Vehicle driving assistance device

Abstract

To provide a driving support apparatus of a vehicle which can select an appropriate parking space for parking an own vehicle from parking spaces existing in a parking area.SOLUTION: When an own vehicle M enters a parking area, a travel_ECU14 detects one or more parking spaces in which the own vehicle M can park, on the basis of travel circumstance information; calculates an evaluation value Ev, including an obstruction factor in leaving the parking area, as an evaluation item for each of the detected parking spaces; and preferentially selects a parking space having a relatively high evaluation value Ev from the detected parking spaces, as a parking space for parking the own vehicle M.SELECTED DRAWING: Figure 14

Description

[Technical Field]

[0001] The present invention relates to a driving assistance device for a vehicle equipped with a parking assistance control function in a parking lot. [Background technology]

[0002] In recent years, driving assistance devices for assisting drivers in driving operations have been put into practical use in vehicles such as automobiles, with the aim of reducing the burden of driving operations on drivers and improving safety. For this type of driving assistance device, various technologies have been developed for a driving assistance mode that performs steering assistance control and acceleration / deceleration control on the premise that the driver is actively driving the vehicle, and a driving assistance mode (so-called automatic driving mode) that allows the vehicle to run without the need for driving operations by the driver.

[0003] The driving assistance control in each driving assistance mode is basically realized by providing an adaptive cruise control (ACC) function, an active lane keep centering control (ALKC) function, etc. Such driving assistance control enables the vehicle to automatically travel along the driving lane while maintaining a distance from the vehicle ahead.

[0004] Furthermore, for this type of driving assistance device, many technologies have been proposed that extend driving assistance control to parking assistance control in parking lots. For example, Patent Document 1 discloses a technology related to parking assistance control that estimates areas in parking spaces set in a parking lot that are likely to become puddles or snow accumulation, and parks a vehicle avoiding those areas. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 2018-149983 Summary of the Invention [Problem to be solved by the invention]

[0006] However, the technology of Patent Document 1 does not set the optimal parking space itself, but sets the optimal parking space within a set parking space. Therefore, the technology of Patent Document 1 does not take into consideration setting the optimal parking space when there are multiple parking spaces in a parking lot where the vehicle can be parked.

[0007] The present invention has been made in consideration of the above circumstances, and aims to provide a vehicle driving assistance device that can select the optimal parking space for parking the vehicle from among the parking spaces available in a parking lot. [Means for solving the problem]

[0008] The driving assistance device for a vehicle according to one aspect of the present invention includes a driving environment recognition unit that recognizes driving environment information outside the vehicle, and when the vehicle enters a parking lot, Within the search area set in front of the vehicle, Based on the driving environment information tree A parking space detection means for detecting one or more parking spaces in which the vehicle can be parked, an evaluation value calculation means for calculating an evaluation value for each of the detected parking spaces, including factors that hinder the vehicle from leaving the parking space as an evaluation item, and a means for calculating an evaluation value for each of the detected parking spaces, including factors that hinder the vehicle from leaving the parking space as an evaluation item. The parking spaces with the highest evaluation value are extracted. and a parking space setting means for preferentially selecting a high parking space as a parking space for parking the vehicle. [Effects of the Invention]

[0009] According to the vehicle driving assistance device of the present invention, it is possible to select the most suitable parking space for parking the vehicle from among the parking spaces present in the parking lot. [Brief explanation of the drawings]

[0010] [Figure 1] Overall configuration of the driving assistance device [Figure 2] An explanatory diagram showing the monitoring areas of the stereo camera, radar, and sonar. [Figure 3] Parking lot map [Figure 4] Parking lot map [Figure 5] An explanatory diagram showing the slope of the parking lot along line VV in Figure 3 [Figure 6] A map showing the evaluation value for the direction of departure of the vehicle [Figure 7] An explanatory diagram showing the height from the road surface to the camera mounting position on a road without snow. [Figure 8] An explanatory diagram showing the height from the road surface to the camera mounting position on an uncompacted snow road. [Figure 9] An explanatory diagram showing the height from the road surface to the camera mounting position on a packed snow road [Figure 10] Map showing the evaluation value of the road surface condition of the parking space [Figure 11] Map showing the evaluation value for the direction of exit from a parking space [Figure 12] FIG. 10 is an explanatory diagram showing the assist screen when parking forward. [Figure 13] FIG. 10 is an explanatory diagram showing the assist screen when parking in reverse [Figure 14] Flowchart showing a parking space setting routine [Figure 15] FIG. 10 is an explanatory diagram showing a parking intention selection screen. [Figure 16] An explanatory diagram showing the parking space selection screen DETAILED DESCRIPTION OF THE INVENTION

[0011] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The following describes embodiments of the present invention with reference to the drawings. The drawings relate to one embodiment of the present invention, and Fig. 1 is a diagram showing the overall configuration of a driving assistance device.

[0012] As shown in FIG. 1, the driving assistance device 1 includes a camera unit 10 fixed to the center of the upper front part of the interior of a vehicle (host vehicle) M, for example.

[0013] The camera unit 10 includes a stereo camera 11, an image processing unit (IPU) 12, an image recognition unit (image recognition_ECU) 13, and a driving control unit (driving_ECU) 14.

[0014] The stereo camera 11 has a main camera 11a and a sub-camera 11b. The main camera 11a and the sub-camera 11b are arranged, for example, at symmetrical positions with respect to the center in the vehicle width direction. The main camera 11a and the sub-camera 11b are configured, for example, with CMOS or the like, and capture stereo images of the driving environment in an area Af (see FIG. 2) outside the vehicle from different viewpoints at a predetermined imaging period that is synchronized with each other.

[0015] The IPU 12 performs predetermined image processing on the driving environment images captured by the stereo camera 11 to detect the edges of various objects such as three-dimensional objects and road markings displayed on the images. The IPU 12 then calculates distance information from the positional deviation of corresponding edges on the left and right images, and generates image information including the distance information (distance image information).

[0016] Based on distance image information received from the IPU 12, the image recognition_ECU 13 calculates the road curvature [1 / m] of the marking lines dividing the left and right sides of the path along which the vehicle M is traveling (the host vehicle path) and the width between the left and right marking lines (lane width). Various methods are known for calculating the road curvature and lane width. For example, the image recognition_ECU 13 recognizes the left and right marking lines by binarizing the road curvature based on the driving environment information using brightness differences, and calculates the curvatures of the left and right marking lines for each predetermined section using a curve approximation formula based on the least squares method. Furthermore, the image recognition_ECU 13 calculates the lane width from the difference in curvature between the left and right marking lines.

[0017] Then, the image recognition_ECU 13 calculates the lane center, the lateral position deviation of the vehicle M, which is the distance from the lane center to the center of the vehicle M in the vehicle width direction, etc. based on the curvature of the left and right lane markings and the lane width.

[0018] Furthermore, the image recognition_ECU 13 performs predetermined pattern matching on the distance image information to recognize three-dimensional objects such as guardrails extending along the road, curbs, and surrounding vehicles. Here, when recognizing three-dimensional objects in the image recognition_ECU 13, for example, the type of the three-dimensional object, the distance to the three-dimensional object, the speed of the three-dimensional object, and the relative speed between the three-dimensional object and the host vehicle M are recognized.

[0019] The various pieces of information recognized by the image recognition_ECU 13 are output to the traveling_ECU (traveling_ECU) 14 as traveling environment information.

[0020] In this manner, in this embodiment, the image recognition_ECU 13, together with the stereo camera 11 and the IPU 12, realizes the function of a driving environment recognition unit that recognizes driving environment information outside the vehicle.

[0021] The traveling_ECU 14 is a control unit for controlling the driving assistance device 1 in an integrated manner.

[0022] This traveling_ECU 14 is connected to various control units, such as a cockpit control unit (CP_ECU) 21, an engine control unit (E / G_ECU) 22, a transmission control unit (T / M_ECU) 23, a brake control unit (BK_ECU) 24, and a power steering control unit (PS_ECU) 25, via an in-vehicle communication line such as a CAN (Controller Area Network).

[0023] Furthermore, various sensors, such as a locator unit 36, a left front side sensor 37lf, a right front side sensor 37rf, a left rear side sensor 37lf, a right rear side sensor 37rr, and a rear sensor 38, are connected to the travel_ECU 14.

[0024] A human-machine interface (HMI) 31 disposed near the driver's seat is connected to the CP_ECU 21. The HMI 31 includes, for example, a switch for issuing an instruction to execute various driving assistance controls, a mode selector switch for switching driving assistance modes, a steering touch sensor for detecting the driver's steering state, a driver monitoring system (DMS) for detecting the driver's facial recognition and line of sight, a touch panel display, a combination meter, a speaker, and the like.

[0025] When the CP_ECU 21 receives a control signal from the travel_ECU 14, it notifies the driver of various types of information, such as various warnings for preceding vehicles, the implementation status of driving assistance control, and the driving environment of the host vehicle M, as appropriate, by displaying, audibly, or the like via the HMI 31. In addition, the CP_ECU 25 outputs to the travel_ECU 14 various types of input information, such as the on / off operation status of various driving assistance controls, input by the driver via the HMI 31.

[0026] The output side of the E / G_ECU 22 is connected to a throttle actuator 32 of an electronically controlled throttle, etc. The input side of the E / G_ECU 22 is connected to various sensors such as an accelerator sensor (not shown).

[0027] The E / G_ECU 22 controls the operation of the throttle actuator 32 based on a control signal from the travel_ECU 14 or detection signals from various sensors. In this way, the E / G_ECU 22 adjusts the amount of intake air into the engine to generate a desired engine output. The E / G_ECU 22 also outputs signals such as the accelerator opening detected by the various sensors to the travel_ECU 14.

[0028] An output side of the T / M_ECU 23 is connected to a hydraulic control circuit 33. Furthermore, various sensors such as a shift position sensor (not shown) are connected to an input side of the T / M_ECU 23. The T / M_ECU 23 performs hydraulic control for the hydraulic control circuit 33 based on an engine torque signal estimated by the E / G_ECU 22 and detection signals from various sensors. As a result, the T / M_ECU 23 operates friction engagement elements, pulleys, and the like provided in the automatic transmission, and shifts the engine output at a desired gear ratio. Furthermore, the T / M_ECU 23 outputs signals such as the shift position detected by the various sensors to the travel_ECU 14.

[0029] The output side of the BK_ECU 24 is connected to brake actuators for adjusting the brake fluid pressures output to the brake wheel cylinders provided on the respective wheels, and the input side of the BK_ECU 24 is connected to various sensors (not shown), such as a brake pedal sensor, a yaw rate sensor, a longitudinal acceleration sensor, and a vehicle speed sensor.

[0030] The BK_ECU 24 controls the driving of the brake actuators based on control signals from the travel_ECU 14 or detection signals from various sensors. As a result, the BK_ECU 24 appropriately generates braking force on each wheel to perform forced braking control, yaw rate control, etc. on the host vehicle M. The BK_ECU 24 also outputs signals of the brake operation state, yaw rate, longitudinal acceleration, vehicle speed (host vehicle speed), etc. detected by the various sensors to the travel_ECU 14.

[0031] An electric power steering motor 35, which applies steering torque to the steering mechanism by the rotational force of the motor, is connected to the output side of the PS_ECU 25. In addition, various sensors such as a steering torque sensor and a steering angle sensor are connected to the input side of the PS_ECU 25.

[0032] The PS_ECU 25 controls the drive of the electric power steering motor 35 based on control signals from the travel_ECU 14 or detection signals from various sensors. As a result, the PS_ECU 25 generates a steering torque for the steering mechanism. The PS_ECU 25 also outputs signals of the steering torque, steering angle, etc. detected by the various sensors to the travel_ECU 14.

[0033] The locator unit 36 includes a GNSS sensor 36a and a high-precision road map database (road map DB) 36b.

[0034] The GNSS sensor 36a receives positioning signals transmitted from a plurality of positioning satellites to determine the position (latitude, longitude, altitude, etc.) of the vehicle M.

[0035] The road map DB 36b is a large-capacity storage medium such as an HDD, and stores high-precision road map information (dynamic map). This road map DB 36b stores lane data required for autonomous driving, such as lane width data, lane center position coordinate data, lane travel azimuth data, and speed limits. This lane data is stored at intervals of several meters for each lane on the road map. The road map DB also stores information on various facilities, parking lots, and the like. For example, based on a request signal from the traveling_ECU 14, the road map DB 36b outputs road map information for a set range based on the vehicle position measured by the GNSS sensor 36a to the traveling_ECU 14 as traveling environment information.

[0036] In this manner, in this embodiment, the road map DB 36b, together with the GNSS sensor 36a, functions as a driving environment recognition means for recognizing driving environment information outside the vehicle.

[0037] The left front side sensor 37lf and the right front side sensor 37rf are configured by, for example, millimeter-wave radars. These left front side sensor 37lf and right front side sensor 37rf are disposed, for example, on the left and right sides of the front bumper, respectively. The left front side sensor 37lf and the right front side sensor 37rf detect, as driving environment information, three-dimensional objects present in areas Alf, Arf (see FIG. 2) diagonally forward and to the left and right of the vehicle M, which are difficult to recognize in the image from the stereo camera 11.

[0038] The left rear side sensor 37lr and the right rear side sensor 37rr are configured, for example, by millimeter-wave radar. The left rear side sensor 37lr and the right rear side sensor 37rr are disposed, for example, on the left and right sides of the rear bumper, respectively. The left rear side sensor 37lf and the right rear side sensor 37rf detect, as driving environment information, three-dimensional objects present in areas Alr, Arr (see FIG. 2) diagonally to the left and right sides and rear of the vehicle M that are difficult to recognize with the left front side sensor 37lf and the right front side sensor 37rf.

[0039] Here, the millimeter wave radar constituting each radar mainly detects three-dimensional objects such as adjacent vehicles by analyzing the waves reflected from the objects in response to the output radio waves. Specifically, each radar detects information about the three-dimensional object, such as the width of the three-dimensional object, the position of a representative point of the three-dimensional object (the relative position with respect to the vehicle M), and the speed.

[0040] In this manner, in this embodiment, the front side sensor 37lf, the right front side sensor 37rf, the left rear side sensor 37lr, and the right rear side sensor 37rr function as a driving environment recognition means for recognizing driving environment information outside the vehicle.

[0041] The rear sensor 38 is configured by, for example, a sonar. The rear sensor 38 is disposed, for example, on the rear bumper. The rear sensor 38 detects, as driving environment information, three-dimensional objects present in an area Ar (see FIG. 2) behind the vehicle M that are difficult to recognize with the left rear side sensor 37lr and the right rear side sensor 37rr.

[0042] In this way, in this embodiment, the rear sensor 38 functions as a driving environment recognition means that recognizes driving environment information outside the vehicle.

[0043] In addition, the coordinates of each object outside the vehicle included in the driving environment information recognized by the image recognition_ECU 13, the driving environment information recognized by the locator unit 36, the driving environment information recognized by the left front side sensor 37lf, the driving environment information recognized by the right front side sensor 37rf, the driving environment information recognized by the left rear side sensor 37lf, the driving environment information recognized by the right rear side sensor 37rr, and the driving environment information recognized by the rear sensor 38 are all converted by the driving_ECU 14 into coordinates of a three-dimensional coordinate system (see Figure 2) with the center of the vehicle M as the origin.

[0044] The driving modes set in the travel_ECU 14 include a manual driving mode, a first driving control mode and a second driving control mode for driving control, and an evacuation mode. These driving modes can be selectively switched in the travel_ECU 14 based on, for example, the operation status of a mode selector switch provided in the HMI 31.

[0045] Here, the manual driving mode is a driving mode that requires the driver to maintain steering, and is a driving mode in which the vehicle M is driven according to driving operations such as steering, accelerator, and brake operations by the driver.

[0046] Similarly, the first driving control mode is a driving mode that requires the driver to maintain steering. That is, the first driving control mode is a so-called semi-automatic driving mode in which the host vehicle M travels along a target driving route by appropriately combining mainly adaptive cruise control (ACC), active lane keep centering (ALKC), and active lane keep bouncing (ALKC) controls through control of the E / G_ECU 22, BK_ECU 24, PS_ECU 25, etc., while reflecting the driving operation by the driver.

[0047] Here, the control for following the preceding vehicle is basically performed based on the traveling environment information input from the image recognition_ECU 13. That is, the control for following the preceding vehicle is performed based on, for example, the preceding vehicle information included in the traveling environment information from the image recognition_ECU 13.

[0048] Furthermore, the lane centering control and lane departure prevention control are basically performed based on the driving environment information input from at least one of the image recognition_ECU 13 and the locator unit 36. That is, the lane centering control and the lane departure prevention control are performed based on, for example, lane marking information and the like included in the driving environment information from the image recognition_ECU 13 or the locator unit 36.

[0049] The second driving control mode is an autonomous driving mode in which the vehicle M is driven along a target route (route map information) without requiring the driver to maintain steering, operate the accelerator, or operate the brakes, and is mainly driven by an appropriate combination of preceding vehicle following control, lane centering control, and lane departure prevention control through control of, for example, the E / G_ECU22, BK_ECU24, PS_ECU25, etc.

[0050] The evacuation mode is a mode for automatically stopping the vehicle M on a roadside or the like, for example, when, while driving in the second driving control mode, driving in that mode cannot be continued and the driver is unable to take over driving operations (i.e., when it is not possible to transition to manual driving mode or the first driving control mode).

[0051] In addition, in each of the above-mentioned driving modes, the travel_ECU 14 appropriately performs emergency braking (AEB (Autonomous Emergency Braking): collision damage mitigation brake) control against obstacles such as vehicles that are highly likely to collide with the host vehicle M.

[0052] Furthermore, when the traveling_ECU 14 determines that it is difficult to avoid a collision with an obstacle by emergency brake control, it is also possible to perform emergency steering control to avoid a collision with an obstacle instead of or in combination with emergency brake control.

[0053] Here, the emergency brake control and emergency steering control are basically performed based on the driving environment information input from the image recognition_ECU 13. That is, the emergency brake control and emergency steering control are performed based on, for example, obstacle information such as a preceding vehicle or a stopped vehicle included in the driving environment information from the image recognition_ECU 13. At this time, in order to avoid a collision with a vehicle running alongside or a following vehicle, reference is made to following vehicle information and following vehicle information included in the driving environment information from the left and right front side sensors 37lf, 37rf, the left and right rear side sensors 37lr, 37rr, and the rear sensor 38.

[0054] Furthermore, the travel_ECU 14 performs parking control when the host vehicle M enters a parking lot.

[0055] In this parking control, the travel_ECU 14 first sets an optimal parking space where the host vehicle M can be parked.

[0056] When setting this parking space, the travel_ECU 14 first searches for a parking space where the host vehicle M can be parked. That is, the travel_ECU 14 searches for a parking space within a search area Sa that is set in advance in front of the host vehicle M, based on, for example, driving environment information input from the image recognition_ECU 13 and the left and right front side sensors 37lf, 37rf. Note that, for example, as shown in FIGS. 3 and 4, the search area Sa moves as the host vehicle M travels.

[0057] Specifically, the traveling_ECU 14 searches for parking spaces within the search area Sa, for example, based on road marking information included in the driving environment information from the image recognition_ECU 13. When a parking space is detected, the traveling_ECU 14 checks whether a parked vehicle exists in the detected parking space, for example, based on three-dimensional object information included in the driving environment information from the image recognition_ECU 13 and the left and right front side sensors 37lf, 37rf. The traveling_ECU 14 then extracts parking spaces that do not contain parked vehicles as parking spaces in which the host vehicle M can park.

[0058] The travel ECU 14 may be, for example, an image recognition ECU 13 Based on the driving environment information from the vehicle M, the vehicle recognizes the slope (road surface gradient) of the parking space where the vehicle M can park, and also recognizes whether or not there is a wheel chock in the parking space where the vehicle M can park (see Figures 3 to 5).

[0059] The travel ECU 14 may be, for example, an image recognition ECU 13 Based on driving environment information from the above, the travel_ECU 14 determines the optimal direction for entering a parking space in which the host vehicle M can park, and also determines the direction in which the host vehicle M can leave the parking space if parked in the optimal direction for entering. Specifically, the travel_ECU 14 determines that, in principle, forward entry is appropriate for a parking space that faces an aisle on both the front and rear ends and does not have wheel chocks or the like. The travel_ECU 14 then determines that leaving such a parking space is possible in both the front and rear directions.

[0060] Also , runThe row_ECU 14 determines that, in principle, a backward entry is appropriate for a parking space where a wheel chock or the like is present. The travel_ECU 14 then determines that a forward exit is possible for such a parking space.

[0061] However, if the travel_ECU 14 determines that it is difficult to reverse the vehicle M into a parking space where wheel chocks or the like are present without making three or more turns, or if a sign or the like instructing forward entry is recognized in the driving environment information, the travel_ECU 14 determines that forward entry is appropriate.Then, the travel_ECU 14 determines that backward entry is possible for such a parking space.

[0062] The information such as the slope of the road surface of the parking space, whether or not there are wheel chocks, the appropriate direction of entry, and the direction in which the vehicle M can be left is stored in the travel_ECU 14 as additional information for each parking space in which the vehicle M can be parked.

[0063] Next, the travel_ECU 14 calculates an evaluation value Ev for the parking space where the host vehicle M can park. This evaluation value Ev includes an evaluation of obstructive factors at the time of leaving the parking space as an evaluation item. Note that the smaller the obstructive factors, the higher the calculated evaluation value Ev.

[0064] Specifically, the travel_ECU 14 evaluates, for example, the exit direction from the parking space as an evaluation of the obstructive factors at the time of exit. That is, the travel_ECU 14 calculates an evaluation value Ev1 by referring to a pre-set map (see FIG. 6, for example) depending on, for example, whether the possible directions for exit from the parking space are forward and backward, forward, or backward. For example, the highest evaluation value Ev1 is set for a parking space that allows exit in both forward and backward directions, followed by a parking space that allows forward exit and a parking space that allows backward exit, in that order.

[0065] Furthermore, the travel_ECU 14 evaluates, for example, the road surface conditions within the parking space as an evaluation of factors hindering leaving. This evaluation of the road surface conditions within the parking space is based at least on the presence or absence of snow. That is, the travel_ECU 14 calculates the evaluation value Ev2 by referring to a pre-set map (see FIG. 10, for example) or the like depending on, for example, whether the parking space has a dry road surface, a wet road surface, a packed snow road surface, an unpacked snow road surface, or an icy road surface. The evaluation value Ev2 is set to a higher value as the road surface conditions make it less likely for the wheels to slip when leaving the parking space. For example, the evaluation value Ev2 is set to be highest when the parking space has a dry road surface, followed by a wet road surface, a packed snow road surface, an unpacked snow road surface, and an icy road surface, in that order.

[0066] Here, the road surface condition within the parking space is estimated based on, for example, the road surface condition of the passage leading to the parking space. That is, the traveling_ECU 14 determines whether the passage is a dry road surface, a wet road surface, or a snowy road surface based on, for example, the brightness of the image of the passage captured by the stereo camera 11. Furthermore, if the traveling_ECU 14 determines that the road surface is a wet road surface, it refers to the outside air temperature, etc., and if the outside air temperature is below a set temperature (for example, below 0°C), it determines that the road surface (wet road surface) is a frozen road surface. Furthermore, if the traveling_ECU 14 determines that the road surface is a snowy road surface, it determines whether the road surface is a packed snow road surface or an unpacked snow road surface based on, for example, the height H from the road surface to the stereo camera 11. That is, for example, when the host vehicle M is traveling on a snowy road surface, the vehicle body sinks into the snow (see FIGS. 8 and 9), and therefore the height H from the road surface to the stereo camera 11 is lower than when the host vehicle M is traveling on a road surface without snow. Furthermore, even if the vehicle M is traveling on a snowy road surface, when the vehicle M is traveling on an uncompacted road surface, the vehicle body generally sinks more, so the height H from the road surface to the stereo camera 11 is lower than when traveling on a packed snow road surface. Therefore, when the vehicle M is traveling on a snowy road surface, the travel_ECU 14 determines that the vehicle M is traveling on a packed snow road surface if the height H is equal to or greater than a preset threshold value, and determines that the vehicle M is traveling on an uncompacted snow road surface if the height H is less than the threshold value.

[0067] In addition, the driving_ECU 14 may, for example, have the vehicle M drive a predetermined distance or more in a parking lot to estimate the road surface friction coefficient in the BK_ECU 24, etc., and set the evaluation value Ev2 for the road surface conditions higher as the road surface friction coefficient becomes higher.

[0068] The travel_ECU 14 also evaluates the slope of the parking space in the exit direction as an evaluation of the obstacles to leaving the parking space. That is, the travel_ECU 14 calculates the evaluation value Ev3 by referring to a pre-set map (see, for example, FIG. 11 ) or the like depending on whether the slope of the road surface of the parking space is flat, has a downward slope in the exit direction, or an upward slope in the exit direction. For example, the evaluation value Ev3 is highest when there is no slope in the exit direction (when the road surface of the parking space is flat), and then higher values are set for a downward slope in the exit direction and an upward slope in the exit direction. Here, a parking space having a flat road surface with no slope is not limited to a strictly horizontal road surface, but refers to, for example, a parking space with an inclination angle of less than ±5°. Furthermore, a parking space with two exit directions (front and rear) and a slope is evaluated as a parking space with a downward slope in the exit direction. Note that the evaluation value Ev3 for a parking space with a slope in the exit direction can also be calculated in detail depending on the slope angle.

[0069] Then, the travel_ECU 14 calculates an overall evaluation value Ev for each parking space based on the evaluation values Ev1 to Ev3 for each of the obstacles at the time of leaving the parking lot that have been set in this way. For example, the travel_ECU 14 can calculate the evaluation value Ev by taking a weighted average of the evaluation values Ev1 to Ev3 for each of the obstacles at the time of leaving the parking lot. Of course, the evaluation value Ev may take into account other obstacles or evaluation items other than the obstacles.

[0070] Next, the travel_ECU 14 preferentially selects, from among the detected parking spaces, a parking space with a relatively high evaluation value Ev as a parking space for parking the host vehicle M.

[0071] Specifically, the travel_ECU14 extracts parking spaces whose evaluation value Ev is equal to or greater than a predetermined threshold value Evth, and preferentially selects and sets the parking space with the highest evaluation value Ev among these extracted parking spaces as the parking space for parking the host vehicle M.

[0072] Here, if a parking space with an evaluation value Ev equal to or greater than the threshold value Evth has not yet been detected, the travel_ECU 14, for example, does not set a parking space and continues searching for a new parking space as the host vehicle M travels. This search for a parking space is continued, for example, until the host vehicle M has finished searching the entire area of the parking lot, or until a parking space with an evaluation value Ev equal to or greater than the threshold value Evth is detected.

[0073] In this way, in this embodiment, the travel_ECU 14 realizes the functions of a parking space detection means, an evaluation value calculation means, and a parking space setting means.

[0074] Once the parking space is set, the travel_ECU 14 performs parking control for the set parking space.

[0075] That is, the traveling_ECU 14 sets a traveling trajectory of the host vehicle M to the parking space in accordance with the supplementary information of the set parking space (i.e., whether the parking space is suitable for forward parking or reverse parking). If the current driving mode is the manual driving mode or the first driving control mode, the traveling_ECU 14 displays the traveling trajectory to the parking space via the HMI 31 or the like (see FIGS. 12 and 13). Alternatively, if the current driving mode is the second driving control mode, the traveling_ECU 14 parks the host vehicle M in the parking space through steering control or the like based on the set traveling trajectory.

[0076] Next, the setting of a parking space executed by the travel_ECU 14 will be described with reference to a flowchart of a parking space setting routine shown in Fig. 14. This routine is an interrupt routine that is repeatedly executed at set time intervals while the host vehicle M is traveling, for example.

[0077] When the routine starts, the travel_ECU 14 first checks in step S101 whether the host vehicle M has entered a parking lot.

[0078] Then, in step S101, if it is determined that the host vehicle M has not entered the parking lot, the travel_ECU 14 exits the routine.

[0079] On the other hand, if it is determined in step S101 that the host vehicle M has entered the parking lot, the travel_ECU 14 proceeds to step S102 and checks whether the driver intends to park the host vehicle M in the parking lot. That is, for example, if a destination has been set by a navigation device or the like and the parking lot into which the host vehicle M has entered is the destination parking lot, the travel_ECU 14 determines that the driver intends to park. Alternatively, the travel_ECU 14 can confirm the driver's intention to park by displaying information on the HMI 31 or the like, as shown in FIG. 15 .

[0080] Then, in step S102, if it is determined that the driver has no intention of parking, the travel_ECU 14 exits the routine as is.

[0081] On the other hand, if it is determined in step S102 that the driver has an intention to park, the travel_ECU 14 proceeds to step S103 and searches for a parking space in which the host vehicle M can be parked. That is, in step S103, the travel_ECU 14 searches for a parking space within a search area Sa that is set in advance in front of the host vehicle M, based on, for example, the traveling environment information input from the image recognition_ECU 13 and the left and right front side sensors 37lf, 37rf.

[0082] In the following step S104, the travel_ECU 14 checks whether or not one or more parking spaces in which the host vehicle M can be parked have been detected by the search in step S103.

[0083] Then, if it is determined in step S104 that a parking space has not been detected, the traveling_ECU 14 proceeds to step S108.

[0084] On the other hand, if it is determined in step S104 that a parking space has been detected, the travel_ECU 14 proceeds to step S105 and calculates an evaluation value Ev for each of the detected parking spaces.

[0085] That is, in step S105, the travel_ECU 14 calculates an evaluation value Ev for each parking space, which includes, as an evaluation item, factors that hinder the vehicle from leaving the parking space.

[0086] In the following step S106, the travel_ECU 14 compares the evaluation value Ev of each parking space with a preset threshold value Evth, and checks whether or not a parking space whose evaluation value Ev is equal to or greater than the threshold value Evth has been detected so far.

[0087] Then, in step S106, if it is determined that a parking space with an evaluation value Ev equal to or greater than the threshold value Evth has not been detected, the travel_ECU 14 proceeds to step S108.

[0088] On the other hand, if it is determined in step S106 that a parking space with an evaluation value Ev equal to or greater than the threshold value Evth has been detected, the travel_ECU 14 proceeds to step S107, sets a parking space based on the evaluation value Ev, and then exits the routine.

[0089] That is, in step S107, the travel_ECU 14 sets, in principle, the parking space with the highest evaluation value Ev as the parking space for parking the host vehicle M.

[0090] However, if there are multiple parking spaces with the highest evaluation value Ev, the travel_ECU 14 can also set, for example, the parking space with the highest evaluation value Ev that is closest to the vehicle M as the parking space for parking the vehicle M.

[0091] Alternatively, for example, as shown in Fig. 16, the travel_ECU 14 may display, via the HMI 31 or the like, the parking space for parking the host vehicle M, so that the driver can select the parking space. In this case, it is desirable to display the parking space with the highest evaluation value Ev as the recommended parking space.

[0092] Furthermore, when the process proceeds from step S104 or step S106 to step S108, the travel_ECU 14 checks whether or not the search for parking spaces has been completed for the entire parking lot.

[0093] Then, in step S108, if it is determined that the search for parking spaces has not yet been completed for the entire parking lot, the travel_ECU 14 returns to step S103.

[0094] On the other hand, if it is determined in step S108 that the search for parking spaces has been completed throughout the entire parking lot, the travel_ECU 14 proceeds to step S109 and checks whether a parking space has been detected within the parking lot, i.e., whether at least one parking space whose evaluation value Ev is less than the threshold value Evth has been detected.

[0095] Then, in step S109, if it is determined that a parking space has not been detected, the traveling_ECU 14 exits the routine.

[0096] On the other hand, if it is determined in step S109 that a parking space has been detected, the traveling_ECU 14 proceeds to step S110, sets a parking space based on the evaluation value Ev, and then exits the routine.

[0097] That is, in step S110, the travel_ECU 14 sets, in principle, the parking space with the highest evaluation value Ev as the parking space for parking the host vehicle M.

[0098] However, if there are multiple parking spaces with the highest evaluation value Ev, the travel_ECU14 can also set, for example, the parking space closest to the vehicle M among the parking spaces with the highest evaluation value Ev as the parking space for parking the vehicle M.

[0099] Alternatively, for example, as shown in Fig. 16, the travel_ECU 14 may display, via the HMI 31 or the like, the parking space for parking the host vehicle M, so that the driver can select the parking space. In this case, it is desirable to display the parking space with the highest evaluation value Ev as the recommended parking space.

[0100] According to this embodiment, when the host vehicle M enters a parking lot, the travel_ECU 14 detects one or more parking spaces in which the host vehicle M can be parked based on the driving environment information, calculates an evaluation value Ev for each of the detected parking spaces that includes, as an evaluation item, obstacles to leaving the parking lot, and preferentially selects, from among the detected parking spaces, a parking space with a relatively high evaluation value Ev as a parking space for parking the host vehicle M. This makes it possible to select the optimal parking space for parking the host vehicle M from among the parking spaces present in the parking lot.

[0101] In other words, the travel_ECU 14 sets the parking space taking into consideration possible wheel slippage and reduced visibility when leaving the parking lot, thereby enabling the optimal parking space to be set taking into consideration the possibility of the wheels getting stuck when leaving the parking lot and safety, etc.

[0102] In this case, the travel_ECU 14 can set an appropriate parking space that takes safety into consideration, such as ensuring visibility when exiting, by evaluating the direction in which the vehicle M can exit the parking space.

[0103] Furthermore, the travel_ECU 14 can set an appropriate parking space that takes safety into consideration, such as preventing slippage when leaving the parking space, by evaluating the road surface conditions of the parking space. In particular, by evaluating the road surface conditions based at least on the presence or absence of snow, a more appropriate decision can be made regarding preventing slippage when leaving the parking space.

[0104] Furthermore, the travel_ECU 14 can set an appropriate parking space in consideration of safety, such as preventing slippage when leaving the parking space, by evaluating the inclination of the parking space.

[0105] In the above-described embodiment, the IPU 12, image recognition_ECU 13, driving_ECU 14, CP_ECU 21, E / G_ECU 22, T / M_ECU 23, BK_ECU 24, and PS_ECU 25 are configured with well-known microcomputers including a CPU, RAM, ROM, non-volatile storage, etc., and their peripheral devices, and the ROM stores programs to be executed by the CPU and fixed data such as data tables in advance. Note that all or part of the functions of the processor may be configured with logic circuits or analog circuits, and the processing of various programs may be realized by electronic circuits such as FPGAs.

[0106] The invention described in the above embodiments is not limited to those embodiments, and various modifications can be made in the implementation stage without departing from the gist of the invention. Furthermore, the above embodiments include inventions at various stages, and various inventions can be extracted by appropriate combinations of the disclosed multiple constituent elements.

[0107] For example, if some constituent elements are deleted from all constituent elements shown in the embodiment, and the stated problem can still be solved and the stated effect can still be obtained, then the configuration from which these constituent elements have been deleted can be extracted as an invention. [Explanation of symbols]

[0108] 1. Driving assistance devices 10...Camera unit 11...Stereo camera 11a ... Main camera 11b ... Sub camera 13...Image Recognition_ECU 14 … Driving_ECU 21 … CP_ECU 22 ... E / G_ECU 23 ... Transmission ECU 24 … BK_ECU 25 … PS_ECU 31...HMI 32 ... Throttle actuator 33... Hydraulic control circuit 35... Electric power steering motor 36 ... Locator unit 36a … GNSS sensor 36b ... Road map DB 37lf ... Left front side sensor 37rf ... Right front side sensor 37lr ... Left rear side sensor 37rr ... Right rear side sensor 38 ... Rear sensor Af … area Alf, Arf … area Alr, Arr… area Ar … area Ev...Evaluation value Ev1...Evaluation value Ev2...Evaluation value Ev3...Evaluation value Evth... threshold M... Vehicle Sa … Search area

Claims

1. a driving environment recognition means for recognizing driving environment information outside the vehicle; a parking space detection means for detecting, when the host vehicle enters a parking lot, one or more parking spaces in which the host vehicle can be parked based on the driving environment information within a search area set in front of the host vehicle; An evaluation value calculation means for calculating an evaluation value for each of the detected parking spaces, the evaluation value including factors hindering exit as an evaluation item; and a parking space setting means for extracting from the detected parking spaces those parking spaces whose evaluation value is equal to or greater than a predetermined threshold, and for preferentially selecting the parking space with the highest evaluation value as the parking space for parking the host vehicle.

2. 2. The vehicle driving assistance device according to claim 1, wherein the evaluation value calculation means evaluates a direction in which the host vehicle can exit the parking space as the factor hindering exit.

3. 3. The vehicle driving assistance device according to claim 1, wherein the evaluation value calculation means evaluates road surface conditions of the parking space as the factor hindering the leaving of the parking space.

4. 4. The vehicle driving support device according to claim 3, wherein the evaluation value calculation means evaluates the road surface conditions based on at least the presence or absence of snow.

5. 5. The vehicle driving assistance device according to claim 1, wherein the evaluation value calculation means evaluates an inclination of the parking space as the factor obstructing leaving the parking space.

6. The vehicle driving assistance device described in Claim 1, characterized in that the parking space setting means continues searching for the parking space in a new search area if a parking space having an evaluation value greater than or equal to the threshold is not detected.

7. A vehicle driving assistance device as described in claim 1, characterized in that the evaluation value calculation means calculates the evaluation value so that it becomes higher as the obstructing factors decrease.

8. The evaluation value calculation means determining whether the vehicle can leave the parking space in one of two directions, forward and backward, or in a forward and backward direction, based on the driving environment information; calculating the evaluation value as a first value in response to a determination that the directions in which the vehicle can exit from the parking space are the two directions, forward and backward; calculating the evaluation value as a second value lower than the first value in response to a determination that the direction in which the vehicle can exit from the parking space is the forward direction; 2. The vehicle driving assistance device according to claim 1, wherein the evaluation value is calculated as a third value lower than the second value in response to a determination that the direction in which the vehicle can exit the parking space is the reverse direction.

9. The evaluation value calculation means determining whether or not there is snow in the parking space based on the driving environment information; calculating the evaluation value as a first value in response to a determination that there is no snow in the parking space; 2. The vehicle driving assistance device according to claim 1, wherein the evaluation value is calculated as a second value lower than the first value in response to a determination that snow has accumulated in the parking space.

10. The evaluation value calculation means determining whether or not there is snow in the parking space based on the driving environment information; calculating the evaluation value as a first value in response to a determination that there is no snow in the parking space; In response to the determination that snow has accumulated in the parking space, it is determined whether the road surface of the parking space is a compacted snow road surface or an uncompacted snow road surface; In response to a determination that the road surface of the parking space is the packed snow road surface, the evaluation value is calculated as a second value lower than the first value; 2. A vehicle driving assistance device according to claim 1, wherein the evaluation value is calculated as a third value lower than the second value in response to a determination that the road surface of the parking space is an uncompacted snow road surface.

11. The evaluation value calculation means determining whether the slope of the road surface of the parking space is flat, has a downward slope in the direction of exit, or has an upward slope in the direction of exit based on the driving environment information; calculating the evaluation value as a first value in response to the determination that the slope of the road surface of the parking space is flat; calculating the evaluation value as a second value lower than the first value in response to a determination that the slope of the road surface of the parking space is a downward slope in the exit direction; 2. The vehicle driving assistance device according to claim 1, wherein the evaluation value is calculated as a third value lower than the second value in response to a determination that the slope of the road surface of the parking space is an upward slope in the direction of exit.

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