JP2010079497A - Vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To run a vehicle in parallel to and following a preceding vehicle with high accuracy. <P>SOLUTION: When a parallel follow-up mode is entered, a second target point G to be finally converted to the side of a preceding vehicle 80 and a final first target point Tl slightly apart from the second target point G are set. Convergence is performed with an "inter-vehicle distance-oriented control" logic toward the final first target point T1. Then, convergence is performed with a "traveling direction-oriented control" logic toward the second target point, and the parallel follow-up mode is continued under the traveling direction-oriented control. In the traveling direction-oriented control, lateral traveling speed is made higher than that in the inter-vehicle distance-oriented control, and proportional constants and differential constants to the right and the left directions under feedback control are set to be larger than those under the inter-vehicle distance-oriented control. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a vehicle and, for example, relates to a follow-up running that follows another vehicle based on a command from another vehicle or the host vehicle.

When a vehicle travels, a vehicle that auto-cruises following a preceding vehicle (hereinafter referred to as a preceding vehicle) has been proposed.
For example, Patent Document 1 proposes a vehicle including an inter-vehicle distance control type constant speed traveling device that performs constant speed traveling while keeping a preset following inter-vehicle distance setting value following a preceding vehicle.
Moreover, in patent document 2, while making a follow-up driving | running | working with respect to a preceding vehicle, using the inter-vehicle communication, the possibility of crossing of the own vehicle and a preceding vehicle is judged, and when this crossing possibility becomes more than a predetermined value. A technique for stopping the follow-up running has been proposed.
Further, in Patent Document 3, in a single-seat vehicle capable of traveling independently, a preceding vehicle travels as a host vehicle, while another vehicle follows the host vehicle as a follower vehicle, or beside the host vehicle. It has been proposed to follow along side by side.

JP-A-10-67254 JP 2007-126146 A JP 2006-338117 A

However, Patent Document 1 and Patent Document 2 describe “longitudinal following traveling” when traveling behind the preceding vehicle, but “parallel traveling following” that travels side by side with the preceding vehicle. Is not described.
On the other hand, in Patent Document 3, it is described that the vehicle travels in a state where it is lined up next to the preceding vehicle. However, when a vehicle traveling in an arbitrary position starts following travel, the vehicle travels next to the preceding vehicle. It does not describe a specific method for shifting to the parallel running following running state and the control in the side by side state.

In the case of tracking control, a target point or target position of the following vehicle is basically set at an arbitrary position around the preceding vehicle, and the deviation between this point or position and the current position of the following vehicle is set to zero. Control is performed.
When following in the front-rear direction, it can be directly controlled by an accelerator or a brake. On the other hand, when following alongside the preceding vehicle (except for a spherical tire that can be driven in any direction), it is not possible to move purely in the lateral direction. It is indispensable and must control lateral movement.
For this reason, in the case of running side by side, the direction of travel must be strictly controlled. At the same time, the distance between the vehicles in the horizontal direction must be controlled more strictly than in the case of longitudinal following. If the direction of travel is strictly controlled, the lateral distance cannot be controlled forever. Conversely, if the emphasis is placed on the lateral distance control, the direction of travel cannot be controlled forever.
This problem is particularly noticeable in a small vehicle with a high degree of lateral turning freedom, such as an inverted pendulum vehicle (such as a single-shaft two-wheel vehicle) proposed in Patent Document 3. The following vehicle cannot sufficiently cope with the sudden turn of the preceding vehicle.

  Then, an object of this invention is to provide the vehicle which can transfer to a parallel running following state safely with respect to a preceding vehicle.

(1) In the first aspect of the invention, the vehicle includes a follow-up control unit that performs follow-up running control on the preceding vehicle, and starts parallel running following running parallel to the side of the preceding vehicle. In this case, the second target point that is the final follow-up target point is set on the lateral side of the preceding vehicle, and the final first target point is set outside the preceding vehicle with respect to the second target point. And the tracking control unit tracks the final first target point as the tracking target point and, after reaching the final first target point, tracks the second target point as the tracking target point. In addition, a vehicle characterized by performing follow-up running control is provided.
(2) In the invention according to claim 2, the follow-up control unit performs follow-up running control that follows the second target point as a follow-up target, rather than follow-up running control until reaching the final first target point. The vehicle according to claim 1, wherein the vehicle has a quick response to turning.
(3) In the invention described in claim 3, the target point setting means is a safe inter-vehicle distance in which the final first target point is secured from the preceding vehicle based on the shapes of the preceding vehicle and the host vehicle. The vehicle according to claim 1 or 2, wherein the vehicle is set at a point separated by a distance.
(4) In the invention according to claim 4, the target setting means sets the final first target point behind the second target point with respect to the preceding vehicle. A vehicle according to claim 2 or claim 3 is provided.
(5) In the invention according to claim 5, the target setting means sets a point at the shortest distance from the current position on the distance separated from the preceding vehicle by the safe inter-vehicle distance as the first target point. The follow-up control unit follows the first target point as a follow-up target point and performs follow-up running control so as to follow the final first target point as the follow-up target point after reaching the first target point. The vehicle according to any one of claims 1 to 4 is provided.

  According to the present invention, the second target point, which is the final follow-up target point, is set on the lateral side of the preceding vehicle, the final first target point is set outside the second target point, and the final first target is set. After following the point as the follow target point, the second target point is followed as the follow target point, so that it is possible to shift to the parallel running follow state safely with respect to the preceding vehicle.

Hereinafter, preferred embodiments of the vehicle of the present invention will be described in detail with reference to FIGS. 1 to 8.
(1) Outline of Embodiment When the vehicle according to the present embodiment travels side by side in the traveling direction with respect to the preceding vehicle (followed vehicle) and shifts to parallel running following traveling, control accuracy by automatic control of the following vehicle To improve.
And in the vehicle of this embodiment, it shifts to the parallel follow-up run as follows from the state which is not following at all, or the state which is carrying out longitudinal follow-up.
That is, when shifting to parallel running follow-up, the second target point for the preceding vehicle (the target point to be finally converged set next to the preceding vehicle) and the final farther from the preceding vehicle than the second target point Set the first target point.
Then, first, the final “first target point” is converged by lateral “control of emphasis on inter-vehicle distance” logic. When the vehicle position has sufficiently converged to the final first target point, control is then performed with the “advanced direction control” logic toward the second target point. After the vehicle has converged to the second target point, the traveling direction Continue parallel running following important control.
The control emphasizing the inter-vehicle distance is a control in the case of following the preceding vehicle as in the conventional case. On the other hand, the control with emphasis on the direction of travel is a control with quicker lateral movement than the control with emphasis on the inter-vehicle distance (control with quick response to turning). This can be realized by making the control larger than the control that emphasizes the inter-vehicle distance. In this embodiment, the turn command value of the preceding vehicle is used as an input for feedforward control in order to further speed up the reaction to the turn.
Note that whether or not the target point is converged is determined to be converged when the distance is within a predetermined distance from the target point. The predetermined distance is set in advance for each target point.

  If the vehicle moves away from the second target point by a certain distance during the parallel follow-up running, the vehicle is changed to the longitudinal follow-up (control logic emphasizing the inter-vehicle distance) again toward the final first target point to ensure safety. Then, after converging to the final first target point by control with emphasis on inter-vehicle distance, switching to control with emphasis on the traveling direction is performed and parallel running following traveling is continued.

Here, the final first target point is a point away from the center of the preceding vehicle by a safe inter-vehicle distance that secures a certain distance from the preceding vehicle, based on the shape of the preceding vehicle and the host vehicle, in the left or right direction. . This safety inter-vehicle distance is multiplied by a safety factor based on the vehicle shape, vehicle acceleration / turning / braking performance, communication leakage, and control delay at a point as far as possible to ensure non-contact while the preceding vehicle and the following vehicle are traveling. To decide.
In the present specification, an aggregate of safe inter-vehicle distances centering on a preceding vehicle is referred to as a safe inter-vehicle distance line. The safe inter-vehicle distance line in the present embodiment is circular, but is not necessarily circular, and may be an elliptical shape that is flat in the traveling direction. This is because the traveling direction is easy to control even near the preceding vehicle, and the safety distance can be shortened.

In order to further ensure the safety at the time of turning, the setting position of the final first target point may be offset slightly behind the preceding vehicle and placed behind the preceding vehicle in the traveling direction. This makes it easier for the control to respond to a sudden turn of the preceding vehicle.
Further, when the straight line connecting the current position of the following vehicle and the final first target point intersects the safe inter-vehicle distance line, that is, a position that must pass within the safe inter-vehicle distance while moving to the final first target point. In this case, a point on the safe inter-vehicle distance line (circle in the present embodiment) closest to the current position is set as the first target point, and after convergence to the first target point by longitudinal follow-up traveling, the first target point Is slid toward the final first target point on the safe inter-vehicle distance line, and finally converges to the final first target point. The first target point is slid not on the front side of the preceding vehicle but on the rear side for safety.

In the present embodiment, the start of the longitudinal follow-up travel and the transition from the normal travel or the longitudinal follow-up travel to the parallel follow-up travel are performed based on a command signal from the preceding vehicle. In the case of a transition command to parallel running following traveling, an instruction on the parallel running side (the right side and the left side of the preceding vehicle) is included.
In addition, you may make it perform these based on the instruction | command from the passenger | crew of a tracking vehicle.

(2) Details of Embodiment The vehicle according to the present embodiment can be applied to a normal four-wheel vehicle, but is particularly effective when applied to a small vehicle having a high degree of lateral turning freedom. It is.
Therefore, in this embodiment, a case where the present invention is applied to an inverted pendulum vehicle (such as a single-shaft two-wheel vehicle) that can turn with a small radius will be described as an example. Although the preceding vehicle will be described as an inverted pendulum vehicle, other four-wheel vehicles may be used.

  The inverted pendulum vehicle travels while sensing the posture of the riding section and performing posture control so as to maintain the balance in the front-rear direction in the driving direction of the drive wheels in accordance with the posture. As the attitude control method, for example, various controls disclosed in US Pat. No. 6,302,230, JP-A 63-35082, JP-A 2004-129435, and JP-A 2004-276727 are disclosed. The method can be used.

FIG. 1 shows a configuration related to the follow-up control of the vehicle (follow-up vehicle) of the present embodiment.
As shown in FIG. 1, the vehicle 1 includes an ECU (Electronic Control Unit) 10, a laser radar 20, a vehicle speed sensor 30, a yaw rate sensor 40, a wireless communication device 50, and drive motors 60a and 60b.
Although not shown, a battery is also provided that supplies drive power to the drive motors 60a and 60b and the like, and supplies a low-voltage power supply for control to the ECU 10.

The ECU 10 includes a computer system including a ROM that stores various programs and data (not shown), a RAM that is used as a work area, an external storage device, an interface unit, and the like.
In the present embodiment applied to an inverted pendulum vehicle, a posture control program for maintaining the posture, a travel control program for controlling travel based on various instruction signals from the control device, and following the preceding vehicle 80 in the present embodiment. Various programs such as a follow-up traveling program for traveling are stored in the ROM, and the ECU 10 performs corresponding processing by executing these various programs.

  The ECU 10 includes a preceding vehicle relative position detection unit 11, a follow-up control unit 12, and a vehicle control unit 13. The ECU 10 controls the inter-vehicle distance in the longitudinal follow-up traveling, and performs the control in the traveling direction in the parallel follow-up running. To do.

The preceding vehicle relative position detection unit 11 detects the relative position and direction (traveling direction) of the preceding vehicle 80 based on the position and distance measured by the laser radar 20, and supplies them to the follow-up control unit 12.
Note that the vehicle speed and yaw rate information may be received from the preceding vehicle 80 by communication.
In addition, although not necessary in the present embodiment, a current position detection device such as GPS is provided to detect the absolute position of the host vehicle 1 when the position coordinate data is received from the preceding vehicle 80 and dead reckoning is performed. You may do it.

The follow-up control unit 12 supplies the vehicle control unit 13 with control command values (front-rear direction command value, left-right direction command value) when performing longitudinal follow-up running and parallel running follow-up running as follow-up running in the present embodiment.
The follow-up control unit 12 acquires the vehicle speed from the vehicle speed sensor 30 and the yaw rate from the yaw rate sensor 40. Further, the target command value of the preceding vehicle 80 received by the wireless communication device 50 is acquired. The wireless communication device 50 transmits and receives data to and from the preceding vehicle 80 and other vehicles (including following vehicles) by inter-vehicle communication.
The follow-up control unit 12 includes a front-rear direction control unit and a left-right direction control unit (both will be described later) by feedback control and feedforward control.
The follow-up control unit 12 is based on each input from the preceding vehicle relative position detection unit 11, the vehicle speed sensor 30, the yaw rate sensor 40, and the wireless communication device 50, and a front-rear control command value (target speed or target Acceleration) and the left / right control command value (target rotational angular velocity u) by the control unit in the left / right direction are supplied to the vehicle control unit 13.

The vehicle control unit 13 controls the drive motors 60a and 60b.
That is, the vehicle control unit 13 controls the drive motors 60a and 60b so that the target speed (or target acceleration) supplied from the follow-up control unit 12 is achieved. Specifically, the vehicle control unit 13 includes a speed (or acceleration) -current map for the drive motor 60, and a target speed (or target acceleration) supplied from the follow-up control unit 12 according to the torque-current map. The current control is performed so that the current corresponding to () is output to the drive motor 60.

  In addition, the vehicle control unit 13 outputs different currents to the drive motors 60a and 60b so that the vehicle 1 turns at the target rotational angular velocity u (left / right control command value) supplied from the follow-up control unit 12. Thus, the turning may be performed by the differential between the drive motors 60a and 60b.

  In the present embodiment, the inverted pendulum vehicle is described as an object. However, the present invention can also be applied to other vehicles such as a four-wheel vehicle. In this case, the vehicle includes a steering motor. Then, the vehicle control unit 13 controls the steering motor so that the steering angle corresponds to the target rotational angular velocity u supplied from the follow-up control unit 12.

FIG. 2 shows a block diagram of the follow-up control in the follow-up control unit 12.
FIG. 2A is a control block diagram that performs front-rear control, and a front-rear feedback control unit 121a to which a deviation is input and a front-rear travel command of the preceding vehicle 80 received via the wireless communication device 50. It is comprised by the front-and-back feedforward control part 121b into which (target speed or target acceleration) is input, and outputs the front-rear control command value (target speed or target acceleration).

The deviation (vertical deviation) input to the front-rear feedback control unit 121a is a component (distance) in the traveling direction of the follower vehicle 1 of the line segment (distance) connecting the follower vehicle 1 and the target point for the preceding vehicle 80, that is, A distance from the target point to a line segment drawn in a direction perpendicular to the traveling direction of the following vehicle 1 (hereinafter referred to as a longitudinal distance).
Here, the target point is a target point set behind the preceding vehicle 80 based on a predetermined tracking method in the case of vertical following traveling, and a first target point Ts, which will be described later, in the case of parallel traveling following traveling. The final first target point Tl and the second target point G correspond.
In the present embodiment, the control in the front-rear direction is the same in both cases of longitudinal follow-up running (control that emphasizes the distance between vehicles) and parallel running follow-up running (control that emphasizes the traveling direction).
That is, in the control block diagram for performing the control in the front-rear direction in FIG. 2A, the input is not changed or the feedback gain is not changed depending on the switching of the follow-up control.

FIG. 2B is a control block diagram that performs left-right control, and includes a left-right feedback control unit 122a and a left-right feedforward control unit 122b, and outputs a left-right control command value (target rotational angular velocity u). It is like that.
In the present embodiment, the control in the left-right direction is the same in vertical follow-up running (control with emphasis on inter-vehicle distance) and parallel running follow-up running (control with emphasis on the traveling direction), but the input is changed by switching the follow-up control. And feedback gain are changed.

That is, in the case of parallel running follow-up, the turn command value T of the preceding vehicle 80 (the target rotational angular velocity of the preceding vehicle 80) received via the wireless communication device 50 is input to the left and right feedforward control unit 122b. In the case of traveling, 0 is input and the feedforward control by the left and right feedforward control unit 122b is not performed.
In this way, by inputting the turn command value T of the preceding vehicle 80 to the left and right feedforward control unit 122b, the turn restricted by the turn of the preceding vehicle compared to the longitudinal follow-up control in which the subordinate vehicle 1 can turn freely. In this way, contact due to a sudden turn of the subordinate vehicle alone is avoided.

On the other hand, the left-right feedback control unit 122a is used for both the parallel follow-up running and the vertical follow-up run, but the values of the proportional constants PT and PD in the feedback control are larger in the parallel follow-up run than in the vertical follow-up run. Is set (changed).
The lateral deviation eW input to the left / right feedback control unit 122a is a component (distance) of a line segment (distance) connecting the following vehicle 1 and the target point with respect to the preceding vehicle 80 in a direction (lateral direction) perpendicular to the traveling direction of the following vehicle 1 ( Distance), that is, a distance from the target point to a line segment drawn in the traveling direction of the following vehicle 1 (hereinafter referred to as a lateral distance).
Here, the target point is a target point set behind the preceding vehicle 80 based on a predetermined tracking method in the case of vertical following traveling, and a first target point Ts, which will be described later, in the case of parallel traveling following traveling. The final first target point Tl and the second target point G correspond.

Next, the operation in the case of performing parallel running following with the vehicle 1 configured as described above will be described.
FIG. 3 illustrates a state in which the vehicle 1 shifts to a parallel running following traveling state in which the vehicle 1 travels side by side with the preceding vehicle 80.
As shown in FIG. 3, when the following vehicle 1 performs parallel running following the preceding vehicle 80, the final target point (second target point) set beside the preceding vehicle 80 (right or left). Rather than moving directly to G), the following steps are taken and the second target point G is moved while changing the control content of the follow-up running.
In other words, when the following vehicle 1 receives a parallel follow-up instruction from the boarding vehicle or from the preceding vehicle (including an instruction on whether to run parallel to the left or right), the following first vehicle 1 is separated from the second target point G. Moving toward the target point Tl by longitudinal follow-up traveling (control with emphasis on inter-vehicle distance) (S1).

Here, the final first target point Tl is set to a point that is separated from the center of the preceding vehicle 80 by a safe inter-vehicle distance on a straight line passing through the second target point from the center point of the preceding vehicle 80.
As shown in FIG. 3B, the safe inter-vehicle distance is determined by a vehicle shape when the vehicle is looked down and a representative point for determining the inter-vehicle distance of the vehicle.
That is, the representative point of the vehicle is set at the center of both wheels (in the case of three or more wheels, the center of gravity of the shape connecting all the vehicles), and the point farthest from the representative point in the outer shape of the vehicle is the farthest point. The safe inter-vehicle distance d is a distance equal to or greater than a distance at which the farthest points do not contact each other when the inter-vehicle distance can be maintained.
Specifically, the distance between the representative points when the farthest points of the two vehicles are superimposed on a line connecting the representative point of the preceding vehicle 80 and the representative point of the following vehicle 1 is d1 (see FIG. 3B). In this case, the safe inter-vehicle distance d = d1 + α + r1.

α is a constant set by the maximum speed, minimum turning radius, tracking control performance, safety factor, etc. of the vehicle.
Although r1 will be described later (FIG. 6), it is assumed that the following vehicle 1 has actually reached the final first target point Tl with a convergence determination radius for determining whether or not the final first target point Tl has converged (arrived). This is a radius for defining the convergence determination area. By including this convergence determination radius r1 in the safe inter-vehicle distance d, contact with the preceding vehicle can be avoided even when the following vehicle 1 reaches the most preceding vehicle 80 side in the convergence determination area. . The value of r1 is set according to the form (inverted pendulum vehicle or four-wheel vehicle, etc.) and shape of each vehicle, but 0.1 m is set in the example of this embodiment.
The safe inter-vehicle distance d set as described above varies depending on the form (inverted pendulum vehicle or four-wheel vehicle, etc.) and shape of each vehicle, but in the example of this embodiment, it is set in the range of 1.8 m to 2 m. Is done.

Note that the center point of rotation when the vehicle travels with the minimum turning radius may be the representative point, and the farthest point on the outer shape of the vehicle when traveling with the minimum turning radius may be the farthest point.
In the case of a vehicle in which each wheel can be controlled to rotate independently, the vehicle can rotate around the center of gravity of all the wheels, so that it is the same representative point and farthest point as described above.

A set of points separated from the center point of the preceding vehicle 80 by a safe inter-vehicle distance is a safe inter-vehicle distance line P.
However, although the safe inter-vehicle distance line P in this embodiment is circular, the safe inter-vehicle distance is a distance that can ensure safety without the preceding vehicle 80 and the following vehicle 1 being in contact with each other. It may be. The reason why the safe inter-vehicle distance is made shorter in the vertical direction than in the horizontal direction by flattening in the traveling direction is that the follow-up in the front-rear direction can be directly controlled by an accelerator or a brake.

3C shows the distance d2 from the specific point of the preceding vehicle 80 to the second target point G, and is the distance between the specific point of the preceding vehicle 80 and the specific point of the following vehicle 1. FIG.
As an example of the case of this embodiment, when the width of the vehicle is 1 m (50 cm from the specific point to the side surface), the second target point distance d2 = 1.5 m, and the distance between the outer shapes of both the vehicles is about 50 cm. .
As a result, in the present embodiment, the distance between the final first target point Tl and the second target point G is 30 to 50 cm.
The distance d2 may be increased as the vehicle speed of the preceding vehicle 80 or the following vehicle 1 increases. In this case, an upper limit may be provided for the distance d2 so that both vehicles are not too far apart.

Returning to FIG. 3 (a), if the following vehicle 1 reaches the final first target point Tl (actually within a convergence determination area in contact with the safe inter-vehicle distance line P, as will be described later) in the longitudinal following traveling, the traveling direction is emphasized. The control target point of the following vehicle 1 is changed to the second target point G and the parallel follow-up running is performed (S2).
Thereafter, the following vehicle 1 continues parallel running following the second target point G as the control target point. When the following vehicle 1 is separated from the second target point G by a predetermined distance or more, the following vehicle 1 is returned to the longitudinal following driving and is again finalized. Move toward the first target point Tl. After that, it moves to the second target point G in the same manner.

In the present embodiment, the final first target point Tl is set at a point separated from the center of the preceding vehicle 80 by a safe inter-vehicle distance on a straight line passing through the second target point from the center point of the preceding vehicle 80.
On the other hand, in order to ensure safety when the preceding vehicle turns to the following vehicle 1 before the following vehicle 1 reaches the second target point, as shown by Tl ′ in FIG. In addition, the setting position of the final first target point may be set behind the preceding vehicle 80 by being offset by an angle θ slightly behind the preceding vehicle 80.
Also in this case, the following vehicle 1 travels vertically following the final first target point Tl as the control target point, and when it converges to the final first target point Tl, performs the parallel following traveling using the second target point G as the control target point.

FIG. 4 is a diagram illustrating a moving method when the following vehicle 1 is in a specific position with respect to the preceding vehicle 80.
As shown in FIG. 4, when the follow-up vehicle 1 is in a specific position and the longitudinal follow-up control is performed directly with the final first target point Tl as the target point, the safety inter-vehicle distance line P (the distance r1 for convergence determination is on the inside It may pass through the region Q surrounded by the line P ′. When the follower vehicle 1 is positioned in such a positional relationship, the first vehicle does not move directly to the final first target point Tl, but reaches the first point on the safe inter-vehicle distance line P that can be reached without passing through the region Q. The target point Ts is set, and the first target point Ts is first converged (within the radius r1) as the target point, and then the first target point Tl is sequentially changed by a predetermined angle or a predetermined distance along the safe inter-vehicle distance line P. Indirectly to the final first target point Tl.
The movement from the first target point Ts to the final first target point Tl is based on the longitudinal follow-up control because the safe inter-vehicle distance d is secured.

When the follower vehicle 1 moves to the target point Tl, the follower vehicle 1 does not pass through the region Q and moves to the target point Tl as to whether it moves directly or indirectly via the first target point Ts. The case of direct movement if it can be moved and the case of indirect movement when passing through the region Q has been described.
On the other hand, in order to facilitate the determination, direct movement and indirect movement may be determined as follows.
That is, as shown in FIG. 4A, when the follower vehicle 1 is located on the opposite side of the preceding vehicle 80 (the left side in the figure), the indirect movement is performed.

  When the following vehicle 1 ′ is located on the right (opposite side of parallel running) rearward with respect to the preceding vehicle 80, the intersection of the line connecting the preceding vehicle 80 and the following vehicle 1 ′ and the safe inter-vehicle distance line P is Set to the first first target point Ts. That is, the point closest to the safe inter-vehicle distance line P from the following vehicle 1 is set as the first first target point Ts.

On the other hand, when the follower vehicle 1 is located right (opposite side of parallel running) ahead of the preceding vehicle 80, the point just beside the preceding vehicle 80 on the safe inter-vehicle distance line P is the first first target point. Set to Ts. As a result, the time during which the vehicle ahead 80 is traveling can be minimized.
Note that the setting of the first target point Ts described above is a simple determination when the following vehicle 1 is located on the opposite side of the preceding vehicle 80 running in parallel (except in the region Q). Regardless, it applies to all cases.

As shown in FIG. 4B, when the follower vehicle 1 is located in the area Q inside the safe inter-vehicle distance line P, the safe inter-vehicle distance line from the follower vehicle 1 is all the same regardless of the position of the follower vehicle 1. A point close to P is set as the first first target point Ts.
As described above, when moving from the area Q to the first target point Ts, the following vehicle 1 originally located in the area Q is instructed to run in parallel running and the second target point G is set to the target point. The case where it is separated from the second target point G by a predetermined distance or more in the state of running in parallel running following.
In addition, although the case where the movement to the first target point Ts is based on the longitudinal follow-up traveling has been described (the same flowchart is described later in FIG. 5), the following vehicle 1 in the region Q moves to the first target point Ts. Since it is inside the safe inter-vehicle distance line P, parallel running following traveling may be performed only in this case.

In the above description, whether the following vehicle 1 moves directly or indirectly to the final target point Tl depends on whether or not it passes through the region Q, and is positioned on the side opposite to the parallel running side of the preceding vehicle 80. The case where it depends on whether or not is done was explained.
On the other hand, regardless of the position where the following vehicle 1 is located, it may be moved indirectly to the final target point Tl via the first target point Ts.

Next, according to the flowchart shown in FIG. 5, the detail of the operation | movement in the case of performing parallel running follow-up is demonstrated.
In this embodiment, there is a feature in the method of shifting to parallel tracking and control of parallel tracking, and the vertical tracking is performed in the same manner as the conventional tracking following the rear of the vehicle. Description of traveling will be omitted, and parallel running following will be described.
This operation is an operation in the case where the follower vehicle 1 always moves indirectly to the final target point Tl via the first target point Ts.
In the present embodiment, the first target point Ts, the final target point Tl, and the second target point G indicate relative positions with respect to the preceding vehicle 80, and therefore each target point is associated with the movement of the preceding vehicle 80. However, it is a fixed point in the relative positional relationship.

When parallel running follow-up is instructed by the operation of the host vehicle or by a command from the preceding vehicle 80, the follow-up control unit 12 determines the nearest first target point Ts (at the shortest distance) (step 10). ).
That is, the follow-up control unit 12 determines the intersection of a line segment connecting the representative point of the preceding vehicle 80 and the representative point of the host vehicle 1 and the safe inter-vehicle distance line P (circle or ellipse) that is a set of the safe inter-vehicle distance d. Calculate and set the intersection as the first first target point Ts.
As described above, the safe inter-vehicle distance d is determined in consideration of the size of the convergence determination area (radius r1), and is d = d1 + α + r1.

Next, the follow-up control unit 12 performs convergence control (details will be described later in FIG. 7) to the first target point Ts set in Step 10 (Step 11). The convergence control to the first target point Ts is based on the longitudinal follow-up traveling that emphasizes the inter-vehicle distance.
Then, the follow-up control unit 12 determines whether or not it has converged to the first target point Ts (step 12).

FIG. 6 shows the convergence determination area and the target maintenance determination area.
As shown in FIG. 6, the convergence determination area is an area in which the following vehicle 1 is considered to have reached the final first target point Tl and the first target point Ts, and is within the radius r1 with the set target points Tl and Ts as the center. It is an area.
In this embodiment, the radius r1 of the convergence determination area is set to 0.1 m. However, other values may be set according to the shape of the vehicle, the maximum vehicle speed, and the like.

On the other hand, the target maintenance determination area is an area within the predetermined distance r2 with the second target point G as the center.
This target maintenance determination area is an area for determining whether or not to maintain parallel running follow-up as it is in parallel running following the second target point G as a target point (step 16 described later). If it is within the area, the parallel follow-up running is continued.
In the present embodiment, the radius r2 of the target maintenance determination area is set to 60% of the target inter-vehicle distance d2, for example.

In this target maintenance determination area, when the following vehicle 1 is closest to the preceding vehicle 80, the size is set such that the vehicles may come into contact with each other. Thus, contact is avoided by the abnormal approach process (steps 17 to 20).
In this way, by avoiding contact with the preceding vehicle 80 by the abnormal approach process, the target maintenance determination area within the safe inter-vehicle distance P can be set large. And in the target maintenance determination area, unlike the longitudinal follow-up running, the parallel running follow-up running in which the turning of the follow-up vehicle 1 is restricted is performed, so that contact by turning can be effectively avoided.

Returning to FIG. 5, if the following vehicle 1 has not reached the convergence determination area with respect to the first target point Ts (step 12; N), the following control unit 12 returns to step 11 to return to the first target point Ts. Convergence control is continued.
On the other hand, when it is determined that the following vehicle 1 has reached the convergence determination area and has converged (step 12; Y), the tracking control unit 12 further determines whether or not it has converged to the final first target point Tl. (Step 13).

When the final first target point Ts has not converged (step 13; N), the follow-up control unit 12 slides the first target point Ts along the safe inter-vehicle distance line P to the next first target point Ts. Is determined and changed (step 14), and the process returns to step 11 to perform convergence control to the changed first target point Ts.
The follow-up control unit 12 equally divides the distance between the “nearest first target point Ts” and the “final first target point Tl” by an angle (for example, 30 degrees) on the safe inter-vehicle distance line P. Among these, the closest one that has not yet converged is selected as the next first target point Ts. In other words, the line segment on the side of the final first target point Tl that forms the predetermined angle θ2 with respect to the line segment connecting the nearest first target point Ts and the specific point (center point) of the preceding vehicle 80, and the safe inter-vehicle distance The intersection with the line P is set as the next first target point Ts.

When the following vehicle 1 has reached the convergence determination area with respect to the final first target point Tl (step 13; Y), the following control unit 12 performs the following control from the longitudinal following traveling to the parallel traveling that is an emphasis on the traveling direction. Switching to follow-up traveling is performed, and convergence control to the second target point (details will be described later in FIG. 8) is performed (step 15).
Then, the tracking control unit 12 determines whether or not the tracking vehicle 1 can maintain the target for the second target point based on whether or not the tracking vehicle 1 is within the target maintenance determination area (see FIG. 6) (step 16).

  When the follower vehicle 1 is out of the target maintenance determination area (step 16; N), the follower control unit 12 returns to step 10, switches the follower traveling to the longitudinal follower, and again returns to the first target point Ts and the final first. Move from the target point Tl to the second target point.

If the following vehicle 1 is within the target maintenance determination area (step 16; Y), the following control unit 12 performs an abnormal approach process.
That is, the follow-up control unit 12 determines whether or not the follow-up vehicle 1 is abnormally approaching the preceding vehicle (step 17). The determination of whether or not this is an abnormal approach is, for example, determined as an abnormal approach when the distance between the side surfaces s between the following vehicle 1 and the preceding vehicle 80 is a predetermined distance or less (for example, 20 cm or less). Note that a value obtained by adding a half of the vehicle width of both vehicles to the side-to-side distance s is set as the inter-vehicle distance threshold value, and when the distance between the side vehicles is equal to or less than the inter-vehicle distance threshold value, it is determined that the vehicle is approaching abnormally. May be.
Further, when the distance between the side surfaces when the following vehicle 1 is at the position of the second target point G with respect to the preceding vehicle 80 is sG, the distance between the side surfaces s ≦ (1 / x) sG (for example, x = 2, 3,...) May be determined as abnormal approach. Also in this case, the determination may be made based on the inter-vehicle distance in consideration of the vehicle width of both vehicles.

When the follow-up control unit 12 determines that it is not abnormal approach (step 17; N), it determines whether or not the second target point is Tl (step 18).
If the second target point is G (step 18; N), the follow-up control unit 12 returns to step 15 and maintains parallel running follow-up by continuing the convergence control to the second target location.

  On the other hand, when it is determined that the vehicle is approaching abnormally (step 17; Y), the follow-up control unit 12 changes the second target point from G to Tl, which is the final first target point set on the safe inter-vehicle distance P. (Step 19). Thus, the follow-up control unit 12 avoids an abnormal approach state by changing the second target point, which is the follow-up target point, to a point further away from the preceding vehicle 80.

When the second target point is changed to Tl in step 19, the follower vehicle 1 moves away from the preceding vehicle 80 toward the follower target point Tl, thereby eliminating the abnormal approach (step 17; N). Since the second target point is set to Tl (step 18; Y), the follow-up control unit 12 returns the second target point to the original G (step 20).
And the follow-up control part 12 returns to step 15, and maintains parallel running follow-up by continuing the convergence control to a 2nd target place.

  In addition, the operation | movement in the case of performing parallel running following driving | running demonstrated above is the case where the command of parallel running following driving | running | working is cancelled | released (in the case of cancellation | release of following driving | running | working itself, and the case of a longitudinal tracking control command), and a vehicle Ends when stops (ignition off).

FIG. 7 is a flowchart showing the operation of the convergence control to the first target point Ts in step 11 (FIG. 5).
The convergence control to the first target point Ts is the convergence control in the longitudinal follow-up traveling that emphasizes the inter-vehicle distance.
The follow-up control unit 12 sets PT = A1 and DT = A2 as the values of the proportional constant PT and the differential constant DT in the left-right feedback control unit 122a in the left-right control block diagram (FIG. 2B) (step 111).
Here, A1 and A2 are proportionality constants and differential constants determined by conducting tests on actual vehicles etc. with emphasis on maintaining the inter-vehicle distance d2.

Next, the tracking control unit 12 acquires the lateral deviation eW input to the left and right feedback control unit 122a (step 112).
This lateral deviation eW is determined by the relative position of the following vehicle 1 with respect to the preceding vehicle 80 detected by the preceding vehicle relative position detecting unit 11 and the following target point (first target point Ts, The deviation calculated from the final first target point Tl) by the follow-up control unit.
That is, the lateral deviation eW is a distance (vertical direction distance) from the follow target point to a line segment drawn in the traveling direction of the follow vehicle 1.

Next, the tracking control unit 12 acquires a lateral deviation history eWold (step 113). The lateral deviation history eWold is a value one cycle before the lateral deviation eW.
Then, the follow-up control unit 12 acquires a left / right control command value u for convergence to the first target point Ts according to the left / right direction control block diagram of FIG. 2B (step 114).
Here, the left / right control command value u is a function of the lateral deviation eW, the proportionality constant PT, the lateral deviation history eWold, and the differential constant DT (u = f (eW, PT, eWold, DT)).
In this longitudinal follow-up control, the input of the left and right feedforward control unit 122b is zero.

When the left / right control command value u is expressed using the transfer function shown in FIG. 2A, the following equation (1) is obtained.
u = PT * eW + DT * (eW−eWold) (1)

  The follow-up control unit 12 inputs the obtained left / right control command value u as the target angular velocity u to the vehicle control unit 13 (step 115), and replaces the value of the lateral deviation history eWold with the lateral deviation eW (step 116). Return to the main routine (FIG. 5).

Next, details of the convergence control to the second target point G (step 15 in FIG. 5) will be described.
The convergence control to the second target point G is the convergence control in the parallel follow-up traveling that places importance on the traveling direction.
FIG. 8 is a flowchart showing the operation of the convergence control to the second target point G.
The follow-up control unit 12 sets PT = A3 and DT = A4 as the values of the proportional constant PT and the differential constant DT in the left-right feedback control unit 122a in the left-right control block diagram (FIG. 2B) (step) 151).
Here, A3 and A4 are proportionality constants and differential constants determined by conducting tests with an actual vehicle or the like with an emphasis on maintaining the traveling direction.

Here, the relationship between the proportional constant PT and the relationship between the differential constant DT in the longitudinal follow-up running and the parallel running follow-up is as follows.
| A1 | <| A3 |
| A2 | <| A4 |
As described above, the proportional constants PT and DT set in the parallel running follow-up that emphasizes the direction of travel rather than the proportional constant PT and the differential constant DT set in the case of the longitudinal follow-up that emphasizes the inter-vehicle distance (step 111). By increasing this value, it is possible to react quickly to a sudden turn or the like of the preceding vehicle 80.

Further, the follow-up control unit 12 acquires an angular velocity command value T of the preceding vehicle 80, which is an input of the left / right feedforward control unit 122b (FIG. 2B) (step 152).
The lateral deviation eW and the lateral deviation history eWold are acquired (steps 153 and 154). The acquisition of both values is the same as step 112 and step 113 in FIG.

Next, the follow-up control unit 12 acquires a left / right control command value u for convergence to the second target point G in accordance with the left / right direction control block diagram of FIG. 2B (step 155).
Here, the left / right control command value u is a function of the angular velocity command value T, the lateral deviation eW, the proportionality constant PT, the lateral deviation eWold before one cycle, and the differential constant DT (u = f (T, eW, PT, eWold, DT)).

When the left / right control command value u is expressed using the transfer function shown in FIG. 2A, the following expression (2) is obtained.
u = T + PT * eW + DT * (eW−eWold) (2)

  In this formula (2), compared to the formula (1) for the longitudinal follow-up travel, the angular velocity command value T of the feedforward control is added and the proportionality constant (PT = A3, DT = A4) becomes a large value. The response to the lateral direction (turning) becomes faster, and it becomes possible to cope with a sudden turn of the preceding vehicle 80.

  The follow-up control unit 12 inputs the obtained left / right control command value u as the target angular velocity u to the vehicle control unit 13 (step 156), and replaces the value of the lateral deviation history eWold with the lateral deviation eW (step 157). Return to the main routine (FIG. 5).

As described above, according to the present embodiment, in response to the parallel follow-up running command, the vehicle does not move directly to the second target point G, which is the final follow-up target point, but is lateral to the second target point G. After moving to the final first target point Tl separated in the direction (in the case of offset, a predetermined angle laterally rearward), it moves to the second target point G.
And, as the final first target point Tl, safety is achieved based on the acceleration / turning / braking performance of the vehicle, communication leakage, and control delay at a point as far away as possible to ensure non-contact while the preceding vehicle 80 and the following vehicle 1 are traveling. Since it is set at a point separated by the safe inter-vehicle distance determined by multiplying by the rate, it is possible to safely shift to the parallel running following state with respect to the preceding vehicle 80.

Further, the first target point Ts is set as the tracking target point, and the longitudinal tracking travel is performed until the final first target point Tl is reached (convergence). After the final first target Tl is reached, the second target point is set as the tracking target point. The parallel follow-up running is performed, and after reaching the second target point G, the parallel follow-up running is continued.
In the longitudinal follow-up traveling, since the final first target point Tl is set at a point away from the safe inter-vehicle distance, the distance in the traveling direction (inter-vehicle distance) is emphasized without being aware of the contact with the follower vehicle 80. By performing vertical tracking control, it is possible to move quickly to the final first target point Tl.
Further, in the movement from the final first target point Tl to the second target point G and the travel after reaching the second target point G (following travel positioned beside the preceding vehicle 80), the response to the lateral direction (turning). Therefore, it is possible to avoid contact by reacting quickly to a sudden turn of the preceding vehicle 80.

Further, when the final target point Tl is reached, the point on the safe inter-vehicle distance line P closest to the current position is set as the first target point Ts, and the first target point Ts is converged as the follow-up target point in the longitudinal follow-up traveling. Thereafter, the first target point Ts is sequentially slid toward the final first target point on the safe inter-vehicle distance line P on the rear side of the preceding vehicle 80 to finally converge to the final first target point Tl.
Thereby, it becomes possible to move quickly and safely to the first target point Tl.

It is a block diagram relevant to the following control of the vehicle (following vehicle) of this embodiment. It is a block diagram of the follow-up control in a follow-up control part. It is explanatory drawing showing the state which transfers to the parallel running follow running state in which a following vehicle runs alongside the preceding vehicle. It is explanatory drawing about the movement method in case a following vehicle exists in a specific position with respect to a preceding vehicle. It is a flowchart showing the operation | movement in the case of performing parallel running follow-up. It is explanatory drawing showing the convergence determination area and the target maintenance determination area. It is a flowchart showing the operation | movement of the convergence control to 1st target point Ts. 5 is a flowchart showing an operation of convergence control to a second target point G.

Explanation of symbols

1 following vehicle 2 preceding vehicle representative point 3 virtual joint 4 target point 5 following vehicle representative point 10 ECU
DESCRIPTION OF SYMBOLS 11 Leading vehicle relative position detection part 12 Tracking control part 13 Vehicle control part 20 Laser radar 30 Vehicle speed sensor 40 Yaw rate sensor 50 Wireless communication apparatus 60a, 60b Drive motor 80 Leading vehicle

Claims (5)

A vehicle including a follow-up control unit that performs follow-up running control on a preceding vehicle,
When starting the parallel follow-up running parallel to the side of the preceding vehicle, a second target point, which is the final follow-up target point, is set on the side of the preceding vehicle, and from the second target point And a target setting means for setting a final first target point outside the preceding vehicle,
With
The follow-up control unit follows the final first target point as a follow-up target point, and performs follow-up running control so as to follow the second target point as the follow-up target point after reaching the final first target point. Do,
A vehicle characterized by that. The follow-up control unit sets the follow-up running control that follows the second target point as the follow-up target rather than the follow-up running control until the final first target point is reached, and is a control that responds quickly to a turn.
The vehicle according to claim 1. The target point setting means sets the final first target point to a point separated from the preceding vehicle by a safe inter-vehicle distance that secures a certain distance based on the shapes of the preceding vehicle and the host vehicle.
The vehicle according to claim 1, wherein the vehicle is a vehicle.   The said target setting means sets the said last 1st target point back on the basis of the said preceding vehicle rather than the said 2nd target point, The Claim 1, Claim 2, or Claim 3 characterized by the above-mentioned. Vehicle. The target setting means sets, as a first target point, a point that is the shortest distance from the current position on a distance that is the safe inter-vehicle distance with respect to the preceding vehicle,
The follow-up control unit follows the first target point as a follow-up target point and performs follow-up running control so as to follow the final first target point as the follow-up target point after reaching the first target point.
The vehicle according to any one of claims 1 to 4, wherein the vehicle is a vehicle.

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