Driving assistance systems

Abstract

This driver assistance system prevents deterioration of passenger comfort by implementing deceleration control that brings the vehicle to a smooth stop at the next stopping point, even if the vehicle's trajectory needs to be modified. [Solution] The system is configured to correct the parking path if it becomes necessary to do so while the vehicle is moving along the generated parking path. When the parking path is corrected, the system selects a deceleration control pattern from a plurality of patterns to stop the vehicle at the next stopping position on the corrected parking path, based on the remaining distance from the vehicle's current position to the next stopping position on the corrected parking path and the vehicle's speed at the time the parking path was corrected. The system is then configured to decelerate the vehicle according to the selected deceleration control pattern.

Description

[Technical Field]

[0001] This invention relates to a driver assistance device that provides assistance for driving a vehicle. [Background technology]

[0002] Conventionally, driver assistance systems have been proposed that provide driving support by having the vehicle perform some or all of the user's driving operations.

[0003] Here, the above-mentioned driving assistance system generates the vehicle's future trajectory in advance and assists the vehicle in traveling according to the generated trajectory. However, the trajectory may change midway through the journey for reasons such as a change in the target destination after the start of travel or the appearance of an obstacle. In particular, when deceleration control is being performed to stop the vehicle at a designated stopping position, if the trajectory changes and the distance to the stopping position becomes shorter, or if a new stopping position appears in the direction of travel along the trajectory, it was necessary to switch the vehicle control to a new deceleration control to stop the vehicle at the stopping position. For example, Japanese Patent Publication No. 2021-62754 proposes a technology for switching vehicle control to a deceleration control to stop the vehicle at a newly created turning position (stopping position) without contacting other vehicles when the parking target position changes and the conditions for turning around are met during automatic driving to a parking target position. [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2021-62754 (paragraphs 0099-0102) [Overview of the Initiative] [Problems that the invention aims to solve]

[0005] In the aforementioned Patent Document 1, when the remaining distance to the stopping point is sufficient after the trajectory has been corrected, deceleration is performed using a deceleration method for gentle braking, while when the remaining distance to the stopping point is short, deceleration is performed using a deceleration method for emergency braking. However, in both cases, the change in deceleration causes what is known as abrupt braking, resulting in a very poor ride for the passengers. This problem was particularly significant when decelerating with an emergency braking method, as the deceleration changes abruptly.

[0006] The present invention was made to solve the aforementioned problems of the conventional system, and aims to provide a driver assistance device that prevents deterioration of the passenger's ride comfort by achieving deceleration control that stops the vehicle as smoothly as possible at the next stopping position, even when the travel trajectory is modified. [Means for solving the problem]

[0007] To achieve the above objective, the driver assistance device according to the present invention includes: a trajectory generation means for generating a vehicle's trajectory; a trajectory correction means for correcting the trajectory when it becomes necessary to correct the trajectory while the vehicle is moving along the trajectory; and a control pattern selection means for selecting a vehicle deceleration control pattern from a plurality of patterns for stopping at the next stopping position on the corrected trajectory, based on the remaining distance from the vehicle's current position to the next stopping position on the corrected trajectory and the vehicle's speed at the time the trajectory was corrected. The vehicle includes a stage and a vehicle control means for controlling the deceleration of the vehicle according to the selected deceleration control pattern, wherein the plurality of deceleration control patterns include a first deceleration control pattern which switches in the following order: a jerk limiting section in which deceleration control is performed by fixing the jerk, which is the rate of change of deceleration; a constant deceleration section in which deceleration is performed by a constant deceleration; a position control section which controls the vehicle speed so that it corresponds to the remaining distance from the vehicle's current position to the stopping position; a second deceleration control pattern which switches in the following order: the constant deceleration section, the position control section; and a third deceleration control pattern which consists only of the position control section. Furthermore, "modification of the running track" includes not only changing the shape of the running track, but also changing the position of the stopping point which is the end of the running track, and adding stopping points (for example, turnaround points) in the middle of the running track. [Effects of the Invention]

[0008] According to the driver assistance device of the present invention having the above configuration, even if the driving trajectory is corrected, the optimal pattern is selected from multiple patterns as the vehicle deceleration control pattern for stopping at the next stopping position on the corrected driving trajectory, and the vehicle is decelerated according to the selected deceleration control pattern, making it possible to stop the vehicle as smoothly as possible at the next stopping position. As a result, deterioration of the passenger's ride comfort is prevented. [Brief explanation of the drawing]

[0009] [Figure 1] This is a schematic diagram of the vehicle according to this embodiment. [Figure 2] This is a block diagram showing the configuration of the driver assistance system according to this embodiment. [Figure 3] This is a flowchart of the driver assistance processing program according to this embodiment. [Figure 4] This diagram shows an example of a parking track. [Figure 5] This diagram shows an example of when a parking track is modified. [Figure 6] This diagram shows the various deceleration control patterns that can be selected. [Figure 7] This diagram illustrates the method for selecting a deceleration control pattern. [Modes for carrying out the invention]

[0010] Hereinafter, one embodiment of the driver assistance device according to the present invention will be described in detail with reference to the drawings. First, the vehicle 2 equipped with the driver assistance device 1 according to this embodiment will be described below. Figure 1 is a schematic configuration diagram of the vehicle 2 according to this embodiment.

[0011] Here, the vehicle 2 may be, for example, an automobile (internal combustion engine vehicle) with an internal combustion engine (such as an engine) as a power source, or an automobile (electric vehicle, fuel cell vehicle, etc.) with an electric motor (such as a motor) as a power source, or an automobile (hybrid vehicle) with both of them as power sources. Also, regardless of the vehicle type, it may be a passenger car, or a commercial large truck, bus, construction machinery, etc. Further, in the following description, it is assumed to be a four-wheel vehicle, but it may also be a two-wheel or three-wheel vehicle.

[0012] However, in addition to the manual driving in which the vehicle 2 travels based on the user's driving operation, the vehicle 2 is a vehicle capable of assisted driving by autonomous driving support in which the vehicle automatically travels without depending on the user's driving operation.

[0013] Also, the autonomous driving support may be performed only under specific situations such as when parking or leaving the garage, or may be performed for all road sections, or may be configured to be performed only while the vehicle travels on a specific road section (for example, a highway where a gate (whether manned or unmanned, toll or free) is provided at the boundary). In the following description, the autonomous driving section where the vehicle's autonomous driving support is performed includes all road sections including general roads and highways as well as parking lots. Further, it is selected by the user to perform autonomous driving support (for example, turning on the autonomous driving start button), and is performed only in a situation where it is determined that driving by autonomous driving support is possible. On the other hand, the vehicle 2 may be a vehicle capable only of assisted driving by autonomous driving support. Or, the assisted driving by autonomous driving support may be performed only for the driving to the parking space when the vehicle parks (that is, parking support).

[0014] In the vehicle control for automatic driving support in this embodiment, for example, the current position of the vehicle, the lane in which the vehicle is traveling, and the positions of surrounding obstacles are detected at any time, and along the generated driving trajectory, vehicle control such as steering, the drive source, and brakes is automatically performed at a speed according to the also generated speed plan. Particularly when performing parking support, as will be described later, the detection results of sensors and cameras are used to check the parking space that the vehicle will park in and the surrounding situation, calculate the parking trajectory to the parking space, and automatically perform vehicle control to enter the vehicle into the parking space along the calculated parking trajectory and complete the parking. Furthermore, in addition to the above normal parking support, it also supports long-range parking, which aims to park in a remote parking space such as a garage at home or a monthly leased parking space in a parking lot. In the parking support for long-range parking, vehicle control to move to the preset remote parking space and complete the parking is automatically performed.

[0015] Also, as shown in FIG. 1, the vehicle 2 has an operation unit 3 that receives operations from the occupant, a liquid crystal display 4 that displays an aerial image or a bird's-eye view image of the vehicle surroundings and other information related to driving support to the occupant, a speaker 5 that outputs voice guidance related to driving support, a front camera 6, a rear camera 7, side cameras 8A and 8B for imaging the vehicle surroundings, ultrasonic sensors 9A to 9L that detect obstacles around the vehicle, and a driving support ECU (Electronic Control Unit) 10 that performs various arithmetic processes based on the input information. Note that the driving support device 1 includes each component including the above driving support ECU 10.

[0016] The following describes the various components of vehicle 2. First, the control unit 3 is located, for example, in front of the steering wheel and includes control buttons that are operated when starting the automated driving assistance system. By operating the control unit 3, the user can switch between manual driving, where the vehicle moves based on the user's driving input, and automated driving assistance, where the vehicle moves automatically without user input. The control unit 3 may also have a touch panel located in front of the liquid crystal display 4. It may also have a microphone and a voice recognition device.

[0017] The liquid crystal display 4 is a type of display device mounted on the instrument panel of the vehicle 2. During automated driving assistance, it displays bird's-eye and overhead views of the area around the vehicle, which are generated by performing viewpoint transformation and synthesis processing on images captured by the front camera 6, rear camera 7, and side cameras 8A and 8B. Furthermore, if there are warning objects such as pedestrians around the vehicle 2, a warning image indicating the presence of the warning object may be displayed at the location of the warning object in the bird's-eye or overhead view. The liquid crystal display 4 may also be used for the navigation system.

[0018] Speaker 5 is also mounted on the instrument panel of vehicle 2 and outputs voice guidance and warning sounds related to driver assistance. Speaker 5 may also be used for the navigation system.

[0019] Furthermore, the front camera 6 is an imaging device that has a camera using a solid-state image sensor such as a CCD, and is installed, for example, above the front bumper of the vehicle 2 or behind the rearview mirror, with the optical axis facing forward in the direction of travel of the vehicle.

[0020] The rear camera 7 is an imaging device that also has a camera using a solid-state image sensor such as a CCD, and is mounted, for example, near the center above the license plate attached to the rear of the vehicle 2, with the optical axis facing the rear of the vehicle.

[0021] Furthermore, the side cameras 8A and 8B are imaging devices that also have cameras using solid-state image sensors such as CCDs, and are mounted, for example, on the left and right side mirrors of vehicle 2, with the optical axis facing the side of the vehicle.

[0022] The driver assistance ECU 10 generates bird's-eye and overhead views of the vehicle's surroundings by performing viewpoint transformation and synthesis processing on the images captured by the front camera 6, rear camera 7, and side cameras 8A and 8B. Furthermore, during automated driving assistance, it performs image recognition processing on the captured images to detect lane markings, parking space markings, and obstacles (other vehicles, pedestrians, bicycles, walls, guardrails, and other structures) around the vehicle, and performs automated driving assistance based on the detection results. In particular, when performing parking assistance, it uses the detection results of parking space markings and obstacles from the cameras to identify parking spaces and check the surrounding conditions.

[0023] On the other hand, ultrasonic sensors 9A to 9L are arranged at predetermined intervals on the front, rear, and sides of the vehicle, respectively. They transmit ultrasonic waves as probe waves around the vehicle 2 and detect objects that reflected the probe waves by receiving reflected waves from objects around the vehicle. Specifically, they are a type of distance measuring sensor capable of detecting the distance (measured distance value) to the object that reflected the probe waves by measuring the time from transmission to reception. Furthermore, ultrasonic sensors 9A to 9L are configured to generate an output signal (including the distance to the detected object) corresponding to the reception result of the received wave and output it to the control unit. The objects to be detected by ultrasonic sensors 9A to 9L include, for example, people, bicycles, other vehicles, walls, and other obstacles that the vehicle 2 needs to avoid when driving, or obstacles that form a parking space. In addition, millimeter-wave sensors or laser sensors may be used as distance measuring sensors instead of ultrasonic sensors.

[0024] Furthermore, while the installation position and direction of each ultrasonic sensor 9A to 9L can be set as appropriate, in this embodiment, in order to make the detection range of the target object encompass all directions in front of, behind, and to the left and right of the vehicle's direction of travel, for example, ultrasonic sensors 9A to 9D are installed on the front of the vehicle 2 facing the direction of travel so that the direction of transmission of the probe wave is in front of the vehicle's direction of travel. Ultrasonic sensors 9E and 9F are installed on the left side of the vehicle 2 facing left so that the direction of transmission of the probe wave is to the left of the vehicle's direction of travel. Ultrasonic sensors 9G and 9H are installed on the right side of the vehicle 2 facing right so that the direction of transmission of the probe wave is to the right of the vehicle's direction of travel. Ultrasonic sensors 9I to 9L are installed on the rear of the vehicle 2 facing the opposite direction of travel so that the direction of transmission of the probe wave is to the rear of the vehicle. The height of each ultrasonic sensor 9A to 9L from the ground surface is approximately the same.

[0025] In this embodiment, among the ultrasonic sensors 9A to 9L, the ultrasonic sensors 9A to 9D on the front of the vehicle 2 and the ultrasonic sensors 9I to 9L on the rear of the vehicle 2 are installed in positions where they can receive reflected waves as indirect waves from adjacent sensors. By receiving both direct and indirect waves, it is possible to determine not only the distance to the object but also the specific position of the object (relative position to the vehicle) using triangulation. The ultrasonic sensors 9E to 9H on the sides are installed spaced apart from each other and cannot receive indirect waves, but as the vehicle moves, it is possible to determine the specific position of the object (relative position to the vehicle) using triangulation with respect to the distance measured at the previous position, the distance measured at the current position, and the distance traveled in between.

[0026] On the other hand, the driver assistance ECU 10 is an electronic control unit that performs various processes related to automated driving assistance. For example, it continuously detects the vehicle's current position, the lane the vehicle is traveling in, and the position of surrounding obstacles, and controls the vehicle, such as steering, drivetrain, and brakes, to ensure that the vehicle travels along the generated driving trajectory at a speed according to the generated speed plan. In particular, when providing parking assistance, it uses the detection results from the aforementioned front camera 6, rear camera 7, side cameras 8A, 8B, and ultrasonic sensors 9A to 9L to identify the parking space to which the vehicle will park and to check the surrounding conditions, calculates the parking trajectory to the parking space, and controls the vehicle to enter the parking space along the calculated parking trajectory and complete the parking. On the other hand, when providing parking assistance for long-range parking, it calculates a parking trajectory that includes travel to a distant parking space, such as a pre-registered home garage or a monthly contracted parking space in a parking lot, and controls the vehicle to enter the parking space along the calculated parking trajectory and complete the parking. Furthermore, the LCD display 4 displays the scenery around the vehicle, and if there are warning targets such as pedestrians around the vehicle, it also displays a superimposed warning image indicating the presence of the warning target at the location of the warning target in the scenery. The driver assistance ECU 10 is connected to the aforementioned control unit 3, LCD display 4, speaker 5, front camera 6, rear camera 7, side cameras 8A, 8B, and ultrasonic sensors 9A~9L via an in-vehicle network such as CAN. It is also connected to various sensors mounted on the vehicle 2, such as a vehicle speed sensor, acceleration sensor, gyro sensor, steering sensor, and shift position sensor, as well as in-vehicle devices such as the navigation system. The detailed configuration of the driver assistance ECU 10 will be described later.

[0027] In addition to the components shown in Figure 1, Vehicle 2 also has other basic components as Vehicle 2, but only the configuration related to the control of the automated driving assistance system and the control related to said configuration will be explained.

[0028] Next, we will describe in detail the driver assistance ECU 10, which is part of the driver assistance system 1 provided by the vehicle 2 described above. Figure 2 is a block diagram showing the configuration of the driver assistance system 1 according to this embodiment.

[0029] As shown in Figure 2, the driver assistance ECU (Electronic Control Unit) 10 is an electronic control unit that controls the entire driver assistance system 1, and includes a CPU 31 as a calculation device and control device, a RAM 32 which is used as working memory when the CPU 31 performs various calculation processes and stores driving trajectory data when the driving trajectory is calculated, a ROM 33 which stores control programs as well as the driver assistance processing program described later (see Figure 3), and a flash memory 34 which stores programs read from the ROM 33. The driver assistance ECU 10 also has various means as processing algorithms. For example, the driving trajectory generation means generates the driving trajectory of the vehicle. The driving trajectory correction means corrects the driving trajectory when it becomes necessary to correct the driving trajectory while the vehicle is moving along the driving trajectory. When the travel trajectory is corrected, the control pattern selection means selects a deceleration control pattern for the vehicle from a plurality of patterns to stop at the next stopping position on the corrected travel trajectory, based on the remaining distance from the vehicle's current position to the next stopping position on the corrected travel trajectory and the vehicle's speed at the time the travel trajectory was corrected. The vehicle control means controls the vehicle's deceleration according to the selected deceleration control pattern. In other words, the driver assistance ECU 10 is an example of a travel trajectory generation means, a travel trajectory correction means, a control pattern selection means, and a vehicle control means.

[0030] Furthermore, the driver assistance ECU 10 is connected to various sensors 36 for detecting the vehicle's behavior, such as a vehicle speed sensor, wheel speed sensor, acceleration sensor, gyro sensor, steering sensor, and shift position sensor, as well as to various drive units 37 of the vehicle, such as the steering, brakes, accelerator, and transmission. Based on the detection results of these sensors 36, the ECU 10 detects the vehicle's current behavior and controls each drive unit 37 to provide automatic driving assistance for the vehicle 2. Specifically, the automatic driving assistance includes, for example, continuously detecting the vehicle's current position, the lane the vehicle is traveling in, and the positions of surrounding obstacles, and controlling the vehicle, such as the steering, drive source, and brakes, to travel along the generated driving trajectory at a speed according to the generated speed plan.

[0031] Furthermore, the flash memory 34 includes a vehicle information database 35, which stores various information about vehicle 2. For example, it stores the installation positions (height from the ground, left-right position) and detection axes (optical axis for cameras) of cameras and ultrasonic sensors 9A-9L installed on vehicle 2, as well as the overall length, vehicle width, wheelbase, and minimum turning radius. This information is entered in advance by the occupants or personnel from the vehicle manufacturer.

[0032] Next, the driver assistance processing program executed by the driver assistance ECU 10 in the driver assistance device 1 having the above configuration will be explained with reference to Figure 3. Figure 3 is a flowchart of the driver assistance processing program according to this embodiment. Here, the driver assistance processing program is executed after the ACC power supply (accessory power supply) of the vehicle 2 is turned ON, and it generates a driving trajectory as the future path the vehicle will travel, and is a program that controls the steering and brakes of the vehicle so that it automatically drives along the generated driving trajectory. In the following explanation, parking assistance, in which the vehicle parks, will be used as an example, but it is also possible to apply it to automatic driving assistance during normal driving, not limited to parking assistance. The program shown in the flowchart in Figure 3 below is stored in the RAM 32 and ROM 33 of the driver assistance device 1 and is executed by the CPU 31.

[0033] First, in step 1 (hereinafter abbreviated as S), the CPU 31 determines whether or not to start parking assistance. In particular, the parking assistance in this embodiment involves automatically identifying a parking space for parking the vehicle and moving the vehicle to the identified parking space.

[0034] For example, parking assistance may be initiated when the user selects to start parking assistance by operating the control unit 3, or it may be automatically initiated when the vehicle is detected to have entered the parking lot, when it is determined that the vehicle has arrived at the set destination, or when the vehicle approaches the parking lot.

[0035] If it is determined that parking assistance should be started (S1:YES), the process proceeds to S2. Conversely, if it is determined that parking assistance should not be started (S1:NO), the driver assistance processing program is terminated.

[0036] In S2, the CPU 31 identifies a parking space for parking the vehicle. The parking space can be identified in several ways: for example, the user can specify a desired parking space from the surrounding image of the vehicle displayed on the screen; or the user can pre-register a parking space (e.g., their home garage), and the system can then identify that registered parking space. Alternatively, ultrasonic sensors 9A-9L or a camera can be used to detect available parking spaces around the vehicle in real time, and the system can identify the detected available parking space. Furthermore, when using ultrasonic sensors 9A-9L or a camera to identify a parking space, it is possible to identify the space based on the detection of obstacles such as walls or other vehicles, or based on the detection of parking space lines drawn on the road surface.

[0037] Furthermore, the parking space identified in S2 becomes the target parking position where the vehicle will ultimately be positioned by the parking assistance, i.e., the endpoint of the generated parking trajectory (driving trajectory). However, for example, the detection of parking spaces using cameras is not highly accurate, and in particular, it may not be possible to accurately detect parking spaces when they are far away, at night, or in bad weather. Also, with ultrasonic sensors, it is difficult to detect obstacles on surfaces in the depth direction from the vehicle's perspective. Therefore, the parking space identified in S2 may be automatically corrected after the parking assistance is started, and in that case, the parking trajectory will also be corrected (S5, S6).

[0038] Subsequently, in S3, the CPU 31 calculates a parking trajectory, which is the driving path for parking the vehicle from its current position to the parking space identified in S2. For example, to explain the calculation of the parking trajectory when performing parallel parking and reverse parking, first the CPU 31 sets a target parking position 42 (i.e., the position of the vehicle when parking is completed) when parking the vehicle in the parking space 41 identified in S2, as shown in Figure 4. For example, the target parking position 42 is the center of the parking space 41 and the position where the vehicle is facing forward (or backward in the case of forward parking) relative to the entrance of the parking space. Furthermore, the CPU 31 sets a reversing start position 43 (i.e., the position of the vehicle when reversing to park) when parking the vehicle in the parking space 41 according to the parking trajectory. The reversing start position 43 is determined relative to the target parking position 42, taking into account the vehicle's length, width, minimum turning radius, etc. Next, the CPU 31 calculates the turning trajectory 44 from the reversing start position 43 to the target parking position 42. Specifically, it is a path that allows the vehicle to enter the parking space 41 without contacting any obstacles and turns with the optimal steering angle derived from the vehicle's turning characteristics. For example, the turning trajectory 44 is calculated as the travel trajectory that turns with the minimum turning radius. The turning trajectory 44 may be a circular arc or a clothoid curve, and may also include a straight trajectory in part. Furthermore, the CPU 31 calculates a preparation trajectory 45 from the vehicle's current position to the reverse start position 43. The preparation trajectory 45 may be a straight line as shown in Figure 4, or it may include a circular arc or a clothoid curve depending on the positional relationship between the vehicle's current position and the reverse start position 43. Furthermore, CPU31 calculates the turning trajectory if it is necessary to correct the vehicle's orientation to the appropriate direction (basically, the direction parallel to the parking space). The turning track 44, the preparation track 45, and any additional turning tracks as needed form the parking track (driving track) for parking the vehicle from its current position to the parking space identified in S2. The parking track generated in S3 is stored in flash memory 34 or the like.

[0039] Subsequently, in S4, the CPU 31 starts parking assistance according to the parking trajectory generated in S3. Specifically, it continuously detects the vehicle's current position and automatically controls the steering, drivetrain, brakes, and other vehicle functions to drive along the generated parking trajectory at a specified speed. If a U-turn is necessary to enter the parking space, the shift position is also automatically changed. The above parking assistance basically continues until parking is completed in the parking space, but it may end before parking is completed if, for example, an obstacle that cannot be avoided by correcting the trajectory is detected on the parking trajectory, or if the user performs a brake operation (an operation to interrupt automatic driving).

[0040] Next, in S5, the CPU31 determines whether or not it is necessary to correct the current parking trajectory. Examples of cases where correction of the parking trajectory is necessary include the following cases (A) and (B). (A) Parking space has been modified. As mentioned above, camera-based parking space detection is not highly accurate, and ultrasonic sensors have difficulty detecting obstacles in the depth direction relative to the vehicle. Therefore, the parking space may be modified after the vehicle approaches it. In such cases, the endpoint of the parking path and the vehicle's orientation at the endpoint will change, and the parking path will also be modified. Additionally, a turning path may be added. (B) An obstacle was detected. During parking assistance, in addition to the vehicle control described in S4, obstacle detection around the vehicle is performed in parallel using cameras and ultrasonic sensors 9A-9L. If the cameras and ultrasonic sensors 9A-9L determine that an obstacle has been detected around the vehicle (especially between the vehicle and the parking space), the parking path will be modified to avoid the obstacle. Obstacles include not only moving objects such as pedestrians and bicycles, but also stationary objects such as walls that are in blind spots and could not be detected at the start of parking assistance. It is also possible that the doors of other vehicles located to the side of the parking path or parking space may be opened. Furthermore, if an obstacle is detected, and the vehicle can reach the parking space by modifying the parking path to avoid the obstacle, the shape of the parking path may change, but the endpoint of the parking path, i.e., the stopping position, will not change. However, if an obstacle that cannot be avoided by modifying the path is detected on the parking path, for example, the endpoint of the parking path may be modified to stop the vehicle before the obstacle, in order to stop the vehicle before the parking space.

[0041] If it is determined that the current parking track needs to be corrected (S5: YES), the process proceeds to S6. Conversely, if it is determined that the current parking track does not need to be corrected (S5: NO), the process proceeds to S13 without correcting the current parking track.

[0042] In S6, CPU31 corrects the current parking trajectory. For example, in case (A) above, the parking path for parking the vehicle in the corrected parking space is calculated from the vehicle's current position, i.e., the vehicle's position at the time the parking path is corrected, and the calculated parking path is designated as the new parking path. The method for calculating the parking path is the same as in S3 above, so the explanation is omitted. On the other hand, in case (B) above, a parking path is calculated to park the vehicle in the parking space while avoiding obstacles detected from the vehicle's current position, i.e., the vehicle's position at the time the parking path is corrected, and this calculated parking path is used as the new parking path. Furthermore, if an obstacle that cannot be avoided by correcting the path is detected on the parking path, the endpoint of the parking path is corrected to a position before the parking space in order to stop the vehicle before the obstacle. In other words, a portion of the parking path is deleted. For example, Figure 5 shows the case where the door 47 of another vehicle located to the side of the parking space 41 is detected to have been opened during parking assistance. Since the door 47 cannot be avoided by correcting the path, the endpoint of the parking path is corrected to a position before the parking space in order to stop the vehicle before the door 47. In other words, a portion of the parking path is deleted. Furthermore, the corrected parking track may be shorter or longer than the original parking track. The process from S5 onward is repeated until parking is complete.

[0043] Furthermore, if a warning target object such as a pedestrian is detected around the vehicle, in addition to correcting the parking trajectory as described above, a warning will also be issued to the warning target object using the LCD display 4 and speaker 5. For example, a warning image indicating the presence of the warning target object will be displayed on the LCD display 4 at the location of the warning target object in the overhead or bird's-eye view image of the area around the vehicle.

[0044] Subsequently, in S7, the CPU 31 obtains the vehicle speed at the current time, i.e., the time when the parking trajectory was corrected, from the vehicle speed sensor installed in the vehicle 2. Furthermore, the CPU 31 obtains the remaining distance from the vehicle's current position along the parking trajectory corrected in S6, i.e., the vehicle's position at the time the parking trajectory was corrected, to the next stopping position. Note that the stopping position includes not only the end of the parking trajectory, but also the reverse starting position 43 where the vehicle switches from forward to reverse (or vice versa) and the point where a U-turn is performed, as shown in Figure 5.

[0045] Subsequently, from S8 onward, the CPU 31 determines how much margin is available for deceleration control to the next stopping position, based on the vehicle speed at the time the parking trajectory was corrected (hereinafter referred to as the trajectory correction speed) acquired in S7, and the remaining distance from the vehicle's position at the time the parking trajectory was corrected to the next stopping position (hereinafter referred to as the trajectory correction remaining distance). Based on the determination result, the CPU 31 selects from multiple deceleration control patterns for the vehicle to stop at the next stopping position on the corrected parking trajectory.

[0046] In this embodiment, there are three deceleration control patterns that can be selected. Figure 6 also shows an example of the change in vehicle speed over time for each deceleration control pattern, with the horizontal axis representing time. (1) First deceleration control pattern: A pattern that switches between the following in order: a "jerk restriction section" in which deceleration control is performed by fixing the jerk, which is the rate of change of deceleration; a "constant deceleration section" in which deceleration is performed at a constant deceleration rate; and a "position control section" in which the vehicle speed is controlled to correspond to the remaining distance from the vehicle's current position to the next stopping position. (2) Second deceleration control pattern: A pattern that controls by switching between "equal deceleration section" and "position control section" in that order. (3) Third deceleration control pattern... A pattern consisting only of a "position control section".

[0047] The selection of the deceleration control pattern is based on the combination of the vehicle speed at the time of track correction and the remaining distance at the time of track correction. For example, Figure 7 shows the correspondence between the combination of the vehicle speed at the time of track correction and the remaining distance at the time of track correction, and the deceleration control pattern selected for that combination. As shown in Figure 7, the first deceleration control pattern is selected when it is determined that there is the most margin for deceleration control to the next stopping position, that is, when the vehicle speed at the time of track correction is sufficiently small relative to the remaining distance at the time of track correction. The second deceleration control pattern is selected when it is determined that there is a relatively large margin for deceleration control to the next stopping position, although it cannot be said that there is sufficient margin. On the other hand, the third deceleration control pattern is selected when it is determined that there is no margin for deceleration control to the next stopping position, that is, when the vehicle speed at the time of track correction is large relative to the remaining distance at the time of track correction.

[0048] Then, if the combination of the vehicle speed at the time of track correction and the remaining distance at the time of track correction falls under the first deceleration control pattern (S8: YES), the first deceleration control pattern is selected as the vehicle deceleration control pattern for stopping at the next stopping position on the corrected parking track, and the vehicle is subsequently decelerated according to the selected first deceleration control pattern (S9). Specifically, the current position of the vehicle is detected in real time, and vehicle control is automatically performed to change the vehicle speed along the corrected parking track according to the first deceleration control pattern shown in Figure 6. After that, the process proceeds to S13.

[0049] Furthermore, if the combination of vehicle speed at the time of track correction and remaining distance at the time of track correction falls under the second deceleration control pattern (S8: NO, S10: YES), the second deceleration control pattern is selected as the vehicle deceleration control pattern for stopping at the next stopping position on the corrected parking track, and the vehicle is subsequently decelerated according to the selected second deceleration control pattern (S11). Specifically, the current position of the vehicle is detected in real time, and vehicle control is automatically performed to change the vehicle speed along the corrected parking track according to the second deceleration control pattern shown in Figure 6. The process then proceeds to S13.

[0050] Furthermore, if the combination of vehicle speed at the time of track correction and remaining distance at the time of track correction falls under the third deceleration control pattern (S8:NO, S10:NO), the third deceleration control pattern is selected as the vehicle deceleration control pattern for stopping at the next stopping position on the corrected parking track, and the vehicle is subsequently decelerated according to the selected third deceleration control pattern (S12). Specifically, the current position of the vehicle is detected in real time, and vehicle control is automatically performed to change the vehicle speed along the corrected parking track according to the third deceleration control pattern shown in Figure 6. The process then proceeds to S13.

[0051] Here, each of the deceleration control patterns (1) to (3) above employs different parameters for at least one of the jerk, maximum deceleration, and position gain used when performing deceleration control for each pattern. Details are explained below.

[0052] First, regarding "(1) First Deceleration Control Pattern," as shown in Figure 6, the first deceleration control pattern includes three sections: a "jerk limiting section," a "constant deceleration section," and a "position control section." The "jerk limiting section" fixes the jerk, but the jerk value adopted in the "jerk limiting section" has a set range of acceptable values. For example, the largest acceptable rate of change is -0.3 m / s. 3 (A negative value indicates deceleration, and the larger the absolute value, the greater the rate of change.) In the example shown in Figure 6, the jerk value for the "jerk limit section" is -0.3 m / s. 3 This is the adopted method. In addition, in the first deceleration control pattern, the jerk value is -0.3 m / s for both the "equal deceleration section" and the "position control section". 3 Ensure that it does not exceed this value. In other words, in deceleration control using the first deceleration control pattern, the rate of change of deceleration is between 0 and -0.3 m / s. 3 It is controlled within the range, and the rate of change of deceleration is -0.3 m / s 3 This suppresses changes beyond a certain point. As a result, extremely smooth deceleration control becomes possible without causing so-called jerky braking at the start of deceleration control, during control, or when stopping. On the other hand, in the "(2) Second deceleration control pattern" and the "(3) Third deceleration control pattern", there is no distance margin to the stop position, so there is no range limitation for the jerk as described above. Therefore, when the change rate of the deceleration exceeds -0.3 m / s 3 (for example, -0.4 m / s 3 or -0.5 m / s 3 ), there are also such cases. However, in the "position control section" near the stop, since it is controlled so that the remaining distance from the current position of the vehicle to the next stop position corresponds to the vehicle speed, at least the jerk value near the stop can be suppressed as much as possible.

[0053] Also, in the "(1) First deceleration control pattern", in addition to the value of the jerk adopted in each section, a range in which the value of the deceleration can be adopted is also set. For example, taking the maximum applicable deceleration as -0.2 m / s 2 (negative indicates deceleration, and the larger the absolute value, the greater the deceleration), in the example shown in FIG. 6, -0.2 m / s 2 is adopted as the deceleration in the "constant deceleration section". Also, in the "jerk limit section" and the "position control section" of the first deceleration control pattern, the deceleration is also made not to exceed -0.2 m / s 2 . That is, in the deceleration control according to the first deceleration control pattern, the deceleration is controlled within the range of 0 to -0.2 m / s 2 , and it is suppressed that the deceleration exceeds -0.2 m / s 2 . As a result, the deceleration G generated during deceleration can be suppressed, and the burden on the passengers can be reduced. On the other hand, in the "(2) Second deceleration control pattern" and the "(3) Third deceleration control pattern", there is no distance margin to the stop position, so there is no range limitation for the deceleration as described above. Therefore, when the deceleration exceeds -0.2 m / s 2 (for example, -0.3 m / s 2 or -0.4 m / s 2 ), there are also such cases.

[0054] Furthermore, in "(1) First Deceleration Control Pattern," in addition to the jerk value and deceleration value used in each section, a range of acceptable values ​​for the position gain is also set. Here, the position gain indicates the strength with which the difference between the target position and the current position, i.e., the remaining distance to the next stopping position, is reflected in the vehicle control. For example, in this embodiment, in the "position control section," deceleration is performed so that the (target) vehicle speed [m / s] is obtained by multiplying the remaining distance [m] from the vehicle's current position to the next stopping position by a coefficient less than 1. The above coefficient is an example of the position gain. In "(1) First Deceleration Control Pattern," the position gain is set to 0.5. Note that a larger position gain will produce a larger speed change near the stopping position, resulting in a larger impact when stopping. In deceleration control using the first deceleration control pattern, it is possible to suppress the impact when stopping by setting the position gain to a relatively small 0.5. Furthermore, the position gain value used in "(2) Second Deceleration Control Pattern" also has a set range of acceptable values, similar to the first deceleration control pattern. In "(2) Second Deceleration Control Pattern," the position gain is set to 0.5. In other words, in the deceleration control using the second deceleration control pattern, there is no limit on the jerk value or deceleration speed due to the limited remaining distance, but by limiting the position gain, it is possible to at least reduce the impact when stopping. On the other hand, in "(3) Third deceleration control pattern," since there is no distance margin to the stopping position, priority is given to stopping at the stopping position, and the above-mentioned restrictions on position gain are not imposed. In other words, a position gain value greater than 0.5 can also be set.

[0055] Here, as described above, when there is sufficient remaining distance to the next stopping position, the first deceleration control pattern is selected as the deceleration control pattern (S9), so it is possible to stop the vehicle most smoothly by changing the "jerk restriction section", "equal deceleration section", and "position control section" in that order. In the graph shown in Figure 7, the boundary line between the first deceleration control pattern and the second deceleration control pattern indicates the limit of the combination of vehicle speed during track correction and remaining distance during track correction that allows the vehicle to stop at the stopping position even with limitations on jerk value and deceleration. On the other hand, if there is not enough margin in the remaining distance to the stopping position, the second deceleration control pattern is selected as the deceleration control pattern (S11), and the stopping is performed with the aim of at least suppressing the impact when stopping by changing in the order of "equal deceleration section" and "position control section". In the graph shown in Figure 7, the boundary line between the second deceleration control pattern and the third deceleration control pattern indicates the limit of the combination of track correction vehicle speed and remaining distance when track correction that allows stopping at the stopping position even with position gain limitations. Then, in the situation where there is the least margin of remaining distance to the stopping position, the third deceleration control pattern is selected as the deceleration control pattern (S12), so control is performed with the aim of stopping the vehicle at least at the stopping position within the "position control section". In other words, in this embodiment, by appropriately changing the deceleration control pattern depending on how much margin there is remaining distance to the next stopping position, it is possible to achieve smooth stopping control that minimizes the burden on the occupants while still stopping at the stopping position. Furthermore, regarding the jerk value in particular, even when there is little margin remaining distance to the stopping position, the jerk value just before stopping is controlled to be at least small, thus preventing the occurrence of sudden braking when stopping.

[0056] Next, in S13, the CPU 31 determines whether or not the vehicle has been parked. Specifically, the CPU determines that the vehicle has been parked when the vehicle is positioned in the target parking position 42 set within the parking space identified in S2 (or the modified parking space if the parking space has been modified), and the vehicle's shift position is changed to "P".

[0057] If it is determined that the vehicle has been parked (S13:YES), the driver assistance processing program is terminated. Conversely, if it is determined that the vehicle has not been parked (S13:NO), the program returns to S5.

[0058] As described in detail above, according to the driving support device 1 and the computer program executed by the driving support device 1 according to this embodiment, if it becomes necessary to correct the parking track while the vehicle is moving along the generated parking track, the parking track is corrected (S6). When the parking track is corrected, a deceleration control pattern for the vehicle to stop at the next stopping position on the corrected parking track is selected from a plurality of patterns based on the remaining distance from the vehicle's current position to the next stopping position on the corrected parking track and the vehicle's speed at the time the parking track was corrected (S8, S10), and the vehicle is decelerated according to the selected deceleration control pattern (S9, S11, S12). Furthermore, the multiple deceleration control patterns include a first deceleration control pattern that switches between a jerk-restricted section where deceleration control is performed with a fixed jerk rate of change, a constant deceleration section where deceleration is performed at a constant rate, and a position control section where the vehicle speed is controlled to correspond to the remaining distance from the vehicle's current position to the next stopping position; a second deceleration control pattern that switches between a constant deceleration section and a position control section; and a third deceleration control pattern consisting only of a position control section. Therefore, even if the parking track is modified, the system selects the optimal deceleration control pattern from multiple patterns to stop the vehicle at the next stopping position on the modified parking track, and controls the vehicle's deceleration according to the selected deceleration control pattern, making it possible to stop the vehicle as smoothly as possible at the next stopping position. As a result, deterioration of the passenger's ride comfort is prevented. Furthermore, since multiple deceleration control patterns employ different parameters for at least one of the jerk, maximum deceleration, and position gain used when performing deceleration control for each pattern, it becomes possible to adjust the parameters for deceleration control to optimal values ​​based on the remaining distance from the vehicle's current position to the next stopping position on the corrected parking track and the vehicle's speed at the time the parking track was corrected. As a result, it becomes possible to adjust the parameters to stop the vehicle as smoothly as possible within the range in which the vehicle can be stopped at the next stopping position. Furthermore, in the first deceleration control pattern, a range of parameters is set for jerk, maximum deceleration, and position gain. In the second deceleration control pattern, there are no restrictions on the range of parameters for jerk and maximum deceleration, but a range of parameters is set for position gain. In the third deceleration control pattern, there are no restrictions on the range of parameters for jerk, maximum deceleration, and position gain. Therefore, it is possible to adjust the parameters used for deceleration control to optimal values ​​for each deceleration control pattern. Furthermore, based on the remaining distance from the vehicle's current position on the corrected parking track to the next stopping position and the vehicle's speed at the time the parking track was corrected, the system determines how much margin is available for deceleration control to the next stopping position and selects a deceleration control pattern based on the determination result. Among the first, second, and third deceleration control patterns, the first deceleration control pattern is selected when it is determined to have the most margin, and the third deceleration control pattern is selected when it is determined to have the least margin (S8, S10). Therefore, when there is ample margin in the remaining distance to the stopping position, the system changes in the order of jerk restriction section, constant deceleration section, and position control section to achieve the smoothest possible stop. On the other hand, when there is not enough margin in the remaining distance to the stopping position, the system changes in the order of constant deceleration section and position control section to achieve a stop that at least minimizes the impact during stopping. And when there is the least margin in the remaining distance to the stopping position, the system uses only the position control section to achieve control aimed at stopping at least at the stopping position.

[0059] It should be noted that the present invention is not limited to the embodiments described above, and various improvements and modifications are possible without departing from the spirit of the invention. For example, in this embodiment, the driving assistance processing program shown in Figure 3 is executed when parking assistance is being performed, but it may also be executed during driving with other types of automated driving assistance, such as driving at a constant speed on public roads or in parking lots. Even when driving with other types of automated driving assistance is being performed, there may be cases where it becomes necessary to perform stopping control, for example, when an obstacle is detected in front of the vehicle, and in such cases the pre-generated driving trajectory will be modified. Then, from S7 onward, when it becomes necessary to perform such stopping control, a deceleration control pattern is selected from the newly generated remaining distance to the stopping position and the current vehicle speed to perform stopping control to the stopping position.

[0060] Furthermore, in this embodiment, jerk, maximum deceleration, and position gain are set as parameters to be changed between the first, second, and third deceleration control patterns. However, it is not necessary to change all of these parameters; only some may be changed. Alternatively, it is possible to change parameters other than jerk, maximum deceleration, and position gain. Also, although there are three types of deceleration control patterns, there may be two or four or more types.

[0061] Furthermore, in this embodiment, the driver assistance ECU 10 of the driver assistance device 1 executes the processing of the driver assistance processing program (Figure 3), but the execution entity can be changed as appropriate. For example, the control unit of the liquid crystal display 4, the vehicle control ECU, the control unit of the navigation device, or other in-vehicle devices may be used to execute the processing. [Explanation of symbols]

[0062] 1...Driving support device, 2...Vehicle, 3...Operating unit, 4...LCD display, 6...Front camera, 7...Rear camera, 8A,8B...Side cameras, 9A~9L...Ultrasonic sensors, 10...Driving support ECU (Example of means for generating driving trajectory, correcting driving trajectory, selecting control pattern, and controlling vehicle), 44...Turning trajectory (Example of driving trajectory), 45...Preparation trajectory (Example of driving trajectory)

Claims

1. A means for generating the vehicle's trajectory, A means for correcting the running track when it becomes necessary to correct the running track while the vehicle is moving along the running track, When the aforementioned trajectory is modified, a control pattern selection means selects from a plurality of patterns a deceleration control pattern for the vehicle to stop at the next stopping position on the modified trajectory, based on the remaining distance from the vehicle's current position to the next stopping position on the modified trajectory and the vehicle's speed at the time the trajectory was modified. The system includes a vehicle control means that controls the deceleration of the vehicle according to the selected deceleration control pattern, The multiple deceleration control patterns include: A first deceleration control pattern switches between the following sections in order: a jerk-restricted section where deceleration control is performed by fixing the jerk, which is the rate of change in deceleration; a constant deceleration section where deceleration is performed at a constant rate; and a position control section where the vehicle speed is controlled to correspond to the remaining distance from the vehicle's current position to the next stopping position. A second deceleration control pattern that switches between the aforementioned equal deceleration section and the aforementioned position control section in that order, A third deceleration control pattern consisting only of the aforementioned position control section, Driving assistance devices including

2. The driving support device according to claim 1, wherein each of the multiple deceleration control patterns employs different parameters for at least one of the jerk, maximum deceleration, and position gain used when performing deceleration control for each pattern.

3. In the first deceleration control pattern, a range of parameters that can be adopted for jerk, maximum deceleration, and position gain is set. In the second deceleration control pattern, there are no restrictions on the range in which jerk and maximum deceleration can be adopted, while the range in which position gain can be adopted as a parameter is set. The driving support device according to claim 2, wherein in the third deceleration control pattern, there is no restriction on the range in which any of the jerk, maximum deceleration, and position gain can be employed.

4. The control pattern selection means is Based on the remaining distance from the vehicle's current position to the next stopping position on the corrected track and the vehicle's speed at the time the track was corrected, it is determined how much margin is available for deceleration control to the next stopping position, Based on the determination result, select the deceleration control pattern. The driving support device according to any one of claims 1 to 3, wherein, among the first deceleration control pattern, the second deceleration control pattern, and the third deceleration control pattern, the first deceleration control pattern is selected when it is determined to have the most margin, and the third deceleration control pattern is selected when it is determined to have the least margin.

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