Parking assistance device and parking assistance method

Abstract

Provided is a parking assistance device capable of providing appropriate parking assistance while considering a measurement error occurring when observing a distant side with external sensors. The parking assistance device, which assists in parking of a vehicle, comprises: an other vehicle information acquisition unit that acquires information about other vehicles around the vehicle on the basis of information acquired from vehicle-mounted external sensors; a parked vehicle line identification unit that identifies parked vehicles and a parked vehicle line around the vehicle on the basis of the information about the other vehicles; a likelihood calculation unit that calculates, on the basis of the distance between adjacent parked vehicles and a parking section width in the parked vehicle line, the likelihood that a space between the adjacent parked vehicles is a vacant parking section; and a vehicle travel control unit that controls travel of the vehicle on the basis of the likelihood, wherein according to a comparison result between a first likelihood at a prescribed reference point within a sensing range of the external sensors and a second likelihood at a parking section farther than the reference point, the vehicle travel control unit generates a travel route passing through the reference point or a travel route for parking at the reference point.

Description

Parking assistance device and parking assistance method

[0001] The present invention relates to a parking assistance device and a parking assistance method for assisting in the parking of a vehicle.

[0002] Patent Document 1 is an example of a document disclosing a parking assistance function. For example, the abstract of this document states that the problem is "to suppress the possibility of mistakenly identifying a no-parking location as a parking space, even when the parking space cannot be recognized when attempting to park one's own vehicle using the parking assistance function," and that the solution is "the parking assistance device 1 detects parked vehicles Pv in the parking lot based on environmental information around the own vehicle M, and even if the width of the space next to this parked vehicle is greater than or equal to the required parking width Ws set in advance for parking the own vehicle M, if no other parked vehicles Pv are detected at the back of this space, it is presumed that parking is prohibited in this space."

[0003] Furthermore, the document discloses external sensors for recognizing the surrounding environment of a vehicle, including monocular cameras and stereo cameras using CCD or CMOS image sensors, ultrasonic sensors, millimeter-wave radar, microwave radar, infrared sensors, laser radar, and LiDAR (Light Detection and Ranging).

[0004] Japanese Patent Publication No. 2023-17462

[0005] However, all of the external sensors exemplified in the document have the characteristic that the measurement error is larger at a distance than at a nearby distance. As a result, in the parking assistance device of Patent Document 1, the reliability of the estimation at a distance is lower than that of the estimation at a nearby distance, which can lead to errors in judgment at a distance and prevent the provision of an appropriate parking assistance function.

[0006] Therefore, the present invention aims to provide a parking assistance device and a parking assistance method that can provide appropriate parking assistance while taking into account measurement errors that occur when observing distant objects with external sensors.

[0007] To solve the above problems, the present invention provides a parking assistance device for assisting in the parking of a vehicle, comprising: an other vehicle information acquisition unit that acquires information on other vehicles in the vicinity of the vehicle based on information acquired from an on-board external sensor; a parking vehicle row identification unit that identifies parked vehicles and rows of parked vehicles in the vicinity of the vehicle based on the information on other vehicles; a likelihood calculation unit that calculates the likelihood that the space between adjacent parked vehicles is an empty parking space based on the distance between adjacent parked vehicles and the width of the parking space in the row of parked vehicles; and a vehicle driving control unit that controls the driving of the vehicle based on the likelihood, wherein the vehicle driving control unit generates a driving path that passes through the reference point or a driving path that parks at the reference point, according to the result of comparing a first likelihood at a predetermined reference point within the sensing range of the external sensor with a second likelihood at a parking space farther from the reference point.

[0008] According to the parking assistance device and parking assistance method of the present invention, it is possible to provide appropriate parking assistance while taking into account measurement errors that occur when observing distant objects with an external sensor.

[0009] Functional block diagram of the vehicle system of Example 1. Functional block diagram of the processing unit of the parking assistance device of Example 1. An example of the parking vehicle row data set of Example 1. Conceptual diagram showing the measurement error characteristics of the external sensor. An example of the measurement error data set of Example 1. Conceptual diagram showing the distance between parked vehicles. Conceptual diagram showing that the position error of parked vehicles increases as they move away from the own vehicle. An example of the parking environment of Example 1. Processing flowchart of the likelihood calculation unit of Example 1. Processing flowchart of the vehicle driving control unit of Example 1. An example of a parking environment progressing from step S16c to step S16e in Figure 9. An example of a parking environment progressing from step S16c to step S16d in Figure 9. Functional block diagram of the processing unit of the parking assistance device of Example 2. An example of a parking environment of Example 2. Functional block diagram of the processing unit of the parking assistance device of Example 3. An example of a parking environment of Example 3. Functional block diagram of the processing unit of the parking assistance device of Example 4. Processing flowchart of the vehicle driving control unit of Example 4.

[0010] The following describes an embodiment of the parking assistance device of the present invention with reference to the drawings.

[0011] First, the parking assistance device 1 according to Embodiment 1 of the present invention will be described using Figures 1 to 11.

[0012] Figure 1 is a functional block diagram showing the configuration of the vehicle system 100 including the parking assist device 1 of this embodiment. This vehicle system 100 is the vehicle V ０ This system is installed in the vehicle and, after confirming the road and obstacle conditions around the vehicle, provides appropriate driving assistance and autonomous driving functions. To realize the parking assistance function, which is one of the driving assistance and autonomous driving functions, the vehicle system 100 of this embodiment includes, in addition to the parking assistance device 1, a vehicle sensor group 2, an external sensor group 3, an actuator group 4, an HMI device group 5, and an in-vehicle network N connecting them. Below, we will sequentially describe the outlines of the vehicle sensor group 2 to the HMI device group 5, and then describe the parking assistance device 1 of this embodiment in detail.

[0013] <Vehicle Sensor Group 2> Vehicle sensor group 2 is the vehicle V ０ It is a collection of sensors that detect various states of the vehicle. Each vehicle sensor, for example, detects the state of the vehicle V ０ The system detects information such as the vehicle's position, driving speed, steering angle, accelerator pedal operation amount, and brake pedal operation amount, and transmits this information to the parking assist device 1 via the in-vehicle network N.

[0014] <External Sensor Group 3> The external sensor group 3 is a collection of on-board sensors that detect the conditions around the vehicle. Examples of external sensors include cameras, millimeter-wave radar, LiDAR, sonar, microphones, etc. The external sensor group 3 detects the conditions around the vehicle V ０ The system detects environmental elements such as visible obstacles, road markings, signs, and signals within a predetermined range, and outputs these detection results to the parking assist device 1 via the in-vehicle network N.

[0015] Here, "obvious obstacle" refers to, for example, your own vehicle V ０ Other objects include other vehicles, pedestrians, objects that have fallen onto the road, and the roadside. "Road markings" include, for example, white lines, pedestrian crossings, and stop lines. In addition, the external sensor group 3 outputs information about the detection status to the parking assist device 1 via the in-vehicle network N, based on its own sensing range and status.

[0016] <Actuator Group 4> Actuator group 4 controls the vehicle V ０ This is a group of devices that control control elements such as steering, brakes, and accelerators that determine the movement of the vehicle V. The actuator group 4 controls the movement of control elements such as steering, brakes, and accelerators based on the driver's operation information for the steering wheel, brake pedal, accelerator pedal, etc., and control command values ​​output from the parking assist device 1, thereby controlling the movement of the vehicle V ０ It controls the vehicle's behavior to perform autonomous driving.

[0017] <HMI Device Group 5> HMI device group 5 is a group of devices called a Human Machine Interface that allows the occupant to input commands to the vehicle system 100 and the vehicle system 100 to notify the occupant of information. HMI device group 5 includes a display, speaker, vibrator, switch, touch panel, etc.

[0018] <Parking Assistance Device 1> Specifically, Parking Assistance Device 1 is the vehicle V ０ It is an ECU (Electronic Control Unit) installed in the vehicle, and comprises a processing unit 10, a storage unit 20, and a communication unit 30.

[0019] The processing unit 10 is configured to include, for example, a CPU (Central Processing Unit), which is a central processing unit. However, in addition to the CPU, it may also be configured to include a GPU (Graphics Processing Unit), FPGA (Field-Programmable Gate Array), ASIC (Application Specific Integrated Circuit), etc., or it may be configured to include any one of these.

[0020] The storage unit 20 is configured to include a storage device such as an HDD (Hard Disk Drive), a flash memory, a ROM (Read Only Memory), and a memory such as a RAM (Random Access Memory). The storage unit 20 stores programs processed by the processing unit 10, data groups necessary for the processing, and the like. Further, it is also used for temporarily storing data necessary for program operations as the main memory when the processing unit 10 executes a program.

[0021] The communication unit 30 has a function of transmitting and receiving data based on various protocols to and from other devices connected via the in-vehicle network N. The communication unit 30 is configured to include, for example, a network card compliant with a communication standard such as IEEE802.3 or CAN (Controller Area Network).

[0022] Next, the details of the processing unit 10 of the parking support device 1 according to the present embodiment will be described using the functional block diagram of FIG. 2. As shown here, the processing unit 10 includes an information acquisition unit 11, an other vehicle information acquisition unit 12, a parking vehicle row identification unit 13, a parking section frame identification unit 14, a likelihood calculation unit 15, a vehicle travel control unit 16, and an information output unit 17. Further, the processing unit 10 is connected to the vehicle sensor group 2 and the external sensor group 3 on the input side, and the actuator group 4 and the HMI device group 5 on the output side via a communication unit 30 not shown in the figure. Each functional unit in the processing unit 10 is realized by the cooperation of hardware such as the processing unit 10 and the storage unit 20 and various software. However, in the following description, well-known techniques in this type of computer technology field will be omitted.

[0023] <<Information Acquisition Unit 11>> The information acquisition unit 11 is a functional unit that stores information acquired by the parking support device 1 from the outside in the storage unit 20. For example, the information acquisition unit 11 stores information related to the behavior such as the movement and state of the host vehicle V detected by the vehicle sensor group 2 in the storage unit 20 as the host vehicle data group D1. Further, the information acquisition unit 11 stores information related to the behavior such as the movement and state of the host vehicle V detected by the external sensor group 3 ０ in the storage unit 20 as the host vehicle data group D1. ０Information regarding surrounding obstacles and the detection area of ​​the external sensor group 3 is stored in the storage unit 20 as sensor recognition data group D2.

[0024] <<Other Vehicle Information Acquisition Unit 12>> The Other Vehicle Information Acquisition Unit 12 is a functional unit that identifies other vehicles (moving vehicles, parked vehicles) around the vehicle based on the sensor recognition data group D2 stored in the storage unit 20, and stores information such as their position, posture, tilt, and speed as the Other Vehicle Data Group D3 in the storage unit 20. Note that the position information of other vehicles in the Other Vehicle Data Group D3 is stored in the vehicle V ０ It is expressed in a relative coordinate system.

[0025] <<Parking Vehicle Row Identification Unit 13, Parking Space Width Identification Unit 14>> The Parking Vehicle Row Identification Unit 13 is a functional unit that identifies parked vehicles around the vehicle based on the other vehicle data group D3 stored in the storage unit 20, as well as identifying parking rows in which multiple adjacent vehicles are parked in the same direction, and the position of each parked vehicle.

[0026] Furthermore, the parking space width identification unit 14 statistically processes the positional relationship of each parked vehicle within the parking row identified by the parking vehicle row identification unit 13, and determines the width d of each parking space. ｐ This is a functional unit that identifies the parking space width d. ｐ You may specify it.

[0027] Figure 3 shows an example of a parking vehicle row data group D4, which combines the outputs of the parking vehicle row identification unit 13 and the parking space width identification unit 14. In the figure, column D4a is a data column showing the parking row ID assigned to each parking row, column D4b is a data column showing the parking vehicle ID assigned to each parked vehicle, and column D4c is the vehicle V ０ Column D4d is a data column showing the relative position of each parked vehicle to the current location of the vehicle, and the data column showing the width of each parking space is a data column showing the width of each parking space.

[0028] <<Likelihood Calculation Unit 15>> The likelihood calculation unit 15 is a functional unit that calculates the likelihood L of each available parking space candidate based on the aforementioned parking vehicle row data group D4 and the pre-prepared measurement error data group D5, and stores it in the storage unit 20 as the available parking space candidate data group D6.

[0029] First, the measurement error data set D5 will be explained using Figures 4 and 5. Figure 4 is a conceptual diagram illustrating the measurement error characteristics of Lidar 3a, a type of external sensor. Lidar 3a is a sensor that measures the distance to an object in the direction of laser irradiation based on the time difference between the irradiation time of the laser light and the reception time of the reflected light. There is an unavoidable angular error α between the design light irradiation direction X of Lidar 3a and the actual light irradiation direction X'. ｅ Therefore, the position information detected by Lidar3a tends to have a position error e that increases in proportion to the distance. Consequently, the position error e in the vicinity １ and positional error e at a distance ２ Comparing them, the latter will naturally be larger.

[0030] Note that in Figure 4, the angular error α of Lidar 3a is shown. ｅ While we focused on this, in reality, depth errors also occur due to light diffusion, etc., so the actual position error e is also affected by depth errors. Furthermore, even when using a stereo camera instead of Lidar3a, a similar tendency occurs where the position error e increases in proportion to the distance due to the effects of quantization errors, calibration errors, etc. Therefore, an example of the measurement error data group D5 corresponding to a certain external sensor is shown in Figure 5, where the position error increases with increasing distance. In the same figure, column D5a is a data column showing the distance from the external sensor, and column D5b is a data column showing the average value of the position error.

[0031] Next, using Figures 6A and 6B, we will explain the accuracy of the distance between parked vehicles calculated based on the parked vehicle row data group D4. As shown in Figure 6A, the vehicle V ０ The Lidar3a installed in the vehicle can detect three parked vehicles. １ , V ２ , V ３ If you measure the position of the parked vehicle V １ , V ２ The distance between the two vehicles is d, which is the difference in their positions. ｂ１ It is possible to calculate the parking vehicle V ２ , V ３ The distance between the two vehicles is d, which is the difference in their positions. ｂ２It is possible to calculate this. However, due to the mechanism explained in Figure 4, the parked vehicle V １ , V ２ , V ３ Position error e １ , e ２ , e ３ As shown in Figure 6B, e ３ > e ２ > e １ Because there is a tendency for this to happen, your own vehicle V ０ The distance d from the neighboring point ｂ１ The reliability is relatively high, and the distance d ｂ２ The reliability of this is relatively low.

[0032] Therefore, as shown in the example of the parking environment in Figure 7, two parking spaces B that can be entered are within the sensing range R of Lidar 3. １ , B ２ If it exists, your vehicle V ０ Parking space B, which is close to parking space B. １ The distance d between the two vehicles that are sandwiched between them. ｂ１ The accuracy is relatively high, and the vehicle V ０ Parking space B, which is far from the parking area. ２ The distance d between the two vehicles that are sandwiched between them. ｂ２ The accuracy becomes relatively lower.

[0033] Therefore, the likelihood calculation unit 15 of this embodiment uses the likelihood L, which is information that the vehicle driving control unit 16 refers to when determining the parking space in which to actually park, as the distance d between parked vehicles. ｂ The calculation is performed while considering the accuracy and measurement error data set D5. Below, the details of the likelihood calculation process by the likelihood calculation unit 15 will be explained according to the processing flowchart in Figure 8.

[0034] First, in step S15a, the likelihood calculation unit 15 obtains the parking vehicle row data group D4 and the measurement error data group D5 from the storage unit 20.

[0035] Next, in step S15b, the likelihood calculation unit 15 refers to column D4a of the parking vehicle row data group D4 and selects a desired parking row ID (for example, the smallest parking row ID).

[0036] In step S15c, the likelihood calculation unit 15 refers to column D4c of the parking vehicle row data group D4 and selects pairs of adjacent parked vehicles that belong to the parking row ID selected in step S15b.

[0037] In step S15d, the likelihood calculation unit 15 refers to column D4d of the parked vehicle row data group D4 and the inter-vehicle distance d of the parked vehicle pair selected in step S15c. ｂ However, the width of the parking space d ｐ Determine if it is greater. If the requirement is met, proceed to step S15e; otherwise, proceed to step S15i.

[0038] In step S15e, the likelihood calculation unit 15 stores the space between the pair of parked vehicles selected in step S15c as a candidate for an available parking space.

[0039] In step S15f, the likelihood calculation unit 15 refers to column D4c of the parking vehicle row data group D4 and calculates its own vehicle V ０ The distance d from there to each of the selected pairs of parked vehicles. １ d ２ Calculate.

[0040] In step S15g, the likelihood calculation unit 15 refers to the measurement error data group D5 and the distance d １ d ２ The corresponding position error e １ , e ２ The distance d is obtained. １ d ２ Position error e １ , e ２ If the data is not registered, you can obtain the position error e corresponding to an arbitrary distance d by linearly interpolating the preceding and succeeding data.

[0041] In step S15h, the likelihood calculation unit 15 calculates a likelihood L for each candidate for an available parking space, which takes a value between 0 and 1. Various methods can be used to calculate the likelihood L, but for example, the following (Equation 1) can be used.

[0042]

[0043] In step S15i, the likelihood calculation unit 15 checks whether the processes in steps S15d to S15h have been performed for all parking vehicle pairs within the parking row ID selected in step S15b. If the requirements are met, the unit proceeds to step S15j; otherwise, it returns to step S15c. This ensures that the above processes are performed for all parking vehicle pairs within the same vehicle row ID.

[0044] In step S15j, the likelihood calculation unit 15 checks whether the processes in steps S15c to S15i have been performed for all parking column IDs registered in column D4a of the parking vehicle column data group D4. If the requirements are met, the process shown in Figure 8 is terminated; otherwise, the process returns to step S15b. This ensures that the above-described process is performed for all vehicle column IDs.

[0045] Through the above process, the likelihood calculation unit 15 calculates the vehicle V ０ The likelihood L can be calculated for all available parking space candidates that exist within the sensing range R, and a data set D6 of available parking space candidates can be generated by summarizing the likelihood L of each available parking space candidate.

[0046] <<Vehicle Driving Control Unit 16>> The vehicle driving control unit 16 controls the vehicle V based on the sensor recognition data group D2, the parked vehicle row data group D4, and the available parking space candidate data group D6. ０ This is a functional unit that determines whether to pass the nearest available parking space candidate (hereinafter referred to as "reference point") on the side of the direction of travel, and stores control command values ​​that automatically drive or propose a replanned route according to the determination result as a vehicle control data group D7 in the storage unit 20. The details of the vehicle driving control unit 16 will be explained below with reference to Figures 9 to 11.

[0047] Figure 9 is a flowchart of the processes performed by the vehicle driving control unit 16.

[0048] First, in step S16a, the vehicle driving control unit 16 obtains the sensor recognition data group D2, the parked vehicle row data group D4, and the available parking space candidate data group D6 from the storage unit 20.

[0049] Next, in step S16b, the vehicle driving control unit 16 sets a hypothetical likelihood L for the reference point, which will be used as a threshold in the next step. ０ Set the hypothetical likelihood L. ０ For example, this is 1.0.

[0050] In step S16c, the vehicle driving control unit 16 controls the vehicle V ０ The sum of the likelihoods of the available parking space candidates other than the reference point on the direction of travel, and the threshold (provisional likelihood L) defined in step S16b. ０ The sum of the values ​​is compared, and it is determined whether the sum is greater than the threshold. If the sum is greater than the threshold, the process proceeds to step S16d; otherwise, the process proceeds to step S16e.

[0051] Here, using Figures 10 and 11, we will explain the case where the process proceeds to step S16d and the case where the process proceeds to step S16e.

[0052] Figure 10 shows the vehicle V ０ Parking space B is a potential available parking space on the near side from this perspective. １ Likelihood L １ The value is 0.8, and the vehicle's V ０ Parking space B is a potential available parking space located further back from the viewer's perspective. ２ Likelihood L ２ This is an example of 0.4. Under these circumstances, the reference point is parking space B. １ For this, the hypothetical likelihood L is 1.0. ０ The setting is configured such that the sum of the likelihoods of available parking spaces other than the reference point is 0.4. Therefore, since the sum (0.4) is less than the threshold (1.0), the process proceeds to step S16e.

[0053] On the other hand, Figure 11 shows the vehicle V ０ Parking space B is a potential available parking space on the near side from this perspective. １ Likelihood L １ The value is 0.8, and the vehicle's V ０ Parking space B is a potential available parking space located further back from the viewer's perspective. ２ , B ３ , B ４ Likelihood L ２ , L ３ , L ４are 0.5, 0.4, and 0.2, respectively. In this situation, the parking section B, which is the reference point １ is set with a likelihood L of 1.0 ０ and the sum of the likelihoods of the vacant parking section candidates other than the reference point is 1.1. Therefore, since the sum (1.1) is greater than the threshold value (1.0), the process proceeds to step S16d.

[0054] In step S16d, the vehicle travel control unit 16 generates a travel route that passes through the current reference point (parking section B in the example of FIG. 11 １ ) and heads toward the next reference point.

[0055] On the other hand, in step S16e, the vehicle travel control unit 16 generates a travel route for parking at the current reference point (parking section B in the example of FIG. 10 １ ). In the example of FIG. 11, when the likelihood L １ of the parking section B ２ which is the next reference point is set to 1.0, the sum of the likelihoods of the vacant parking section candidates other than the reference point becomes 0.6, and since the threshold value > the sum, the process of step S16e is carried out. ０

[0056] In step S16f, the vehicle travel control unit 16 calculates a predetermined vehicle control command value so as to travel along the travel route generated in step S16d or step S16e.

[0057] Through the above processing, the vehicle travel control unit 16 can generate a vehicle control data group D7 for parking in any parking section existing within the sensing range R of the host vehicle V ０ .

[0058] <<Information output unit 17>> The information output unit 17 is a functional unit that outputs various information to the actuator group 4 and the HMI device group 5 via the in-vehicle network N. Thereby, if the host vehicle V ０ is an autonomous driving vehicle, the actuator group 4 can be controlled to automatically pass through the reference point or automatically park at the reference point according to the vehicle control data group D7. Also, for the host vehicle V ０ ​If the vehicle has a driving assistance function, the parking section proposed by the vehicle driving control unit 16 is notified to the passengers via the HMI device group 5.

[0059] In any case, the location of the available parking section candidates, the likelihood of each available parking section candidate, the judgment result as to whether or not to pass the nearest available parking section candidate, etc. may be notified to the passengers via the HMI device group 5. In this case, the passengers of the host vehicle V ０ can select actions based on the recommendations of the parking support device 1.

[0060] <Effect of this embodiment> According to the parking support device of this embodiment described above, it is possible to realize appropriate parking support while considering the measurement error that occurs when observing the distance with an external sensor. In the environment as shown in FIG. 11, the host vehicle V ０ does not immediately park in the nearest available parking section candidate (parking section B １ ), because it is also conceivable that other available parking section candidates (parking section B １ to B ４ ) are closer to the target facility and are more preferable parking sections.

[0061] Next, a second embodiment of the present invention will be described with reference to FIGS. 12 and 13. Duplicate descriptions of the common points with the first embodiment will be omitted.

[0062] In the first embodiment, only the currently available parking sections are used as the available parking section candidates, but in this embodiment, even if there is a parked vehicle at the current time, any parking section that is expected to be vacated soon is used as an available parking section candidate. To cope with this, the processing unit 10 of this embodiment adds an outgoing vehicle time level estimation unit 18 that provides information regarding the outgoing vehicle to the vehicle driving control unit 16. Hereinafter, the details of the parking support device 1 of this embodiment will be described centering on the operation of the outgoing vehicle time level estimation unit 18.

[0063] FIG. 12 is a functional block diagram of the processing unit 10 of the parking support device 1 of this embodiment. As shown in the figure, the outgoing vehicle time level estimation unit 18 receives the sensor recognition data group D2 from the information acquisition unit 11 and the parked vehicle column data group D4 from the parked vehicle column identification unit 13, and based on both data groups, the host vehicle V ０The system identifies nearby vehicles likely to leave the depot and estimates the time until those vehicles leave. The estimated time is stored in the storage unit 20 as a group of vehicle departure data D8, and then used by the vehicle travel control unit 16.

[0064] Figure 13 shows an example of the parking environment in this embodiment, and parking space B １ The parked vehicle in parking space B is about to leave. ２ This is an example of a situation where there are no parked vehicles. In this embodiment, parking space B １ and parking space B ２ Both become candidates for available parking spaces, and your vehicle V ０ The nearest available parking space on the side in the direction of travel is parking space B. １ Therefore, first, parking space B １ This will be the reference point.

[0065] Here, the method for estimating the time level by the vehicle departure time level estimation unit 18 will be explained in detail. For example, if the engine of a parked vehicle is running, the headlights are on, or the turn signals are flashing, the vehicle departure time level estimation unit 18 determines that the parked vehicle will be leaving soon and estimates the time level to be T1. On the other hand, if there is a person getting into the parked vehicle, the unit determines that it will take some time for the parked vehicle to leave and estimates the time level to be T2.

[0066] Therefore, in step S16b, the vehicle driving control unit 16 calculates the provisional likelihood L corresponding to the time level T estimated by the departure time level estimation unit 18. ０ After setting the reference point, the processing from step S16c onward is carried out. For example, the provisional likelihood L is assigned to the reference point at time level T1. ０ The value is 0.6, and the hypothetical likelihood L is set as the reference point at time level T2. ０ If it is 0.3, then parking space B in Figure 13 １ If someone is attempting to get into a parked vehicle, time level T2 is set for that vehicle, and parking space B １ For this, the threshold is 0.3 (hypothetical likelihood L ０ ) is set. Therefore, parking space B ２ Likelihood L ２If it is 0.4, then the sum > threshold, so the vehicle driving control unit 16 performs step S16d (parking space B which is the reference point). １ Select (pass through)

[0067] According to the parking assistance device of this embodiment described above, it is possible to identify a parking space while also considering the behavior of parked vehicles that are expected to leave the parking space soon.

[0068] Next, Embodiment 3 of the present invention will be described using Figures 14 and 15. Note that repetitive explanations of points common to the above embodiments will be omitted.

[0069] In Examples 1 and 2, only parked vehicles within the parking space are considered, and the vehicle V ０ A driving path was generated, but in this embodiment, the vehicle V ０ Non-parked vehicles such as vehicles traveling in front of V Ａ Taking the behavior of your own vehicle into consideration, V ０ The processing unit 10 of this embodiment generates a driving path for the non-parked vehicle V. Ａ A non-parked vehicle identification unit 19 has been added to provide information to the vehicle driving control unit 16. The details of the parking assistance device 1 of this embodiment will be described below, focusing on the operation of the non-parked vehicle identification unit 19.

[0070] Figure 14 is a functional block diagram of the processing unit 10 of the parking assistance device 1 in this embodiment. As shown in the figure, the non-parked vehicle identification unit 19 receives a group of other vehicle data D3 from the other vehicle information acquisition unit 12, and based on that data group, the own vehicle V ０ Non-parked vehicles V that are driving ahead or temporarily stopped outside of a parking space Ａ Identify the non-parked vehicle V identified here. Ａ The information regarding this is stored in the storage unit 20 as non-parked vehicle data group D9, and then used by the vehicle driving control unit 16.

[0071] The non-parked vehicle data group D9 generated by the non-parked vehicle identification unit 19 includes vehicle ID, vehicle position, vehicle speed, direction of travel, parking schedule flag, exit flag, etc., for non-parked vehicles V ＡThis is a set of data recorded for each instance. Note that the parking intention flag indicates a non-parked vehicle (V) that flashes its hazard lights near an empty parking space or changes direction towards an empty parking space. Ａ This is a flag assigned to a non-parked vehicle V that has left its parking space. Ａ This is a flag to be assigned to [the object].

[0072] In this embodiment, each step of the processing flowchart in Figure 8 is carried out as follows.

[0073] In step S15a, the likelihood calculation unit 15 acquires the parking vehicle row data group D4 and the measurement error data group D5, as well as the non-parked vehicle data group D9, from the storage unit 20.

[0074] In step S15h, the likelihood calculation unit 15 calculates the likelihood in the same manner as in Example 1, and then adjusts the provisionally calculated likelihood appropriately by referring to the non-parked vehicle data group D9. The likelihood adjustment method referring to the parking schedule flag and the exit flag will be described in detail below.

[0075] <How to use the parking plan flag> For example, as shown in the example of a parking environment in Figure 15, your vehicle V ０ Within the sensing range R, there are four potential vacant parking spaces (parking space B １ ~B ４ ) exists, and each of the likelihoods is L １ = 0.8, L ２ = 0.5, L ３ = 0.4, L ４ If the result is 0.2, the likelihood calculation unit 15 of this embodiment will determine the value of the unparked vehicle V in front. Ａ When the parking scheduled flag is assigned to a vehicle, non-parked vehicle V Ａ The likelihood L of the nearest available parking space candidate is reduced by a certain value (e.g., 0.4). As a result, under the circumstances shown in Figure 15, parking space B ２ Likelihood L ２ The value is adjusted from 0.5 to 0.1, and the sum also decreases from 1.1 to 0.7.

[0076] Therefore, under the conditions shown in Figure 15, the vehicle driving control unit 16 of Example 1 would determine that the threshold < sum and park in the nearest parking space B. １The system generates a driving path that passes through [location], but in this embodiment, the vehicle driving control unit 16 determines that the threshold > sum and selects the nearest parking space B １ This will generate a driving route that includes parking.

[0077] In the example above, non-parked vehicle V is assigned the parking planned flag. Ａ Only the likelihood L of the nearest available parking space candidate was adjusted, but the non-parked vehicle V Ａ You may also adjust the likelihood L of all the potential vacant parking spaces in the vicinity.

[0078] <How to use the exit flag> On the other hand, non-parked vehicles V that have exited the parking space Ａ If the exit flag is assigned to the non-parked vehicle V, the likelihood calculation unit 15 of this embodiment calculates the likelihood of the non-parked vehicle V Ａ The system changes the parking space from which a vehicle has exited to a candidate for an available parking space, and then sets the likelihood L of that candidate for an available parking space to, for example, 1.0. Furthermore, since it can be predicted that a vehicle that has just exited will not re-enter the parking space, the likelihood calculation unit 15 calculates the likelihood of that non-parked vehicle V Ａ Even in an environment like Figure 15, where there are potential empty parking spaces in the direction of travel, the likelihood L of the potential empty parking spaces is not adjusted.

[0079] As a result, the vehicle driving control unit 16 in this embodiment controls the non-parked vehicle V Ａ It can generate appropriate driving routes depending on the situation, such as a driving route that parks in a parking space immediately after exiting the parking lot.

[0080] Next, Embodiment 4 of the present invention will be described using Figures 16 and 17. Note that repetitive explanations of points common to the above embodiments will be omitted.

[0081] Figure 16 is a diagram illustrating the details of the processing unit 10 of the parking assist device 1 in this embodiment. As is obvious from comparing Figure 2 and Figure 16, the HMI device group 5 is not connected to the input side of the processing unit 10 in Embodiment 1, whereas the HMI device group 5 is connected to the input side of the processing unit 10 in this embodiment. Therefore, the processing unit 10 in this embodiment is connected to the vehicle V ０ It is equipped with the function of receiving commands entered by the crew into the HMI device group 5.

[0082] Figure 17 is a flowchart of the processes performed by the vehicle driving control unit 16 in this embodiment. As is obvious from comparing Figure 9 and Figure 17, the vehicle driving control unit 16 in this embodiment can perform steps S16b1 to S16b7 in addition to the processes of steps S16a to S16f in Embodiment 1. The details of each process of steps S16b1 to S16b7, which are unique to this embodiment, will be described in order below.

[0083] In step S16b1, the vehicle driving control unit 16 determines whether a flag indicating that the occupant is waiting for a response is set in the vehicle control data group D7. If the requirement is met, the unit proceeds to step S16b2; otherwise, the unit proceeds to step S16b5.

[0084] In step S16b2, the vehicle driving control unit 16 determines whether it has received a response from the occupant via the HMI device group 5. If the requirements are met, the process proceeds to step S16b3; otherwise, the process ends.

[0085] If the requirements of step S16b2 are met, the vehicle driving control unit 16 deletes the response waiting flag in step S16b3 and generates a driving route that reflects the occupant selection in step S16b4.

[0086] Furthermore, if the requirements of step S16b1 are not met, the vehicle driving control unit 16 determines in step S16b5 whether the difference between the sum of the likelihoods of the available parking space candidates and the threshold is less than or equal to a certain value. If the requirements are met, the process proceeds to step S16b6; otherwise, the process proceeds to step S16c.

[0087] If the requirements of step S16b5 are met, the vehicle driving control unit 16 sets a response waiting flag in step S16b6 and generates a driving path for a temporary stop in step S16b7.

[0088] By adding these processes, the parking assistance device 1 of this embodiment enables the vehicle V ０If the difference between the likelihood (threshold) of the nearest available parking space candidate (reference point) and the sum of the likelihoods of available parking spaces at a distance is below a certain value, the vehicle can be controlled via an HMI device such as a touch panel display to ask the occupant whether to park at the reference point or pass by it, and the vehicle can be controlled according to the occupant's response. ０ The vehicle can be temporarily stopped in a safe location while waiting for the occupants to input their responses.

[0089] 100 Vehicle System 1 Parking Assist Device 10 Processing Unit 11 Information Acquisition Unit 12 Other Vehicle Information Acquisition Unit 13 Parking Vehicle Row Identification Unit 14 Parking Space Width Identification Unit 15 Likelihood Calculation Unit 16 Vehicle Driving Control Unit 17 Information Output Unit 18 Exit Time Level Estimation Unit 19 Non-Parked Vehicle Identification Unit 20 Storage Unit 30 Communication Unit 2 Vehicle Sensor Group 3 External Sensor Group 3a Lidar 4 Actuator Group 5 HMI Device Group 5a Input HMI Device 5b Output HMI Device D1 Own Vehicle Data Group D2 Sensor Recognition Data Group D3 Other Vehicle Data Group D4 Parking Vehicle Row Data Group D5 Measurement Error Data Group D6 Candidate Empty Parking Space Data Group D7 Vehicle Control Data Group D8 Exiting Vehicle Data Group D9 Non-Parked Vehicle Data Group

Claims

1. A parking assistance device for assisting in the parking of a vehicle, comprising: an other vehicle information acquisition unit that acquires information on other vehicles in the vicinity of the vehicle based on information acquired from an on-board external sensor; a parking vehicle row identification unit that identifies parked vehicles and rows of parked vehicles in the vicinity of the vehicle based on the information on other vehicles; a likelihood calculation unit that calculates the likelihood that there is an empty parking space between adjacent parked vehicles based on the distance between adjacent parked vehicles in the row of parked vehicles and the width of the parking space; and a vehicle driving control unit that controls the driving of the vehicle based on the likelihood, wherein the vehicle driving control unit generates a driving path that passes through the reference point or a driving path that parks at the reference point, according to the result of comparing a first likelihood at a predetermined reference point within the sensing range of the external sensor and a second likelihood at a parking space farther from the reference point.

2. A parking assistance device according to claim 1, further comprising an HMI device that notifies the occupant of a driving route generated by the vehicle driving control unit and allows the occupant to select whether or not to adopt the notified driving route.

3. A parking assistance device according to claim 1, wherein the vehicle driving control unit controls the driving of the vehicle according to the generated driving path.

4. A parking assistance device according to claim 1, further comprising a parking space width determination unit that determines the width of the parking space based on the positional relationship of each parked vehicle determined by the parking vehicle row determination unit.

5. A parking assistance device according to claim 1, wherein the likelihood calculation unit calculates the likelihood that the space between adjacent parked vehicles is an empty parking space, taking into account the positional error when the positions of both parked vehicles are detected by the external sensor, when the distance between adjacent parked vehicles is greater than the width of the parking space.

6. The parking assistance device according to claim 5, wherein the vehicle driving control unit generates a driving path to park at the reference point when the first likelihood at the reference point is greater than the second likelihood, which is the sum of the likelihoods at parking spaces further away from the reference point, and generates a driving path to pass through the reference point when the first likelihood is less than the second likelihood.

7. The parking assistance device according to claim 1, wherein the reference point is located in front of the vehicle and is between adjacent parked vehicles at a distance greater than the width of the parking space.

8. The parking assistance device according to claim 1, characterized in that the reference point is a parking space where a parked vehicle that is estimated to be about to leave is parked.

9. A parking assistance device according to claim 8, further comprising a vehicle departure time level estimation unit that estimates a parked vehicle that is about to leave the parking space if the engine is started, the headlights are turned on, or the turn signals are flashing.

10. A parking assistance device according to claim 1, further comprising a non-parked vehicle identification unit that identifies non-parked vehicles in the vicinity of the vehicle based on information of other vehicles, wherein when the non-parked vehicle identification unit generates a parking schedule flag indicating that the non-parked vehicle is scheduled to be parked, the likelihood calculation unit reduces the likelihood of parking in the nearest space to the non-parked vehicle.

11. A parking assistance device according to claim 1, further comprising a non-parked vehicle identification unit that identifies non-parked vehicles around the vehicle based on information of other vehicles, wherein when the non-parked vehicle identification unit generates an exit flag indicating that the non-parked vehicle has exited, the likelihood calculation unit increases the likelihood of the parking space from which the non-parked vehicle exited, and does not adjust the initial likelihood of the parking space in the direction of travel of the non-parked vehicle.

12. A parking assistance method for assisting vehicle parking, performed by an ECU, comprising: an other vehicle information acquisition step of acquiring information on other vehicles in the vicinity of the vehicle based on information acquired from an on-board external sensor; a parking vehicle row identification step of identifying parked vehicles and rows of parked vehicles in the vicinity of the vehicle based on the information on other vehicles; a likelihood calculation step of calculating the likelihood that the space between adjacent parked vehicles is an empty parking space based on the distance between adjacent parked vehicles and the width of the parking space in the row of parked vehicles; and a vehicle driving control step of controlling the driving of the vehicle based on the likelihood, wherein the vehicle driving control step generates a driving path that passes through the reference point or a driving path that parks at the reference point, according to the result of comparing a first likelihood at a predetermined reference point within the sensing range of the external sensor and a second likelihood at a parking space further away from the reference point.

13. A parking assistance device according to claim 12, characterized in that, in the likelihood calculation step, when the distance between adjacent parked vehicles is greater than the width of the parking space, the likelihood that the space between adjacent parked vehicles is an empty parking space is calculated by taking into account the positional error when the positions of both parked vehicles are detected by the external sensor.

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