JP2005035498A - Vehicle travel support device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a traveling support device for a vehicle, surely preventing contact with an obstacle, and improved in possibility of reaching a target position. <P>SOLUTION: In determining a position 220 to be avoided by a vehicle in the course of guiding from initial positions A<SB>1</SB>, A<SB>2</SB>, setting a margin for a distance r<SB>1</SB>to be kept by the vehicle 200 in the course of guiding from the position 220 according to the relationship between the position 220 and the initial positions A<SB>1</SB>, A<SB>2</SB>, and guiding the vehicle along the set route, the guiding enable state is determined when the vehicle 200 can be guided at a distance more than a preset margin for a distance r<SB>1</SB>. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a vehicular travel support apparatus that obtains a trajectory to a target position and assists the travel so that the vehicle travels along the trajectory.

A technique for guiding a vehicle to a target position using automatic steering or a steering instruction is known (see, for example, Patent Document 1). For example, when performing parking support for parallel parking, it is necessary for the vehicle to guide the vehicle to a target parking position, which is a limited space, while avoiding contact with a vehicle parked laterally. In the technique of Patent Document 1, in order to avoid contact with other vehicles that are parked on the side, a reference line that matches the operation state is displayed on the rear view image of the vehicle using the back monitor. It is described that it is possible to make the vehicle reach the target parking position while avoiding contact with other vehicles by performing an operation so that the predetermined position of the vehicle matches.
Japanese Patent Laid-Open No. 2002-321581 (paragraphs 0030 to 0047, FIGS. 2 to 6)

  In order to surely avoid contact with other vehicles or obstacles during such support traveling, guidance may be provided so as to pass a route sufficiently away from the obstacles. However, if it is attempted to pass a sufficiently distant route, for example, in parallel parking, if the parking space (the distance between the front and rear vehicles) is not long enough, there is a possibility of reaching the target position, such as impossible to guide. Lower. In order to be able to guide even to a short parking space, that is, to improve the reachability to the target position, it is necessary to allow access to obstacles, but even in that case, contact with obstacles etc. Is not allowed. In order to improve the usability of the support device, it is necessary to make these conflicting conditions compatible.

  Then, this invention makes it a subject to provide the driving assistance device for vehicles which improved the reachability to a target position, avoiding the contact to an obstruction reliably.

  In order to solve the above problems, a vehicle travel support device according to the present invention includes a means for calculating a target movement locus from an initial position to a target position, and a guidance means for guiding the vehicle based on the movement locus. Means for determining a position that should be avoided by the vehicle during guidance, and means for calculating a margin distance between the determined position to be avoided based on the relationship between the initial position and the position to be avoided, And a means for determining that guidance is possible when guidance is possible while maintaining a margin distance equal to or greater than the margin distance calculated for the position to be avoided during guidance based on the set movement trajectory. And

  That is, a position to be avoided by the vehicle during guidance (for example, an obstacle or other vehicle on the guidance route) is determined, and this avoidance is based on the relationship between the determined position to be avoided and the initial position of the vehicle guidance route. The marginal distance that the vehicle should secure during guidance with respect to the position to be calculated is calculated. Then, when the vehicle is guided by the set movement trajectory, it is determined whether or not the vehicle can be guided away from the position to be avoided by more than this marginal distance.

  In the case of guidance based on the initially set movement trajectory, if it is determined that guidance with a margin distance greater than the margin distance calculated for the position to be avoided is impossible, the means for calculating the target movement trajectory changes the route setting method. Thus, it is preferable to calculate another movement trajectory.

  That is, in the guidance based on the initially set movement trajectory, if it is determined that the vehicle is closer to the position to be avoided than the margin distance, another route that can secure the margin distance is reset.

  Alternatively, the vehicle travel support apparatus according to the present invention is a vehicle travel support apparatus including means for calculating a target movement trajectory from the initial position to the target position and guidance means for guiding the vehicle based on the movement trajectory. Means for determining a position to be avoided by the vehicle during guidance, and means for calculating a margin distance between the determined position to be avoided based on the relationship between the initial position and the position to be avoided. The means for calculating the movement trajectory may be characterized in that the target movement trajectory is set so as to enable guidance while maintaining a margin distance equal to or greater than the margin distance calculated for the position to be avoided.

  In this case, a position to be avoided by the vehicle during guidance (for example, an obstacle or other vehicle on the guidance route) is determined, and based on the relationship between the determined position to be avoided and the initial position of the guidance route of the vehicle. A margin distance to be secured by the vehicle during guidance with respect to the position to be avoided is calculated. Then, a route that can be guided is calculated while maintaining a distance equal to or larger than the set margin distance with respect to the position to be avoided.

  This margin distance is preferably set based on the distance between the initial position and the position to be avoided. It is preferable to set the margin distance larger as the travel distance from the initial position to the point closest to the position to be avoided becomes longer. At this time, the travel distance is preferably calculated as a movement distance of the center of the rear wheel shaft of the vehicle.

  This margin distance may be set for each of a plurality of locations on the vehicle. When there are a plurality of determined positions to be avoided, it is preferable to set a margin distance for each position to be avoided.

  The means for determining the position to be avoided includes an imaging means for acquiring an image near the target position and a recognition means for recognizing a position to be avoided based on the position to be avoided in the acquired image. The distance is preferably adjusted based on the position in the image of the position to be avoided.

  It has a function of resetting the target position during guidance, and it is preferable to reset the margin distance when resetting the target position.

  According to the present invention, a margin distance is set for these obstacles and the like in order to avoid contact with the obstacles and the like during guidance. When setting the allowance distance, it is necessary to consider steering delay, tire dynamic load radius variation, turning radius characteristic variation, and avoidance point position variation. Among these, the steering delay can be corrected when the support device performs automatic steering or steering instruction, but other variations cannot be handled by the support device. On the other hand, the variation that cannot be dealt with by these support devices has the property of acting cumulatively on the path error during guidance.

  Therefore, in the present invention, by setting the margin distance based on the initial position and the position of the obstacle to be avoided, it is expected that the path error will increase at the position of the obstacle due to these variations. In such a case (for example, when the distance between the initial position and the position of the obstacle or the distance to the obstacle is large), the margin distance is set large, and when the error is expected to be small, the margin distance is small. By setting, it is possible to approach the obstacles by providing flexibility in setting the margin distance while reliably avoiding contact with obstacles, etc., increasing the degree of freedom of route setting, and the target position Reachability is improved.

  Here, if the possibility of avoidance is determined after setting the target route, the target route can be set by simple logic. In this case, when it is determined that the marginal distance from the obstacle cannot be maintained, the reachability to the target route can be further increased by resetting the target route using another logic. . Further, if the target route is set in consideration of the margin distance, the route setting logic is somewhat complicated, but the reachability is improved.

  When the margin distance is set for a plurality of locations on the vehicle (for example, the obstacle side end of the rear wheel axle and the vehicle front end on the obstacle side), the positions at which the locations approach the obstacle differ. By making the marginal distances different at this time, it is possible to improve the degree of freedom of route setting while avoiding contact of the vehicle with the obstacle as compared with the case where the marginal distances are set to be the same. The same is true when there are multiple obstacles.

  When setting the position to be avoided based on the image acquired by the imaging means (not only when the position to be avoided is automatically recognized by the image recognition process, but the position to be avoided by the driver from the acquired image) In this case, the relative position of the position to be avoided with respect to the initial position in the real space can be set based on the position in the image. However, it is difficult for the image pickup means to completely eliminate the image distortion caused by the aberration of the photographing lens or the like and the characteristics of the image pickup element. This image distortion causes an error in the position determination of the position to be avoided. In the present invention, contact with an obstacle can be reliably avoided by adjusting the margin distance according to the position in the image, that is, the distortion.

  When the target position is reset during guidance, the position of an obstacle or the like to be avoided can be determined again at the same time, and the error that cumulatively affects the path setting error described above can be reset. Therefore, in this case, by resetting the margin distance, avoiding contact with obstacles, increasing the degree of freedom of setting when resetting the route, and improving the reachability to the target position Can do.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments of the invention will be described in detail with reference to the accompanying drawings. In order to facilitate the understanding of the description, the same reference numerals are given to the same components in the drawings as much as possible, and duplicate descriptions are omitted.

  Hereinafter, a parking assistance device will be described as an example of the driving assistance device according to the present invention. FIG. 1 is a block configuration diagram of a parking assistance apparatus 100 according to an embodiment of the present invention. The parking assistance device 100 includes an automatic steering device 20 and is controlled by a parking assistance ECU 1 that is a control device. The parking assist ECU 1 includes a CPU, a ROM, a RAM, an input signal circuit, an output signal circuit, a power supply circuit, and the like, and controls an image processing unit 10 that processes an image acquired by a rear camera 32 described later, and an automatic steering device. It has the steering control part 11 which performs. The image processing unit 10 and the steering control unit 11 may be separated in hardware in the parking assist ECU 1, but may be divided in software using a common CPU, ROM, RAM, and the like.

  A steering angle sensor 23 that detects a steering amount of the steering shaft 21 and a steering actuator 24 that applies a steering force are connected to the steering shaft 21 that transmits the movement of the steering wheel 22 to the steered wheels 25. Here, the steering actuator 24 may also serve as a power steering device that applies an assist steering force during steering by the driver, in addition to applying a steering force during automatic steering. The steering control unit 11 controls driving of the steering actuator 24 and receives an output signal of the steering angle sensor 23.

  In addition to the output of the steering angle sensor 23, the steering control unit 11 is also supplied with outputs of a wheel speed sensor 41 that is disposed on each wheel and detects the wheel speed, and an acceleration sensor 42 that detects the acceleration of the vehicle. ing.

  The image processing unit 10 described above of the parking assistance ECU 1 receives an image signal that is an output signal of a rear camera 32 that is arranged at the rear of the vehicle and obtains a rear image, and also receives a driver's operation input for parking assistance. An input means 31 for accepting, a monitor 34 for displaying information to the driver by an image, and a speaker 33 for presenting information by voice are connected.

  Next, some of the assistance operations in the parking assistance apparatus 100 will be specifically described. Hereinafter, as shown in FIG. 2, the parking space 215 between the vehicle 201 (hereinafter referred to as the front vehicle) parked beside the road 211 and the vehicle 202 (hereinafter referred to as the rear vehicle) A case of parallel parking in which the vehicle 200 is reached by reversing will be described as an example. FIG. 3 is a flowchart of a first processing form of this route setting processing. In this control, the driver operates the input means 31 to instruct the parking assist ECU 1 to start the parking assist control until reaching the vicinity of the instructed target parking position or once to the target parking position. Until it is determined that the vehicle cannot be reached in reverse, the parking assistance ECU 1 continues to execute unless the driver cancels the assistance operation from the input means 31.

  Specifically, the driver moves the vehicle 200 to an arbitrary parking assistance start position (right front of the front vehicle 201), and the target in the rear image captured by the rear camera 32 displayed on the monitor 34. After confirming the parking space 230 as the position, the input means 31 is operated to start this parking support control. If the parking space 230 cannot be confirmed in the display image of the monitor 34, the vehicle is moved to a position where the parking space 230 can be confirmed, and support is started. Hereinafter, the reference point of the vehicle 200 at the parking assistance start position (in the following description, the center of the axle of the rear wheel of the vehicle will be described as a reference point. Of course, other positions such as the center and the center of gravity of the rear end of the vehicle are described. The front end or the rear end on one side may be used as a reference point.) Is point A, and the vehicle at this position is represented by 200a.

  When parking assistance is started, the driver sets the target position and the avoidance location by operating the input means 31 while viewing the image captured by the rear camera 32 displayed on the monitor 34 (step S1). . FIG. 4 shows an example of a display image on the monitor 34 at this time. On the monitor 34, an image of the rear of the vehicle 200 is displayed in a state where the left and right are reversed as if looking at the rear with a rearview mirror. Then, by moving the parking frame 230 displayed on the screen (set as a rectangular frame larger than the vehicle 200 by a margin distance from front to back and left and right) and moving it to the target parking position, the target parking position is set. Set up. In addition, the avoidance pole 220 position is also set by moving the pole displayed on the screen. The avoidance pole 220 is set at the rear end of the front vehicle 201, for example. Here, a touch panel is used as the input means 31, and a cursor 310 and a confirmation button 320 are displayed on the screen.

  The parking assist ECU 1 obtains the vehicle position 200g at the target parking position, specifically, the position of the reference point G, the direction of the vehicle at that position, and the position of the avoidance pole 220 by image recognition processing (step S2). What is necessary is just to obtain | require this G point and the position of the avoidance pole 220 as a relative coordinate with respect to the reference point A in the present vehicle position, for example.

  Next, a route from the current position A to the target position G is set (step S3). Specific route setting will be described with reference to FIGS. FIG. 5 is a conceptual diagram of a two-circle model used for route setting, and FIG. 6 is a diagram for explaining conversion from a route based on the two-circle model to a route used for actual guidance.

  An actual guidance path is set by combining an arc, a straight line, and a clothoid curve, but the calculation involves complicated calculations. Therefore, in order to easily determine the turn-back position, each route is modeled and handled as being formed by an arc, and a guidance route is generated based on the calculation result.

In this two-circle model, as shown in FIG. 5, the arc reaches a switching position C (X _C , Z _C ) by following an arc of radius R _A centered on O ₁ (X _A , Z ₀ ) from the initial path. From there, the target position G (0, 0) is reached by following an arc of radius R _min centered on O ₂ (X _B , 0). Here, from the switching position, it shall move with the minimum turning radius _Rmin which can be used in route setting. This R _min may be made to coincide with the minimum turning radius peculiar to the vehicle. However, since there is an error with the actual route by assuming the two-circle model, the R _min is slightly more than the minimum turning radius peculiar to the vehicle. It is preferable to set a large value to provide a margin.

  As is clear from FIG.

が成立する。これを解くと、

Is established. Solving this,

であり、切換位置Ｃの座標と、この位置における偏向角θmaxを求めることができる。

Thus, the coordinates of the switching position C and the deflection angle θmax at this position can be obtained.

As shown in FIG. 6A, this path (referred to as a circular orbit) moves to a point C with a curvature γ _A (= 1 / R _A ), and from there, a curvature −γ _B (= 1 / R _min ) is a route that moves to the target position G. A positive curvature indicates a left turn, and a negative curvature indicates a right turn. Each area (corresponding to an integral value of the curvature according to the travel distance) θ _1A and θ _{1B in} the travel distance-curvature diagram is equal to the change amount of the deflection angle. Therefore, if the initial deflection angle is 0, θ _1A = θ _1B = θmax.

  This route needs to be stationary from the maximum steering angle to the reverse maximum steering angle at the switching position, which is not practical. Therefore, a clothoid trajectory as shown in FIG. 6B is calculated based on this path. The clothoid trajectory reaches a predetermined curvature with a constant rate of curvature change (hereinafter referred to as a curvature speed) from the initial position to a travel distance, and maintains the predetermined curvature for a certain period of time. The curvature is decreased to a constant value, the curvature is set to 0 at the switching position, the curvature speed is made constant to decrease the curvature to reach a predetermined negative curvature, and the target parking position G is reached in that state.

  When calculating the clothoid trajectory, it is assumed that in the two-circle trajectory and the clothoid trajectory, the path length to the switching position and the entire path length are the same, the maximum curvature is the same, and no straight section exists in the clothoid trajectory.

  The difference Lc in the arc section length of the second turning circle is assumed that the deflection angle at the switching point is substantially equal.

で表せる。

It can be expressed as

Also, the deflection angle change amount θ _2D in this section is

と仮定できる。

Can be assumed.

Assuming that each clothoid section is generated by similarity transformation and θ _2A = θ _2C = θ _2D is established, the corrected value Δθmax of θmax is

こうして設定したθmax２と、中間位置Ｃの位置を用いて、経路を設定する。そして、経路生成に成功したか否かを判定する（ステップＳ４）。設定できなかったと判定した場合には、ステップＳ５０へと移行して、現在位置Ａからは目標位置Ｇ点に到達できない旨をモニタ３４やスピーカー３３を用いて運転者に報知し、処理を終了する。運転者は、必要であれば、車両２００を移動させて再度駐車支援動作を作動させればよい。

A path is set using θmax2 set in this way and the position of the intermediate position C. Then, it is determined whether or not the route generation is successful (step S4). If it is determined that the setting could not be made, the process proceeds to step S50 to notify the driver that the target position G cannot be reached from the current position A using the monitor 34 or the speaker 33, and the process is terminated. . If necessary, the driver may move the vehicle 200 and activate the parking assist operation again.

  When the route can be set, the process proceeds to step S5. Here, first, a margin distance is set from the current position (initial position) and the position of the avoidance pole 220. 7 to 9 are explanations of this margin distance. The estimation of the vehicle position in the parking support process is performed based on the number of pulse signals (wheel pulses) obtained from the wheel speed sensor 41 and the steering angle δ, which is the output of the steering angle sensor 23. FIG. 7 is a diagram for explaining the vehicle position estimation.

  That is, the number of wheel revolutions is obtained from the number of wheel pulses, and the travel distance p is obtained by multiplying this by the circumferential length of the tire. On the other hand, the current curvature γ is obtained from the relationship between the steering angle δ and the curvature γ obtained from the output of the steering angle sensor 23. The deflection angle θ is obtained as an integral value with respect to the travel distance of the curvature γ, and the own vehicle positions X and Z are obtained as integral values with respect to the travel distance of sin θ and cos θ, respectively. As described above, since both are integral values with respect to the travel distance, the deviation of the parking track due to variations in the tire load radius, the turning radius characteristic, the setting of the avoidance point on the monitor, and the like increases as the travel distance increases. . FIG. 8 shows the relationship between the deviation of the track and the travel distance.

  Therefore, in the present invention, the longer the travel distance (specifically, the travel distance from the initial positions A1 and A2 to the points C1 and C2 closest to the avoidance pole 220 as shown in FIG. 9), The margin distance M with respect to 201 and the avoidance pole 220 and the margin radius r1 to be maintained are set large. This travel distance is preferably the reference point described above, preferably the center point of the rear axle. This is because the turning center of the vehicle is set on the rear wheel axle, and the distance from the center point of the rear wheel axle to the turning center of the vehicle has the same rudder angle when turning left or right. This is because the route calculation is simplified because of the same in the case of.

In step S6, interference is determined when passing through the set route. Whether it obtains the passing track P _FL1 of the front left corner FL ₁ of the vehicle 200 when the traced vehicle route set, or can pass the passage locus keep the margin distance M and margin radius r1 or more positions What is necessary is just to determine.

Further, as shown in FIG. 10, different margin radii r _FL and r _BL are set for a plurality of locations (for example, the left end BL of the rear wheel axle in addition to the left front end FL), Interference determination may be performed. The position closest to the avoidance pole 220 differs depending on the location of the vehicle. For example, when the initial position of the vehicle 200 is on the left side of the position in FIG. 10 (from the front vehicle 201) and the target position G is positioned below (further away from the front vehicle 201), the position BL is Even when the avoidance pole 220 is closer than FIG. 10, the front end portion FL of the vehicle passes through a position sufficiently away from the avoidance pole 220. If the same margin radius is used at any location, it may be determined that the position BL interferes in such a case. However, in the present invention, by setting the margin radius for each location, interference may occur even in such a case. It can be determined that it will not occur, and the vehicle can be reliably guided to the target position.

  In step S7, the result of the interference determination in step S6 is determined. If it is determined that there is interference, the process proceeds to step S50, and the driver is notified using the monitor 34 and the speaker 33 that there is a possibility of contact with the avoidance pole 220 from the current position A. finish. If necessary, the driver may move the vehicle 200 and activate the parking assist operation again.

  If it is determined that there is no interference, the process proceeds to actual guidance control. Here, it is preferable that the parking assist ECU 1 instructs the drive system (not shown) to perform torque-up control of the engine when the shift lever is set to the reverse position. The torque-up control is to shift the engine to a high driving force state (torque-up state) by rotating the engine at a higher rotational speed than during normal idling. As a result, the vehicle speed range that can be adjusted only with the brake pedal without the driver performing the accelerator operation is expanded, and the controllability of the vehicle is improved. When the driver operates the brake pedal, the vehicle speed is adjusted by adjusting the braking force applied to each wheel according to the pedal opening. At this time, it is preferable to guard the upper limit vehicle speed by controlling the braking force applied to each wheel so that the vehicle speed detected by the wheel speed sensor 41 does not exceed the upper limit vehicle speed.

  In the guidance control, first, the current position of the vehicle is determined (step S8). The current position can be determined based on the movement of the feature points in the image captured by the rear camera 32, or the travel distance change based on the output of the wheel speed sensor 41 or the acceleration sensor 42. It is also possible to make a determination based on a change in the steering angle based on the output of the steering angle sensor 23.

  Then, actual steering angle control is performed on the basis of the travel distance-curvature setting path set in advance based on the current position (travel distance) (step S9). Specifically, the steering control unit 11 controls the steering actuator 24 while monitoring the output of the steering angle sensor 23 to drive the steering shaft 21, and the steering angle of the steered wheels 25 that can realize the set curvature is determined. Control to obtain.

  Since the movement along the route set in this way is performed, the driver can concentrate on safety confirmation on the route and vehicle speed adjustment. When an obstacle, a pedestrian, or the like is present on the course, when the driver steps on the brake pedal, a braking force corresponding to the step is applied to each wheel, so that the vehicle can be decelerated and stopped safely.

  After the steering angle control, it is determined whether or not the current position has deviated from the target route. If the deviation is large, it is determined that route correction is required (step S10). The deviation from the target route can be obtained by integrating the deviation between the target position and the current position or the deviation between the target steering amount and the actual steering amount with respect to the travel distance. If route correction is required, the route is reset by moving to step S3.

  On the other hand, when the deviation from the target route is small, the process proceeds to step S11 to determine whether or not the vicinity of the target parking position G point has been reached. If the target parking position has not been reached, support control is continued by returning to step S8. If it is determined that the vehicle has reached the target parking position, the process proceeds to step S12, the monitor 34 and the speaker 33 notify the driver that the vehicle has reached the target parking position, and the process is terminated.

  Thus, by changing the margin distance in the interference determination according to the initial position, the occurrence of an excessive interference warning is suppressed, so that the degree of freedom of route setting is increased and the usability of the support device is improved.

  In the above description, an example in which guidance is stopped when there is a possibility of interference has been described, but the present invention is not limited to this. FIG. 11 is a flowchart of the second processing mode of the route setting process. In the second processing mode, unlike the first processing mode, a position where parking is possible is calculated based on the avoidance location, and the parking position where interference does not occur is set by the driver.

  When parking assistance is started, first, the driver is caused to set the avoidance pole 220 position in the image captured by the rear camera 32 displayed on the monitor 34 by the input means 31 (see FIG. 4, step S21). Next, parking assistance ECU1 calculates | requires the position of the avoidance pole 220 with respect to a vehicle from the avoidance pole 220 position in an image (step S22). What is necessary is just to obtain | require the position of the avoidance pole 220 calculated | required here as a relative coordinate with respect to the reference point A in the present vehicle position, for example.

  Next, based on the positional relationship between the initial position and the avoidance pole 220, a margin distance to be set between the parking space and the avoidance pole 220 position (which may be the front vehicle 201) is calculated (step S23). Then, a position that is more than the margin distance is displayed on the monitor 34 as a settable target position (step S24). The driver sets the target parking position by moving the parking frame 230 displayed on the screen to the target parking position within the settable target position (step S25).

  The parking assist ECU 1 obtains the vehicle position 200g at the target parking position, specifically, the position of the reference point G and the vehicle direction at the position by the image recognition process (step S26). What is necessary is just to obtain | require the position of this G point as a relative coordinate with respect to the reference point A in the present vehicle position, for example. Since the processing after calculating the target position is basically the same as the first processing mode, description thereof is omitted.

  According to this processing mode, since the target parking position can be set in a range that does not interfere in advance, the vehicle can be reliably guided to the target position without contacting an obstacle or the like. The degree of freedom increases and the usability of the support device improves. In particular, since the guidance cannot be disabled due to the interference warning after the route is set, the usability of the support device is further improved.

  In the first processing mode, when interference is determined, another target trajectory may be generated. FIG. 12 is a flowchart showing an example of another target trajectory setting process. First, the deflection angle θmax at the switching position is set based on the two-circle model described above (step S31).

  Next, θmax correction is performed (that is, using the above-described θmax2) to generate a target trajectory (step S32). Then, interference determination is performed (steps S33 and S34), and when it is determined that there is no interference, guidance is performed using the route determined in step S32. On the other hand, if it is determined that there is interference, the route is set and guidance is performed without correcting θmax (that is, using the value of θmax obtained in step S31 as it is).

  When θmax correction is performed, the path to the switching point M is set as a path with a gentle curvature change as shown in FIG. On the other hand, when the θmax correction is not performed, the route to the switching point M is set as a route in which the curvature change is abrupt and a straight route is added before and after the change as shown in FIG. When the distance from the avoidance pole 220 has a margin, the route of FIG. 13 in which the change in curvature is gentle is preferable because the steering load becomes small because the change in the steering angle is gentle. On the other hand, in the route of FIG. 14 where the curvature change is abrupt, it is possible to move far away from the avoidance pole 220. Therefore, in the route of FIG. Guidance can be performed at a distance. In this way, by switching the route according to the interference determination result with the avoidance position, it is possible to select an optimal route that can reliably prevent contact with an obstacle.

  In the above embodiment, the position setting is performed by arranging the avoidance pole 220 in the image captured by the rear camera 32. Incidentally, the camera has image distortion caused by its optical system. For example, even when the grid shown in FIG. 15 (a) is photographed, it is distorted into a barrel shape as shown in FIG. 15 (b), or distorted into a pincushion shape as shown in FIG. 15 (c). Alternatively, there is a case where a Jinkasa-shaped distortion combining these occurs. If the image is distorted in this way, the positions of the avoidance pole 220 and the parking space 230 that are set also shift. Therefore, it is necessary to correct this distortion.

  The amount of distortion increases with the end from the middle of the captured image (see FIG. 16). Therefore, the camera distortion amount corresponding to the monitor coordinates is grasped, and the margin distance used for the interference determination is set larger as the target position or the avoidance pole position exists at a position where the camera distortion amount is large. Thereby, it is possible to set a margin distance in consideration of the deviation of the trajectory due to the camera distortion amount.

  The variation in the tire dynamic load radius, the variation in the turning radius characteristic, and the variation in the position determination of the avoidance point, which cause the deviation of the parking track described above, act cumulatively on the route error. However, when the target position is reset, the position of an obstacle or the like to be avoided can be re-determined, and the parking track deviation accumulated so far is reset. Therefore, when the target position is reset as described above, the margin distance may be reset. Thereby, the freedom degree of the route setting at the time of resetting can be raised.

  Note that the position of the avoidance pole 220 or the like that should be avoided by the vehicle may be determined automatically by image processing or the like, in addition to being set by the driver. In the above description, the method for obtaining the switching position using the two-circle model has been described. However, if there is a margin in the calculation capability of the parking assist ECU 1, the switching position can be obtained by calculating backward from the target position. Good. In the route from the switching position to the target position, the path length is shortened so that parking assistance is possible even when the distance between the front vehicle 201 and the rear vehicle 202 is short. The maximum speed is preferred. Moreover, it is applicable not only to parallel parking but also to garage storage. Furthermore, the present invention can also be applied when there are a plurality of obstacles and a plurality of locations to be avoided. In this case, the margin distance may be changed according to the location to be avoided.

  In the above description, the embodiments in the parking assist device having the automatic steering function have been described. However, not only the technology for automatically performing the steering, but also the technology for performing the steering guidance for instructing an appropriate steering amount to the driver. Can be used in the same manner. Further, the present invention is not limited to a parking assistance device, and can be applied to a traveling assistance device that guides the movement of a vehicle in the presence of an obstacle, a lane keeping system, and the like.

It is a block block diagram of the parking assistance apparatus 100 which is embodiment of this invention. It is a figure explaining the parallel parking which is an example of the assistance process of the apparatus of FIG. It is a flowchart of the 1st processing form of the route setting process in the apparatus of FIG. FIG. 4 is an example of a display image on a monitor at the time of processing of FIG. 3. FIG. It is a conceptual diagram of the 2-circle model used for a route setting. It is a figure explaining the conversion from the path | route by a 2-circle model to the path | route used for an actual guidance. It is explanatory drawing about the own vehicle position estimation. It is a figure which shows the relationship between the deviation | shift of a track | orbit, and travel distance. It is a figure which shows the relationship between the driving | running route from an initial position, and an avoidance pole. It is a figure explaining the interference determination with respect to the several location of a vehicle. 7 is a flowchart of a second processing form of route setting processing in the apparatus of FIG. 1. It is a flowchart which shows the setting process example of another target track | orbit. It is a figure which shows the path | route set by the process of FIG. It is a figure which shows another path | route set by the process of FIG. It is a figure explaining distortion of a camera picture. It is a figure explaining the relationship of the distortion in a monitor image.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Parking assistance ECU, 10 ... Image processing part, 11 ... Steering control part, 20 ... Automatic steering device, 21 ... Steering shaft, 22 ... Steering wheel, 23 ... Steering angle sensor, 24 ... Steering actuator, 25 ... Steering wheel, DESCRIPTION OF SYMBOLS 31 ... Input means, 32 ... Back camera, 33 ... Speaker, 34 ... Monitor, 41 ... Wheel speed sensor, 42 ... Acceleration sensor, 100 ... Parking assistance apparatus, 200 ... Own vehicle, 201 ... Front vehicle, 202 ... Rear vehicle, 211: road, 220: avoidance pole, 230: parking space.

Claims (10)

In a vehicle travel support apparatus comprising: means for calculating a target movement locus from an initial position to a target position; and guidance means for guiding the vehicle based on the movement locus.
Means for determining a position that the vehicle should avoid during guidance;
Means for calculating a margin distance to the determined position to be avoided based on the relationship between the initial position and the position to be avoided;
Means for determining that guidance is possible when guidance is possible while maintaining a margin distance equal to or greater than the margin distance calculated for the position to be avoided during guidance based on the set movement trajectory;
A vehicular travel support apparatus, further comprising: In a vehicle travel support apparatus comprising: means for calculating a target movement locus from an initial position to a target position; and guidance means for guiding the vehicle based on the movement locus.
Means for determining a position that the vehicle should avoid during guidance;
Means for calculating a margin distance from the determined position to be avoided based on the relationship between the initial position and the position to be avoided; and
The means for calculating the target movement trajectory sets the target movement trajectory so as to enable guidance while maintaining a margin distance equal to or greater than the margin distance calculated for the position to be avoided. .   The vehicle travel support device according to claim 1, wherein the margin distance is set based on a distance between an initial position and a position to be avoided.   The vehicular travel support apparatus according to claim 3, wherein the margin distance is set to be larger as the travel distance from the initial position to the point closest to the position to be avoided becomes longer.   The vehicle travel support device according to claim 4, wherein the travel distance is calculated as a travel distance of an axis center of a rear wheel shaft of the vehicle.   The vehicle travel support apparatus according to any one of claims 1 to 3, wherein the margin distance is set for each of a plurality of locations of the vehicle.   The vehicle travel support apparatus according to claim 1, wherein when there are a plurality of determined positions to be avoided, a margin distance is set for each position to be started.   The means for determining the position to be avoided includes an imaging means for acquiring an image near the target position, and a recognition means for recognizing a position to be avoided based on the position to be avoided in the acquired image. The vehicle travel support apparatus according to claim 1, wherein the margin distance is adjusted based on a position in the image of a position to be avoided.   The vehicle travel support apparatus according to claim 1, further comprising a function of resetting the target position during guidance, wherein the margin distance is reset when the target position is reset. In the guidance based on the initially set movement trajectory, if it is determined that guidance with a margin distance equal to or greater than the margin distance calculated with respect to the position to be avoided is impossible, the means for calculating the target movement trajectory uses a route setting method. The vehicle travel support apparatus according to claim 1, wherein another travel locus is calculated by changing.

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