JP2008030704A - Parking support apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a parking support apparatus that can guide a vehicle to an appropriate position. <P>SOLUTION: The parking support apparatus comprises an imaging means for imaging the vicinity of an associated vehicle, a target parking position setting means for setting a target parking position, where the vehicle is to be parked, on the basis of the image captured by the imaging means, a target parking position correction means for receiving a correction to the target parking position from the user on an operation screen displaying the image captured by the imaging means, and a vehicle guidance means for guiding the vehicle to the set or corrected target parking position. The target parking position setting means sets an initial position of the target parking position at a predetermined start timing, and resets the target parking position according as the vehicle is guided by the vehicle guidance means unless the target parking position has been corrected with the target parking position correction means since the initial position setting. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a parking assist device, and more particularly to a parking assist device that guides the host vehicle to a target parking position set based on a captured image captured from the host vehicle.

  Conventionally, a control system that performs control (hereinafter referred to as parking assist control) that outputs a steering force for guiding the host vehicle to a set target parking position from an electric power steering device is known by a name such as intelligent parking assist. (See, for example, Non-Patent Document 1).

In this control system, a target parking position is superimposed and set on an operation screen that displays a captured image of a camera that captures the rear of the vehicle. In order to facilitate the setting of a user (driver or passenger), a white line is used. For example, the parking frame drawn on the road is recognized in the captured image, and the initial position of the target parking position is set based on the position of the recognized parking frame on the image. After that, if the target parking position is not corrected (changed) by the user, the vehicle is guided to the set initial position as it is, and if the target parking position is corrected (changed) by the user, the vehicle is moved to the corrected target parking position. Is induced.
4. Toyota Motor Corporation, “Prius New Car Guide (Part No. 7108100)”, Toyota Motor Corporation Service Department, issued on September 1, 2003. Electrical, p120-133

  By the way, when the vehicle is guided based on the target parking position set on the captured image of the camera as in the control system, the target parking position on the captured image (the position on the camera coordinate system, i.e., each image forming the captured image). It is necessary to map the position on the coordinate system (the pixel is regarded as a coordinate point) to the position on the plane coordinate (position on the real coordinate system) (even if there is no independent mapping processing step) The mapping process should be included in any stage). However, in order to accurately perform this mapping, it is necessary to grasp not only the camera installation parameters (roll, pan, pitch, installed height, focal length, etc.) but also the road gradient and road unevenness behind the vehicle. This has to be difficult.

  Therefore, especially when the vehicle is guided to the initial position based on the white line recognized in the captured image, there may be a deviation between the position reached as a result of guiding the vehicle and the position where the parking frame is actually drawn. .

  The present invention has been made to solve such problems, and it is a main object of the present invention to provide a parking assistance device capable of guiding a vehicle to an appropriate position.

  In order to achieve the above object, a first aspect of the present invention includes: an image pickup unit that picks up an image of the periphery of the own vehicle; A target parking position comprising: means; target parking position correcting means for accepting correction of a target parking position by a user; and vehicle guidance means for guiding the host vehicle to the set or corrected target parking position. The setting means sets an initial position of the target parking position at a predetermined start timing, and if the target parking position is not corrected using the target parking position correction device after the initial position is set, the vehicle guiding means The target parking position is reset according to the guidance of the host vehicle.

  According to the first aspect of the present invention, by resetting the target parking position according to the guidance of the host vehicle, the position reached as a result of guiding the vehicle and the position where the parking frame is actually drawn are between It is possible to suppress the inconvenience that the deviation occurs. In addition, when the target parking position is corrected by the user, the target parking position may be unclear in the captured image of the imaging unit, so the target parking position is reset. Absent. Thereby, the inconvenience that the target parking position is set at a position completely different from the user's intention can be suppressed. From these, the own vehicle can be guided to an appropriate position.

  According to a second aspect of the present invention, there is provided imaging means for imaging the periphery of the host vehicle, target parking position setting means for setting a target parking position where the host vehicle should be parked based on a captured image of the imaging means, and the target by the user A parking assist device comprising target parking position correcting means for receiving correction of a parking position and vehicle guiding means for guiding the host vehicle to the set or corrected target parking position, wherein the target parking position setting means If the initial position of the target parking position is set at the start timing, and the target parking position is not corrected more than a predetermined level using the target parking position correction device after the initial position is set, the host vehicle by the vehicle guiding means The target parking position is reset according to the guidance.

  In the first or second aspect of the present invention, the target parking position setting means is a means for setting the target parking position by recognizing a characteristic portion in the captured image of the imaging means, and the target parking position setting means The vehicle guiding means may be stopped when the characteristic portion becomes unrecognizable, or the resetting of the target parking position by the target parking position setting means is stopped. It is good.

  ADVANTAGE OF THE INVENTION According to this invention, the parking assistance apparatus which can guide a vehicle to an appropriate position can be provided.

  Hereinafter, the best mode for carrying out the present invention will be described with reference to the accompanying drawings.

  The best mode for carrying out the present invention will be described below with reference to the drawings. It is a figure which shows an example of the whole structure of the parking assistance apparatus 1 which concerns on one Example of this invention. As shown in FIG. 1, the parking assistance device 1 is configured around a parking assistance ECU (Electronic Control Unit) 10, and is automatically set at a target parking position superimposed on a screen displaying a captured image of the back monitor camera 40. The main function is to perform parking support control for guiding the vehicle.

  The parking assist ECU 10 is, for example, a computer unit in which a ROM, RAM, and the like that store programs and the like centered on a CPU are connected to each other via a bus. In addition, reading such as a hard disk, DVD, CD-ROM, EEPROM A memory 10A, an input / output interface, a timer, a counter, etc.

  The parking assist ECU 10 is connected to a vehicle speed sensor 20 and a steering angle sensor 32 and a controller 38 constituting the steering device 30 via a bus using an appropriate communication protocol such as CAN (Controller Area Network). .

  The vehicle speed sensor 20 includes, for example, a wheel speed sensor attached to each wheel and a skid control computer. The skid control computer converts a wheel speed pulse signal output from the wheel speed sensor into a vehicle speed rectangular wave pulse signal (vehicle speed signal). And output.

  The steering device 30 includes, for example, a steering angle sensor 32, a torque sensor 34, an assist motor 36, and a controller 38 that controls the entire steering device. The steering angle sensor 32 is disposed, for example, inside the steering column, and transmits a steering angle signal to the controller 38 and the parking assist ECU 10. For example, the torque sensor 34 is disposed inside the steering column, and transmits a signal corresponding to the steering torque to the controller 38 by detecting torsion of a torsion bar attached between the input shaft and the output shaft. The assist motor 36 is, for example, a DC motor disposed in the column housing part, and assists the driver's steering operation by outputting torque necessary for steering the vehicle. The torque output from the assist motor 36 is deflected and decelerated by the worm gear and the wheel gear and transmitted to the column shaft, and finally changes the direction of the wheel. The controller 38 outputs a torque necessary for steering the vehicle based on a steering torque signal from the torque sensor 34 and other vehicle state signals (vehicle speed, yaw rate, etc.) during normal times when parking assist control is not performed. Then, a control signal is output to the drive circuit of the assist motor 36. Further, when parking assist control is being performed, the assist motor 36 is controlled based on an instruction signal from the parking assist ECU 10.

  In addition, a back monitor camera 40, a shift position sensor 50, a parking switch 52, a height sensor 60, a multi-display 70, and a speaker 80 are connected to the parking assist ECU 10.

  The back monitor camera 40 includes an image sensor such as a CCD (charge-coupled device) or a CMOS (complementary metal oxide semiconductor) and a wide-angle lens, and is attached to the rear part of the vehicle. The mounting angle and the angle of view (viewing angle) of the back monitor camera 40 are appropriately determined so that the scenery behind the vehicle is imaged at a predetermined angle substantially symmetrically about the vehicle longitudinal axis.

  The parking switch 52 is provided in the passenger compartment and can be operated by the user. The parking switch 52 is normally maintained in an off state, and is turned on by a user operation. The parking switch 52 includes an indicator lamp, and displays an operating state of parking assist control. The height sensor 60 is attached to, for example, a rear cross member and detects a change in vehicle height.

  The multi-display 70 is a display device that employs a VGA (Video Graphics Array) as a graphic system to display an image including a moving image and allows a user to perform various input operations as a touch panel. The multi-display 70 detects a change in voltage caused by a user touching the surface, and recognizes the touch-operated position. The multi display 70 and the speaker 80 may be shared with the in-vehicle navigation device. In this case, it is preferable that the function of the parking support control is executed when the parking support control is in operation, and switched to be used for route guidance or the like of the navigation device at other times.

  Communication between the back monitor camera 40 and the multi-display 70 and the parking assist ECU 10 is performed using an audio and visual dedicated communication protocol (for example, AVC-LAN).

  The parking assistance ECU 10 starts parking assistance control based on the output signal of the parking switch 52. That is, parking support control is started when the output signal from the parking switch 52 indicates an on state. In addition, although parking assistance control may be selected from a plurality of control modes such as parallel parking control and garage entry control, for the application of the present invention, such a difference in control mode is not an essential problem. Only the parking support control for supporting parallel parking will be described.

  FIG. 2 is a diagram illustrating main functional blocks of the parking assist ECU 10 according to the present embodiment. The parking assist ECU 10 includes a target parking position setting unit 12, a mapping unit 14, a vehicle guiding unit 16, and an information output control unit 18. The outline of the functions of these functional blocks will be described below.

  The target parking position setting unit 12 recognizes the parking frame drawn on the road with a white line or the like in the captured image of the back monitor camera 40, and sets this as the target parking position. In addition, the correction of the target parking position by the user is accepted in the display image of the multi-display 70 that displays the captured image.

  The mapping unit 14 partially functions as a part of the target parking position setting unit 12, but installation parameters (roll, pan, pitch, installed height, focal length, etc.) of the back monitor camera 40. Based on the above, a coordinate point on the image coordinate system (a coordinate system in which each pixel forming the captured image is regarded as a coordinate point) and a coordinate point on the real coordinate system for control (planar coordinate system) are mapped to each other . The mapping is performed, for example, by adding the output value of the height sensor 60 to a mapping map stored in a ROM or the like.

  The vehicle guiding unit 16 transmits an instruction signal to the steering device 30 so that the host vehicle is within the target parking position. Further, the information output control unit 18 controls the multi-display 70 and the speaker 80 so as to make various announcements to the user in each process.

  Hereinafter, the content of the parking assistance control performed by cooperation of these functional blocks is demonstrated. FIG. 3 is an example of an imaging screen of the back monitor camera 40 immediately before the parking support control is started. As shown in the drawing, the images of the parked vehicles A and B and the vehicle C traveling behind the host vehicle are captured. In addition, the bumper end line D of the rear bumper of the host vehicle, the road shoulder E, and the parking frame F to be used as a reference for parallel parking are captured. Note that this image has been subjected to left-right reversal processing for convenience of display to the user.

  FIG. 4 is a flowchart showing the flow of the parking assist control process. This flow is started when the parking switch 52 is turned on, for example.

  First, the target parking position setting unit 12 and the mapping unit 14 recognize the parking frame F from the image as illustrated in FIG. 3, and set the initial position of the target parking position on the real coordinate system based on this (S100). . The recognition of the parking frame F can use various methods. As an example, for example, first, feature points on the imaging screen of the back monitor camera 40 (points where the luminance change exceeds a threshold) are extracted. Then, the position of the feature point on the image is mapped to the position on the real coordinate system set on the memory 10A by the processing of the mapping unit 16, and arranged in a straight line recognized using a straight line extraction method such as Hough transform. The feature point is recognized as the outline of the parking frame F. Eventually, two parallel pairs of contour lines are recognized as a parking frame F, and further subjected to pattern matching processing, etc., so that the parking frame F is in a “U” shape, a box shape, or opposed. Then, an inner area (excluding an area where an object such as another vehicle is recognized) of the parking frame F drawn in two is set as the target parking position. FIG. 5 is a diagram illustrating an initial position of the target parking position on the real coordinate system set based on the captured image of FIG.

  When the initial position of the target parking position is set on the real coordinate system, this is mapped onto the image coordinate system, and the target parking frame F *, which is the outer frame line of the target parking position, is superimposed on the imaging screen of the back monitor camera 40. indicate. At this time, an arrow switch G that enables the user to correct the target parking frame F * (that is, correction of the target parking position; the same applies hereinafter) and a confirmation switch H that determines the target parking position are simultaneously displayed and set. The FIG. 6 is a diagram showing an example of a screen displayed on the multi-display 70 at this time. Further, in order to satisfy the start condition of the parking assistance control, it is confirmed by the signal from the shift position sensor 50 that the shift position is a reverse position, and if the shift position is not the reverse position, the reverse position Voice guidance using the speaker 80 is performed so as to change to

  Then, when the confirmation switch H is touched, it is determined whether or not the arrow switch G is touched by the user to correct the target parking frame F * (S110). When the target parking frame F * has not been corrected, the vehicle guiding unit 16 starts a process of guiding the host vehicle to the initial position of the target parking position on the real coordinate system (S120). Specifically, an optimum guidance route is generated based on the positional relationship between the target parking position and the host vehicle as shown in FIG. 5, and the target steering angle is transmitted to the controller 38 based on the curvature on the route. When the driver releases the brake pedal, the host vehicle starts to reverse due to a creep phenomenon or the like at a steering angle according to the target steering angle. In the middle of parking support control, the parking support control is set to stop in a predetermined case such as when the vehicle speed signal from the vehicle speed sensor 20 exceeds a predetermined speed.

  By the way, in order to accurately perform the process of grasping the position on the plane from the position on the image, it is necessary to grasp not only the installation parameters of the back monitor camera 40 but also the road gradient and road unevenness behind the vehicle. The size of the object on the captured image of the back monitor camera 40, the distance between the objects, and the like are not only due to the distance between the object and the back monitor camera 40, but also due to the relative height difference between the host vehicle and the object and the unevenness of the road Because it also changes. However, since it is technically difficult to grasp the road gradient around the vehicle, it is difficult to accurately set the target parking position on the real coordinate system based on the captured image of the back monitor camera 40.

  Therefore, in this embodiment, every time the vehicle travels a predetermined distance (for example, obtained by integrating the output value of the vehicle speed sensor 20) from when the vehicle guidance is started until the host vehicle is settled at the target parking position, The target parking position is reset (S130, 140, 150). That is, the same processing as the setting of the initial position of the target parking position is repeatedly performed every time a predetermined distance is moved. As the host vehicle approaches the target parking position, the effect of errors due to road gradients and unevenness decreases, so the target parking position that was set repeatedly in this way is the actual one that was set last. It will be close enough to the position. Therefore, the guidance is performed at a sufficiently accurate position around the time when the host vehicle reaches the target parking position.

  However, the situation is different when the target parking frame F * is corrected by the user. In this case, the user intends to park in a place where there is no parking frame such as a white line, or to park in a place where the parking frame is present but does not appear in the image of the back monitor camera 40 (not clearly captured). It is assumed that Therefore, even if the target parking position is reset by image analysis of the back monitor camera 40, the target parking position may be set at a position completely different from the user's intention.

  Therefore, in this embodiment, when the target parking frame F * is corrected by the user, the target parking position is not reset as described above, and the target parking position is fixed at the position corrected by the user. The host vehicle is guided to this position (S160). As a result, inconvenience due to the resetting of the target parking position by image analysis is not appropriate, for example, the target parking position is set at a position completely different from the user's intention. Can be suppressed.

  Note that it is determined whether or not the parking frame can no longer be recognized (lost) after the processing of S130 (S135). If it is determined that the parking frame has been lost, the lost control is performed (S170). The control at the time of lost may stop parking assistance control at that time, or may be fixed at the target parking position set immediately before and continue the parking assistance control. In addition, if the parking frame drawn on the road cannot be recognized when setting the initial target parking position, parking assist control is performed on condition that the user manually sets the target parking position.

  According to the parking assistance device 1 according to the embodiment of the present invention described above, if the target parking frame F * is not corrected by the user, the target parking position is reset according to the movement of the host vehicle. Therefore, it is possible to avoid the disadvantage that the position of the target parking position set on the real coordinate system is shifted from the actual position due to the influence of the road gradient and unevenness. When the user corrects the target parking frame F *, the user is trying to park in a place where there is no parking frame such as a white line, or there is a parking frame, but it does not appear in the image of the back monitor camera 40 (clearly In other words, the target parking position is not reset. Thereby, the inconvenience that the target parking position is set at a position completely different from the user's intention can be suppressed. From these, the own vehicle can be guided to an appropriate position.

  As mentioned above, although the best mode for carrying out the present invention has been described using one embodiment, the present invention is not limited to such one embodiment, and within the scope not departing from the gist of the present invention, Various modifications and substitutions can be made to the above-described embodiment.

  For example, in the above embodiment, the target parking position is not reset when the target parking frame F * is corrected by the user, but if the correction is less than a predetermined level, the target parking position is not reset. Re-setting may be performed. This is because, if the correction by the user is very small, it is expected to converge to an appropriate position by subsequent resetting.

  Further, in the above embodiment, the correction of the target parking frame F * by the user is accepted only before the touch operation of the confirmation switch H. However, the user also repeatedly sets the target parking position and guides the vehicle. You may be comprised so that correction of the target parking frame F * may be received. In this case, if the target parking frame F * is corrected by the user in the middle of guidance, the vehicle may be guided by fixing it to the corrected position for the same purpose as in the embodiment. . For example, as shown in the flowchart of FIG.

  The present invention can be used in the automobile manufacturing industry, the automobile parts manufacturing industry, and the like.

It is a figure which shows an example of the whole structure of the parking assistance apparatus 1 which concerns on one Example of this invention. It is a figure showing the main functional blocks of ECU10 for parking assistance of a present Example. It is an example of the imaging screen of the back monitor camera 40 just before parking assistance control is started. It is a flowchart which shows the flow of a process of parking assistance control. It is a figure which shows the initial position of the target parking position on a real coordinate system set based on the captured image of FIG. It is a figure which shows an example of the screen displayed on the multi display at the time of the start of parking assistance control. It is another example of the flowchart which shows the flow of a process of parking assistance control.

Explanation of symbols

1 Parking assistance device 10 ECU for parking assistance
10A Memory 12 Target parking position setting unit 14 Mapping unit 16 Vehicle guidance unit 18 Information output control unit 20 Vehicle speed sensor 30 Steering device 32 Steering angle sensor 34 Torque sensor 36 Assist motor 38 Controller 40 Back monitor camera 50 Shift position sensor 52 Parking switch 60 Height sensor 70 Multi display 80 Speaker

Claims (4)

Imaging means for imaging the periphery of the vehicle;
Target parking position setting means for setting a target parking position where the host vehicle should be parked based on a captured image of the imaging means;
Target parking position correction means for receiving correction of the target parking position by the user;
A vehicle support means for guiding the host vehicle to the set or corrected target parking position,
The target parking position setting means sets an initial position of the target parking position at a predetermined start timing, and the target parking position is not corrected using the target parking position correcting means after the initial position is set. In this case, the target parking position is reset according to the guidance of the host vehicle by the vehicle guidance means. Imaging means for imaging the periphery of the vehicle;
Target parking position setting means for setting a target parking position where the host vehicle should be parked based on a captured image of the imaging means;
Target parking position correction means for receiving correction of the target parking position by the user;
A vehicle support means for guiding the host vehicle to the set or corrected target parking position,
The target parking position setting means sets an initial position of the target parking position at a predetermined start timing, and corrects the target parking position to a predetermined degree or more using the target parking position correcting means after the initial position is set. In the case where the parking assistance is not performed, the target parking position is reset according to the guidance of the host vehicle by the vehicle guidance means. The parking assistance device according to claim 1 or 2,
The target parking position setting unit is a unit that sets the target parking position by recognizing a characteristic portion in a captured image of the imaging unit,
When the target parking position setting means becomes unable to recognize the characteristic portion, the vehicle guiding means stops,
Parking assistance device. The parking assistance device according to claim 1 or 2,
The target parking position setting unit is a unit that sets the target parking position by recognizing a characteristic portion in a captured image of the imaging unit,
When the target parking position setting unit becomes unable to recognize the characteristic portion, the resetting of the target parking position by the target parking position setting unit is stopped.
Parking assistance device.

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