acceleration calculated by the vehicle speed change calculation unit 23.

Further, the allowable deceleration setting unit 24 calculates the road condition based on the road surface friction coefficient μ and the road gradient SL based on the road condition.
An allowable deceleration XgLim, which is an allowable deceleration of the vehicle, is set.

The method of estimating the road gradient SL and the method of calculating the allowable deceleration XgLim have already been described in Japanese Patent Application Laid-Open No. H11-83501 previously submitted by the present applicant. Is omitted.

On the other hand, in the forward road attribute calculation storage unit 25,
Based on the information for each node P sent from the navigation device 7 (see FIG. 3), the distance Lp to the immediately preceding node, the radius of curvature rp of the curve, and the like are calculated for each of the nodes, and as the node attributes, It is stored in a storage means such as a RAM. In addition, the intersection attribute ip, the road width attribute wp, etc. are also stored in the storage means as respective node attributes.

That is, the navigation device 7 during traveling
Are the coordinates P0 (xp [0], yp [0]) and P1 (xp [1], yp [1] of each node based on the position of the vehicle, as shown in FIG.
),... Pj-1 (xp [j-1], yp [j-1]), Pj (xp [j]
, Yp [j]),... Pn-1 (xp [n-1], yp [n-1]), the node interval Lp [j] between the node Pj and the adjacent node Pj-1 is calculated from the following equation. calculate. Lp [j] = ｛(xp [j] −xp [j−1]) ² + (yp [j] −yp [j−
1]) ² ｝ ^1/2, where 1 ≦ j ≦ n−1.

Next, the node interval Lp at the node Pj
Node angle tp [j] which is the angle at which [j] and Lp [j + 1] intersect
(See FIG. 5) is calculated from the following equation. tp [j] = sin ^-1 [｛(xp [j-1] −xp [j]) · (yp [j]
−yp [j + 1]) − (xp [j] −xp [j + 1]) · (yp [j−1] −yp
[j])｝ / (Lp [j] · Lp [j + 1])] The node angle tp [j] obtained here is represented by a positive value in the case of a right curve, and in the case of a left curve. , Expressed as a negative value.

Then, based on the node intervals Lp [j], Lp [j + 1] and the node angle tp [j], the curvature radius rp [j] at the node Pj is calculated from the following equation. rp [j] = min (Lp [j], Lp [j + 1]) / 2 / tan (|
tp [j] | / 2) Here, min (Lp [j], Lp [j + 1]) means to select any shorter node interval, and in FIG. 5, Lp [j]
Since Lp [j + 1], the above equation is as follows: rp [j] = Lp [j] / 2 / tan (| tp [j] | / 2)

If there is an intersection at each node, the value of the intersection flag sent from the navigation device 7 is used as it is and stored as the intersection attribute ip [j]. In other words, the intersection attribute ip [j] is based on the value of the intersection flag sent from the navigation device. If the intersection is not an intersection, ip [j] = 0. If the intersection is an intersection, ip [j] = 1. In the case of an intersection on a guide route, ip [j] = 2 is set.

Further, the road width attribute wp [j] regarding the road width at each node is set using a road width flag sent from the navigation device 7. The road width attribute wp [j] has a value as shown in the following table for the range of the actual road width corresponding to the road width flag sent from the navigation device 7.

In the allowable lateral acceleration setting section 26, the road surface friction
Calculate the reference value ayl1 of the allowable lateral acceleration ayl according to several μ,
This reference value ayl1 is corrected by the road gradient SL, and the allowable lateral
Set the speed ayl2 and enter this allowable lateral acceleration ayl2 into the curve
Limit speed ((ayl1 / rp [j]) ^1/2)
Set the final allowable lateral acceleration ayl.

Here, the reference value ayl1 is as disclosed in Japanese Patent Application Laid-Open No. 11-83501 previously submitted by the present applicant, and can be obtained by the following equation. ayl1 = μ · Kμ · g where Kμ is a safety coefficient and g is a gravitational acceleration.

Further, the allowable lateral acceleration ayl2 can be obtained, for example, from the following equation. ^{ayl2 = (ayl1 2 - (g} · SL / 100) 2) 1/2

Further, the allowable lateral acceleration ayl can be calculated, for example, according to the following equation. ayl = ayl2 · Kv Here, Kv is a vehicle speed correction coefficient, which is set to a smaller value as the curve approach limit speed increases. That is, in order to enhance the safety during high-speed code binary ring running, the allowable lateral acceleration ayl at a curve with increasing curve approach limit speed is corrected so as to decrease.

The allowable lateral acceleration ayl is read by the allowable approach speed setting section 27. As shown in FIG. 2, the allowable approach speed setting unit 27 includes a reference value setting unit 27a, a curve configuration node identification unit 27b, and a node angle addition calculation unit 27.
c, curve depth correction unit 27d, tight corner correction unit 27
e, a speed smoothing correction unit 27f.

The reference value setting unit 27a calculates the allowable lateral acceleration ay set by the allowable lateral acceleration setting unit 26 for each node.
Based on l and the curve curvature radius rp [j] stored in the front road attribute calculation storage unit 25, a reference value vap0 of the allowable approach speed to the node Pj is calculated according to the following equation. vap0 = (ayl · | rp [j] |) ^1/2 Curve Configuration Node Identifying Unit 27b is for identifying a node group configuring one curve, the purpose of which is to specify an allowable approach speed reference value vap0, which will be described later. Curve depth (opening angle) tp
The object of the present invention is to perform a smoothing process for correcting the allowable approach speed at each node in the same curve by correcting with a.

As shown in FIG. 6, a pattern that constitutes one curve is composed of a single node Pj, and a pattern composed of a plurality of nodes Pj-1, Pj,. There is.

Here, whether or not the adjacent nodes Pj-1 and Pj belong to the same curve is determined by their node interval Lp [j].
And the sign (positive value or negative value) of the node angles tp [j-1] and tp [j].

That is, the node interval Lp [j] is a predetermined value (L
K · wp [j] LK (constant) (Lp [j] <
(LK · wp [j])) and each node angle tp [j-1],
If the sign of tp [j] is the same, it is determined that the nodes Pj-1 and Pj belong to the same curve.

Based on this condition, the node Pj- shown in FIG.
When examining 1, Pj, Pj + 1, Pj + 2, they belong to the same curve.

The node angle addition calculation unit 27c sequentially adds the node angles of the nodes on the same curve determined by the curve configuration node identification unit 27b, and calculates the curve depth t.
Calculate pa.

In FIG. 7, the curve depth tpa at the node Pj
Is: tpa = tp [j-1] + tp [j] Similarly, the curve depth tpa of the node Pj + 1 is: tpa = tp [j-1] + tp [j] + tp [j + 1] The curve depth tpa of the node Pj + 2 is as follows: tpa = tp [j-1] + tp [j] + tp [j + 1] + tp [j + 2]. Since the node Pj-1 shown in FIG. 7 is at the beginning of the curve, the curve depth tpa of the node Pj-1 is tpa = tp [j-1].

Further, as shown in FIG.
When one curve is constituted by j, the node angle tp [j] is directly substituted for the curve depth tp regarding this node Pj, and tpa = tp [j].

The curve depth correction unit 27d first calculates an offset angle T_OFSET. As shown in FIG. 8, the offset angle T_OFSET is an angle at which the vehicle can substantially travel on the curve without operating the steering wheel when entering the curve, and is located radially outward from the curve radius of curvature rp [j]. If the width of 1 m is assumed to be the allowable width of the road, it is calculated based on the following equation. T_OFSET = COS ^-1 {rp [j] / (1 + rp [j])} Then, the allowable approach speed reference value vap0 set by the reference value setting means 27a is converted to the curve depth tpa and the offset angle T_OFSE.
T, the curve radius of curvature rp, and the road surface friction coefficient μ obtained by the road surface friction coefficient estimating unit 21 to correct the allowable approach speed vap1.
(m / sec) is calculated. vap1 = ｛vap0 ² + 1 / (| tpa | −T_OFSET) ² · | 1 /
rp [j] | ² · (μ / vap1_k1)｝ ^{1/2 In} the present embodiment, vap1_k1 = 2.

As a result, as shown in FIG. 9, the allowable approach speed vap1 is set to the maximum value vapH until the curve depth tpa reaches the offset angle T_OFSET, and gradually increases as the curve depth tpa becomes deeper than the offset angle T_OFSET. The characteristic is set so as to approach the allowable approach speed reference value vap0. That is,
Here, a correction is made so that the allowable approach speed vap gradually decreases as the curve depth tpa increases.

The tight corner correction unit 27e is connected to the node Pj
The curve at is a tight corner and the curve radius of curvature is
When rp [j] is equal to or less than the value wk of the predetermined ratio rwk of the road width wp [j], the allowable approach speed Vap1 is corrected to increase to a larger allowable approach speed Vap2 so as not to become extremely small. As a result, when the vehicle travels in a tight corner with a turning radius slightly larger than the actual radius of curvature (out-in-out), it is possible to prevent a warning or deceleration control against the driver from being executed. You. Note that the magnitude of this correction may be variably set according to the ratio between the curve curvature radius rp [j] and the road width wp [j].

As another example, a predetermined value (ayl.wp.rwk) ^1/2 corresponding to the road width wp [j] is compared with an allowable approach speed vap1 obtained by the curve depth correction unit 27d. The larger one may be selected, and the selected value may be set as the allowable approach speed vap2.

In this case, the curve at the node Pj is a tight corner, and the curve radius of curvature rp [j] is the road width wp [j].
In a situation where the predetermined ratio rwk is equal to or less than the predetermined ratio rwk, a predetermined value (ayl · wp · rwk) corresponding to the road width wp [j] is selected,
It is guarded that the allowable approach speed does not become extremely small.

Here, the set ratio rwk is 1, 1.5, 2,
A value (set ratio) indicating a constant multiple of the road width wp, such as 3, which may be a fixed value or a variable value. In the case of a variable value, the value is variable depending on the curve direction, road type, or the like. Set.

When the set ratio rwk is variably set depending on the curve direction, the set ratio rwk of the outer curve (right curve in a country traveling on the left side, left curve in a country traveling on the right) is set to a value larger than the set ratio rwk of the inner curve. For example, if the set ratio rwk of the inner curve is 1 (100%), the set ratio rwk of the outer curve
Is set to 1.5 (150%). This means that when traveling on an outer curve, it is possible to travel with a slightly larger turning radius than the curve radius of curvature rp, as compared with traveling on an inner curve. By setting the outer curve to be higher than that, it is possible to perform control suitable for the actual driving situation.

When the set ratio rwk is variably set according to the type of road, the set ratio rwk of the expressway is set to a value larger than the set ratio rwk of the general road, for example, the set ratio rwk of the general road is set to 1.5 (150 %), The highway setting ratio rwk is set to twice (3% (300%)). This is because a sharp curve close to the road width does not actually exist on a highway with a good road environment.

The speed smoothing correction unit 27f performs a smoothing process correction of each allowable approach speed vap2 for the node group identified as being on the same curve by the curve configuration node identification unit 27b. For example, in FIG. 7, nodes Pj−1, P
j, Pj + 1, and Pj + 2, each allowable approach speed vap2 [j-
1], vap2 [j], vap2 [j + 1], and vap2 [j + 2] are subjected to smoothing processing correction. In this case, if the node interval Lp [j] is larger than a predetermined value (WK2 · wp [j] WK2: constant) (Lp [j] ≧ WK2 · wp [j]), the averaging process correction is not performed.

The reason for performing the smoothing process correction is as follows. Even within one curve, there is variation in the allowable approach speed vap2 of each of a plurality of nodes constituting the curve, and if the alarm / deceleration control is performed based on the lowest value among them, an extremely sensitive alarm・ Deceleration control is performed. On the other hand, if the warning / deceleration control is performed on the value obtained by simply averaging the allowable approach speeds vap2 of the plurality of nodes in order to prevent such a problem, the alarm / deceleration is insensitive because the node having a large allowable approach speed is strongly affected. It becomes control.
In the present embodiment, in order to prevent these, the allowable approach speed vap2 of each component node is corrected.

The correction is performed by calculating the allowable approach speed of the target node Pj, the allowable approach speed, and the nodes Pj + 1 before and after the allowable approach speed.
, Pj-1 and the average value with the allowable approach speed, and the median value is adopted as the final allowable approach speed vap at the node Pj.

That is, for example, in FIG. 7, 1) the allowable approach speed vap2 [j] of the node Pj is read, and 2) the allowable approach speed vap2 [j] of the node Pj and the next node P
An average value vap21 with the allowable approach speed vap2 [j + 1] of j + 1 is calculated, and vap21 = (vap2 [j] + vap2 [j + 1]) / 2 3) The allowable approach speed vap2 [j] of the node Pj An average value vap20 of the allowable approach speed vap2 [j-1] of the preceding node Pj-1 is calculated. vap20 = (vap2 [j-1] + vap2 [j]) / 2 Then, the median of the values vap2 [j], vap21, and vap20 is adopted as the final allowable approach speed vap at the node Pj.

However, for a node corresponding to the entrance of the curve, the average value of the allowable entry speed of the node and the allowable entry speed of the next node is adopted, and for the node corresponding to the exit of the curve, the allowable entry speed of that node is used. The speed is compared with the average value of the allowable approach speed and the allowable approach speed of the preceding node, and the larger value is adopted.

Incidentally, the average values vap21 and vap20 may be obtained by a general arithmetic expression shown in the following equation.

F (vap21) = ｛f (vap2 [j]) + f (v
ap2 [j + 1]) / 2 f (vap20) = {f (vap2 [j-1]) + f (vap2 [j])}
/ 2 In this case, if, for example, f (X) = X ² , the above equation becomes: vap21 ² = (vap2 [j] ² + vap2 [j + 1] ² ) / 2 vap20 ² = (vap2 [j−1] ² + vap2 [j] ² ) / 2, and the average values vap21 and vap20 may be obtained from the square values.

The alarm speed calculation storage unit 28 stores the farthest node Pn-1 from the node coordinates P0 immediately after passing the own vehicle among the n nodes sent from the navigation device 7. For all the nodes up to this point, the allowable approach speed vap [j] set by the allowable approach speed setting unit 27 and the forward road attribute calculation storage unit 25
The alarm speed vw [j] at the current vehicle position is obtained based on the node interval Lp [j] of each node and the allowable deceleration XgLim set by the allowable deceleration setting unit 24 stored in the.

Here, the distance LL [j] from the vehicle position to each node is LL [j] = (xp [1] ² + yp [1] ² ) ^1/2 2 ≦ j when j = 1. When ≤n- ¹ , LL [j] = LL [1] + Lp [2] + Lp [3] +... + Lp [j]. From this, the alarm speed vw [j] for each node
Is: vw [j] = (vap [j] ² + 2 · (Kx · XgLiM) · LL
[j]) Can be set in ^1/2 . Where Kx is the safety factor,
In the present embodiment, 0.5, that is, the allowable deceleration XgLim
50% of safety deceleration.

The alarm judgment output unit 29 calculates the alarm speed vw [j] of the alarm speed vw [j] for each node obtained by the alarm speed calculation storage unit 28 and the output signal of the vehicle speed sensor 5. The vehicle speed v is compared with the vehicle speed v, and further, the vehicle speed v is compared with the allowable approach speed vap [j] at the target node having the minimum alarm speed vw [j].

The own vehicle speed v is the minimum warning speed vw.
[j] greater than vehicle speed v and allowable approach speed vap
When the difference from [j] is equal to or larger than the allowable value vk1 (for example, 5 km / h), it is determined that the vehicle is in the overspeed state.

Therefore, for example, as shown in FIG. 10, when the own vehicle is traveling at a constant speed v, when the own vehicle speed v is slightly overspeed with respect to the alarm speed vw [j], An alarm is issued early or deceleration control is performed. On the other hand, when the excess amount of the own vehicle speed v with respect to the allowable approach speed vap [j] is equal to or less than the allowable value vk1, when the own vehicle position is extremely close to the target node position, the own vehicle speed v Although the speed exceeds the warning speed vw [j], no warning or deceleration control is performed. This is because there is no practical problem since the allowable approach speed vap has a safety margin value added in advance.

The deceleration judgment output section 30 is provided with the alarm judgment output section 2
9, when it is determined to be an alarm target, a predetermined time (for example, 2
If the driver does not perform an appropriate deceleration operation after sec), it is determined that the target node is to be decelerated. In the present embodiment, the brake pressure is detected based on the output signal from the brake pressure sensor 9, and based on the brake pressure, the driver's brake operation can be performed by the allowable deceleration setting unit 24.
It is determined whether or not the deceleration set in the step is achieved. If the deceleration has not been achieved, it is determined that the vehicle is to be decelerated.

The control execution judging section 31 determines whether or not to actually permit the control of the node judged to be an alarm by the above-mentioned alarm judgment output section 29 or to be judged to be a deceleration object by the deceleration judgment output section 30. Judge.

That is, first, for a node determined to be an alarm target, whether or not this target node exists on an actual road is determined, for example, in the road attribute stored in the forward road attribute calculation storage unit 25. From the target node, and the road LL to the target node stored in the alarm speed calculation storage unit 28 is read. The curve radii rp and the road LL are read from the road shape detecting device 1.
The degree of curve of the road ahead and the distance to the start point of the curve recognized at 0 are compared, and if they match, it is determined that the target node exists on the actual road, and a warning or deceleration control is performed. Permission to execute. or,
If they do not match, the CD-RO of the navigation device 7
Since the road information in the map stored in the storage means such as the road may be different from the actual road when a new road is constructed or renovated, the warning for the target node and the execution of the deceleration control are not performed. Ban.

When the control execution determining unit 31 permits the execution of the alarm control or the deceleration control of the target node,
An alarm command signal is output to the alarm device 11 from the alarm determination output 29 to notify the driver that the vehicle is approaching a curve and call the driver's attention. Further, the deceleration determination output section 30 outputs a deceleration command signal to the speed reduction device 12. The deceleration device 12 forcibly performs a deceleration operation according to a deceleration command from the deceleration determination output unit 30 by downshifting the transmission, lowering the engine torque, operating the brake, and the like.

As described above, in the present embodiment, the curve curvature radius rp [j] obtained by the front road attribute calculation storage unit 25 is:
In a tight corner where the road width Wp [j] is equal to or less than the set ratio rwk, a predetermined value (ayl) corresponding to the road width wp [j] is used.
・ Wp ・ rwk) ^1/2 is adopted as the permissible approach speed vap2, so that the permissible approach speed vap is not set to be extremely small, and a troublesome alarm against actual driving is prevented beforehand. Can be.

Also, by setting the predetermined ratio rwk to a larger value on an expressway than on a general road, according to the road conditions,
An allowable approach speed vap suitable for the actual road shape can be set.

In the curve entry control device according to the present embodiment, the radius of curvature of the curve is calculated based on the node data transmitted from the navigation device. However, the present invention is not limited to this, and the navigation device is not limited to this. The present invention can be applied to any form, such as one obtained directly from a computer, one calculated based on a signal from a visual sensor such as a camera or a radar, and one obtained from an external system such as an intelligent transportation system (ITS).

[0066]

According to the present invention, the radius of curvature of the front curve is calculated, and when the radius of curvature of the curve is a tight corner of a set ratio or less with respect to the road width of the curve, the allowable approach speed for this curve is increased and corrected. As a result, it is possible to set the curve allowable approach speed to an appropriate value according to the turning of the actual running, and it is troublesome that the curve allowable approach speed is too low with respect to the actual running state. Warnings and deceleration control can be eliminated, and discomfort given to the driver can be reduced.

In this case, by setting this set ratio such that the value when the outer curve travels is larger than that when the inner curve travels, the allowable approach speed of the outer curve is adjusted to a value suitable for the actual travel. , And the sense of discomfort given to the driver can be further reduced.

Further, by setting the set ratio variably according to the type of road, it becomes possible to set an optimum curve allowable approach speed according to the road environment.

Further, the allowable approach speed set based on at least the radius of curvature of the curve is compared with at least a predetermined card value set according to the road width of the card, and the larger one is set as the allowable approach speed. Thus, it is possible to set an appropriate allowable approach speed along the turning radius of the actual traveling.

[Brief description of the drawings]

FIG. 1 is a functional block diagram of a control unit provided in a curve entry control device.

FIG. 2 is a functional block diagram of an allowable approach speed setting unit.

FIG. 3 is an explanatory diagram of information transmitted from a navigation device.

FIG. 4 is an explanatory diagram of node coordinates based on the position of the vehicle;

FIG. 5 is an explanatory diagram showing a method of calculating a curve radius of curvature.

FIG. 6 is an explanatory diagram in the case where a curve is composed of one node;

FIG. 7 is an explanatory diagram when a curve is configured by a plurality of nodes;

FIG. 8 is an explanatory diagram showing a method of calculating an offset angle when entering a curve.

FIG. 9 is a characteristic diagram showing a relationship between a curve depth and an allowable approach speed.

FIG. 10 is a characteristic diagram showing a relationship between a vehicle speed and a warning speed.

FIG. 11 is an explanatory view of a vehicle traveling line when passing through a tight corner.

[Explanation of symbols]

 7 Navigation device 25 Forward road attribute calculation storage unit 26 Allowable lateral acceleration setting unit 27 Allowable approach speed setting unit ayl Allowable lateral acceleration rp Curve radius of curvature rwk Setting ratio tpa Curve depth vap Allowable approach speed Wp Road width

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-11-208386 (JP, A) JP-A-8-194886 (JP, A) Preprints of the meeting of the Society of Automotive Engineers of Japan, No. 912, Vol. 1 (1991), Yoshihiro Tsurumaki (two other), P1.201-P1.204 "Modeling of driving behavior considering road width" (58) Fields investigated (Int. Cl. ⁷ , DB name) G08G 1/00-1/16 B60K 31/00 B60T 7/12-8/00 B60T 8/32-8/96 JICST file (JOIS)

Claims (4)

(57) [Claims] 1. A curve approach control device which calculates an allowable approach speed to a curve based on at least a radius of curvature of a forward curve and performs an alarm or a deceleration control based on the allowable approach speed. A curve entry control device for increasing the allowable entry speed for the curve when the ratio is equal to or less than a set ratio with respect to the road width. 2. The curve entry control device according to claim 1, wherein the set ratio is set to a larger value when the vehicle travels on an outer curve than when the vehicle travels on an inner curve. . 3. The method according to claim 1, wherein the setting ratio is variably set according to a road type of the curve.
The described curve approach control device. 4. A curve entry control device which calculates an allowable approach speed to a curve based on at least a radius of curvature of a forward curve, and performs an alarm or deceleration control based on the allowable approach speed. A curve entry control device which compares a set allowable approach speed with at least a predetermined value set according to the road width of the curve, and selects a larger one as the allowable approach speed.