JPH05341839A - Driving controller for mobile vehicle - Google Patents

Abstract

PURPOSE:To offer the steering information to secure a stable and proper driving line of a vehicle by storing the driving actions of a driver as the driving rules and also processing the road linear information obtained by an image processing means based on those stored driving rules for calculation of the steering angle of the vehicle. CONSTITUTION:An image processing means 12 extracts the road linear information on plural front watching points out of the images which are photographed by a photographing means 11 that is attached to a vehicle and photographs the front road. Meanwhile, the driving actions of a driver are previously stored by a driving rule storage means 13 as the driving rules. Then, a steering angle calculation means 14 processes the road linear information on the watching points based on the driving rules and calculates the steering angle of the vehicle. Thus, it is possible to output the smooth command steering angle signals to secure the driving equivalent to an expert driver with no unstable control output despite the partial mismeasurement, the measurement errors of the road linear information on the white lines, etc.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an operation control device for providing a proper operation control amount of a moving vehicle, particularly a steering angle thereof.

[0002]

2. Description of the Related Art As a conventional driving control device for giving a driving control amount of a moving vehicle, particularly a steering angle, a driving steering model which has been used for analysis of driving behavior of a driver is incorporated into an algorithm of an automatic driving vehicle. is there. As the steering model, a forward gaze model, a secondary prediction model, a program model, etc. are known. The program model is to steer the program value determined from the pattern of the target course and the correction amount of the actual course error. The front gaze model determines the steering amount from the course error at a predetermined distance ahead of the vehicle, and closely approximates the actual control operation on a straight line or a gently curved road. The second-order prediction model also predicts the vehicle trajectory after τ seconds, determines the steering amount based on the course error at that point, and has characteristics similar to the steering of the driver even at high speed running and a curve with a large curvature. Since these models may well represent the steering characteristics of the driver under the limited driving conditions as described above, they are used as a driving support system that not only facilitates automatic driving but also driving by the driver. It is possible to do it.

[0003]

However, in such a conventional operation control device, since the control is basically performed only by the course error at one gaze point, information concerning the gaze point is lacking. If a measurement error occurs, the control becomes unstable. In addition, the actual selection of the driving line does not always match the driver's steering feeling. Therefore, it is an object of the present invention to provide a driving control device for a moving vehicle, which is suitable for a driving assistance system, by giving steering information that stably takes an appropriate travel line.

[0004]

Therefore, as shown in FIG. 1, the invention according to claim 1 is obtained by the photographing means 11 attached to the vehicle for photographing the road ahead of the vehicle, and the photographing means. The image processing means 12 for extracting road linear information at a plurality of gazing points ahead of the vehicle from the image, the driving rule storing means 13 for storing the driving operation of the driver as a driving rule, and the road linear information as the driving rules. Steering angle calculation means 14 for calculating the steering angle of the vehicle by processing based on

According to a fifth aspect of the present invention, in addition to the above configuration, a driving condition judging means 15 for judging whether the driving condition conforms to the driving rule, and the driving condition judging means deviates from the driving rule. The driving means 16 drives the steering with the steering angle calculated by the steering angle calculating means 14 when it is determined that the steering angle is calculated.

[0006]

According to the first aspect of the present invention, the driving motion of the driver is stored in advance as a driving rule, and the road alignment information of a plurality of gazing points is processed based on the driving rule to calculate the steering angle of the vehicle. Even if there is a partial missing or measurement error of road linear information such as a white line, the control output does not become unstable, and a smooth command steering angle signal equivalent to driving by a skilled driver is output. Further, according to claim 5, the driving state of the driver is monitored by the driving state determination means, and when the actual traveling route of the vehicle deviates from the traveling line in accordance with the above-mentioned driving rules, the calculated command steering angle is used. The steering is driven and automatic steering is performed.

[0007]

FIG. 2 shows the structure of an embodiment in which the present invention is applied to a driving support system. Here, depending on the driving condition of the vehicle, it is automatically determined whether to select the normal driving mode in which the driver steers the vehicle or the driving assist driving mode in which automatic steering control is performed regardless of the driver. White lines drawn on both sides of the road are used for this determination and road alignment information as control information in the driving support traveling mode.

A TV camera 20 is attached to the vehicle 1 and photographs a road ahead of the vehicle as a traveling route. Based on the image signal from the TV camera 20, the image processing device 30 detects the position coordinates of the white line at a preset gazing point distance in front of the vehicle and the inclination of the white line with respect to the vehicle at that point as white line information. That is, here, T
FIG. 3 showing a camera coordinate system in an image obtained by the V camera 20.
At the positions (xr) of the left and right white lines Wl and Wr at a plurality of gazing points Li for every 1 m from 5 m to 25 m in front of the vehicle.
[I], xl [i]) and their tangent angles (tr [i], tl
[I]) is detected with the camera position as the origin. Further, a vehicle speed sensor 40 that detects the actual vehicle speed v (km / h) as vehicle information is provided.

Further, the TV camera 20 is provided with a camera swing drive unit 25, and a traveling control unit 70 described later provides information on the shooting direction of the TV camera 20, that is, the real angle φ (deg) of the camera swing angle. In addition to receiving a command to swing the camera from the traveling control unit 70, the shooting angle of the TV camera is changed. On the other hand, a global traveling control unit 60 is provided, and determines a route along which the vehicle should travel based on the current position of the vehicle 1 and destination information. At the time of this determination, the map information from the map information unit 50 that stores the map information such as the nodes and paths on the travel route is referred to.

White line information from the image processing device 30, route information from the global travel control unit 60, and camera swing drive unit 2
The camera swing angle from 5 and the vehicle speed information from the vehicle speed sensor 40 are input to the traveling control unit 70, and the traveling control unit calculates the steering angle Sout using these information and the driving rule stored in the memory 75. To do. The steering angle command signal is sent to the steering drive unit 100 via the signal switching unit 90. The signal switching unit 90 is controlled by a signal from a traveling mode determination unit 80 as a driving state determination unit.

The traveling control unit 70 is formed by a microcomputer, and its operation will be described below. The information related to the processing function in the traveling control unit 70 is represented as shown in FIG. That is, in the gaze information processing 710, the vehicle information A including the front white line information and the vehicle speed from the image processing device 30 and the vehicle speed sensor 40, the recognition / intention information B for instructing a turning instruction and a command vehicle speed at the next intersection, and The operation rule C including the weighting coefficient at each gazing point and the parameter for determining the traveling target point is input, and the arithmetic processing for determining the weighting of the traveling target point and each gazing point is performed. The white line information includes camera swing angle information φ from the camera swing drive unit 25.

Then, based on the result of this calculation, the steering angle calculation processing 720 next calculates the steering angle at each gazing point, weights the left and right white lines Wl and Wr at both ends of the road, and finally determines the command steering angle. Sout is calculated. In the gaze information processing 710, a white line follow-up command for swinging the TV camera 20 and an intersection turning direction command are calculated as a swing command D.

The recognition / intention information B is, for example, the road recognition information indicating the shape of the road obtained from the white line information in front of the vehicle, and the travel direction and speed at which the vehicle should turn at the next intersection as general travel command information. , Traveling direction information and traveling speed information determined for each pass.

The driving rule C is a navigation rule consisting of preset parameters in order to ensure stable driving of the vehicle based on the above-mentioned global driving command information, front white line information and the actual vehicle speed. Is. These are Rule-i: a control parameter of a control function for determining the "running target point", Rule-j: a setting parameter of a weight function for determining the "weight of the gazing point", Rule-k: "following". It is an adjustment parameter of the conditional expression for determining the “white line instruction”. Since these rules are in the form of tasks on software, new Rule can be added to add or improve the operation control function.

Next, details of the gaze information processing 710 will be described. Here, the running target point and weighting are determined at each gazing point. First, in the rule (Rule-i) regarding the traveling target point, the traveling target point is basically determined from the degree of inclination between the vehicle and the front white line. That is,
From the coordinate position of the intersection point Pl [i] of the road with the left white line Wl and the intersection point Pr [i] of the right white line Wr at the forward gazing point Li shown in FIG. 5, the target point Ti (X0 [i], Li) is obtained. Is calculated. Along with this, the target yaw angle T0 [i] is also calculated.

Here, when the shift amount of the target point calculated from the degree of inclination is dw [i], X0 [i] is represented by X0 [i] = dw [i]. Therefore, the target positions of the left and right white lines at the target point Ti are: X10 [i] =-w [i] * u-X0 [i] Xr0 [i] = w [, where w [i] is the road width at the gazing point Li. i] * (1-u) -X0 [i]. When the shift amount of the yaw angle at the target point Ti is represented by dy [i] = | av_t | * target_f ′, the target yaw angles at X10 [i] and Xr0 [i] are T10 [i] = Tr0 [i] = dy [i] = T0 [i].

Where 0 ≦ u ≦ 1 w [i] = | xl [i] −xr [i] | dw [i] = | av_t | * target_f av_t = (Tl * kl0 [i] + Tr * kr0
[I]) / (kl0 [i] + kr0 [i]) Tl = tl [i] + φ, Tr = tr [i] + φ. u is a reference traveling target point coefficient, and u is set to 0.5 when the target point is set at the center of the road in the straight line portion.

Target_f and target_f '
Is a control parameter set by Rule-i, and by adjusting this, the travel target line T_1ine connecting the travel targets calculated at each gazing point can be arbitrarily set. In the figure, T_1ine0 is the central traveling line of the road, and shows the case where target_f = 0 is set. av_t is the average inclination of the vehicle and the white line. Further, kl0 and kr0 are weighting factors for the inclinations Tl and Tr of the vehicle and the white lines Wl and Wr, respectively, and will be described later, using the weighting factor (k_sh) depending on the driving scene and the weighting factor (k_get) at the time of missing the white line. , Kl0 [i] = k_shl [i] * k_getl [i] kr0 [i] = k_shr [i] * k_getr [i].

Next, a rule (Ru
In le-j), the weighting used for determining the above-mentioned traveling target point and the weighting for the steering angle calculated based on the left and right white lines of each gazing point are determined. Where R
ule-j is as shown in FIGS. 6A to 6D,
It is composed of various weighting functions. The function k_st is
It is used to set the gazing point to enhance the followability to the white line and the running stability with respect to the steering angle calculated from each gazing point information. Forward gazing point distance-weighting factor k_ as shown in FIG.
It is a membership function of st [i]. Note that in FIG. 6, each weighting factor is read on the vertical axis of the figure for the value at each i of the horizontal axis parameter. Further, the subscripts (l, r) indicating left and right are omitted.

The function k_dt is set to, for example, a right curve road in FIG. 7 in order to improve followability and running stability to a white line of a steering control type indicating a steering angle on a curved road or an intersection road with a large curvature. Deviation angle dt_R of the tangent angle of the right white line Wr at each gazing point in the camera coordinate system shown
[I] = | Tr0-tr [i] | with a small gazing point (here, L2) is weighted. Where Tr0
Is a reference angle with respect to the white line tangent angle tr [i] of the right white line Wr, which is normally set to Tr0 = 0 from the camera coordinate axis reference line. This weighting compensates for a decrease in control stability caused by an increase in the steering control output error as the tangent angle deviation amount increases. This is Figure 6
Tangential angle deviation amount-weighting coefficient k_dt
It is regarded as the membership function of [i] and the gazing point adjustment coefficient d
It is adjusted by t_max.

The function k_sh weights the white line information for each gazing point using the judgment rule set according to the driving scene from the driving command information and the road recognition information. This determination rule is set in the form of, for example, "if turning right at an intersection, set the weight of left white line information to 0" and "set the weight of white line information at an intersection to 0 when passing an intersection".
Based on this determination rule, the weighting function of the forward gazing point distance-weighting factor k_shl [i] (and k_shr [i]) is set, and for example, in FIG. It becomes a function as shown.

The function k_get sets the weight of the white line information at the gazing point to 0 when the white line information is missing,
As in (d) of FIG. 6, white line distance information-weighting factor k_g
It is set as a weight function of etl [i] (and k_getr [i]).

Next, a rule regarding the following white line (Rule)
-K) is to determine the output command from the front white line state without depending on the global travel command as much as possible. If there is a missing point or an error in the white line information if there is only a single gaze point, an accurate command cannot be sent, so here the size of the averaged degree of inclination T_out in the gaze area with the front white line. Determines the timing of changing the white line follow-up command. T_out is the weight k_ltl for the tangent angles tl [i] and tr [i] of the white line at each gazing point.
Multiplying [i] and k_ltr [i], TL = Σ (tl [i] * k_ltl [i]) / Σk_l
tl [i] TR = Σ (tr [i] * k_ltr [i]) / Σk_l
tr [i] T_out = (TL + TR) / 2 is calculated. The weighting function is as shown in FIG. 8, the distance from the forward gazing point-the weighting coefficient k-ltl [i] (and k-ltr.
It is set by the membership function in [i]).

Using the above results, the rule here is expressed as: if [T_out <0] then [Command
to camera; Follow Right l
ine] else [Command timer
a; same] if [T_out> 0] then [Command
to camera; Follow Left li
ne] else [Command timer
a; same]

Here, by adjusting the weighting function, the degree of inclination of the next curve can be grasped in advance while traveling on the curve.
Since the camera swing command can be sent so that the swing control of the TV camera 20 does not lag the following white line, the following white line can be accurately captured even on a general road where the left and right curves are continuously continuous.

Next, at an intersection or a branch road, a rule is set for the case where the follow-up white line shifts from one of the left and right white lines to the other or when the follow-up white line shifts to the one-side white line, and the follow-up switching parameter δ is used. Be done. For example, when it is necessary to shift from following the right white line Wr to following the left white line Wl, if [| SL-SR | <δ] then [based on weighted steering angles SL and SR obtained from the left and right white lines described later. Follow
Line; from Right to Left]
else [Follow Line; same], and as the follow-up switching parameter, δ = 2 to 3 deg. As a result, the stability of steering control is maintained, and smooth steering angle control is achieved.

In the steering angle calculation processing 720, the steering angle is determined by paying attention to the inclination of the front white line with respect to the vehicle and the distance to the white line at each gazing point. To calculate the steering angle based on the left white line Wl at the front gazing point Li (m), the deviation between the lateral distance xl [i] and the target lateral distance Xl0 [i] to the white line of the gazing point shown in FIG. dxl [i] (= X10 [i]-
xl [i]), and the target yaw angle T0 [i] with respect to the reference line Lc parallel to the tangent line li at the target point Ti and the tangent line angle tl [i] of the white tangent line li at the gazing point.
That is, dtl [i] = T0 [i] + | tl [i] | is obtained from the tangent angle tl [i] and the target yaw angle T0 [i],
This and the above-mentioned deviation dxl [i] are respectively proportional gain t
The steering angle correction amount hgi is added to the product obtained by multiplying and adding gi and xgi, and sl [i] = xgi * dxl [i] + tgi * dtl
The steering angle can be calculated by [i] + hgi. Similarly, from the right white line Wr, sr [i] = xgi * dxr [i] + tgi * dtr
The steering angle can be calculated by [i] + hgi.

Here, the proportional gain xgi is a quadratic function xgi = xg (Li) having the gazing point distance Li as a variable, and the proportional gain tgi is the gazing point distance Li and the slope tl of the white line.
Quadratic function having [i] as a variable tgi = tg (Li, tl
[I]). Further, the steering angle correction amount hgi is for correcting a steering error due to input white line information in which the coordinate system changes due to camera swing, and a cubic function hgi = hg (having a gazing point distance Li and a camera swing angle φ as variables. Li, φ)
There is. Each parameter of these steering control formulas is set by multiple regression identification so that the steering angle when a skilled driver drives various curved roads at a constant speed and the output steering angle calculated by the control system are the closest to each other. To be done.

In order to correspond to the vehicle speed, the gain ε (v) consisting of a quadratic function of the vehicle speed v is obtained as sl [i], sr.
Multiplying [i], the steering angle at each gazing point becomes: Sl [i] = sl [i] * ε (v) Sr [i] = sr [i] * ε (v)

Next, the weighted steering angle is calculated using the weight set in Rule-j. Now, considering the left white line as a basis, the weight Kl [i] at the gazing point Li is
The product of the weighting factors set by Rule-j is calculated, and Kl [i] = k_st [i] * k_dt [i] * k_s
It can be represented by hl [i] * k_getl [i]. Therefore, the steering angle SL calculated from the left white line is calculated by SL = Σ (Sl [i] * Kl [i]) / ΣKl [i].

Similarly from the right white line, the weight Kr [i] at the gazing point Li is as follows: Kr [i] = k_st [i] * k_dt [i] * k_s
It is represented by hr [i] * k_getr [i] and is calculated by SR = Σ (Sr [i] * Kr [i]) / ΣKr [i]. From the above, the finally output command steering angle Sout is Sout = (SL + SR) / 2.

FIG. 10 shows a summary of the processing procedure from the gaze information processing to the steering angle calculation processing in the traveling control unit 70. That is, based on the information shown in FIG. 4, in step 1000, the travel target point is at its position X10 [i] and yaw angle T0 for each gazing point.
It is determined as [i]. Then in step 1100,
Based on this traveling target point, the steering angle Sl at each gazing point
[I] is calculated. In step 1200, the weighted steering angle SL in which the steering angle of each gazing point thus obtained is weighted based on the driving rule is obtained. Although steps 1000 to 1200 above are for the left white line, SR is similarly calculated for the right white line,
In step 1300, Sout is calculated by averaging the weighted steering angles of the left and right white lines.

On the other hand, in the driving mode judging section 80,
It is determined whether the vehicle deviates from the driving lane by driving the driver. In the normal driving mode of the driver, while obtaining the shape of the front white line as visual information, the driving target line is set in the center of the road so that the degree of influence from the left and right shoulders in the straight part, that is, the degree of danger is minimized. However, in the curved portion, a traveling target line is set inside the curve of the road so as to suppress lateral acceleration and lateral jerk during traveling on the curve to improve the riding comfort. In the traveling control unit 70, the above-described command steering angle Sout is constantly calculated from the front white line information in accordance with the driving rule according to the driving mode of the driver.

Here, the determination is made by comparing the command steering angle Sout with the steering wheel angle Sdr obtained by the driver's steering. That is, as a determination rule, Sout−α (v, γ) <Sdr <Sout + α (v,
γ) is set. α is a dead zone region coefficient, which is a function that changes depending on the vehicle speed v and the front running white line curvature γ. When v is large or γ is large, α becomes small.

In the case of Sdr that does not satisfy this rule, a command to switch from the manual drive mode to the drive assist drive mode is issued to the signal switching unit 90, and the unstable steering operation caused by the driver side is replaced with automatic steering control. To do. When the above determination rule is satisfied, the steering driver 100 with the command steering angle Sout
The transmission to the vehicle is cut off, and the manual driving mode is set.
Accordingly, when the actual travel route of the vehicle deviates from the above travel target line by a predetermined amount due to driver's fatigue or operation error, Rule-i, Rul
By the command steering angle Sout based on the rules such as e-j and Rule-k, smooth steering control corresponding to driving by a skilled driver is performed in consideration of the degree of danger of the road shoulder and the riding comfort.

The present embodiment is configured as described above, the white line information of a plurality of gazing points is taken by the TV camera, the normal driving operation of the driver is made into a rule and stored as a driving rule, and based on this driving rule. By weighting each gazing point to change the running target point, a stable command steering angle signal can be output even if there is a partial missing of white line information or measurement error. .. Then, when the actual travel route of the vehicle deviates from the line based on the command steering angle, smooth automatic steering equivalent to driving by a skilled driver is performed by the command steering angle.

Further, since the above-mentioned driving rules can be increased or decreased, they can be added according to the capacity of the memory, and further, the driving rules corresponding to many new driving situations can be sequentially added. There is. Further, since the driving rule for weighting is expressed by the membership function, it is possible to linguistically control and adjust.

Although the embodiment has been applied to a vehicle driving support system based on driving by a driver, the present invention is not limited to this and may be applied to an unmanned autonomous vehicle. Alternatively, or as another aspect of the driving support system, the driver is informed of the deviation from the proper travel route based on the comparison between the commanded steering angle calculated by the steering angle calculation means and the actual steering situation by the driver. You may do so.

[0039]

As described above, the present invention is provided with the storage means for storing the driving operation of the driver as the driving rule,
Since the road linear information obtained from the image processing means is processed based on this driving rule to calculate the steering angle of the vehicle, partial missing or measurement error of the road linear information such as the white line at the road side end Even if there is such a situation, the control output does not become unstable, and there is an effect that a smooth command steering angle signal equivalent to driving by a skilled driver can be obtained. When the actual driving route of the vehicle deviates from the driving line according to the driving rule by monitoring the driving condition of the driver by providing the driving condition judging means, the steering is driven by the command steering angle calculated above. Therefore, deviation from the proper driving route due to driver's fatigue or operation mistake is automatically switched to automatic steering, which is equivalent to driving by a skilled driver in consideration of road shoulder risk and riding comfort. Smooth operation is secured.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of the present invention.

FIG. 2 is a block diagram showing a configuration of an exemplary embodiment of the invention.

FIG. 3 is a diagram showing road white lines in a camera coordinate system.

FIG. 4 is a block diagram showing a process in a traveling control unit.

FIG. 5 is an explanatory diagram of setting a traveling target line.

FIG. 6 is a diagram illustrating an example of a gazing point weighting function.

FIG. 7 is an explanatory diagram of weighting for a tangent angle deviation amount.

FIG. 8 is a diagram showing an example of a weighting function for a tracking white line.

FIG. 9 is an explanatory diagram of calculating a steering angle.

FIG. 10 is a flowchart showing a flow of steering angle calculation.

[Explanation of symbols]

 1 Vehicle 11 Photographing Means 12 Image Processing Means 13 Driving Rule Storage Means 14 Steering Angle Calculation Means 15 Driving State Judging Means 16 Driving Means 20 TV Cameras 25 Camera Swing Drives 30 Image Processing Devices 40 Vehicle Speed Sensors 50 Map Information Department 60 Global Travel control unit 70 Travel control unit 75 Memory 80 Travel mode determination unit 90 Signal switching unit 100 Steering drive unit A Vehicle information A, B Recognition / intention information C Driving rule D Swing command Sout Command steering angle Li Note point Wl Left white line Wr Right white line T_1ine Travel target line T_1ine0 Central travel line tr [i], tl [i] Tangent angle φ Swing angle

Claims (5)

[Claims] 1. A photographing means attached to a vehicle for photographing a road in front of the vehicle, and an image obtained by the photographing means,
Image processing means for extracting road linear information at a plurality of gazing points ahead of the vehicle, driving rule storing means for storing the driving motion of the driver as a driving rule, and road linear information at the plural gazing points based on the driving rules. A driving control device for a moving vehicle, comprising: steering angle calculation means for processing and calculating a steering angle of the vehicle. 2. The driving rule includes a weighting rule for the plurality of gazing points, and the steering angle calculation means calculates the steering angle by weighting the road linear information at each gazing point. The operation control device for a moving vehicle according to claim 1. 3. The operation control device for a mobile vehicle according to claim 2, wherein the weight rule represents weight by a membership function. 4. The driving rule includes a traveling target point rule for each of the plurality of gazing points, and the steering angle calculation means calculates the steering angle by obtaining a traveling target point from the road alignment information at each gazing point. 2. The method according to claim 1, wherein
An operation control device for the moving vehicle described. 5. A photographing means attached to the vehicle for photographing a road in front of the vehicle, and an image obtained by the photographing means,
Image processing means for extracting road linear information at a plurality of gazing points in front of the vehicle, driving rule storing means for storing the driving operation of the driver as a driving rule, and processing the road linear information based on the driving rule Steering angle calculating means for calculating the steering angle of the vehicle, driving state judging means for judging whether the driving state complies with the driving rule, and the driving state judging means judges that the driving rule deviates from the driving rule. And a drive unit that drives the steering at the steering angle calculated by the steering angle calculation unit.