Parking assistance device

Abstract

To provide a parking support device, which in parking an own vehicle in a parking space utilizing a parking support function, can perform parking support, even in a situation where the device cannot recognize a parking frame.SOLUTION: A parking support device 1 comprises an operation support control unit 11. The operation support control unit 11 obtains environment information about a circumference of an own vehicle M from sensors 21, 26-28; determines a parking space width Wp between parked vehicles Pv parked in a parking lot on the basis of the environment information; when the parking space width Wp is larger than a required parking width Ws of a virtual parking frame 41 that is required in parking the own vehicle M, sets in the parking space the virtual parking frame 41, and sets a parking priority in accordance with marks 51 of shoes and wheel tracks 101 in the virtual parking frame 41 and the parked vehicles Pv facing the virtual parking frame 41; and collectively displays on an HMI monitor 31 estimated parking frames Ps set while associating the parking priority with the virtual parking frame 41 and makes a driver select the frames.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a parking assistance device that notifies a driver of the parking priority when the driver is allowed to select, in a parking lot where parking frames drawn on the road surface cannot be recognized, when a plurality of parking spaces are detected.

Background Art

[0002] Conventionally, there is known a parking assistance device that assists an operation when a driver parks his / her own vehicle in a parking frame that demarcates a parking space set in a parking lot, and reduces the burden on the driver. In this type of parking assistance device, when the driver operates his / her own vehicle and drives in the parking lot, the control unit detects candidates for available parking frames and displays the parking frames listed in the candidates on a monitor. The driver selects a desired parking frame from the displayed candidates for the parking frames.

[0003] Then, the control unit sets a parking guidance route for parking the own vehicle in the parking frame selected by the driver. And the control unit guides the own vehicle to the parking frame along the parking guidance route. Alternatively, the driver operates his / her own vehicle and parks it in the parking frame along the parking guidance route displayed on the monitor.

[0004] In the above-described conventional parking assistance device, when parking the own vehicle in a parking frame, first, it detects a parking frame where parking is possible. Therefore, when the road surface of the parking lot is covered with snow, standing water, or mud left after flooding, etc., and the parking frame drawn on the road surface cannot be recognized, it becomes difficult for the parking assistance device to construct a parking guidance route for guiding the own vehicle to the parking frame.

[0005] Drivers need parking assistance by a parking assistance device more in a bad environment where it is difficult to recognize a parking space than in a good environment. For example, in Patent Document 1 (Japanese Patent Application Laid-Open No. 2006-7875), first, to determine whether there is a parking space for the host vehicle between parked vehicles parked in parallel, the width of each parked vehicle is subtracted from the distance between the centers in the vehicle width direction of the two parked vehicles to obtain the gap distance between the two parked vehicles. If this gap distance is wider than the vehicle width of the host vehicle plus a predetermined margin, it is determined that parking is possible. Then, a technique is disclosed in which the center of this gap process is set as the center of the planned parking area to guide the host vehicle.

Prior Art Document

Patent Document

[0006]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0007] By the way, when trying to park the host vehicle in a parking lot of a store or the like, since the parking position changes according to the vehicles already parked (parked vehicles), it is difficult to always park in a fixed location. Also, the layout of the parking spaces set in the parking lot differs for each store.

[0008] Therefore, as disclosed in Cited Document 1, even if a gap distance in which the host vehicle can be parked between two parked vehicles parked in parallel is detected, in a state where the road surface is covered with snow, crown mud remaining after flooding, etc., the parking frame drawn on the road surface cannot be recognized. Therefore, this gap may not be a parking space but a sidewalk or a traffic lane where parking is prohibited.

[0009] In the technology disclosed in the above-cited Patent Document 1, it merely determines whether the host vehicle can be parked based on the gap distance between adjacent parked vehicles. Therefore, there is a possibility that the control unit may guide the host vehicle to a sidewalk or a traffic lane where parking is prohibited, which is set between parking frames.

[0010] However, even in a space where the control unit determines that there is a high possibility that it is a sidewalk or a traffic lane where parking is prohibited, if the driver recognizes that the space is clearly a parkable space from the surrounding situation and deviates from the determination of the control unit, the driver will feel uncomfortable. On the other hand, if the control unit notifies the driver every time it detects all spaces including the space determined to be a sidewalk or a traffic lane and requests a choice of whether to park or not, it will impose a great burden on the driver.

[0011] An object of the present invention is to provide a parking support device that can reduce the burden on the driver by not requiring the driver to make a selection one by one when attempting to park the host vehicle using a parking support function in a parking space, in a situation where a parking frame cannot be recognized, and even when a parking space between parked vehicles is detected.

Means for Solving the Problems

[0012] The present invention relates to a parking assistance device that guides a host vehicle to a parking available space in a parking lot, and includes an environmental information acquisition unit that acquires environmental information around the host vehicle, a storage unit that stores a virtual parking frame necessary for parking the host vehicle, a parking space width calculation unit that obtains the width of the parking space between object marks based on the environmental information acquired by the environmental information acquisition unit, a parking width comparison unit that compares the width of the parking space between the object marks obtained by the parking space width calculation unit with the width of the virtual parking frame stored in the storage unit, a virtual parking frame setting unit that sets the virtual parking frame within the parking space when it is determined by the parking width comparison unit that the width of the parking space is wider than the width of the virtual parking frame, a movement trace detection unit that detects a movement trace based on the environmental information acquired by the environmental information acquisition unit within the virtual parking frame set by the virtual parking frame setting unit, an object mark detection unit that checks whether an object mark faces at least one side of the virtual parking frame excluding the side on the host vehicle side of the virtual parking frame, a parking priority setting unit that sets the parking priority of the virtual parking frame according to the movement trace detected by the movement trace detection unit and the object mark facing the virtual parking frame detected by the object mark detection unit, a display selection unit that collectively displays an estimated parking frame in which the parking priority set by the parking priority setting unit is associated with the virtual parking frame set by the virtual parking frame setting unit and allows a driver to select, and a parking assistance unit that sets the estimated parking frame selected by the driver by the display selection unit as a target parking space and guides the host vehicle with respect to the target parking space.

Effect of the Invention

[0013] According to the present invention, since the estimated parking frame is set by associating the parking priority with the virtual parking frame, and this estimated parking frame is collectively displayed on the display selection unit and the driver is allowed to select, when trying to park the host vehicle using the parking assistance function in the parking space, even in a situation where the parking frame cannot be recognized and when the parking space between parked vehicles is detected, the burden on the driver caused by requiring the driver to make selections one by one can be reduced.

Brief Description of the Drawings

[0014]

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Mode for Carrying Out the Invention

[0015] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. The parking assistance device 1 shown in FIG. 1 is mounted on a host vehicle M (see FIG. 9). This parking assistance device 1 includes a driving assistance control unit 11. This driving assistance control unit 11 is composed of a microcontroller including a CPU, a RAM, a ROM, a rewritable nonvolatile memory (flash memory or EEPROM), and peripheral devices. The ROM stores programs and fixed data necessary for the CPU to execute each process. The RAM is provided as a work area for the CPU, and various data in the CPU are temporarily stored. Note that the CPU is also called an MPU (Microprocessor) or a processor. Alternatively, a GPU (Graphics Processing Unit) or a GSP (Graph Streaming Processor) may be used instead of the CPU. Or, the CPU, the GPU, and the GSP may be selectively combined and used.

[0016] When the driver sets a desired assistance mode, this driving assistance control unit 11 performs driving assistance according to the corresponding assistance mode. The driving assistance control unit 11 includes a driving assistance mode and a parking assistance mode as assistance modes.

[0017] Based on the host vehicle position information acquired by the GNSS sensor 22a of the map locator unit 22 described later, the driving assistance mode performs map matching on a road map in the road map database 22b, and autonomously drives an interval where automatic driving is possible along a preset target driving route. Also, in a driving route where automatic driving is difficult, this driving assistance mode executes well-known follow - vehicle distance (ACC: Adaptive Cruise Control) control, lane keeping (ALK: Active Lane Keep) control, and lane departure suppression (LDP: Lane Departure Prevention) control, and when the host vehicle M detects a preceding vehicle while traveling along a lane, executes a driving control to follow the preceding vehicle.

[0018] On the one hand, in the parking support mode, when the host vehicle M enters a parking lot and the driver selects this mode while driving in the parking lot by himself / herself, the driving support control unit 11 searches for a parkable parking space and notifies the driver. Then, when the driver selects a desired parking space from among the parkable parking spaces, the host vehicle M is automatically parked in the selected parking space. Alternatively, a parking guidance route for parking the host vehicle M in the parking space is superimposed on an overhead view of a surrounding image displayed on an HMI monitor 31, which will be described later, and an image of the host vehicle M, and parking support is provided when the driver parks by his / her own operation.

[0019] In addition, on the input side of the driving support control unit 11, sensor units for acquiring driving state information (including position and direction) of the host vehicle M and surrounding environment information of the host vehicle M, which are required when executing the driving support mode and the parking support mode, are connected.

[0020] In this embodiment, as the sensor units required when executing each support mode, a front recognition sensor 21, a map locator unit 22, an autonomous driving sensor 23, a brake sensor 24 that detects depression of the brake pedal and turns on, a select position sensor 25 that detects a select position selected by the driver operating a select lever, a rear sensor 26 that acquires environmental information behind the host vehicle M, left and right front side sensors 27, and left and right rear side sensors 28 are provided. Note that the environmental information acquisition unit of the present invention is configured by each of the sensors 21, 26 to 28.

[0021] The front recognition sensor 21 is an image sensor, which in this embodiment is a stereo camera composed of a main camera 21a and a sub-camera 21b using a CCD, CMOS, etc. as an imaging element, and an image processing unit (IPU) 21c. Both cameras 21a and 21b have a predetermined baseline length and are installed horizontally at equal intervals to the left and right from the center in the vehicle width direction at a position above the rearview mirror in the front part of the vehicle interior, for example, close to the windshield. After the front recognition sensor 21 processes the images of the environmental information of a predetermined area captured by both cameras 21a and 21b with the IPU 21c, it transmits the processed images to the driving support control unit 11.

[0022] In addition, the map locator unit 22 includes a GNSS (Global Navigation Satellite System) sensor 22a and a road map database 22b. The GNSS sensor 22a receives positioning signals transmitted from a plurality of positioning satellites to obtain the position coordinates of the host vehicle M. The road map database 22b is a large-capacity storage medium such as an HDD, in which road map information is stored. The road map information stored in this road map database 22b includes road information (general roads, arterial roads, highways, road shapes, road orientations, number of lanes, lane widths, etc.) required when the driving support mode is executed, and static information of parking lots (position information of entrances and exits of parking lots, site information, etc.) required when the parking support mode is executed.

[0023] The driving support control unit 11 performs map matching of the position coordinates (latitude, longitude, altitude) of the host vehicle M acquired by the GNSS sensor 22a on the road map information stored in the road map database 22b to estimate the position of the host vehicle on the road map (current position).

[0024] The autonomous driving sensor 23 is a general term for sensors required when the host vehicle M is driven autonomously, and is composed of a vehicle speed sensor for detecting the vehicle speed (own vehicle speed) of the host vehicle M, a yaw rate sensor for detecting the yaw rate acting on the host vehicle M, a front-rear acceleration sensor for detecting the front-rear acceleration, and the like.

[0025] Further, the rear sensor 26 is configured as a combination of a monocular camera using a CCD, a CMOS, or the like as an imaging element and at least one of an ultrasonic sensor, a millimeter-wave radar, a microwave radar, an infrared sensor, a lidar (Light Detection And Ranging), or the like. Alternatively, the rear sensor 26 may be a stereo camera including a main camera and a sub camera, similar to the above-described front recognition sensor 21.

[0026] Further, the left and right front side sensors 27 are respectively disposed, for example, at the left and right ridge portions of the front bumper of the host vehicle M, and scan in a fan shape an area (scanning area) from the left and right diagonally forward to the side of the host vehicle M. On the other hand, the left and right rear side sensors 28 are disposed, for example, at the left and right ridge portions of the rear bumper, and scan in a fan shape an area that cannot be scanned by the left and right front side sensors 27 from the rear to the left and right of the host vehicle M. Each of these side sensors 27, 28 includes a millimeter-wave radar, a microwave radar, a lidar, or the like, receives a reflected wave from a target (a parked vehicle Pv or an outer wall in the parking support mode), and acquires environmental information such as the distance and azimuth from the host vehicle M to the target.

[0027] Further, the driving support control unit 11 is connected to an HMI (Human Machine Interface) monitor 31. On this HMI monitor 31, as a support mode executed by the driving support control unit 11, a mode selection screen for a driver to select either a driving support mode or a parking support mode, a parking space selection screen (see FIG. 8) for displaying a parking space where parking is possible together with a parking priority and allowing the driver to select, etc. are displayed. Incidentally, this HMI monitor 31 may be used in combination with a multi-information display of a combination meter or a navigation display device (navi monitor) of a car navigation system.

[0028] Further, a drive control actuator 32 and a notification device 33 are connected to the output side of the driving assistance control unit 11. The drive control actuator 32 is a general term for a power actuator, an electric power steering (EPS) actuator, a brake actuator, etc., which assist the running state of the host vehicle M. Here, the power actuator controls the output of a drive source such as an engine or an electric motor. The EPS actuator controls the drive of the EPS motor. Also, the brake actuator adjusts the brake hydraulic pressure supplied to the brake wheel cylinders provided on each wheel. Further, the notification device 33 audibly notifies the driver of various information required when each assistance mode is being executed.

[0029] The driving assistance control unit 11 has a parking assistance control function for parking the host vehicle M in a parking space on behalf of the driver, or assisting the driver when the driver attempts to park the host vehicle M in a parking space by his / her own driving. The parking assistance control executed by the driving assistance control unit 11 is specifically processed according to the parking assistance control routine shown in FIG. 2. This routine is executed at every predetermined calculation cycle after the system is started up.

[0030] In this routine, first, in step S1, the host vehicle position information estimated by the map locator unit 22 is acquired, and the process proceeds to step S2, where the surrounding map information of the host vehicle position is acquired from the map locator unit 22 based on the host vehicle position information.

[0031] Next, the process proceeds to step S3, where the host vehicle position is map-matched to the surrounding map, and it is checked whether the host vehicle M has entered the parking lot. If it is determined that the vehicle has entered the parking lot, the process proceeds to step S4. If it is determined that the vehicle has not entered the parking lot, the routine is exited.

[0032] When proceeding to step S4, the notification device 33 audibly notifies the driver whether to set the assistance mode to the parking assistance mode, and at the same time, displays a selection screen for the parking assistance mode on the HMI monitor 31 and proceeds to step S5. When proceeding to step S5, it is determined whether the driver has selected the parking assistance mode. If the driver assistance mode is selected, proceed to step S6. Also, if the driver does not select the driving assistance mode even after a predetermined time has elapsed after the announcement, or if the driver selects manual driving on the HMI monitor 31, the routine is exited as it is.

[0033] When proceeding to step S6, the parking assistance mode is executed and the routine is exited. This parking assistance mode is executed according to the parking assistance mode execution subroutine shown in FIG. 3. In this subroutine, first, in step S11, the front and front side environment information recognized by the front recognition sensor 21 and the left and right front side sensors 27 is acquired. Next, proceed to step S12 and check whether a parking frame drawn on the road surface for partitioning the parking space is recognized from the acquired front and front side environment information. This parking frame is recognized, for example, based on the luminance difference between the road surface and the edge of the parking frame, or the change in the intensity (reflectivity) of the reflected light or reflected wave from the road surface and the parking frame, from the front and front side environment information acquired by the front recognition sensor 21.

[0034] And when the driving support control unit 11 determines that the parking frame is recognized, it proceeds to step S13, executes the parking support process in a good environment, and exits the routine. Note that this parking support process in a good environment is the same as the conventional parking support for guiding the host vehicle M to the parking space based on the parking frame, so the description is omitted.

[0035] On the other hand, when it is determined that the parking frame cannot be recognized, that is, the road surface is covered with snow, crown mud remaining after flooding, etc., and the parking frame drawn on the road surface cannot be recognized, proceed to step S14, execute the parking support process in a bad environment, and exit the routine. This parking support process in a bad environment is executed according to the parking support subroutine in a bad environment shown in FIGS. 4 to 6.

[0036] In this subroutine, first, in step S21, the virtual parking frame 41 is read. The data of this virtual parking frame 41 is pre-stored as fixed data in a storage unit such as a ROM or a non-volatile memory, and is a frame indicating a criterion for checking whether the host vehicle M can be parked in a parking space when parking the host vehicle M in a bad environment. That is, as shown in FIGS. 7A to 7C, this virtual parking frame 41 is set as a rectangle with four sides orthogonal to each other, the front-rear direction is set to the front-rear length of the host vehicle M, and the left and right have a required parking width Ws obtained by adding a margin width to the vehicle width of the host vehicle M.

[0037] Next, proceed to step S22 to detect the width of the parking space (parking space width) Wp. This parking space width Wp is based on the front and front-side environment information acquired by the front recognition sensor 21 and the left and right front-side sensors 27, recognizes object targets such as parked vehicles (parked vehicles) Pv (see FIG. 9) and outer walls parked in the parallel direction, and determines the width of the recognized object targets (parked vehicle Pv, outer wall) and the front distance from the object target to the host vehicle M, and obtains the interval between adjacent object targets (parking space width Wp) from this data. Therefore, the process in this step S22 has a function as a parking interval calculation unit of the present invention.

[0038] Thereafter, proceed to step S23 to compare the parking space width Wp and the required parking width Ws. And when Wp≧Ws, it is determined that it is a space where the host vehicle M can be parked, and proceed to step S24. Also, when Wp<Ws, it is determined that it is difficult to park the host vehicle M, and jump to step S36. Note that the process in this step S23 corresponds to the parking width comparison unit of the present invention.

[0039] In step S24, the virtual parking frame 41 is set in the detected parking space, and proceed to step S25. This virtual parking frame 41 sets the center in the width direction of the virtual parking frame 41 to the center in the width direction of the parking space, and sets the side on the host vehicle M side of the virtual parking frame 41 to the same plane as the tip of the front object target. Note that the process in this step S24 corresponds to the virtual parking frame setting unit of the present invention.

[0040] At this time, for example, when the distance (Wp) between object marks is twice or more the required parking width Ws, a number of virtual parking frames 41 that can fit within the parking space are set at equal intervals in the parking space. Also, if the space between adjacent parked vehicles Pv is wide and three or more virtual parking frames 41 can be set, since the space is too wide, the virtual parking frames 41 may not be selected and the process may jump to step S36.

[0041] By the way, in the conventional driving support control unit, each time the virtual parking frame 41 is set in step S24, the virtual parking frame 41 is displayed on the HMI monitor 31, and an announcement is made to confirm with the driver whether to automatically park the host vehicle M in the virtual parking frame 41, and the driver is required to make a selection one by one. Therefore, it was necessary to confirm the presence or absence of a parking position one by one, increasing the number of selections and imposing a great burden. In contrast, in the present embodiment, as shown in steps S36 and S37 described later, based on the front and front-side environment information, when all the virtual parking frames 41 are set, they are displayed on the HMI monitor 31 all at once, so that the number of times the driver selects a parking position can be reduced.

[0042] Next, when proceeding to step S25, from step S25 onward, the parking priority when parking the host vehicle M in the set virtual parking frame 41 is examined. First, in step S25, it is examined whether or not footprint marks 51 are detected as movement traces within the virtual parking frame 41 set in step S24 in the front and front-side environment information acquired by the front recognition sensor 21 and the left and right front-side sensors 27. The footprint marks 51 are recognized, for example, based on the front and front-side environment information acquired by the front recognition sensor 21 and the left and right front-side sensors 27, by performing well-known pattern matching processing or the like on a series of feature points indicating the contour of the footprint marks from the luminance difference generated at the step (edge) with the snow-covered surface or mud-covered surface derived from the footprint marks 51, or the change in the intensity of the reflected light or reflected wave (reflectivity). Note that the processing in this step S25 and step S31 described later corresponds to the movement trace detection unit of the present invention.

[0043] When footprint 51 is detected within the virtual parking frame 41, proceed to step S26. If footprint 51 is not detected, jump to step S36. Note that in this step S25, the number of footprints 51 within the virtual parking frame 41 is counted. If the number of these footprints 51 exceeds a preset sidewalk determination threshold, proceed to step S26; otherwise, jump to step S31.

[0044] When proceeding to step S26, based on the above-described front and front-side environment information, check which side of the four sides of the virtual parking frame 41 a target is facing. When a target is facing two sides other than the side of the host vehicle M, proceed to step S27. When a target is facing three sides or only one side other than the side of the host vehicle M, branch to step S28. As modes where a target (parked vehicle Pv in the figure) is facing two sides other than the side of the host vehicle M, as shown in FIG. 10, there is a case where the target is facing the two sides 41b adjacent to the side 41a of the host vehicle M; and as shown in FIG. 11, there is a case where the target (parked vehicle Pv in the figure) is facing either one of the two sides 41b adjacent to the side 41a of the host vehicle M and the side 41b opposing the side 41a of the host vehicle M. Note that in FIGS. 10 to 16, the side of the virtual parking frame 41 where no target is facing is designated as 41a, and the side where a target is facing is designated as 41b. The processing in this step S26 and step S22 described later corresponds to the target detection unit of the present invention.

[0045] On the other hand, as shown in FIG. 14, the mode where a target is facing three sides other than the side of the host vehicle M is a state where the three sides other than the side where the vehicle enters and exits are surrounded by targets (parked vehicles Pv in the figure). Also, as shown in the estimated parking frames Ps5 and Ps6 (described later) in FIG. 9, the mode where a target is facing one side other than the side of the host vehicle M is a state where the interval between adjacent targets (parked vehicles Pv) is wide and two virtual parking frames 41 are set between adjacent parked vehicles Pv.

[0046] Then, when proceeding to step S27, it is examined whether the footprints 51 detected within the virtual parking frame 41 are continuous across (crossing) two sides 41b not facing the object target. In the virtual parking frame 41, when there are two sides 41b facing the object target, one of the sides 41a not facing the object target will necessarily be the side on the host vehicle M side. As shown in FIG. 10, the modes of these two sides 41a are the side 41a on the host vehicle M side and the side 41a opposite thereto, or as shown in FIG. 11, the side 41a on the host vehicle M side and the side 41a adjacent thereto. When the footprints 51 cross (cut across) and are continuous from such a side on the host vehicle M side to the other side 41a, it is determined that the currently set virtual parking frame 41 is highly likely to be a sidewalk, and the process proceeds to step S29.

[0047] Also, for example, as shown in FIG. 12, although no object target faces the side 41a on the host vehicle M side and the side 41a opposite thereto (or the adjacent side 41a), when the footprints 51 cross only the side 41a on the host vehicle M side, it is determined that the footprints 51 detected within the currently set virtual parking frame 41 are highly likely to be the footprints 51 left by a passenger getting on and off a parked vehicle, and the process branches to step S30.

[0048] On the other hand, when branching from step S26 to step S28, it is examined whether the footprints 51 cross only the side 41a on the host vehicle M side. As described above, even when the object target faces only one side other than the side 41a on the host vehicle M side, when the footprints 51 cross only the side 41a on the host vehicle M side, as described above, it is determined that the footprints 51 of the currently set virtual parking frame 41 are highly likely to be those left when the passengers of the vehicle parked in this space get on and off. In addition, when the object target faces the three sides 41a other than the side 41a on the host vehicle M side, the currently set virtual parking frame 41 is highly likely to be parkable, but by determining whether the footprints 51 cross only the side 41a on the host vehicle M side, it is possible to determine whether parking is possible with a higher accuracy.

[0049] If it is determined in step S28 that the footprint 51 intersects only the side 41a on the own vehicle M side, it is estimated as the footprint 51 left when getting in and out of the parked vehicle Pv, and the process proceeds to step S30. Also, if the footprint 51 intersects the side 41b that does not face any object, it is determined that the virtual parking frame 41 set this time is likely not a parking space, and the process proceeds to step S29. When proceeding to step S27, or steps S28 to S29, since the virtual parking frame 41 set this time is likely not a parking space, the parking priority is set low, and the process proceeds to step S36. On the other hand, when proceeding from step S27, or from step S28 to step S30, since the set virtual parking frame 41 is likely a parking space, the parking priority is set high (recommended), and the process proceeds to step S36. Note that the processing in steps S26 to S30 and steps S32 to S35 described later corresponds to the parking priority setting unit of the present invention.

[0050] On the other hand, when branching from step S25 to step S31, it is checked whether or not a rut 101 as a movement trace is detected in the virtual parking frame 41 set in step S24 based on the front and front-side environment information acquired by the front recognition sensor 21 and the left and right front-side sensors 27. The rut 101 is recognized, for example, by performing well-known pattern matching processing or the like on a series of feature points indicating the edge of the rut from the luminance difference generated at the step (edge) between the snow-covered surface or mud-covered surface derived from the rut 101, or the change in the intensity of the reflected light or reflected wave (reflectivity) in the front and front-side environment information.

[0051] If the rut 101 is detected, the process proceeds to step S32. If the rut 101 is not detected, the process jumps to step S34. When proceeding to step S32, it is checked based on the above-described front and front-side environment information whether or not objects (parked vehicle Pv, outer wall) face the three sides other than the side 41a on the own vehicle M side of the virtual parking frame 41. If objects face the three sides other than the side on the own vehicle M side, the process proceeds to step S34. As shown in FIG. 14, when the three sides 41b other than the side on the own vehicle M side are surrounded by objects, the rut 101 detected in the virtual parking frame 41 is considered to be the one left when the vehicle enters and exits, and it can be estimated that the space is likely a parking space.

[0052] On the other hand, if a target object faces one side or two sides other than the side of the virtual parking frame 41 on the own vehicle M side, the process branches to step S33. In this case, as an aspect where the target object (parked vehicle Pv in the figure) faces two sides other than the own vehicle M side, as shown in FIG. 15, when the target object (parked vehicle Pv) faces the two sides 41b adjacent to the side 41a that the own vehicle M faces, and as shown in FIG. 16, there are cases where the target object (parked vehicle Pv) faces either one of the two sides 41b adjacent to the side 41a on the own vehicle M side and the side 41b opposite to the side 41a on the own vehicle M side.

[0053] When branching to step S33, it is examined whether the rut 101 intersects (crosses) the two sides 41a that are not facing the target object. And as shown in FIG. 15 or FIG. 16, when the rut 101 intersects (crosses) the other side 41a continuously from such a side on the own vehicle M side, it is determined that the currently set virtual parking frame 41 is highly likely to be a traffic lane, and the process proceeds to step S35.

[0054] Also, when the rut 101 does not intersect the two sides 41a of the virtual parking frame 41, that is, when it intersects only one side 41a, it is presumed that it was formed during parking and is highly likely to be a parking space, and the process proceeds to step S34. In this case, even when the target object faces only one side 41b other than the side of the virtual parking frame 41 on the own vehicle M side, if the rut 101 intersects the other two sides 41b, it is presumed that it is highly likely to be a traffic lane, and if the rut 101 intersects only one side 41b, it is presumed that it is highly likely to be a parking space.

[0055] Then, when proceeding from any of steps S31 to S33 to step S34, since the currently set virtual parking frame 41 is highly likely to be a parking space, the parking priority is set high and the process proceeds to step S36. Also, when proceeding from step S33 to step S35, since the currently set virtual parking frame 41 is highly likely to be a traffic lane, the parking priority is set low and the process proceeds to step S36.

[0056] Next, when proceeding from any of steps S29, S30, S34, and S35 to step S36, it is checked whether all the settings of the parking priorities for the virtual parking frame 41 set in the parkable parking space detected based on the forward and front-side environmental information acquired this time are completed. If not yet completed, it returns to step S22 to search for the next candidate of the virtual parking frame 41. Also, when the settings of the parking priorities for all the virtual parking frames 41 are completed, it proceeds to step S37.

[0057] In step S37, the virtual parking frame 41 set this time is set as the estimated parking frame Ps associated with the parking priority and is collectively displayed on the HMI monitor 31. At this time, for example, as shown in FIG. 8, the estimated parking frame Ps with a high parking priority recommended by the driving support control unit 11 is displayed in blue (shown as a thick frame in the figure), and the estimated parking frame Ps with a low parking priority is displayed in orange (shown as a thin frame in the figure) so that it can be visually and instantly identified. As shown in FIG. 9, when the estimated parking frames Ps1 to Ps6 are set on the left and right in the traffic lane in which the host vehicle M travels, all of them are displayed in an overhead view on the HMI monitor 31.

[0058] Next, it proceeds to step S38, and the driving support control unit 11 drives the notification device 33 to announce to the driver which one to select from the estimated parking frames Ps (Ps1 to Ps6 in FIG. 8) displayed on the HMI monitor 31. Then, it proceeds to step S39, and it is determined which estimated parking frame Ps the driver has selected. The driver selects the desired estimated parking frame Ps by touching any one of the estimated parking frames Ps (Ps1 to Ps6 in the figure) displayed on the HMI monitor 31.

[0059] Then, in step S39, when it is determined that the driver has selected any of the estimated parking frames Ps, it proceeds to step S40. Also, when a predetermined time has elapsed after the announcement or when the host vehicle M has passed in front of the estimated parking frame Ps displayed on the HMI monitor 31, it branches to step S44.

[0060] When proceeding to step S40, it is checked whether the driver has selected a predicted parking space Ps with a low parking priority (any one of Ps1 to Ps3 in FIG. 8). If the driver has selected a predicted parking space Ps with a high parking priority (any one of Ps4 to Ps6 in FIG. 8), the process jumps to step S43. On the other hand, if a predicted parking space Ps with a low parking priority is selected, the process proceeds to step S41.

[0061] In step S41, since there is a possibility that the driver has mistakenly selected a predicted parking space Ps with a low parking priority, the driving support control unit 11 drives the notification device 33 to give an announcement to the driver to confirm whether the selection is in line with the intention. In this way, when the driver selects a predicted parking space Ps with a low parking priority, by giving an announcement to confirm whether the selection is possible, the inconvenience of misguiding the own vehicle M to a sidewalk or a traffic lane where parking is prohibited can be reduced, and the burden on the driver can be alleviated.

[0062] Next, the process proceeds to step S42 to check whether the driver has changed the selection of the predicted parking space Ps. The change in the selection of the predicted parking space Ps is made, for example, by touching one of the predicted parking spaces Ps (Ps1 to Ps6 in FIG. 8) displayed on the HMI monitor 31. If the driver has changed the selection of the predicted parking space Ps, the process returns to step S40. On the other hand, if a predetermined time has elapsed after the announcement or if the confirmation button displayed on the HMI monitor 31 is touched, it is determined that there is no change in the selection, and the process proceeds to step S43.

[0063] For example, as shown in FIG. 9, when the driving support control unit 11 sets the estimated parking frame Ps1, even if the parking priority is set low because the tire marks 51 intersect two sides, there may be a case where the driver visually determines that it is clearly a parking space. In such a situation, if the driving support control unit 11 excludes the parking space from the candidates for the estimated parking frame Ps and does not display it on the HMI monitor 31, a deviation from the driver's recognition will occur, resulting in a decrease in reliability. On the other hand, in the present embodiment, by associating the parking priority with the estimated parking frame Ps, the driver has more opportunities to select the estimated parking frame Ps, and good parking support can be realized. Note that the processes of steps S37 to S42 correspond to the display selection unit of the present invention.

[0064] Then, when proceeding from step S40 or from step S42 to step S43, the driving support control unit 11 sets the estimated parking frame Ps (for example, Ps4 in FIG. 8) selected by the driver as the target parking space Pt and proceeds to step S45. In step S45, control for automatically parking the host vehicle M in the target parking space Pt is executed, and the routine ends.

[0065] On the other hand, when branching from step S39 to step S44, if the driver does not select any of the estimated parking frames Ps even after a predetermined time has elapsed, the driving support control unit 11 clears all the displayed estimated parking frames Ps. Also, if the host vehicle M has passed in front of the corresponding estimated parking frame Ps, the display of the estimated parking frame Ps is cleared, and the process proceeds to step S46.

[0066] In step S46, it is checked whether the parking support mode has ended. If it is determined that the mode has ended, the routine is exited. On the other hand, if the parking support mode is continued, the process returns to step S22. The end of the parking support mode is performed by an operation of the driver via the HMI monitor 31 or the like. Alternatively, this parking support mode is automatically ended when the driving support control unit 11 detects that the host vehicle M has exited the parking lot.

[0067] Here, the automatic parking control executed in step S45 by the driving support control unit 11 will be briefly described. In this automatic parking control, first, as shown in FIG. 9, a target parking guidance path Gr for guiding the host vehicle M to the target parking space Pt is set. This target parking guidance path Gr is set such that the center in the vehicle width direction of the host vehicle M coincides with the center in the width direction of the target parking space Pt. Alternatively, for example, when the parking space width Wp between the targets (parked vehicles Pv) is equal to or greater than a predetermined value (e.g., 1.5 times) the required parking width Ws of the target parking space Pt of the host vehicle M, the end of the required parking width Ws set on the driver's seat side of the host vehicle M is shifted toward the side of the adjacent target (parked vehicle Pv), and the target parking space Pt is set. Then, in order to park the center in the width direction of the host vehicle M at the center in the width direction of this target parking space Pt, the target parking guidance path Gr may be set.

[0068] Thereafter, after the driving support control unit 11 automatically parks the host vehicle M at a predetermined position with respect to the target parking space Pt, the routine is exited. Note that this target parking guidance path Gr is set in accordance with the normal target parking guidance path set when a parking frame is recognized.

[0069] As a result, if the host vehicle M circles around the passage area of the parking lot, it is possible to acquire the position information of all the parked vehicles Pv parked in the parking lot, and based on this, it is also possible to set an estimated parking frame Ps for the entire parking lot.

[0070] Thus, when attempting to automatically park the host vehicle in a parking space in a parking lot, if the parking frame that demarcates the parking space is covered with snow, mud, etc. and cannot be recognized, the width Wp of the parking space between adjacent landmarks (parked vehicle Pv, wall) and the required parking width Ws of the virtual parking frame 41 set for the host vehicle M are compared. When Wp ≥ Ws, the virtual parking frame 41 is set in the parking space, and each virtual parking frame 41 is collectively displayed on the HMI monitor 31 as an estimated parking frame Ps (Ps1 to Ps6 in FIG. 8) associated with a parking priority according to the tire marks 51, ruts 101 within the virtual parking frame 41, and the landmarks facing each side of the virtual parking frame 41. As a result, the driver can select a desired estimated parking frame Ps at once from the collectively displayed estimated parking frames Ps (Ps1 to Ps6). Consequently, the burden on the driver can be reduced.

[0071] Also, since the parking priority is associated with this estimated parking frame Ps, the driver can easily grasp the parking available space. Further, even for an estimated parking frame Ps with a low parking priority, if the driver determines that parking is possible, the driver can select the estimated parking frame Ps, so the opportunity for the driver to select the estimated parking frame Ps increases, and good parking support can be realized.

[0072] Note that the present invention is not limited to the above-described embodiment. For example, within the parking lot, the driver manually operates the host vehicle M to drive around and searches for a parking space where the virtual parking frame 41 fits while visually recognizing the HMI monitor 31. When the driver identifies a parking space where the virtual parking frame 41 fits, the host vehicle M is once stopped before that, and the driving support mode is selected. Thereby, the driving support control unit 11 may examine the parking priority of the identified parking space and notify the driver.

[0073] Also, for example, in the process of step S45 described above, the target parking guidance path Gr may be superimposed and displayed on the HMI monitor 31 for an aerial view around the parking space where parking is to be performed, and the driver may park the host vehicle M along the target parking guidance path Gr by their own driving.

Explanation of Reference Numerals

[0074] 1… Parking support device, 11… Driving support control unit, 21… Forward recognition sensor, 21a… Main camera, 21b… Sub camera, 21c… Image processing unit (IPU) 22… Map locator unit, 22a… GNSS sensor, 22b… Road map database, 23… Autonomous driving sensor, 24… Brake sensor, 25… Select position sensor, 26… Rear sensor, 27… Left and right front side sensors, 28… Left and right rear side sensors, 31… HMI monitor, 32… Drive control actuator, 33… Notification device, 41… Virtual parking frame, 41a, 41b… Sides of the virtual parking frame, 51… Footprint, 101… Rut, Gr… Target parking guidance route, M… Own vehicle, Ps, Ps1~Ps6… Estimated parking frame, Pt… Target parking space, Pv… Parked vehicle, Wp… Parking space width, Ws… Required parking width

Claims

1. In a parking assistance device that guides a host vehicle to a parking available space in a parking lot, an environment information acquisition unit that acquires environment information around the host vehicle; a storage unit that stores a virtual parking frame necessary for parking the host vehicle; a parking interval calculation unit that obtains the width of the parking space between object marks based on the environment information acquired by the environment information acquisition unit; a parking width comparison unit that compares the width of the parking space between the object marks obtained by the parking interval calculation unit with the width of the virtual parking frame stored in the storage unit; a virtual parking frame setting unit that sets the virtual parking frame within the parking space when it is determined by the parking width comparison unit that the width of the parking space is wider than the width of the virtual parking frame; a movement trace detection unit that detects a movement trace based on the environment information acquired by the environment information acquisition unit within the virtual parking frame set by the virtual parking frame setting unit; an object mark detection unit that checks whether an object mark faces at least one side of the virtual parking frame excluding the side on the host vehicle side; a parking priority setting unit that sets the parking priority of the virtual parking frame according to the movement trace detected by the movement trace detection unit and the object mark facing the virtual parking frame detected by the object mark detection unit; a display selection unit that collectively displays estimated parking frames associated with the parking priority set by the parking priority setting unit for the virtual parking frame set by the virtual parking frame setting unit and allows a driver to select; a parking assistance unit that sets the estimated parking frame selected by the driver in the display selection unit as a target parking space and guides the host vehicle to the target parking space A parking assistance device characterized by comprising the above.

2. When the movement trace intersects and continues two sides of the virtual parking frame, the parking priority setting unit sets the parking priority lower than the parking priority set when the movement trace intersects only one side of the virtual parking frame. The parking assistance device according to claim 1, characterized by the above.

3. When the object mark faces two sides of the virtual parking frame other than the side on the host vehicle side and the movement trace intersects and continues two sides of the virtual parking frame, the parking priority setting unit sets the parking priority lower than the parking priority set when the movement trace intersects only the side on the host vehicle side of the virtual parking frame. The parking assistance device according to claim 1, characterized by the above.

4. When the movement trace intersects only the side on the host vehicle side of the virtual parking frame, the parking priority is set high. The parking assistance device according to claim 3, characterized in that...

5. When the display selection unit selects the estimated parking frame associated with the low parking priority by the driver, the display selection unit confirms the selection with the driver. The parking assistance device according to any one of claims 1 to 4, characterized in that...

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