JP2511851Y2 - Autonomous vehicle - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Field of Industrial Application) The present invention relates to an autonomous vehicle that autonomously travels on a road, and particularly, to appropriately drive the vehicle according to the shape of the road. The present invention relates to an autonomous vehicle.

(Prior Art) In recent years, various types of unmanned guided vehicles that are automatically driven by an unmanned vehicle have been proposed (see, for example, JP-A-62-162113).

In such a conventional automated guided vehicle, a guiding cable is laid on a preset traveling path, and the automated guided vehicle is guided along the guiding cable. That is, a predetermined signal is given to the guiding cable, and a pickup coil provided on the side of the unmanned guided vehicle detects the signal so as to discriminate the deviation from the traveling path so that the vehicle travels.

Also, instead of the guiding cable, an optical reflection tape such as aluminum tape or vinyl tape is attached to the traveling road surface, and an unmanned guided vehicle side is equipped with a projector and a light receiver. It has been proposed that a light receiver catches the light reflected by the light guide and guides the automatic guided vehicle along the optical reflection tape.

(Problems to be solved by the invention) However, the system using the guiding cable requires a large scale of equipment, and it is not easy to change the route of the traveling path later.

Further, in the method using the optical reflection tape, if the reflection surface of the optical reflection tape is contaminated by dust or the like existing on the traveling path, the reflectance of light will decrease,
The traveling road surface and the optical reflection tape have to be constantly cleaned, and the processing related to maintenance has been troublesome.

In addition, in the conventional system, when the shape of the guideway such as the guide cable or the optical reflection tape is a linear line that is sharply bent, the steering of the transport vehicle must be suddenly performed, and the smooth running is required. Was difficult.

The present invention has been made in view of the above, and for example, even when the shape of the traveling path is a sharply bent polygonal line,
An object of the present invention is to provide an autonomous vehicle that can travel smoothly according to the shape of a road.

[Structure of the Invention] (Means for Solving the Problem) In order to achieve the above object, an autonomous vehicle according to the present invention divides a vehicle traveling path into a plurality of sections in advance, as shown in FIG. Incidentally, the storage means 1 for respectively storing the information regarding the traveling path including the radius of curvature for each section.
Based on the image capturing means 3 for capturing an image of the traveling road in the traveling direction of the vehicle, the image information of the captured traveling road, and the information regarding the traveling road, the traveling road for each section is a straight road. A discriminating means 5 for discriminating which one of the following types, a curved road, a branch road, or an intersection, belongs to,
A global control that stores a global control rule that predetermines a target traveling state including a target vehicle speed and a target steering angle for each section corresponding to each of a plurality of combinations of the types of the sections that are continuous with each other. Rule storage means 7 and setting means 9 for setting the target traveling state extracted from the general control rule for each section based on the general control rule and the type of the traveling path determined for each section. And a travel control means 11 for performing travel control for causing the vehicle to travel along the travel route based on the information regarding the set target travel state.

(Operation) According to the autonomous vehicle according to the present invention, first, the determination means 5 travels including the image information of the traveling road imaged by the imaging means 3 and the radius of curvature for each section read from the storage means 1. Based on the information about the road, it is determined whether the traveling road for each section belongs to any one of a straight road, a curved road, a branch road, and an intersection. For example, when the traveling road of a certain section is a straight road, the curvature radius of the information regarding the traveling road is set to infinity,
When the traveling road of a certain section is a curved road, the radius of curvature is set according to the degree of the curve of the curved road. In response to this, the setting means 9 reads the global control rule storage means 7 and reads the global control rules corresponding to a plurality of combinations of mutually continuous types, and for each section determined by the determination means 5. The target traveling state including the target vehicle speed and the target steering angle extracted from the general control rule is set for each section based on the type of the traveling path. Based on the information on the target traveling state, the traveling control means 11 performs traveling control for traveling the vehicle along the traveling path. That is, for example, the combination of the types of mutually continuous sections is
In the case of a form that goes from a straight road to a straight road via a curved road, as a general control rule, on the first straight road, the target vehicle speed is set to a low speed and the target steering angle is set to a constant angle. Immediately before approaching the road, the target vehicle speed is set to a low speed and the target steering angle is set to a constant steering angle according to the radius of curvature of the curved road, and the target vehicle speed is set immediately before passing through the curved road and returning to the straight road. The target rudder angle is set to 0 as well as set to high speed. As a result, the vehicle runs while gradually decelerating before entering the curved road from the first straight road, runs slowly at a constant steering angle on the curved road, and accelerates from the latter half of the curved road. The vehicle can be driven by gradually returning the steering angle. When an intersection exists on the traveling road, the vehicle can be stopped at the intersection, or the vehicle can travel slowly. Thus, according to the autonomous vehicle according to the present invention,
For example, even if the shape of the traveling path is a polygonal line that is sharply bent, the target traveling state suitable for the combination of the traveling paths of mutually continuous sections extracted from the global control rule is set for each section. Since the traveling control of the vehicle is performed based on the target traveling state set globally,
The vehicle can smoothly and autonomously travel along the traveling path.

Embodiment An embodiment of the present invention will be described below with reference to the drawings.

FIG. 2 is a block diagram showing the overall configuration of an autonomous vehicle to which the present invention is applied. The autonomous traveling vehicle shown in FIG. 2 autonomously travels on a traveling path based on various information while appropriately determining the road condition in the traveling direction detected by a camera, a sensor, or the like. This autonomous vehicle is for calculating the vehicle position in the absolute coordinate system based on the image information processing unit 100 that captures an image of the traveling direction of the vehicle and performs image processing, and detection information such as a wheel speed sensor and a gyroscope. Detection unit 200
And an actuator control unit 300 for controlling each of the actuators for operating a steering wheel, an accelerator, a brake, a winker and the like for autonomously driving the vehicle, and map information to a destination and information about a traveling route. Is stored in the information storage unit 400, a travel control unit 500 that controls the actuator control unit 300 and the like to drive the vehicle toward the final target point based on information from each unit, and the travel control unit 500. On the other hand, the interface device 600 is configured to input information about a destination, that is, a plurality of target points set on a traveling road, and to display an image from the image information processing unit 100 and other information.

The image information processing unit 100 has a pair of cameras 101 and 102. The cameras 101 and 102 are provided, for example, on the left and right sides of the front part of the vehicle, and thereby capture a stereo image in the traveling direction of the vehicle, that is, a stereo perspective image.
The perspective images picked up by the cameras 101 and 102 are supplied to an image processing unit 105 having a built-in image processing computer for image processing. Also, the perspective image is the image processing unit 105.
Is converted into a plane image, that is, an inverted perspective view is converted. The image processing unit 105 uses, for example, a white line (guideline) that is a pair of vehicle guide lines drawn on the road from this planar image.
Alternatively, the roadside belt, the center line, etc. are detected and the position thereof is measured.

Further, more specifically, by detecting a white line or the like on the road, the relative relationship between the road and the vehicle, that is, the distance from the vehicle to the white line on the left side, the distance to the white line on the right side, the traveling direction of the vehicle and the road The angle and the like are calculated, and the curve direction and curvature of the road are obtained from these values. Further, before the intersection, the distance to the intersection is obtained by measuring how the white line is broken.

Further, the image information processing unit 100 has an ultrasonic sensor 103, a laser radar (not shown), and the like, detects an object existing in the traveling direction or the side of the vehicle, such as a preceding vehicle or a guardrail, and detects these. Information is sent to the local vehicle position detection unit 107. Further, the distance, angle, and the like obtained by the image processing unit 105 described above are supplied to the local vehicle position calculation unit 107. Thereby, the positional relationship between the road and the vehicle, that is, the local vehicle position is calculated.

It should be noted that about three sets of cameras are installed in order to obtain a wide angle of view, and by switching and using them, the above parameters can be obtained more finely from the images of the front right, the front left, and the center front.

The detection unit 200 has a pair of wheel speed sensors 211 and 213 provided on the left and right of the rear wheel, and the outputs of these sensors are supplied to the wheel speed data processing unit 218, and further from this wheel speed data processing unit 218. It is supplied to the global vehicle position calculation unit 219. The wheel speed sensors 211 and 213 detect the rotation of the wheels, and generate thousands of pulses (specifically, 1000 to 4000) for each of the left and right wheels in synchronization with this rotation. . Therefore, if the difference between the numbers of both pulses generated for each of the left and right wheels is calculated, it becomes the difference in the traveling distance, and from this difference, it can be determined whether the vehicle is traveling in a curve.
Further, the traveling distances of the left and right wheels are directly the traveling distances of the vehicle. Therefore, the displacement of the vehicle can be obtained by calculating these pieces of information moment by moment. In particular,
The posture of the vehicle at a certain point in time, that is, the relative position information of the vehicle based on the position, that is, the information such as the relative position in X and Y coordinates and the angle θ, can be obtained. If the position is known, the current position of the running vehicle can always be detected by successively performing the wheel speed data processing. However, since the error is accumulated, the measurement error increases as the traveling distance increases. Therefore, the gyroscope 214 is provided to calculate the position of the own vehicle in the absolute coordinate system with high accuracy. The vehicle position thus obtained is the global vehicle position.

The actuator control unit 300 has various actuators required to autonomously drive the vehicle, that is, a steering actuator 301 that steers the steering wheel, a throttle actuator 303 that corresponds to an accelerator, and a brake actuator 305 that drives a brake mechanism. The actuator drive unit 309 controls each of these actuators based on the control information from the travel control unit 500. When the vehicle is an AT (automatic transmission) vehicle and only travels forward, only the above-mentioned actuator is necessary, but when controlling an MT (manual transmission) vehicle or reverse, the clutch, shift lever, etc. An operating actuator and the like are also required. The actuator control unit 300 receives an acceleration / deceleration command or a target vehicle speed command from the traveling steering control unit 505, and controls an accelerator, a brake, and the like. The steering control by the actuator control unit 300 similarly operates in response to a right or left rotation command or a target steering angle command from the traveling steering control unit 505.

The information storage unit 400 is a data storage unit 401 that stores map information about a destination, map information up to the destination, for example, map information such as an intersection position depending on the road to the destination, an inter-intersection distance, and the like. The data storage unit 401 includes an access control unit 403 that controls access from the travel control unit 500.

Referring again to FIG. 2, the traveling control unit 500 appropriately determines the road information in the traveling direction detected by the image information processing unit 100 and the detection unit 200, while referring to the information from the information storage unit 400. Is for driving and controlling the actuator control unit 300 to drive the vehicle toward the destination input from the interface device 600, and includes an obstacle avoidance direction determination unit 501, a travel command unit 503, and a traveling steering control unit. 505 and. The obstacle avoiding direction determination unit 501 is supplied with obstacle data from the image processing unit 105 of the image information processing unit 100, and determines an obstacle avoiding direction based on the obstacle data. The travel command unit 503 uses the information from the information storage unit 400, the global vehicle position information from the global vehicle position calculation unit 219 of the detection unit 200, and the local vehicle position from the local vehicle position calculation unit 107 of the image information processing unit 100. Information such as vehicle position information and destination information from the interface device 600 is supplied, and control information relating to traveling operations such as straight ahead, right / left turn, deceleration, acceleration, and stop is output according to these information. The traveling steering control unit 505 is control information from the traveling command unit 503, local vehicle position information including a distance from the road edge from the local vehicle position calculation unit 107 of the image information processing unit 100, an angle, and the like,
Based on the information about the obstacle avoiding direction from the obstacle avoiding direction determining unit 502 and the vehicle attitude (position) information including the displacement of the vehicle from the wheel speed data processing unit 218 of the detecting unit 200, the control of the actuator control unit 300 is performed. Various necessary control signals, for example, information such as target vehicle speed and target rudder angle information are supplied to the actuator control section 300, and steering control and the like are thereby performed.

The interface device 600 includes a keyboard 601 for inputting information relating to a plurality of target points set on a route to a destination, a route to the destination, and various other information such as the plurality of target points. A display device 603 for displaying information related to Instead of the keyboard 601, a digitizer or the like may be used. Further, the interface device 600 may include a voice recognition device, a voice synthesis device, or the like as a man-machine interface.

Next, an embodiment of the essential part of the present invention will be described with reference to FIG.

The route information unit 11 has a storage unit, and stores node information and path information as information about the traveling path.

The node information is stored in a format as shown in FIG. 4 (A), a specific point on the traveling road is set as a node, and the x coordinate, y coordinate and node name of this point are stored. A plurality of such nodes are set on the road, and the above contents are stored for each node. Also, the above x
Coordinates and y coordinates are set by an absolute coordinate system.

The path information is stored in a format as shown in FIGS. 4 (B) and 5. As shown in Fig. 5, from the start point node 21 on the road to the next end point node
Set routes up to 23 as paths. This path information includes the distance between the road center line 25 and the turning center 27, that is, the radius of curvature R and the distance from the start point node 21 to the end point node 23.
That is, the path length D, the angle θ _S formed by the x coordinate axis in the absolute coordinate system at the start node 21 and the tangent to the circle of curvature, and the angle formed by the x coordinate axis in the absolute coordinate system at the end node 23 and the tangent to the circle of curvature. θ _c , the width W of the traveling road 29, the number of lanes on the traveling road 29, the shape of the starting point node 21, the shape of the ending point node 23, and various information such as the distinction between one-way traffic and mutual traffic .

The sensor 13 is formed by the cameras 101 and 102, the ultrasonic sensor 103, and the like, and detects the so-called local vehicle position. The local vehicle position is a relative vehicle position from the road edge, for example, the white line (guideline) or the guardrail.

The global travel control unit 15 is connected to the route information unit 11, and based on the node information (data) and the path information (data) from the route information unit 11, the travel command PR (j) and the target point command PO ( i) is output. That is, as shown in FIG.
Node data N (0), N (1) ... N from the route information section 11
(N max-1), N (n max) and path data P (1), P
(2) ... When P (n max-1) and P (n max) are input, the target point commands PO (0) and PO are sequentially output based on these information.
(1) ... PO (o max-1), PO (o max), and travel command P
R (1), PR (2) ... PR (o max-1), PR (o max) are output. These target point commands PO (i) (i = 0,1,2 ... nm
ax) and the travel command PR (j) (j = 1,2 ... o max) are always i =
It is output as a pair as j.

The travel command PR (j) includes items as shown in FIG. 7 (A). Specifically, the travel command PR
In (j), the target point command name to be paired, that is, the command name n of the target point ahead of the traveling direction, the distance d of the road center line between the target points, the target vehicle speed V _pr during traveling, Select target rudder angle S _pr and white line to be captured by the camera while driving Q ₀
And the distance Q ₁ that the vehicle should hold from the white line and the own vehicle attitude that must be maintained during traveling, that is, the local target own vehicle attitude Q ₂ .

The target point command PO (i) includes items as shown in FIG. 7 (B). More specifically, the target point command PO
In (i), the positions in the absolute coordinate system, that is, the global target position (x _g , y _g , θ) and the local target position (xl, x
_r , θ _d ), the target vehicle speed V _PO, and various information on the target steering angle S _PO .

The steering control unit 17 is connected to each of the sensor 13 and the global travel control unit 15, and has information on the local vehicle position from the sensor 13 and a target point command PO (i) from the global travel control unit 15. Steering control is executed based on the travel command PR (j).

 Next, the operation will be described with reference to FIG.

In step 31, a route search is executed and the path data from the route information section 11 is input. In step 33, the start point node, the end point node, the radius of curvature R of the input path data, the angle θ _S between the x coordinate axis and the tangent of the circle of curvature in the absolute coordinate system at the start point node 21, and the absolute coordinate system at the end point node 23. Based on the angle θ _c formed by the x-coordinate axis and the tangent to the circle of curvature, the shape of the traveling road, for example, whether it is a straight road, a curved road, a branch road, or an intersection road is determined for each path data. to decide. In step 35, a global travel command based on the global control rule is determined according to the determined shape of the traveling path. As this general control rule, ten kinds of rules (Rule) as shown in FIG. 9 are set corresponding to the shape of the traveling path. Rules 1 to 3 are applied when moving from a straight road to a straight road via a curved road. Rules 4 to 6 are applied when the vehicle includes a branch point and moves from a straight road to a straight road. Rules 7 to 9 are applied when an intersection is included and when moving from a straight road to a straight road. Rule 10 also applies when moving from a curved road to a curved road.

 Next, each rule will be described with reference to FIG.

Rule 1 is the target point command PO as shown in Fig. 9 (A).
(I + 1) is set to the same point as the point of the node N, and at this point, the target vehicle speed V _PO is set to a low speed and the target steering angle S _PO is set to a constant angle. Therefore, steer gradually while decelerating before entering a curved road.

Rule 2 is, as shown in FIG. 9 (B), the target point command PO
Set (i + 1) by shifting it to the front of the point of node N,
At this point, the target vehicle speed V _PO is set to a high speed and the target steering angle S _PO is set to 0. In addition, the travel command PR (i
+1), the traveling target vehicle speed V _pr is set to a low speed, the traveling target steering angle S _pr is set to a constant angle, and the white line captured by the camera is set to the outer white line, that is, Q ₀ is set to the right or left. Therefore, the steering angle is gradually returned while accelerating from the latter half of the curved road.

Rule 3 is the target command PO as shown in Fig. 9 (C).
As (i) is set in front of the node N, the route distance d of the travel command PR (i + 1) is corrected.

Rule 4 is the target command PO (i
+1) is set before the point of the node N, which is a branch point, and the target vehicle speed V _{po of} this target point command PO (i + 1) is set.
Is set to a low speed and the target steering angle is set to a constant angle. Therefore, the vehicle gradually steers while decelerating before approaching the branch point.

Rule 5 is the target point command PO as shown in Fig. 9 (E).
(I + 1) is set to be shifted ahead of the node N, which is the branch point, and the target vehicle speed V _{PO of} this target command PO (i + 1) is set.
And set the target rudder angle S _PO to 0. Further, the travel target vehicle speed V _pr of the travel command PR (i + 1) is set to a low speed, and the travel target steering angle S _pr is set to a constant angle. Therefore, the steering angle is gradually returned to the original while accelerating after passing through the latter half of the branch road, that is, the branch point.

Rule 6 is the target point command PO as shown in FIG. 9 (F).
The route distance d of the travel command PR (i + 1) is corrected as (i) is set ahead of the node N, which is a branch point.

Rule 7 is the target point command PO as shown in Fig. 9 (G).
(I + 1) is set before the point of the node N which is the intersection, and the target vehicle speed V _PO of this target point command PO (i + 1) is set to a low speed. Therefore, it slows down slowly before approaching the intersection.

Rule 8 is the target point command PO as shown in FIG. 9 (H).
(I + 1) is set in front of the point of the node N which is the intersection, and the target vehicle speed V _PO of this target point command PO (i + 1) is set to a high speed. In addition, the travel target vehicle speed V _pr of the travel command PR (i + 1) is set to a low speed, and the white line selected by the camera is selected Q ₀
Is set to “none”. Therefore, since information about the white line cannot be obtained before and after the intersection, the vehicle passes through the intersection at a low speed and accelerates after passing through the intersection.

Rule 9 is the target point command PO as shown in Fig. 9 (I).
The route distance d of the travel command PR (i + 1) is corrected as (i) is set in front of the intersection of the node N. Moreover, the selection Q _o of the white line to be taken into the camera of the driving command PR (i + 1) is set to the normal state, for example, “left” or “right”.
Set to. Therefore, after passing the intersection, the vehicle collects information about the white line and travels.

Rule 10 is the target point command PO as shown in Fig. 9 (J).
(I + 1) is set to the same point as the node N, and the target vehicle speed V _PO is set to a low speed and the target steering angle S _PO is set to 0 at this point. Also, run command PR (i + 1)
Set the traveling target vehicle speed V _{pr of} to a certain angle. Therefore, while traveling at a low speed on the curved road, the steering angle is gradually restored from the latter half of the curved road.

Referring again to FIG. 8, in step 37, a traveling command is issued in response to the setting of the global traveling command, and in step 39, a target point command is issued in accordance with the setting of the global traveling command. Thus, the traveling control corresponding to the shape of the traveling path is executed based on the above-mentioned general control rule.

As described above, the target point command PO (i) and the travel command PR (j) are given, and the travel control is executed based on the information on the target point and the information on the target travel mode included in these commands. Therefore, the vehicle can be autonomously driven along the traveling path without using a special guiding means such as a guiding cable or an optical reflection tape.

[Effects of the Invention] As described above, according to the autonomous vehicle of the present invention, first, the determining means determines the image information of the traveling road imaged by the image capturing means and the sections read from the storage means for each section. Based on the information about the traveling road including the radius of curvature, it is determined whether the traveling road for each section belongs to any one of a straight road, a curved road, a branch road, and an intersection. For example, when the traveling road of a certain section is a straight road, the curvature radius of the information related to the traveling road is set to infinity, while when the traveling road of a certain section is a curved road, the radius of curvature is It is set according to the degree of curve of the curved road. In response to this, the setting means reads the global control rule storage means and corresponds to a plurality of combinations of mutually continuous types of the respective sections, and the running route for each section determined by the determination means. The target traveling state including the target vehicle speed and the target steering angle extracted from the global control rule is set for each section on the basis of the type. Based on the information on the target traveling state, the traveling control means performs traveling control for traveling the vehicle along the traveling path. That is, for example, the combination of the types of mutually continuous sections is
In the case of a form that goes from a straight road to a straight road via a curved road, as a general control rule, on the first straight road, the target vehicle speed is set to a low speed and the target steering angle is set to a constant angle. Immediately before approaching the road, the target vehicle speed is set to a low speed and the target steering angle is set to a constant steering angle according to the radius of curvature of the curved road, and the target vehicle speed is set immediately before passing through the curved road and returning to the straight road. The target rudder angle is set to 0 as well as set to high speed. As a result, the vehicle runs while gradually decelerating before entering the curved road from the first straight road, runs slowly at a constant steering angle on the curved road, and accelerates from the latter half of the curved road. The vehicle can be driven by gradually returning the steering angle. When an intersection exists on the traveling road, the vehicle can be stopped at the intersection, or the vehicle can travel slowly. Thus, according to the autonomous vehicle according to the present invention,
For example, even if the shape of the running path is a polygonal line that is sharply bent, the target running state suitable for the combination of the running paths of the mutually continuous sections extracted from the global control rule is set for each section. Since the traveling control of the vehicle is performed based on the target traveling state set globally,
This has an extremely excellent effect that the vehicle can smoothly and autonomously travel along the traveling path.

[Brief description of drawings]

FIG. 1 is a claim correspondence diagram, FIG. 2 is a block diagram showing an overall configuration of an autonomous vehicle to which the present invention is applied, and FIG. 3 is a block diagram showing an embodiment of a main part of the present invention. 4 (A) and 4 (B) are explanatory views showing information about the traveling path,
FIG. 5 is an explanatory diagram showing path information, FIGS. 6 and 7 are explanatory diagrams showing traveling commands and target point commands, and FIG. 8 is a flowchart showing a flow of control operation in FIG. FIG. 9 is an explanatory diagram showing a general control rule regarding traveling. DESCRIPTION OF SYMBOLS 1 ... Storage means, 3 ... Imaging means 5 ... Discrimination means, 7 ... Global control rule storage means 9 ... Setting means, 11 ... Travel control means

Claims (1)

(57) [Scope of utility model registration request] 1. A storage means for dividing a traveling path of a vehicle into a plurality of sections in advance and storing information about the traveling path including a radius of curvature for each section, and a traveling path in the traveling direction of the vehicle. Based on the image pickup means for picking up the image, the image information of the picked up running road, and the information on the running road, the running road for each section is a straight road,
Each of the sections corresponding to a plurality of combinations of the sections of the sections that are mutually continuous, and a determination unit that determines which of a curved path, a branch path, and an intersection belong to each section. Based on the global control rule storage means for storing the global control rule for predetermining the target traveling state including the target vehicle speed and the target steering angle for each, and the type of the traveling road determined for each global control rule and each section. Setting means for setting the target traveling state extracted from the general control rule for each of the sections, and traveling for causing the vehicle to travel along the traveling path based on information about the set target traveling state. An autonomous traveling vehicle, comprising: a traveling control unit that performs control.