JP2003276472A - Target vehicle speed determination device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To automatically output a suitable target vehicle speed according to weather and sunshine states. <P>SOLUTION: A trace mode is a dedicated mode for constructing a traveling history DB 10 formed of traveling history data. A road environment parameter Y is led based on road environment actual time information X. In a generation mode, a block number BKN and the road environment parameter Y are specified by using present position coordinate (r) and the road environment actual time information X, and the traveling history data matching these keys BKN and Y is retrieved from the traveling history DB 10 by using a traveling history retrieval means 130. When both keys matches each other, the averaged value (u) of the element data on vehicle speed can be used as the target vehicle speed VO. In addition, a suitably estimated processing by a suitably estimating means 150 based on the road environment actual time information X is effective as a means for canceling a trade-off between the maintenance of a hit ratio to the road environment parameter Y and the subdividing of the definition of the road environment parameter Y. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle-mounted target vehicle speed determining device for determining a target speed of a running vehicle based on the current position of the vehicle. Therefore, the target vehicle speed determination device of the present invention is useful for a vehicle speed control device such as an adaptive cruise control system for automatically controlling the speed of a vehicle, or an overspeed warning device.

[0002]

2. Description of the Related Art As a prior art relating to an on-vehicle target vehicle speed determining device for determining a target speed of a running vehicle based on the current position of the vehicle, for example, "United States P
atent6161072: AUTOMATIC CRUISE CONTROL "
(Hereinafter referred to as known example 1),
Alternatively, the one described in Japanese Unexamined Patent Publication No. Hei 8-290728: Auto Cruise Control Method (hereinafter referred to as Known Example 2) and the like are generally widely known.

FIG. 9 exemplifies a system configuration diagram of a target vehicle speed determination device 300 according to the prior art and a well-known general ACC system 200, as represented by, for example, the known example 1 described above. The user DB in the figure stores the travel history (trace data) when the user traveled in the past. As the data that constitutes the traveling history, the traveling position r1 of the vehicle and the vehicle speed v1 when the vehicle passes through the point are stored in association with each other, and the traveling position r1 substantially coincides with the traveling position r1 when the target vehicle speed determination device 300 is in use. When the vehicle passes the position r, the traveling position r at that time becomes a search key,
The vehicle speed v1 when the vehicle passed the position r1 in the past is read,
The value is used as the current target vehicle speed V0 and the adaptive cruise control system (ACC system 20
0) is output.

When the target speed determining means (FIG. 9) does not have the corresponding trace data (that is, there is no hit) during the search operation, the speed limit in the figure is displayed. The legal speed limit Vs at the corresponding point during traveling is read from the DB, and the value is output to the ACC system 200 as the current target vehicle speed V0. Further, for example, in the above-mentioned known example 2, the legal speed limit V
Even in the case of using s, a method of calculating a more desirable target vehicle speed V0 in consideration of the radius of curvature R on the road map without directly outputting the legal speed limit Vs as the target vehicle speed V0 is disclosed. There is.

[0005]

The road environment, such as the road surface condition and the driver's view condition, dynamically changes due to the weather condition and the sunshine condition which can change naturally and over time. However, in the conventional technology as described above, no special consideration is made from this point of view, and therefore, the conventional apparatus may have the following problems.

(Problem 1) If a constant vehicle speed that is sufficiently safe for all situations is adopted as the target vehicle speed at all times, the target vehicle speed will be lower than the desired value on a dry road with a clear view during daytime fine weather. It tends to be relatively slow. (Problem 2) Therefore, originally, with respect to the weather (sunny / rain / snow etc.) and the sunshine state, which naturally change with time,
It is desirable to change the target vehicle speed at any time, but these changes must be performed at any time by manual setting or the like. Therefore, it is not always possible to ensure sufficient convenience when using the ACC system.

The present invention has been made in order to solve the above-mentioned problems, and its object is to optimize the target vehicle speed determining device in accordance with the weather condition, the sunshine condition, etc. which can change naturally and with time. It is to realize a means for automatically outputting a target vehicle speed that has been optimized or optimized.

[0008]

Means for Solving the Problems, and Functions and Effects of the Invention In order to solve the above problems, the following means are effective. That is, the first means is related to the weather, the sunshine state, etc., which can change naturally and with time in the vehicle-mounted target vehicle speed determination device that determines the target speed of the vehicle based on the current position of the traveling vehicle. It is provided with environment information acquisition means for acquiring road environment real-time information and road environment consideration means for determining the target speed of the vehicle based on the road environment real-time information and the current position.

Adaptive Cruise Control
The target speed of the vehicle to be set in the automatic vehicle speed control system such as the system is preferably determined based on the motion performance of each vehicle, the easiness of steering operation, and the like. In addition, the dynamic performance of the vehicle largely depends on the road surface condition (friction coefficient) of the road on which the vehicle is running, and the easiness of steering operation is
It depends largely on the visibility (visibility) of the road being driven.
However, if the road environment real-time information described above is used properly, it is possible to measure or estimate the road surface state and the visibility state, which are useful for determining the optimum or suitable target vehicle speed. Thus, the target speed of the vehicle can be optimized or optimized. Therefore, according to the present invention, the target vehicle speed can be adapted to the road environment more easily (automatically) than in the past.

The second means uses the environment information acquisition means of the first means as "a wiper operation signal, a raindrop detection signal, an outside air temperature signal, as the road environment real-time information,"
Means for acquiring a road surface temperature signal, a headlight operation signal, an optical sensor output signal, a current date and time signal, an ABS operation signal, a wheel rotation speed signal, an image captured by a vehicle-mounted camera, or a reception signal of a wireless device. .

The above-mentioned various signals are very useful for observing or estimating the weather condition, the sunshine condition and the like, and the road condition and the visibility condition can be determined from at least some of these signals. For example, it is possible to estimate the current precipitation amount based on the output signal of the wiper or raindrop sensing device, and it is also possible to estimate whether the precipitation is due to rain or snow from the outside air temperature and the road surface temperature. Is. In addition, since it is possible to determine the day or night or the sunshine state based on the operating state of the headlight, it is possible to determine whether the visual field is good or bad (that is, the operability of the steering wheel).

Further, since the optical sensor can be used, for example, to determine the brightness of the environment outside the vehicle, this output signal is useful for estimating the sunshine condition and the visual field condition. For example, if the current date and time is known, the standard outdoor lightness can be estimated, and thus the current sunshine state and weather can be estimated by comparing the estimated value with the optical sensor output signal. For example, if it is darker than normal and the wiper is operating, it can be estimated that it is rain, snow, or fog, and if it is darker than normal and the wiper is not operating, it is cloudy.

Further, the road surface temperature can be measured or estimated based on the image analysis result of the taken image of the road surface taken by an infrared camera, for example. As a result, it is possible to estimate the frozen condition, snow cover condition, etc. of the road surface. Also,
When the ABS operates relatively frequently, or when the rotation speed of each wheel varies greatly, it may be possible to estimate that the vehicle is traveling on a snowy road surface. Further, it is possible to estimate the road surface condition (friction coefficient or the like) according to the ABS operation signal (ABS operation frequency) for each vehicle speed of the host vehicle.

Further, if a general well-known level image analysis technique is used, the sunshine condition, rain condition, snow condition, snow condition, etc. on the spot are sufficiently useful for controlling the vehicle speed based on the image captured by the vehicle-mounted camera. It can be detected at the detection level.

Further, the third means is the above-mentioned first or second.
In the road environment consideration means of the means, the current position of the vehicle currently traveling and the road environment are selected from the traveling history data in which the traveling position of the vehicle, the road environment real-time information, and the vehicle speed V are recorded in association with each other. A travel history search means is provided for searching corresponding data substantially matching the real-time information, and the target speed of the vehicle currently traveling is based on the vehicle speed V recorded in the corresponding data searched by the travel history searching means. Is to decide.

However, there can be a plurality of vehicle speeds V that can be recorded at a certain passing point depending on the number of times the vehicle travels at the same point. In such a case, the vehicle speed V is
A plurality of raw data (vehicle speed V) may be recorded as they are, or only an average value thereof may be recorded, or all statistical values such as average value and variance and raw data may be recorded. You can do it as well. Further, in the case of obtaining any of the above statistical values, the timing of calculating each statistical value for the measured vehicle speed may be arbitrary, for example, during data recording or data retrieval. The vehicle speed V to be recorded in the above-mentioned relevant data does not exclude arbitrariness regarding these statistical operations. That is, at least one or more vehicle speeds or vehicle speed-related values are recorded in the corresponding data.

According to the above means, the target speed can be determined on the basis of the past traveling history in which both the position and the road environment real-time information match, so that the past traveling history in which various conditions concerning the road environment are close can be determined. The most realistic vehicle speed for the driver at the time of recording can be set as the target speed. In addition, when the driver when recording the travel history data and the driver who tries to reproduce the target vehicle speed based on the travel history data are different, and the driving skills related to steering wheel operation and the like are different between them. Also in, even if the means for quantitatively taking into account the difference in the skill level is added, by the above means,
It is possible for the latter driver to set (reproduce) an ideal target speed. As a means for quantifying (converting) such a difference in skill level, for example, one disclosed in Japanese Patent Application Laid-Open No. 7-306998: Safe traveling control system for vehicle and safe traveling control method for vehicle. Etc. are known.

The fourth means is the above first to third means.
In any one of the means, a travel history recording means is provided for creating travel history data by recording the current road environment real-time information of the vehicle, the position, and the vehicle speed V in association with each other. By using such means, it is possible to create (trace) the above-mentioned travel history data by itself, while entrusting the operation and effect of each of the above means. Therefore, by creating the travel history data on its own, the above-mentioned "means for quantifying (converting) the difference in skill level" becomes unnecessary, and the target speed most suitable for one's skill and preference is set (reproduced). It becomes possible to do.

The fifth means is the above first to fourth means.
The road environment consideration means of any one of the means is provided with a suitable value estimation means for theoretically or deterministically estimating a suitable value of the target speed of the vehicle based on the road environment real-time information. However, the term "theoretical or deterministic estimation" as used herein means that based on a predetermined mathematical formula or procedure and a predetermined value serving as a calculation reference of the vehicle speed, the current value for the precondition (road environment) A desired target speed is calculated by adding and converting the road environment (variation). Further, the "predetermined value serving as a vehicle speed calculation reference" here means the vehicle speed in the travel history data, the legal speed limit at the corresponding point, or any other reference value. Is also good.

According to this means, if the convertible reference value (a predetermined value serving as a vehicle speed calculation reference) and the conditions related to the road environment premised on the reference value are known, the current road environment is substantially matched. Even when the vehicle does not have the travel history data for the target vehicle, it is possible to estimate the preferable value of the target speed of the vehicle at the corresponding point.

The sixth means is the deceleration coefficient α depending on the detected or estimated road surface state or the deceleration dependent on the detected or estimated visual field state in the preferable value estimating means of the fifth means. A deceleration factor analyzing means for calculating the coefficient β and a deceleration factor reflecting means for calculating a suitable value based on the deceleration coefficient α or the deceleration coefficient β are provided. Regarding the action and effect of this means, in the following examples,
It is specifically or fragmentally illustrated. By the means of the present invention described above, the above problems can be effectively or rationally solved.

[0022]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described below based on specific embodiments. However, the present invention is not limited to the examples shown below. [Embodiment] FIG. 1 is a system configuration diagram of a target vehicle speed determination device 100 according to an embodiment of the present invention. The DVD 105 stores data such as map information and legal speed limits, and a program. The computer positioned at the center of the target vehicle speed determination device 100 is a CPU 101, a RAM 10
2. In addition to the ROM 103, the memory card 104 and an input / output interface (not shown) are included. For example, the memory card 104 has a configuration that can be easily prepared, carried, replaced, etc. for each user, and the skill of each individual regarding the operation of the steering wheel and the degree of stability related to the lateral G etc. It is effective as a means to solve individual differences such as preferences.

The GPS device 170 provides the current position information of the vehicle sent from the artificial satellite. The environment information acquisition unit 120 includes a wiper changeover switch, control wiring, or drive wiring (hereinafter, simply referred to as “wiper 121”) and a headlight changeover switch, control wiring, or drive wiring (hereinafter, referred to as “wiper 121”).
It is simply referred to as "headlight 122") and a temperature sensor 123. As the temperature sensor 123, it is desirable to provide an infrared sensor for measuring the road surface temperature, but it is also possible to use a generally popular outside air temperature sensor or the like. That is, the environment information acquisition unit 120 provides a wiper operation signal, a headlight operation signal, and a road surface temperature (or outside air temperature). Reference numeral 180 is a vehicle speed sensor that outputs a vehicle speed signal.

The target vehicle speed determination device 100 is connected to the ACC system 200, and outputs the target vehicle speed V0 to the ACC system 200 and receives various control signals from the ACC system 200. However, FIG. 1 shows a logical functional configuration, and of course, the target vehicle speed determination device 100 and the ACC system 200 may be configured by one physically identical computer or the like. .

FIG. 2 is a data flow-related diagram illustrating the outline of the operation of the target vehicle speed determination device 100 described above. It is sufficiently possible to configure a target vehicle speed determination device which does not have the trace mode in the figure realized mainly by the traveling history recording means 140 and the like, and such a target vehicle speed determination device also has the above-mentioned present invention. Although the operation and effect of the present invention by means can be entrusted to a great extent, the following embodiments disclose an implementation method having both a "trace mode" and a "playback mode".

The traveling history recording means 140 and the road environment consideration means 110 are each realized by software operating on the computer. The road environment consideration means 110 is a travel history search means 130 and a suitable value estimation means 1
Have 50. The trace mode is a dedicated mode for constructing the traveling history DB 10 composed of traveling history data. During the execution of this tracing mode, the target vehicle speed V0 is not output and the above ACC system is not used. However, in the present embodiment, as will be mentioned later, the traveling history data may be added or updated depending on the situation even in the reproduction mode.

[Trace Mode] In the trace mode, the traveling history recording means 140 acquires the position information (current position coordinates r) from the GPS 170 and divides the traveling direction on the road in steps of about 20 m. The position (block number) of the traveling block defined by is specified. The traveling block DB 20 is a database used to specify the block number BKN of this traveling block, and here, the block range coordinates (r
1, r2), the legal speed limit Vs of the traveling block, the minimum radius of curvature R of the traveling block, etc. are the block numbers BKN.
It is stored in association with.

In addition to the above, the traveling history recording means 140
Road environment real-time information X (wiper operation signal, headlight operation signal, road surface temperature) obtained from the environment information acquisition means 120
Then, the current vehicle speed V obtained from the vehicle speed sensor 180 is also input at any time.

FIG. 3 is a table showing an example of the record format of the traveling history data 11 recorded in the traveling history DB 10. The second item from the top "direction or lane division"
Is for distinguishing the current traveling direction (up / down, etc.) on the road on which the vehicle is traveling, but it is not necessary when the block number BKN of the traveling block is separately defined for each traveling direction. In that case, the lane classification and the like may be stored here. However, the lane division is not necessary when the overtaking lane and the traveling lane cannot be distinguished by the accuracy of GPS, and it is not always necessary to make a difference in the set value of the target speed between the overtaking lane and the traveling lane.

The road environment parameter Y in FIG. 2 is obtained by the traveling history recording means 140 as the road environment real time information X described above.
“Weather code y1 and sunshine code y2” in the travel history data 11 of FIG. 3 corresponds to this parameter Y. Weather code y1 and sunshine code y
The definition example of 2 is as follows. [Definition example 1] (Weather code y1) "Hare": When it is fine "Ame": When it is raining "Yuki": When it is snowing (sunshine code y2) "Hill": When it is bright "Yor": When it is dark

The natural number n of the travel history data 11 in FIG. 3 represents the number of valid vehicle speed data, and a plurality of valid raw vehicle speed data can be recorded (see FIG. 3).
Then v1 to v5). u is the average value of valid vehicle speed data, and if this value is calculated in advance in this mode,
In the subsequent reproduction mode, the average value u can be used as it is as the target vehicle speed V0. Further, σ ² is the variance of n pieces of vehicle speed data, and can be used when performing various known statistical operations such as evaluating the reliability of the vehicle speed data.
In addition, the natural number n and the like can be similarly used to evaluate the reliability of the vehicle speed data. Of course, dispersion is not used (CPU
Other evaluation methods (with a relatively small overhead) may be used.

[Reproduction Mode] In the reproduction mode, the block number BKN is calculated from the current position coordinate r and the road environment real-time information X by the same method as the above-mentioned running history recording means 140.
And the road environment parameter Y are specified, and the travel history search means 1
30 is used to search the traveling history DB 10 for traveling history data 11 in which these keys (BKN, Y) match. However, instead of BKN, r (coordinates) may be directly used as a key for searching.

I) When two keys are hit When the traveling history data 11 in which both keys (BKN, Y) are the same is present, the average value u can be used as it is as the target vehicle speed. However, the above variance σ ²
When the reliability of the data is low, such as when the average value u is large, the average value u is recalculated again after performing processing such as excluding the raw data (one of v1 to v5) that is distant from the average value u. You may implement statistical operations, such as doing.

In order to maintain the hit rate for the road environment parameter Y at a certain value, it is better not to subdivide the weather code y1 and the sunshine code y2, but by subdividing these, the actual road environment It is possible to respond in detail. As a means for eliminating these trade-offs, for example, a process corresponding to the suitable value estimating means 150 of FIG. 2 exemplified below is effective.

Ii) When only the block number BKN is hit For example, the target vehicle speed V0 is calculated by the following equation (1).

## EQU1 ## V0 = u × (α ₂ / α ₁ ) × (β ₂ / β ₁ ) (1) where α and β are deceleration coefficients illustrated in FIG. 4,
As illustrated in FIG. 4, α is a coefficient depending on the detected or estimated weather (that is, road surface condition ⇒ vehicle motion performance), and β is the detected or estimated sunshine condition (that is, visual condition ⇒ This is a coefficient depending on the visibility of the driver). In addition, the subscript 1 is the above road environment parameter Y (weather code y) from the retrieved record (driving history data 11).
1 and the sunshine code y2)
The subscript “2” indicates the coefficient value of each deceleration coefficient obtained from the road environment real-time information X observed in the reproduction mode. According to the definition of FIG. 4, there can be six road environment parameters Y, so BKN when BKN matches and Y does not match.
There can be a maximum of 5 entries that match. Therefore, when the equation (1) is used, the target vehicle speed V0 to be finally output is based on the five target vehicle speeds V0.
May be selectively determined or recalculated.

Iii) When the block number BKN is missed For example, the target vehicle speed V0 is calculated by the following equation (2).

## EQU2 ## V0 = (Vs × γ) × α ₂ × β ₂ , γ = f (R, Vs) (2) where Vs is the legal speed limit, and α ₂ , β
₂ indicates the value of each deceleration coefficient (Fig. 4) obtained from the road environment real-time information X observed in the reproduction mode.

The value of γ is given by a predetermined function f based on (the minimum value of) the radius of curvature R of the corresponding traveling block. For example, when R≈∞ (when the road extends straight), γ = 1, and the value of γ monotonically increases / decreases with R. Of course, when R → 0, γ → 0. This function f has an empirically appropriate shape depending on the degree of sideslip of the vehicle due to the centrifugal force during cornering, or the degree of stability expected by the driver or occupant with respect to the lateral G (lateral acceleration). Functions can be defined. When determining this function, for example, Japanese Patent Laid-Open Publication No. Hei 5-1419
79: Overspeed Prediction Device "and" JP-A-8-2
90728: automatic cruise control method "
“-263729: Vehicle control device” and the like can be referred to.

The value of γ or (Vs × γ) may be stored in advance in the traveling block DB 20 or the traveling history data 11 in the traveling history DB 10. For example, with such a method, the CP in the real-time control in the playback mode
U overhead can be reduced.

Further, α and β are not likely to suddenly change due to a traveling block unless in a special environment such as a tunnel, but the radius of curvature R is a parameter that can suddenly change as the vehicle progresses. It is desirable to pre-read in advance and aim at the smallest value among them to determine the argument (independent variable R) of the function f. Further, as a method of determining the number of prefetches at this time, it is effective to use a predictive measure such as making the number of prefetches substantially proportional to the reciprocal of the block length of the traveling block or the current vehicle speed V.

FIG. 5 is a sensing level judgment reference table for estimating the amount of precipitation, the brightness of the field of view, etc. from the operating state of the wiper or headlight. For example, based on such a judgment reference table, the definition example 1 of the weather code y1 and the sunshine code y2 can be concretely rewritten as the definition example 2 below. [Definition example 2] (Weather code y1) "Hare": When x1 = 0 "Ame": x1> 0 and when the road surface temperature is higher than 0 ° C "Yuki": x1> 0 and the road surface temperature is When the temperature is 0 ° C or lower (sunshine code y2) "Hill": When x2≤1 "Yor": When x2> 1 Therefore, for example, the value of the deceleration coefficient α depending on the road surface condition is x1> 0, Further, when the road surface temperature is 0 ° C. or lower (FIG. 4B), α = 0.5.

Of course, the definition and judgment of the road environment parameter Y such as y1 and y2 may be further subdivided according to each sensing level of FIG. In addition, various other sensors may be used. For example, if an optical sensor is used instead of the headlight, determination with higher accuracy can be performed. That is, the definition of the road environment parameter Y (combination of sensing levels) and various sensors introduced as the environment information acquisition means 120 may be determined according to desired determination accuracy, expected cost, and the like.

As useful as these various sensors, for example, “as the above-mentioned road environment real-time information,
Wiper operation signal, raindrop detection signal, outside air temperature signal, road surface temperature signal, headlight operation signal, optical sensor output signal, current date and time signal, ABS operation signal, wheel rotation speed signal, in-vehicle camera captured image, or reception of wireless device Means Of Acquiring Signal "
Etc. can be mentioned.

FIG. 6 mainly shows the road environment consideration means 11 of FIG.
0 to implement 0 based on software using the computer system of FIG. 1 (process execution procedure 400)
It is a flowchart which illustrates. This process execution procedure 4
00, first, in step 410, the GP
The current position r is input from S170.

Next, at step 415, the running block is specified based on the input current position r. Block range coordinates (r1, r
2) may be read directly from the traveling block DB 20 described above, but basically, the traveling history DB is basically first read.
In many cases, it is desirable from the viewpoint of access performance to read from 10 and, if there is no hit, read from the running block DB 20 next.

Next, at step 420, it is judged whether or not the current position r is a road designated (defined) as an object of automatic speed control. That is, if there is no entry of the traveling block having the corresponding range coordinates (r1, r2) in the traveling block DB 20, the process (process execution procedure 400) is ended. In this case, for example, A
It is also possible to execute a predetermined termination process for shifting the CC system to the off state.

If the current position r is on the road designated (defined) as the target of the automatic speed control, step 42
Go to 5. In step 425, both block numbers BKN of the current traveling block and the previous traveling block are compared, and if the block number BKN has changed (moving forward), the process proceeds to step 430; otherwise, step 41
The process moves to 0.

At step 430, the current vehicle speed V and the road environment real-time information X are input from the vehicle speed sensor 180 and the environment information acquisition means 120. However, the actual physical input operation may be executed asynchronously with this process (process execution procedure 400). The information input cycle of the environment information acquisition unit 120 may be longer than the information input cycle of the GPS 170 or the vehicle speed sensor 180. For example, such a sensor input cycle setting is effective as a measure for reducing the input processing overhead when the road environment real-time information X is composed of a physical quantity that is hard to change suddenly.

In step 440, the operating status of the ACC system 200 of FIG. 1 is determined, and if it is on (operating), the process proceeds to step 450, and if not, the process proceeds to step 600. This step 600 is a process that is substantially equivalent to the running history recording means 140 that realizes the above-mentioned trace mode, and this process is a subroutine "RECORD" which will be described later.
2 "(FIG. 8).

In step 450, the operating condition of the ACC system 200 is further determined, and if follow-up control (automatic control of the inter-vehicle distance to the preceding vehicle) is being executed, step 410 is executed.
Otherwise, the process proceeds to step 460.

In step 460, the traveling history search means 130 shown in FIG. 2 is used to retrieve the traveling history data 11 recorded in the traveling history DB 10. The search key may be the above-mentioned (BKN, Y). The following processing is selectively executed according to the search result.

(A) When there is a hit When there is a hit, the process of i) of the above-mentioned [reproduction mode] is executed at step 470.

(B) When only block number BKN is hit In this case, in step 480, the suitable value estimating means 150 of FIG. That is, the target speed V0 is calculated by the equation (1).

(C) When the block number BKN is missed In this case, in step 480, the suitable value estimating means 150 of FIG. 2 executes the above-mentioned [reproduction mode] iii). That is, according to the equation (2), the target speed V0
Is calculated.

In step 490, the target speed V0 calculated in (b) or (c) above is set to the ACC system 20.
Output to 0. In step 500, the subroutine "RECORD1" of FIG. 7 is called and executed. Figure 7
7 is a flowchart exemplifying a process execution procedure of a subroutine “RECORD1” that is called and executed from the process execution procedure 400 (step 500) of FIG. 6.

In this flowchart, first, in step 520, it is determined whether or not the current vehicle speed V is higher than the lower limit value V _{min of the} vehicle speed to be recorded. For example, when traveling on a highway with a legal speed limit of 100 km / h, this lower limit value V _min may be about 40 km / h.
This is because when the vehicle is traveling below this value, it is considered to be a special case such as near the tollgate, and the current vehicle speed V is not suitable as the vehicle speed to be recorded (v1 in FIG. 3).

At step 540, the traveling history data 11 is newly created in accordance with the record format of FIG. 3 by either one of the following (a) and (b), and the traveling history DB 10
To record. (A) When BKN misses First, the traveling block DB 20 is set with the current position r as a key.
The corresponding record above is read out and six data items from BKN to R in FIG. 3 are obtained. Next, the road environment parameter Y (y1, y2) is obtained from the road environment real-time information X input from the environment information acquisition means 120. Finally, each data item is obtained so as to satisfy the following expression (3).

## EQU00003 ## u = V, n = 1, σ ² = 0, v1 = V, vj = 0 (j = 2, 3, 4, 5) (3) where V is the current vehicle speed is there. The traveling history data 11 is newly created by the above processing.

(B) When hitting only BKN First, based on the hitting history data 11, FIG.
6 data items from BKN to R are obtained. However, this portion (6 data items) is necessary and sufficient if there is only one for each BKN, so it is not always necessary to create it for each traveling history data 11, and for example, traveling history DB
You may make it common by the entry (driving history data 11) unit which has the same BKN on 10. Next, the road environment real-time information X input from the environment information acquisition unit 120
Then, the road environment parameter Y (y1, y2) is obtained. Finally, each data item is obtained so as to satisfy the above equation (3). The traveling history data 11 is newly created by the above processing.

On the other hand, when executing the trace mode,
The subroutine "RECORD2" in FIG. 8 is called and executed. FIG. 8 is a flowchart exemplifying the processing execution procedure of the subroutine “RECORD2” that is called from the processing execution procedure 400 (step 600) of FIG. 6 and executed.

In this flowchart, first, at step 620, the traveling history D is set with the current position r as a key.
B10 is searched and the road environment parameter Y obtained from the traveling block (block definition range or BKN) and the road environment real-time information X input from the environment information acquisition unit 120 is searched.
The presence or absence of the traveling history data 11 in which both (y1, y2) match is checked. At this time, if there is no hit, in step 500 of FIG.
Call and execute ECORD1 ".

On the other hand, if both (BKN, Y) are hit, step 640 is executed in the same manner as step 520 described above. In step 660, each applicable data item other than v1 among the data items of the above formula (3) is updated. For example, 3 in the same travel history data 11
If a valid vehicle speed v3 to be recorded is obtained,
It suffices to set n = 3, v3 = V, and further update the average value u and the variance σ ² .

However, if the area for storing the vehicle speed is already full, either (a) or (b) below may be executed. (A) The vehicle speed with the lowest reliability is deleted from the six vehicle speeds (v1 to v5, and the current vehicle speed V) to obtain the current vehicle speed V.
If remains, the vehicle speed addition registration process similar to the above is performed. However, if the current vehicle speed V is to be deleted, no update process is performed. As a method of evaluating the reliability, for example, an average value or a difference from a default value that can be obtained by the above equation (2) may be used as an index. By performing such an updating process, the reliability of the recorded vehicle speed data can be increased.

(B) The oldest vehicle speed data is deleted, and the vehicle speed addition registration processing similar to the above is performed. By performing such an updating process, it is possible to deal with a change in the driving skill of the driver, a change in the preference for the lateral G, etc. at any time.

For example, according to the processing execution procedure as described above,
The above-mentioned data flow of FIG. 2 can be realized. Therefore, according to the target vehicle speed determination device 100 of the present embodiment, the target vehicle speed can be adapted to the road environment more easily (automatically) than before.

[Other Modifications] The following information is very useful when tentatively setting default values, that is, when determining the coefficients α, β, γ, etc. (1) Tunnel Information This tunnel information relates to whether or not the vehicle is currently traveling in a tunnel, and it is desirable to adopt a method of recording it on a CD, a DVD or the like like map information or the like. Alternatively, it may be acquired in real time from a radio or beacon. Since there is no fear of precipitation or snow in the tunnel and it is under special environmental conditions such as darker than outdoors during fine daytime, this tunnel information is very useful for calculating the above-mentioned coefficients α and β.

(2) Tire information This tire information relates to the tires of the running vehicle, and it is desirable to adopt a method of setting by a simple manual operation. Type of tires installed (summer / winter, etc.)
Since the presence or absence of a chain is strongly related to the braking force, the cornering power, etc., this tire information is very useful for calculating the coefficients α and γ.

(3) Received information from wireless device This received information is related to the road condition during running, traffic jam condition, traffic regulation, etc. In the above embodiment, the legal speed limit Vs is exemplified as a method of searching for it from a predetermined recording medium such as a CD or a DVD at any time. However, for example, the legal speed limit Vs may often be temporarily changed due to various circumstances such as traffic jam conditions and traffic regulations. Normal,
Natural traffic congestion, traffic accidents, road construction, road peripheral construction, large events, large holidays, etc. are the factors that change them. Therefore, real-time received information from the radio is useful in properly addressing these real-time changes.

In addition, even if the snowfall stops, there is still snow,
On the contrary, it is possible that there is no snow even if there is snowfall. However, even when the method of estimating the road surface condition based on the snowfall condition (outside temperature, wiper operation, etc.) is adopted, the snowfall information etc. delivered in real time is received and used. By doing so, it is possible to deal with a slightly exceptional road surface condition as needed. That is, such information is very useful for calculating the above-mentioned coefficients α and γ.

For example, the above information (1), (2),
It is sufficiently possible to use (3) and the like for the optimization of the default value and the like, and by utilizing these pieces of information, more accurate speed control can be realized.

Further, a shared recording medium or sharing system capable of publishing (sharing) the above-mentioned running history DB to other people (or other vehicles), sharing or integrating (sharing) is configured. It is also effective to do. According to this configuration, trace data (observation information) can be rented out or shared by persons having similar skill levels. Therefore, such a method is effective even before the DB is complete. That is, according to such a method, persons having substantially the same skill level cooperate with each other without carrying out a special conversion process relating to individual differences in driving skill (mainly operation skill relating to steering wheel operation). The above running history D
It is also possible to build B. However, if conversion / standardization processing regarding individual differences in skills such as steering wheel operation is performed,
It is also possible that persons having different driving skills gather and cooperate with each other to construct the above-mentioned travel history DB.

Furthermore, the running history DB created as described above is subjected to integration / editing / statistical processing, etc., so that the standardized standard can be shared by a plurality of drivers. A DB may be constructed. In the case of constructing such a standard DB, the number of drivers (who have similar skills as described above) for collecting observation information is not limited at all, and at least one may be used. If the means for quantifying and adding the individual skill is also used for the standard DB constructed in this way, the individual skill level based on the skill level of the above-mentioned “persons with almost the same skill level” is used as a reference. It is also possible to use this standard DB for any other person whose skill level is known.

A technique for measuring such an individual skill (individual skill evaluation means) is described in, for example, Japanese Patent Laid-Open Publication No. Hei 7-306998: Vehicle Safe Driving Control System and Vehicle Safe Driving Control Method. Those which are known are known. That is, by appropriately combining these technologies, it is possible to give the shared recording medium a high added value and the sharing system a high utility value.

Further, if such a technique is used, the above-mentioned shared recording medium and sharing system need only be prepared by the automobile manufacturer or its affiliated company. As a result, the end user can always obtain the optimum or suitable target vehicle speed simply by registering his or her individual skill in the ACC system or the like.

The target vehicle speed determining device of the present invention is, of course, obviously applicable to an overspeed warning device or the like which automatically warns of an overspeed unsuitable for the road environment during traveling, as is apparent from the above-mentioned effects. It is useful. For example, a procedure such as giving a warning is effective when the vehicle is traveling at a traveling speed that exceeds 30% or more of the target speed V0 obtained by the above equation (2). Regarding the overspeed that violates such a regulation (predetermined determination using the equation (2) or the like), the vehicle speed (v1 to v5) is also recorded in the traveling history recording means 140 that executes the above-described trace mode. Safety measures such as removing it are effective in realizing safe ACC.

[Brief description of drawings]

FIG. 1 is a target vehicle speed determination device 10 according to an embodiment of the present invention.
0 system configuration diagram.

FIG. 2 is a data flow-related diagram illustrating an operation outline of the target vehicle speed determination device 100.

FIG. 3 is a table table illustrating a record format of travel history data 11 recorded in a travel history DB 10.

FIG. 4 is a deceleration coefficient determination reference table for determining deceleration coefficients β and α from the sunshine condition and the weather.

FIG. 5 is a detection level determination standard table when estimating the amount of precipitation, the brightness of the field of view, and the like from the operating state of the wiper and the headlight.

FIG. 6 is a flowchart illustrating a process execution procedure 400 when the road environment consideration unit 110 (FIG. 2) is implemented by software.

FIG. 7 is a flowchart exemplifying a process execution procedure (500) of a subroutine “RECORD1” that is called from the process execution procedure 400 (FIG. 6) and executed.

FIG. 8 is a flowchart exemplifying a processing execution procedure (600) of a subroutine “RECORD2” that is called and executed from the processing execution procedure 400 (FIG. 6).

FIG. 9 shows a target vehicle speed determination device 300 according to the related art and A
The system block diagram of CC system 200.

[Explanation of symbols]

10 ... Travel history DB 11 ... Travel history data 20 ... Travel block DB 100 ... Target vehicle speed determination device 101 ... CPU (Central processing unit) 102 ... RAM (Writable memory at any time) 103 ... ROM (Read-only memory) 104 ... Memory Card 105 ... DVD reading device 110 ... Road environment consideration means 120 ... Environment information acquisition means 121 ... Wiper 122 ... Headlight 123 ... Temperature sensor 130 ... Travel history search means 140 ... Travel history recording means 150 ... Suitable value estimation means 170 ... GPS (current position confirmation means) 180 ... Vehicle speed sensor 200 ... ACC system r ... Current position coordinates r1, r2 ... Travel block range coordinates BKN ... Travel block number Vs ... Travel block legal speed limit R ... Travel block minimum Half curvature X ... Road environment real-time information Y ... Road environment parameter V0 obtained from road environment real-time information ... Target vehicle speed V ... Current vehicle speed n ... Recorded number of vehicle speeds vj ... Recorded vehicle speed (j is a natural number) u ... Vehicle speed data Mean value σ ² of variance of recorded vehicle speed vj

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Yuji Uchiyama             Aichi Prefecture Nagachite Town Aichi District             Ground 1 Toyota Central Research Institute Co., Ltd. (72) Inventor Shinki Shiraki             Aichi Prefecture Nagachite Town Aichi District             Ground 1 Toyota Central Research Institute Co., Ltd. F-term (reference) 3D044 AA01 AA21 AA24 AA35 AA36                       AB01 AC26 AC56 AC59 AC61                       AC62 AD02 AD21 AE04 AE21                 3G093 AA01 BA07 BA23 BA27 DB05                       DB09 DB16 EA01 EB04 FA04                 5H180 AA01 CC04 CC12 EE13 FF05                       LL01 LL02 LL09 LL15 LL16

Claims (6)

[Claims] 1. A target vehicle speed determining device for a vehicle, which determines a target speed of a running vehicle based on a current position of the vehicle, and a road environment related to weather, a sunshine state, etc., which can change naturally and with time. Environment information acquisition means for acquiring real-time information, based on the current position and the road environment real-time information,
A target vehicle speed determination device, comprising: road environment consideration means for determining a target speed of the vehicle. 2. The environment information acquisition means, as the road environment real time information, wiper operation signal, raindrop detection signal, outside air temperature signal, road surface temperature signal, headlight operation signal, optical sensor output signal, current date and time signal. The target vehicle speed determination device according to claim 1, wherein the target vehicle speed determination device is a unit that acquires a signal from a vehicle, an ABS operation signal, a wheel rotation speed signal, an image captured by a vehicle-mounted camera, or a received signal from a wireless device. 3. The current position of the vehicle currently traveling and the road environment real time from the travel history data in which the traveling position of the vehicle, the road environment real time information, and the vehicle speed V are recorded in association with each other. The vehicle has a travel history search means for searching corresponding data substantially matching the information, and the road environment consideration means has the vehicle speed V recorded in the corresponding data searched by the travel history searching means.
The target vehicle speed determination device according to claim 1, wherein the target speed of the vehicle currently traveling is determined based on the above. 4. A travel history recording means for creating travel history data by associating and recording the current road environment real-time information, position, and vehicle speed V of a vehicle. The target vehicle speed determination device according to claim 3. 5. The road environment consideration means includes a suitable value estimation means for theoretically or deterministically estimating a suitable value of the target speed of the vehicle based on the road environment real-time information. The target vehicle speed determination device according to any one of claims 1 to 4. 6. The deceleration factor analysis means for calculating the deceleration coefficient α depending on the detected or estimated road surface state or the deceleration coefficient β depending on the detected or estimated visibility state, The target vehicle speed determination device according to claim 5, further comprising a deceleration factor reflecting unit that calculates the suitable value based on the deceleration coefficient α or the deceleration coefficient β.