Parking Assistance Device

Abstract

A parking assistance device according to the present invention includes an environment information acquisition unit, and a parking assistance control unit that causes the own vehicle to perform automatic parking on the basis of environment information regarding inside of a parking lot that is acquired by the environment information acquisition unit. The parking assistance control unit further includes a parking-available space detecting unit, a target guidance route setting unit, a target stopping position setting unit, and a steering control unit. The parking-available space detecting unit detects a parking-available space in the parking lot on the basis of the environment information. The target guidance route setting unit sets a target guidance route to guide the own vehicle to the parking-available space that has been detected by traveling in reverse. The target stopping position setting unit sets a parking target stopping position to the parking-available space side of the target guidance route, and also sets a switchback target stopping position to which to the own vehicle is caused to travel in reverse after stopping on the target guidance route. At the switchback target stopping position, the steering control unit performs stationary steering of steering wheels to a steering angle for causing the own vehicle to travel in reverse following the target guidance route and fixes the steering angle, and at the parking target stopping position, performs stationary steering of the steering wheels to a steering angle for causing the own vehicle to travel in reverse in a state parallel to the parking-available space.

Description

[Technical field]

[0001] The present invention relates to a parking assistance device that automatically parks a vehicle in a parking space. [Background technology]

[0002] Conventionally, parking assistance devices are known that assist a driver in parking a vehicle in a parking space set in a parking lot and defined by parking lane lines, thereby reducing the burden on the driver. In this type of parking assistance device, while the driver is operating the vehicle to drive in the parking lot, a control unit detects vacant parking space candidates and displays the candidate parking spaces on a monitor. The driver selects a desired parking space from the displayed parking space candidates. The control unit then sets a parking guidance route for parking the vehicle in the parking space selected by the driver. The control unit then automatically parks the vehicle in the parking space along the parking guidance route.

[0003] When the control unit attempts to park the vehicle backwards in a parking space, for example, as disclosed in Japanese Patent Publication No. 2021-94932, when the driver attempts to park the vehicle in a parking space detected by the control unit, the control unit first calculates a trajectory (path) from the current position of the vehicle through a turning position to entering the parking space. Next, the control unit executes a driving process to make the vehicle travel along the trajectory, first moving the vehicle forward and stopping it once at the turning position, then turning the steering wheel while driving the vehicle backward to guide it into the parking space, and ends the driving process when the vehicle enters the parking space.

[0004] Generally, when using automatic parking to park a vehicle parallel to the parking space lines dividing the left and right sides of a parking space from a steering position, the control unit first reverses the vehicle at a low speed while gradually turning the steering wheel, and then gradually returns the steering wheel to allow the vehicle to enter the parking space in a parallel position between the left and right parking space lines.

[0005] When reversing from a turning position toward a parking space, the vehicle stops at the turning position. This means that two transient controls must be performed simultaneously when reversing: a control to start turning the steering wheel and a control to start accelerating even at low speeds. This makes the control more complicated, which is an inconvenience.

[0006] In addition, the guided route (trajectory) to the parking space is set based on the current position of the vehicle, but since the positional relationship between the current position of the vehicle and the parking space is different each time, the guided route needs to be calculated, which inconveniently complicates the calculation process.

[0007] In view of the above circumstances, the present invention aims to provide a parking assistance device that can easily perform transient control for turning the steering wheel back and forth and transient control for accelerating and decelerating the vehicle speed when automatically parking the vehicle, and can also easily calculate a guide route from the turning position to a parking space. DISCLOSURE OF THEINVENTION [Means for solving the problem]

[0008] One aspect of the present invention is a parking assistance device including an environmental information acquisition unit that acquires environmental information around a vehicle in a parking lot, and a parking assistance control unit that automatically parks the vehicle in reverse into a parking space based on the environmental information acquired by the environmental information acquisition unit. The parking assistance control unit includes a parking space detection unit that detects a parking space in the parking lot based on the environmental information acquired by the environmental information acquisition unit, and a parking space detection unit that guides the vehicle in reverse into the parking space when the parking space detection unit detects the parking space. Minimum steering angleThe vehicle is provided with a target guidance path setting unit that sets a target guidance path in accordance with a width of a traffic lane and a width of the vehicle itself; a target stopping position setting unit that sets a parking target stopping position on the target guidance path set by the target guidance path setting unit on the side of the parking space where the vehicle will be parked on the target guidance path and sets a turning target stopping position at which the vehicle will move backward after stopping; and a steering control unit that turns the steering wheels stationarily and fixes them to a steering angle when the vehicle will move backward along the target guidance path at the turning target stopping position set by the target stopping position setting unit, and turns the steering wheels stationarily to a steering angle at which the vehicle will move backward in a parallel line toward the parking space at the parking target stopping position.

[0009] One aspect of the present invention is a parking assistance device including a circuit that automatically parks the vehicle in reverse into a parking space based on environmental information acquired by an environmental information acquisition unit that acquires environmental information about the surroundings of the vehicle in a parking lot. The circuit detects a parking space in the parking lot based on the environmental information, and when the circuit detects a parking space, guides the vehicle in reverse into the parking space. Minimum steering angle A target guidance route is set according to the width of a traffic lane and the width of the vehicle, a parking target stopping position is set on the side of the parking space of the set target guidance route, and a turning target stopping position where the vehicle is reversed after being stopped is set on the target guidance route, and the steering wheels are fixed at a steering angle when reversing the vehicle along the target guidance route at the turning target stopping position, and the steering wheels are fixed at a steering angle at which the vehicle reverses in a vertical position toward the parking space at the parking target stopping position. [Brief description of the drawings]

[0010] [Figure 1] Overall schematic diagram of a parking assistance device [Diagram 2] FIG. 1 is an explanatory diagram showing a search area using a camera and a sensor installed on a vehicle. [Diagram 3] Flowchart showing the processing routine in automatic parking mode (part 1) [Figure 4]Flowchart showing the processing routine in automatic parking mode (part 2) [Diagram 5] Flowchart showing the processing routine in automatic parking mode (part 3) [Figure 6] Schematic diagram showing the entire parking lot [Figure 7A] FIG. 13 is an explanatory diagram showing a state in which an available parking space is being searched for. [Figure 7B] FIG. 13 is an explanatory diagram showing a state in which an available parking space is detected; [Figure 8] An explanatory diagram showing the target route set during automatic parking. [Figure 9A] FIG. 13 is an explanatory diagram showing a state in which a parking space is detected. [Figure 9B] FIG. 11 is an explanatory diagram showing a state in which a parking target stopping position and a turning target stopping position are set. [Figure 9C] FIG. 13 is an explanatory diagram showing a state in which the vehicle is turned around and moved to a target stopping position; [Figure 9D] FIG. 13 is an explanatory diagram showing a state in which the vehicle is moved to a parking target stop position; [Figure 9E] FIG. 1 is an explanatory diagram showing a state in which a vehicle is entering a parking space; [Figure 9F] FIG. 13 is an explanatory diagram showing a state in which the vehicle has completed entering a parking space; [Figure 10] Illustration of two-wheeled vehicle model [Figure 11] A diagram showing the lateral and longitudinal movement amounts of the host vehicle when turning, calculated according to the steering angle based on a two-wheel model. [Figure 12] FIG. 13 is an explanatory diagram showing a movable area to a turning target stopping position; [Figure 13] FIG. 13 is an explanatory diagram showing a moving target detection area during automatic parking. [Figure 14] A time chart showing the relationship between the steering angle and the vehicle speed when automatically parking the vehicle. BEST MODE FOR CARRYING OUT THEINVENTION

[0011] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. Note that the drawings are schematic and the ratios and the like may differ from those of the actual product, and it goes without saying that the drawings also include parts with different dimensional relationships and ratios.

[0012] A parking assistance device 1 shown in FIG. 1 is mounted on a vehicle M (see FIG. 2). The parking assistance device 1 includes a driving assistance control unit 11 as a parking assistance control unit. The driving assistance control unit 11 is configured with a microcontroller including a CPU, a RAM, a ROM, a rewritable non-volatile memory (flash memory or EEPROM), and peripheral devices. The ROM stores programs and fixed data required for executing each process in the CPU. The RAM is provided as a work area for the CPU, and temporarily stores various data in the CPU. The CPU is also called an MPU (Microprocessor) or a processor. Instead of the CPU, a GPU (Graphics Processing Unit) or a GSP (Graph Streaming Processor) may be used. Alternatively, the CPU, the GPU, and the GSP may be selectively combined.

[0013] The driving assistance control unit 11 includes a mode setting unit 12. The mode setting unit 12 has an automatic driving mode and an automatic parking mode, and when the driver selects a desired mode, the driving assistance control unit 11 executes the corresponding driving mode.

[0014] In the autonomous driving mode, the vehicle position is map-matched on the road map in the road map database 22b based on vehicle position information acquired by the GNSS sensor 22a of the map locator unit 22 described later, and the vehicle autonomously drives along a preset target route in a section where autonomous driving is possible. In addition, in the autonomous driving mode, on a road where autonomous driving is difficult, well-known adaptive cruise control (ACC), active lane keep (ALK), and lane departure prevention (LDP) controls are executed, and when the vehicle M stays in the lane and detects a preceding vehicle, driving control is executed to drive the vehicle M by following the preceding vehicle.

[0015] On the other hand, in the automatic parking mode, when the driver selects this assistance mode when the vehicle M enters a parking lot, the driving assistance control unit 11 searches for a parking space where the vehicle can be parked, and automatically parks the vehicle M in the parking space found.

[0016] The input side of this driving assistance control unit 11 is connected to sensor units that acquire driving condition information (including position and direction) of the vehicle M and information on the surrounding environment of the vehicle M, which are required when executing each driving mode.

[0017] In this embodiment, the sensor units required for executing each driving mode of the mode setting unit include a camera unit 21, a map locator unit 22, an autonomous driving sensor 23, a rear sensor 24 for acquiring environmental information behind the vehicle M, left and right front side cameras 25, and left and right rear side sensors 26. The sensors 21, 24 to 26 constitute an environmental information acquisition unit of the present invention.

[0018] The camera unit 21 is an image sensor This is an example. In this embodiment, , as camera unit 21The camera unit 21 includes a stereo camera consisting of a main camera 21a and a sub camera 21b, each of which uses a CCD or CMOS 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 on the left and right from the center of the vehicle width direction at a position close to the windshield, for example, above the rearview mirror at the front of the vehicle. As shown in FIG. 2, the camera unit 21 transmits to the driving assistance control unit 11 an image of environmental information captured in a forward imaging area 21Ar recognized by both cameras 21a and 21b after image processing by the IPU 21c.

[0019] The map locator unit 22 also 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 acquire the position coordinates of the vehicle M. The road map database 22b is a large-capacity storage medium such as an HDD, and stores road map information. The road map information stored in the road map database 22b includes road information (general roads, main roads, expressways, road shapes, road directions, number of lanes, lane width, etc.) required when executing the automatic driving mode, and static information of parking lots (position information of entrances and exits of parking lots, parking space information within the site, etc.) required when executing the automatic parking mode.

[0020] The driving assistance control unit 11 estimates the vehicle's position (current position) on the road map by map matching the position coordinates (latitude, longitude, altitude) of the vehicle M acquired by the GNSS sensor 22a onto the road map information stored in the road map database 22b.

[0021] The autonomous driving sensor 23 is a general term for sensors required when causing the host vehicle M to drive autonomously, and is composed of a vehicle speed sensor that detects the vehicle speed (host vehicle speed) of the host vehicle M, a yaw rate sensor that detects the yaw rate acting on the host vehicle M, a longitudinal acceleration sensor that detects longitudinal acceleration, etc.

[0022] The rear sensor 24 is configured by combining a monocular camera using a CCD, CMOS, or the like as an imaging element with at least one of an ultrasonic sensor, a millimeter wave radar, a microwave radar, an infrared sensor, a laser radar, a LiDAR (Light Detection And Ranging), or the like, and searches a rear area 24A behind the vehicle M. Note that the rear sensor 24 may be a stereo camera consisting of a main camera and a sub camera, similar to the above-mentioned camera unit 21.

[0023] The left and right front side cameras 25 are image sensors using imaging elements such as CCDs or CMOSs ​​attached to the outer parts of the side mirrors provided on the left and right sides of the vehicle M. As shown in Fig. 2, the left and right front side cameras 25 capture images of the left and right front side areas 25lA, 25rA of the vehicle M and perform predetermined image processing. The driving assistance control unit 11 obtains information about the parking lot, such as the dividing lines dividing the left and right parking spaces on the front sides through which the vehicle M is about to pass, the parked vehicles parked in the parking spaces, and the intervals between adjacent parked vehicles, from the information obtained by the left and right front side cameras 25 and subjected to predetermined image processing.

[0024] The left and right rear side sensors 26 are scanning type sensors such as millimeter wave radar, microwave radar, LiDAR, etc., and are arranged, for example, on the left and right ridges of the rear bumper to scan areas (left and right rear side areas) 26lA, 26rA (see FIG. 2) from the rear to the left and right sides of the vehicle M that cannot be recognized by the left and right front side cameras 25, and receive reflected waves from targets such as parked vehicles, exterior walls, and moving objects. Based on the information from the left and right rear side sensors 26, the driving assistance control unit 11 obtains environmental information such as the distance and direction from the vehicle M to the targets. Note that the symbol Ps in FIG. 2 denotes a parking space for parallel parking, and each parking space Ps is divided on the left and right by a dividing line.

[0025] The driving assistance control unit 11 is also connected to an HMI (Human Machine Interface) monitor 31. This HMI monitor 31 displays a driving mode selection screen where the driver selects either an automatic driving mode or an automatic parking mode as an assistance mode executed in the driving assistance control unit 11, a screen showing the positional relationship between the target parking space and the vehicle M when automatic parking is started, and the like. Incidentally, this HMI monitor 31 may also be used as a multi-information display of a combination meter or a navigation display device (navigation monitor) of a car navigation system.

[0026] Furthermore, a drive control actuator 32, a shift change actuator 33, an alarm device 34, and a hazard lamp 35 are connected to the output side of the driving assistance control unit 11.

[0027] The drive control actuator 32 is a general term for a power actuator, an electric power steering (EPS) actuator, a brake actuator, and the like, which support the driving 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.

[0028] The shift change actuator 33 is a mechanism for automatically switching the shift position (drive (D), reverse (R), parking (P)) of the automatic transmission mounted on the vehicle M in accordance with a command signal from the driving assistance control unit 11. Furthermore, the notification device 34 notifies the driver by voice of various information required when each assistance mode is being executed. Furthermore, the driving assistance control unit 11 turns on the hazard lamps 35 when automatic parking is started.

[0029] The map locator unit 22 constantly checks the vehicle's position (current position) on the road map against the road map data. When the driving assistance control unit 11 determines that the vehicle M has entered a parking lot from a general road, for example, as shown in FIG. 6, based on the information from the map locator unit 22, the driving assistance control unit 11 displays a driving mode selection screen on the HMI monitor 31 for selecting whether or not to select the automatic parking mode. When the driver selects the automatic parking mode displayed on the HMI monitor 31, the driving assistance control unit 11 searches for a parking space available in the parking lot, and first sets a parking target stop position Mf2 for the searched parking space available for parking. Next, a target guide route Rp is set from the parking target stop position Mf2 to the turning target stop position Mf1, and the vehicle M is guided along the target guide route Rp to automatically park the vehicle M in the parking space.

[0030] The automatic parking control executed by the driving assistance control unit 11 is specifically processed according to an automatic parking control routine shown in FIGS.

[0031] This routine is executed at a predetermined calculation cycle after the automatic parking mode is selected. First, in step S1, a travel route for searching for a parking space for the vehicle M is set in a lane in the parking lot. This travel route is set according to preset travel conditions. For example, if data on the lane in the parking lot and the parking space Ps facing the lane are registered in the road map database 22b, the travel route is set based on the data.

[0032] In this case, for example, in a parking lot shown in Fig. 6, if a lane (outer perimeter in the figure) that is regulated to one-way traffic is set, the driving route is set according to the traffic regulation. Also, if the details of the lane in the parking lot are not registered in the road map information, the driving route may be set based on the driving environment information of the front side acquired by each of the sensors 21, 25 that acquires information of the front side. Then, for example, in the parking lot shown in Fig. 6, the lane facing the parallel parking parking space Ps that is first detected by the host vehicle M entering from the entrance is set as the driving route.

[0033] Next, proceed to step S2, where the vehicle M is driven automatically along the driving route at a slow speed (10 to 15 km / h), and proceed to step S3, where a parking space (parkable space) Psa in which the vehicle M can be parked is detected from among multiple parking spaces Ps arranged in parallel facing the traffic lane.

[0034] When the driving assistance control unit 11 detects a parking space, the front-side images captured by the left and right front-side cameras 25 are converted into a two-dimensional bird's-eye view. Then, the distance between adjacent parked vehicles is compared with a parking frame (required parking frame) Mf required for parking the host vehicle M, which is stored in advance in the storage unit of the driving assistance control unit 11.

[0035] For example, as shown by the dashed line in FIG. 7A, if the interval between adjacent parked vehicles is narrower than the required parking frame Mf of the vehicle M, parking is not possible and the vehicle is excluded from the target of available parking spaces. On the other hand, as shown in FIG. 7B and FIG. 9A, if the interval between the parked vehicles is wider than the required parking frame Mf and the required parking frame Mf fits between the parked vehicles, the dividing lines dividing the left and right sides of the parking space Ps are detected. Then, if the dividing lines on the left and right sides are detected, the parking space Ps is set as a available parking space Psa, and the process proceeds to step S4. On the other hand, if the dividing lines dividing the parking space Ps cannot be recognized, the parking space Ps is not set as a available parking space and the process proceeds to step S4.

[0036] When the process proceeds to step S4, it is checked whether or not a parking space Psa has been set. If not, the process returns to step S2 to detect the next parking space candidate. If a parking space Psa has been set, the process proceeds to step S5. The processes in steps S3 and S4 are the same as those in the parking space detection section of the present invention. Processing It supports.

[0037] When the process proceeds to step S5, the driving assistance control unit 11 first drives the brake actuator provided in the drive control actuator 32 to apply the brakes, as shown in Fig. 9B, and stops the host vehicle M in the traffic lane facing the parking space Psa. After that, the driving assistance control unit 11 sets a target guided route Rp for automatically parking the host vehicle M in the parking space Psa by moving backward. The process in step S5 corresponds to the target guided route setting unit of the present invention.

[0038] In this embodiment, the turning target stopping position Mf1 of For parking target stop position Mf2 do The range of the target guide route Rp can be set at any angle. In this embodiment, for ease of explanation, the target guide route Rp is set at a substantially right angle, that is, parallel to the direction in which the lane extends. Therefore, as shown in FIG. 8, the target guide route Rp is set within a range in which the yaw angle θ of the host vehicle M turns by 90[deg].

[0039] When setting this target guide route Rp, first, the total width 2W of the traffic lane (the distance between the ends of the demarcation lines dividing the opposing parking spaces Ps) is detected as shown in Fig. 9A based on the road map information stored in the road map database 22b or the environmental information captured by the forward imaging area 21Ar of the camera unit 21. The width of one side of the traffic lane is W.

[0040] Then, based on the vehicle width Wcar of the host vehicle M, the lateral position movement amount X is calculated as follows: W-(Wcar / 2) <X<2W-(Wcar / 2) The minimum steering angle for automatically parking the host vehicle M in reverse is calculated, which satisfies the relationship:

[0041] Here, the lateral position movement amount X is a movement distance from the end of the partition line that partitions the parking space Psa to the center (Wcar / 2) in the vehicle width direction of the host vehicle M, and is expressed as follows, as shown in FIG. 9A: W-(Wcar / 2)=Xmin 2W-(Wcar / 2)=Xmax It becomes.

[0042] In this connection, the relationship between the steering angle δ of the front wheels, which are the steered wheels, and the yaw rate γs and vehicle body slip angle βs acting on the center of gravity of the host vehicle M in the general two-wheel model shown in FIG. 10 is as follows:

[0043] γs=(V / L)δ βs=(Lr / L)δ In the figure, L is the wheel base, Lf is the distance from the front wheel axle to the center of gravity, and Lr is the distance from the center of gravity to the rear wheel axle.

[0044] In addition, the lateral position movement amount X and the longitudinal position movement amount Y of the host vehicle M from the parking target stop position Mf2 to the turning target stop position Mf1 are as follows: where k is the previous calculated value, K+1 is the current calculated value, V is the reverse vehicle speed of the host vehicle M, and θ is the yaw angle.

[0045] Xk+1=Xk+Vk·COS(θk+βs)Δt Yk+1=Yk+Vk·sin(θk+βs)Δt θk+1=θk+(γk Δt) Based on the above formula, the lateral position movement amount X and the longitudinal position movement amount Y can be uniformly calculated from the reverse vehicle speed V and the steering angle δ for every Δt. Incidentally, the lateral position movement amount X [m] and the longitudinal position movement amount Y [m] at the center of gravity position when the host vehicle M is turned in the reverse direction by βs = 90 [deg] at a steering wheel angle θh for every 90 [deg] at V = 5 [Km / h] can be uniformly calculated as shown in Fig. 11. Note that the steering wheel angle θh [deg] shown in Fig. 11 is an example, and this steering wheel angle θh [deg] can also be set more finely.

[0046] For example, in Fig. 11, when the calculated lateral position movement amount X is 8 [m], the candidates for the steering wheel angle θh are 270 [deg], 360 [deg], and 450 [deg]. Then, from among these candidates for the steering wheel angle θh, the minimum steering angle of 270 [deg] is selected. Therefore, the target guidance route Rp is set from the lateral position movement amount X and the longitudinal position movement amount Y calculated based on the steering angle δ corresponding to the steering wheel angle θh = 270 [deg].

[0047] In this embodiment, as shown in Fig. 8, the target guide path Rp from the parking target stop position Mf2 to the turning target stop position Mf1 is set as a movement path at the midpoint between the left and right rear wheel axles of the vehicle M. Meanwhile, the lateral position movement amount X and the longitudinal position movement amount Y shown in Fig. 11 are the center of gravity position of the vehicle M. Therefore, the lateral position movement amount X and the longitudinal position movement amount Y are converted into values ​​obtained by moving the distance Lr from the center of gravity position to the rear wheel axle, and the target guide path Rp is set. As a result, the target guide path Rp is set as an arc shape with a turning radius R at a yaw angle θ of 90 [deg]. Note that this target Induction The route Rp may be set as the movement route of the vehicle M at the center of gravity position.

[0048] Next, proceed to step S6, and set the parking target stop position Mf2 at the entrance of the parking space Psa so that the attitude of the host vehicle M is connected to the extension of the parking space Psa. As shown in FIG. 8, in this embodiment, a stop position st2 is set at a position corresponding to the rear wheel axle of the host vehicle M at the parking target stop position Mf2. Then, this stop position st2 is set to a predetermined position in front of the parking space Psa, for example, so as to be perpendicular to the end of the partition line. Furthermore, the center in the width direction of the parking target stop position Mf2 is set to the center of the parking frame width Pw between the partition lines that partition the parking space Psa to the left and right.

[0049] Then, the process proceeds to step S7, and the parking target stop position Mf2 is set as a reference (θ=0[deg]) and the turning target stop position Mf1 is set at a position of θ=90[deg] along the target guide route Rp set in step S5. The processes in steps S6 and S7 correspond to the target stop position setting unit of the present invention.

[0050] Next, proceed to step S8. The driving assistance control unit 11 includes: It is checked whether or not the vehicle M can be moved to the turning target stopping position Mf1. As shown in FIG. 12, whether or not the vehicle M can be moved to the turning target stopping position Mf1 is determined based on the ratio of the turning target stopping position Mf1 to the width W of one side of the lane. Width That is, the distance from the end of the demarcation line on the side where the parking target stop position Mf2 is set to the center in the width direction of the turning target stop position Mf1 is determined based on Xf1. Width If Xf1 exceeds half the width W of one side of the lane (Xf1>W / 2), it is determined that movement is possible, and the process proceeds to step S9. Width If Xf1 is equal to or less than half the width W of one side of the lane (Xf1≦W / 2), it is determined that movement is not possible, and the process returns to step S2.

[0051] When the process proceeds to step S9, the driving assistance control unit 11 transmits an ON signal to the hazard lamps 35 to cause the hazard lamps 35 to flash, and then proceeds to step S10. In step S10, when the vehicle M is moved to the turning target stopping position Mf1, it is checked whether or not a moving object OB such as a pedestrian, a bicycle, or an oncoming vehicle is detected in a waiting determination area Zf that is set in advance. In this embodiment, the waiting determination area Zf is set within a range of a predetermined distance Lpe from the center in the width direction of the parking target stopping position Mf2 toward the turning target stopping position Mf1 in the overall width 2W of the traffic lane. This predetermined distance Lpe is set to the shorter distance between a predetermined distance (for example, 20 [m]) and the end point Ep of the parking area.

[0052] Then, when a moving target OB is detected within the waiting determination area Zf from the environmental information acquired based on the forward image and the front side image captured by the camera unit 21 and the left and right front side cameras 25, the driving assistance control unit 11 branches to step S11. On the other hand, when a moving target OB is not detected within the waiting determination area Zf, the driving assistance control unit 11 proceeds to step S12.

[0053] When the process proceeds to step S11, the process waits until the moving target OB leaves the waiting judgment area Zf or stops in front of the turning target stopping position Mf1 as viewed from the host vehicle M. Then, when it is determined that the moving target OB leaves the waiting judgment area Zf or stops in front, the process proceeds to step S12.

[0054] When proceeding from step S10 or step S11 to step S12, the driving assistance control unit 11 starts automatic driving to move the host vehicle M to the turning target stopping position Mf1. That is, the driving assistance control unit 11 first sets a target travel path to move the host vehicle M from the current position of the stopped host vehicle M to the turning target stopping position Mf1 set along the traffic lane. Next, the driving assistance control unit 11 releases the brake operation by the brake actuator provided in the drive control actuator 32, and operates the power actuator to start the host vehicle M. In addition, the driving assistance control unit 11 operates the EPS actuator to move the host vehicle M along the target travel path to the turning target stopping position Mf1 shown in FIG. 9B.

[0055] Then, the process proceeds to step S13, where it is determined whether or not the vehicle M has reached a preset deceleration start position based on, for example, the position coordinates of the vehicle M acquired by the GNSS sensor 22a and the road map information stored in the road map database 22b, and if the vehicle M has not yet reached the deceleration start position, the process repeats the process of step S12. If it is determined that the vehicle M has reached the deceleration start position, the process proceeds to step S14.

[0056] When the process proceeds to step S14, the driving assistance control unit 11 executes stopping control. In the stopping control by the driving assistance control unit 11, the output of the drive source by the power actuator and the braking operation by the brake actuator are adjusted to decelerate the host vehicle M and stop the host vehicle M at the turning target stopping position Mf1. As a result, as shown in Fig. 9C, the host vehicle M is stopped at a position where the rear wheel axle coincides with the stopping position st1 set in the turning target stopping position Mf1. Note that the steering angle δ at this time is 0 [deg] (elapsed time t0 in Fig. 14).

[0057] The following description will be given with reference to the time chart in Fig. 14. When the process proceeds from step S14 to step S15, the left and right front wheels are controlled to turn while the host vehicle M is stopped. The driving assistance control unit 11 operates the EPS actuator provided in the drive control actuator 32, and steers the left and right front wheels (stationary steering) to the steering angle δ set in the above-mentioned step S5 and fixes them (elapsed time t1 to t2 in Fig. 14). The process in step S15 and step S22 described later corresponds to the steering control unit of the present invention.

[0058] Thereafter, the process proceeds to step S16, where the driving assistance control unit 11 operates the shift change actuator 33 to set the shift position of the automatic transmission to R (reverse), and the process proceeds to step S17.

[0059] In step S17, it is determined whether or not a moving object OB has been detected in the reverse waiting judgment area Zr, which is set from the host vehicle M stopped at the turning target stopping position Mf1 to the parking target stopping position Mf2, based on rear environmental information detected by the rear sensor 24 and the left and right rear side sensors 26.

[0060] As shown in Fig. 13, the width direction of the reverse waiting judgment area Zr is set at a position slightly beyond the lane marking on the parking space Psa side of the traffic lane and the opposite side of the turning target stopping position Mf1. Also, the length direction is set at a length (Lr+R+Lex) of a position extended by a predetermined length Lex (for example, parking frame width Pw / 2) from the center of the width direction of the parking target stopping position Mf2 on the parking target stopping position Mf2 side from the center of gravity position of the turning target stopping position Mf1.

[0061] Then, when a moving target OB is detected in the backward movement waiting judgment area Zr, or when there is a possibility that the moving target OB will enter the backward movement waiting judgment area Zr, it is determined that the moving target OB is not allowed to move, and the process branches to step S18. On the other hand, when a moving target OB is not detected in the backward movement waiting judgment area Zr, or when there is no possibility that the moving target OB will enter the backward movement waiting judgment area Zr, it is determined that the moving target OB is allowed to move, and the process proceeds to step S19.

[0062] Whether or not there is a possibility that the moving target OB will enter the reverse waiting judgment area Zr is determined by, for example, comparing a target predicted time for the moving target OB to enter the reverse waiting judgment area Zr ([distance of the moving target OB to the reverse waiting judgment area Zr] / [moving speed of the moving target OB]) with a host vehicle predicted time for the host vehicle M to reach the parking target stopping position Mf2 ([distance from the host vehicle M to the parking target stopping position Mf2] / [host vehicle speed]). If the target predicted time<host vehicle predicted time, it is determined that there is a possibility that the moving target OB will enter the reverse waiting judgment area Zr.

[0063] When the process branches to step S18, the process waits until it is determined that the moving target OB has left the reverse waiting judgment area Zr or that another vehicle as the moving target OB shown in Fig. 13 has stopped at a position outside the movement path of the host vehicle M from the turning target stopping position Mf1 to the parking target stopping position Mf2. Then, when it is determined that the moving target OB has left the reverse waiting judgment area Zr or has stopped at a position outside the movement path of the host vehicle M, the process proceeds to step S19. The processes in steps S17 and S18 correspond to the movement possibility judgment unit of the present invention.

[0064] When the process proceeds from step S17 or step S18 to step S19, the driving assistance control unit 11 starts automatic driving to move the host vehicle M to the parking target stop position Mf2 (elapsed time t3 in FIG. 14).

[0065] That is, the driving assistance control unit 11 first releases the braking operation by the brake actuator while fixing the left and right front wheels at the steering angle δ set in the above-mentioned step S15. (Time t3 in Figure 14)Next, the power actuator is operated to move the vehicle M at a preset slow speed (for example, 5 [Km / s h 9C ]) (elapsed time t4 to t5 in FIG. 14). Then, the host vehicle M is moved from the turning target stopping position Mf1 to the parking target stopping position Mf2. At this time, since the steering angle δ is fixed, the host vehicle M ends up moving in the direction of the parking target stopping position Mf2 along the target guide path Rp shown in FIG. 9C .

[0066] Then, the process proceeds to step S20, where it is determined whether the vehicle M has reached a preset deceleration start position based on, for example, the position coordinates of the vehicle M acquired by the GNSS sensor 22a and the road map information stored in the road map database 22b, and if the vehicle M has not yet reached the deceleration start position, the process repeats step S19. If it is determined that the vehicle M has reached the deceleration start position, the process proceeds to step S21. The processes in steps S19 and S20 and steps S23 and S24 described later correspond to the movement control unit of the present invention.

[0067] In step S21, the driving assistance control unit 11 executes vehicle stopping control. In the vehicle stopping control by the driving assistance control unit 11, the output of the drive source by the power actuator and the braking operation by the brake actuator are adjusted to decelerate the host vehicle M and stop the host vehicle M at the parking target stopping position Mf2 (elapsed time t5 to t6 in FIG. 14).

[0068] As shown in Fig. 9D, the parking target stop position Mf2 is set at the entrance of the available parking space Psa in a vertical line with the available parking space Psa. The vehicle M is stopped with its rear wheels aligned with the stop position st2 set at the parking target stop position Mf2.

[0069] Next, proceed to step S22, return the steering wheel angle θh (steering angle δ) to 0 [deg] without turning, and proceed to step S23 (elapsed time t7 to t8 in FIG. 14). As described above, since the host vehicle M is parked in a parallel position relative to the parking space Psa, there is no need to turn the steering wheel while driving the host vehicle M into the parking space Psa. Note that the steering wheel angle θh (steering angle δ) does not need to be 0 [deg] as long as the steering wheel angle θh (steering angle δ) is an angle that allows the host vehicle M to move backward in a parallel position relative to the parking space Psa.

[0070] After that, when the process proceeds to step S23, the driving assistance control unit 11 starts driving control to make the host vehicle M enter the parking space Psa. Then, as shown in Fig. 9E, the host vehicle M starts moving backward toward the parking space Psa while its speed is adjusted by the output of the driving source by the power actuator and the braking operation by the brake actuator (elapsed time t9 in Fig. 14). Note that the steering angle δ at this time is 0 [deg], and the host vehicle M moves backward straight.

[0071] Then, the process proceeds to step S24 to check whether entry of the vehicle M into the parking space Psa has been completed, and if entry has not been completed, the process of step S23 is repeated (elapsed time t9 to t12 in FIG. 14). Also, as shown in FIG. 9F, if it is determined that entry has been completed, the process proceeds to step S25 to stop the vehicle M by braking the brake actuator (elapsed time t12 in FIG. 14). Next, the routine proceeds to step S26, where the driving assistance control unit 11 sends an OFF signal to the hazard lamps 35 to turn off the hazard lamps 35, and then proceeds to step S27, where the shift change actuator 33 is operated to set the shift position of the automatic transmission to P (parking), and the routine ends.

[0072] As described above, according to this embodiment, as shown in the time chart of Fig. 14, the driving assistance control unit 11 turns the vehicle M while it is stopped (stationary steering) (elapsed time t1 to t2), and then moves the vehicle M from the target parking position Mf1 to the parking target parking position Mf2 (elapsed time t3 to t6). After that, the vehicle M is stationary steered while it is stopped to return the steering wheel angle θh (steering angle δ) to 0 [deg] (elapsed time t7 to t8). Therefore, the transitional control section (elapsed time t0 to t2, t7 to t8) of the steering angle δ of the left and right front wheels and the acceleration / deceleration control section (t3 to t4, t5 to t6) of the reverse vehicle speed V are not performed simultaneously during automatic parking, making the control easier.

[0073] In addition, since the movement from the turning target stopping position Mf1 to the parking target stopping position Mf2 is performed with the steering wheel angle θh (steering angle δ) fixed, not only can the calculation of the guide route leading from the turning position to the parking space be easily performed, but also, since there is no need to control the steering wheel angle θh (steering angle δ) while reversing, the initial position (turning target stopping position Mf1) can be set with high accuracy. Furthermore, since the vehicle is guided to the parking target stopping position Mf2 with the steering wheel angle θh (steering angle δ) fixed, the driver can easily imagine the vehicle behavior for parking the host vehicle M in the parking space Psa, and can feel at ease.

Claims

1. an environmental information acquisition unit that acquires environmental information about the surroundings of the vehicle within the parking lot; a parking assistance control unit that automatically parks the host vehicle in a parking space in reverse based on the environmental information acquired by the environmental information acquisition unit; A parking assistance device comprising: The parking assistance control unit is a parking space detection unit that detects available parking spaces in the parking lot based on the environmental information acquired by the environmental information acquisition unit; a target guided path setting unit that, when the available parking space detection unit detects the available parking space, sets a target guided path with a minimum steering angle for guiding the host vehicle in reverse to the available parking space in accordance with a width of a traffic lane and a width of the host vehicle; a target stop position setting unit that sets a parking target stop position on the parking space side of the target guided route set by the target guided route setting unit and sets a turning target stop position for reversing the host vehicle after parking the host vehicle on the target guided route; a steering control unit that turns the steering wheels stationarily and fixes them at a steering angle when moving the host vehicle backward along the target guide path at the turning target stopping position set by the target stopping position setting unit, and turns the steering wheels stationarily at a steering angle at which the host vehicle moves backward in a vertical state into the parking space at the parking target stopping position; A parking assistance device comprising:

2. The parking assistance control unit further includes a movement control unit that controls the movement of the host vehicle, The movement control unit starts the movement of the host vehicle after the steering control unit turns the steering angle of the steering wheel to a stationary state.

2. The parking assistance device according to claim 1.

3. The parking target stop position set by the target stop position setting unit is set in a vertical line state in the traffic lane facing the parking space, and the turning target stop position is set at a position rotated by an arbitrary angle from the parking target stop position.

3. The parking assistance device according to claim 1 or 2.

4. The parking assistance control unit further includes a movement possibility determination unit, The movement possibility determination unit, when the movement control unit moves the host vehicle from the turning target stop position to the parking target stop position, sets a reverse movement waiting determination area in the movement direction of the host vehicle, and stops the movement of the host vehicle when a moving target is detected in the reverse movement waiting determination area.

3. The parking assistance device according to claim 2.

5. 2. A parking assistance device comprising: a circuit for automatically parking a vehicle in a parking space in reverse based on environmental information acquired by an environmental information acquisition unit that acquires environmental information about a surrounding area of ​​the vehicle in a parking space; The circuit comprises: Detecting available parking spaces in the parking lot based on the environmental information; When the available parking space is detected, a target guide path with a minimum steering angle for guiding the host vehicle in reverse to the available parking space is set according to a width of a traffic lane and a width of the host vehicle; a parking target stop position is set on the side of the set target guide route on which the vehicle can be parked, and a turning target stop position is set on the target guide route where the vehicle is to be stopped and then moved backward; At the turning target stopping position, the steering wheel is turned to a steering angle for moving the vehicle backward along the target guide path and fixed, and at the parking target stopping position, the steering wheel is turned to a steering angle for moving the vehicle backward in a vertical state toward the parking space. A parking assistance device comprising:

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