DRIVING ASSISTANCE DEVICE

Abstract

Driving assistance device (20) that provides driving assistance to a vehicle (10) based on environmental information collected by a plurality of sensors (14a to 14l, 16a to 16d) provided in the vehicle (10), the driving assistance device (20) comprising: a route calculation unit (204) configured to calculate a movement route (TR) of the vehicle (10) to a target position (DP) based on the environmental information from the plurality of sensors (14a to 14l, 16a to 16d); a motion control unit (206) configured to move the vehicle (10) along the movement route (TR) at a target speed within a speed limit (A, B) according to the current situation of the vehicle (10);and an acceleration determination unit (205) configured to determine the acceleration at which the vehicle (10) reaches the target speed based on a predetermined acceleration time (AD, RT) and the speed limit (A, B).

Description

TECHNICAL FIELD

[0001] The present disclosure relates to a driving assistance device. BACKGROUND

[0002] There is a driving assistance device that automatically parks and exits a vehicle into and out of a parking space. During execution of the driving assistance, a speed limit is set according to a current situation of a vehicle. The driving assistance device accelerates a vehicle at an acceleration within a predetermined range to cause a vehicle speed to reach, for example, a set speed limit, and moves the vehicle to a target position.

[0003] For example, in the technique of WO 2020 / 066331 A, it is possible to stop a vehicle at a target position by setting an acceleration profile, which is a temporal change of a target acceleration value at the time of deceleration of the vehicle according to a distance to the target position. Furthermore, in the technique of JP 5 257 647 B2, the acceleration of a vehicle is limited within an upper acceleration limit set according to a vehicle speed, making it possible to prevent the occurrence of an unexpected acceleration condition.

[0004] However, in the technique of WO 2020 / 066331 A, a situation may arise in which a vehicle occupant senses a sudden acceleration depending on the distance to the target position. Furthermore, in the technique of JP 5257647 B2, even if the occurrence of an unexpected acceleration condition is prevented and a safe driving condition is maintained, a situation may arise in which an occupant senses a sudden acceleration.

[0005] There is therefore a need for a driving assistance device that can improve the driving comfort of a vehicle occupant while performing driving assistance. SUMMARY

[0006] To solve the problems described above and achieve the object, a driving assistance device of one embodiment is a driving assistance device that performs driving assistance of a vehicle based on environmental information collected by a plurality of sensors provided in the vehicle, the driving assistance device comprising: a route calculation unit configured to calculate a movement route of the vehicle to a target position based on the environmental information from the plurality of sensors; a movement control unit configured to move the vehicle along the movement route at a target speed within a speed limit according to a current situation of the vehicle;and an acceleration determination unit configured to determine an acceleration at which the vehicle reaches the target speed based on a predetermined acceleration time and the speed threshold;

[0007] The driving assistance device of the embodiment can improve the driving comfort of a vehicle occupant during execution of the driving assistance. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] The foregoing and additional features and characteristics of this disclosure will become more apparent from the following detailed description considered with reference to the accompanying drawings, in which: Fig. 1 is a plan view of a vehicle on which a driving assistance device according to an embodiment is mounted; Fig. 2 is a block diagram showing an example of the overall configuration of a driving support system according to the embodiment; Fig. 3 is a block diagram illustrating an example of a functional configuration of the driving support device according to the embodiment; Fig. 4 is a diagram illustrating an example of an acceleration time determined by the driving support device according to the embodiment at the time of forward movement of the vehicle; Fig. 5 is a diagram illustrating an example of an acceleration time determined by the driving support device according to the embodiment at the time of backward movement of the vehicle; Fig. 6 is a schematic view illustrating an example of driving assistance by the driving assistance device according to the embodiment; Fig. 7 is a schematic view illustrating an example of the driving support operation by the driving support device according to the embodiment; Fig. 8 is a schematic view illustrating an example of the driving support operation by the driving support device according to the embodiment; Fig. 9 is a flowchart illustrating a method example of a driving support process by the driving support device according to the embodiment; and Fig. 10 is a diagram illustrating an example of an acceleration time determined by a driving support device according to a comparative example. DETAILED DESCRIPTION

[0009] In the following exemplary embodiment, the same components or the like are designated by common reference numerals, and redundant description will be omitted where appropriate. (Example of vehicle configuration)

[0010] Fig. 1 is a plan view of a vehicle 10 to which a driving assistance device 20 according to an embodiment is mounted. The front, rear, left, and right sides of the vehicle 10 in Fig. 1 indicate directions seen from the driver’s seat of the vehicle 10.

[0011] The vehicle 10 of the embodiment may be, for example, an internal combustion car that uses an internal combustion engine as a power source, an electric car, a fuel cell car, or the like that uses an electric motor as a power source, or a hybrid vehicle that uses both as a power source.

[0012] Furthermore, the vehicle 10 can be equipped with various switching devices and can be equipped with devices such as various systems and components required to drive the internal combustion engine or the electric motor. Furthermore, the type, number, arrangement, and the like of devices associated with driving a wheel 13 in the vehicle 10 can be configured differently.

[0013] As in Fig. 1, the vehicle 10 includes a vehicle body 12, a plurality of wheels 13, a plurality of distance measuring units 14a to 14l, and a plurality of imaging units 16a to 16d. In a case where it is not necessary to distinguish the distance measuring units 14a to 14l, the distance measuring units are simply referred to as distance measuring unit 14. Additionally, in a case where distinction between the imaging units 16a to 16d is not required, the imaging units are simply referred to as imaging unit 16. The distance measuring units 14a to 14l and the imaging units 16a to 16d are examples of a sensor that detects environmental information of the vehicle 10.

[0014] The vehicle body 12 forms a vehicle interior in which an occupant is located. The plurality of wheels 13, the plurality of distance measuring units 14a to 14l, and the plurality of imaging units 16a to 16d are mounted on the vehicle body. In the example of Fig. 1, the vehicle body 12 comprises four wheels 13, twelve distance measuring units 14 and four imaging units 16. However, the number of distance measuring units 14 and imaging units 16 attached to the vehicle body 12 can be arbitrary.

[0015] The four wheels 13 are mounted at the front, rear, left, and right of the vehicle body 12. For example, the two front wheels 13 function as steered wheels, and the two rear wheels 13 function as driven wheels.

[0016] The distance measuring unit 14 is, for example, a sonar provided on the outer periphery of the vehicle 10 to emit a sound wave, such as an ultrasonic wave, as a detection wave and detect the detection wave reflected from an object, such as an obstacle, in the surroundings of the vehicle 10. Note that the distance measuring unit 14 may be a radar that emits a detection wave, such as a laser light, a millimeter-wave radar, or the like.

[0017] The distance measuring unit 14 collects environmental information indicating a situation around the vehicle 10 and outputs the environmental information to the driving assistance device 20. For example, the distance measuring unit 14 collects a response time, which is a time from the transmission to the reception of a detection wave, as environmental information to specify a distance between an object and the vehicle 10. The driving assistance device 20 can detect the presence or absence of an obstacle or the like around the vehicle 10 and a distance to the obstacle based on the environmental information acquired by the distance measuring unit 14.

[0018] In a case where the detection unit 14 receives a plurality of detection waves reflected from a plurality of points of an object in response to transmission of a detection wave, only the response time of an earliest received detection wave may be included in the environmental information.

[0019] The distance measuring units 14a to 14d are mounted on the front side of the vehicle body 12. Of the distance measuring units 14a to 14d, the distance measuring units 14b and 14c are also called front sonars and are mounted on the front side of the vehicle 10. The distance measuring units 14b and 14c detect an object in front of the vehicle 10 to collect environmental information in front of the vehicle 10. Furthermore, the distance measuring units 14a and 14d are also called corner sonars and are mounted on the corner portions of the front part of the vehicle 10. The distance measuring units 14a and 14d detect an object on the front outside of the vehicle 10 to collect environmental information on the front outside of the vehicle 10.

[0020] The distance measuring units 14e to 14h are mounted on the rear of the vehicle body 12. Of the distance measuring units 14e to 14h, the distance measuring units 14f and 14g are also called rear sonars and are mounted on the rear end of the vehicle 10. The distance measuring units 14f and 14g detect an object behind the vehicle 10 to collect environmental information behind the vehicle 10. Furthermore, the distance measuring units 14e and 14h are also called corner sonars and are mounted on the corner portions of the vehicle rear 10. The distance measuring units 14e and 14h detect an object on the rear outside of the vehicle 10 to collect environmental information on the rear outside of the vehicle 10.

[0021] The distance measuring units 14i to 14l are also referred to as side sonars and are mounted on the sides of the vehicle body 12. Of the distance measuring units 14i to 14l, the distance measuring units 14i and 14j are mounted on the front sides of the vehicle 10. The distance measuring units 14k and 14l are located on the rear sides of the vehicle 10. The distance measuring units 14i to 14l detect an object on the sides of the vehicle 10 to collect environmental information on the sides of the vehicle 10.

[0022] The imaging unit 16 is, for example, a digital camera with an imaging element such as a charge-coupled device (CCD) or a CMOS image sensor (CIS). The imaging unit 16 generates a captured moving image comprising a plurality of individual images or frames captured at a predetermined frame rate, or a captured still image.

[0023] The imaging unit 16 is mounted on the outer periphery of the vehicle body 12. Each imaging unit 16 includes a wide-angle lens or a fisheye lens and can capture an image in a horizontal range of, for example, 140° to 190°. The optical axis of the imaging unit 16 is oriented obliquely downward.

[0024] As a result, the imaging unit 16 collects the environmental information obtained by imaging the surroundings of the vehicle 10, including a road surface, and outputs the environmental information to the driving assistance device 20. The driving assistance device 20 can detect the presence or absence of an obstacle or the like in the surroundings of the vehicle 10, as well as the position of the obstacle, based on the environmental information collected by the imaging unit 16. Furthermore, the driving assistance device 20 can detect a parking space around the vehicle 10 and the position of the parking space based on the environmental information acquired by the imaging unit 16.

[0025] The imaging unit 16c is arranged at a longitudinal center portion of the left end of the vehicle body 12, for example, at the bottom of a left side mirror. The imaging unit 16c collects, as surrounding information, a captured image obtained by imaging an area around the lower left side of the vehicle 10. The imaging unit 16d is arranged at a longitudinal center portion of the right end of the vehicle body 12, for example, at the bottom of a right side mirror. The imaging unit 16d collects, as surrounding information, a captured image obtained by imaging an area around the lower right side of the vehicle 10.

[0026] The imaging unit 16a is mounted at a transverse center portion of the front end of the vehicle body 12, for example, at a front bumper. The imaging unit 16a collects, as surrounding information, a captured image obtained by capturing an area around the front of the vehicle 10. The imaging unit 16b is mounted at a transverse center portion of the rear end of the vehicle body 12, for example, at a rear bumper. The imaging unit 16b collects, as surrounding information, a captured image obtained by capturing an area around the rear of the vehicle 10. (Configuration example of driving support system)

[0027] Fig. 2 is a block diagram showing an example of the overall configuration of a driving assistance system 200 according to the embodiment. The driving assistance system 200 is mounted on, for example, the vehicle 10 and performs driving assistance such as parking into or exiting a parking space of the vehicle 10.

[0028] As in Fig. 2, the driving support system 200 comprises the driving support device 20, a monitor device 30, a braking system 40, an acceleration system 50, a steering system 60, a switching system 70, a vehicle speed sensor 83, the distance measuring unit 14, and the imaging unit 16. These components are interconnected such that they can send and receive information to and from each other via an on-board network NT.

[0029] The on-board network NT includes, for example, a controller area network (CAN) and a local interconnect network (LIN). The on-board network NT may be included in a portion of the driving support system 200.

[0030] The driving assistance device 20 is configured as a microcomputer, e.g., an electronic control unit (ECU), and performs the driving assistance of the vehicle 10.

[0031] The driving assistance device 20 includes a central processing unit (CPU) 21, a display control circuit 23, a solid-state drive (SSD) 24, a read-only memory (ROM) 25, and a random access memory (RAM) 26. The CPU 21, the ROM 25, and the RAM 26 may be integrated into the same housing.

[0032] The CPU 21 is an example of a hardware processor that reads a program stored in a non-volatile device such as the ROM 25 and performs various calculation processing and control according to the program.

[0033] The ROM 25 stores various programs, parameters required for program execution, and the like. The RAM 26 temporarily stores various data used in calculations by the CPU 21. The SSD 24 is a rewritable, non-volatile storage device that retains data when the driving assistance device 20 is turned off.

[0034] Among the calculation processing performed by the driving support device 20, the display control circuit 23 mainly performs image processing of an image obtained from the imaging unit 16, data conversion of an image for display to be displayed on a display unit 31 included in the monitor device 30 (which will be described later), and the like.

[0035] The braking system 40 includes a braking unit 41, a braking control unit 42 and a braking unit sensor 43 and controls the deceleration of the vehicle 10.

[0036] The brake unit 41 is a device that includes, for example, a brake and a brake pedal, and brakes or decelerates the vehicle 10. The brake control unit 42 is, for example, a microcomputer that includes a hardware processor such as a CPU. The brake control unit 42 controls the brake unit 41 based on an instruction from the driving support device 20 to control the deceleration of the vehicle 10. The brake unit sensor 43 is, for example, a position sensor and detects the position of the brake pedal included in the brake unit 41. The brake unit sensor 43 outputs the detected brake pedal position to the on-board network NT.

[0037] The acceleration system 50 includes an acceleration control unit 51, an acceleration control unit 52, and an acceleration unit sensor 53, and controls an acceleration of the vehicle 10.

[0038] The acceleration unit 51 is a device including, for example, an accelerator pedal, and accelerates the vehicle 10. The acceleration control unit 52 is, for example, a microcomputer including a hardware processor such as a CPU. The acceleration control unit 52 controls the acceleration unit 51 based on an instruction from the driving support device 20 to control the acceleration of the vehicle 10. The acceleration unit sensor 53 is, for example, a position sensor and detects the position of the accelerator pedal included in the acceleration unit 51. The acceleration unit sensor 53 outputs the detected accelerator pedal position to the on-board network NT.

[0039] The steering system 60 includes a steering unit 61, a steering control unit 62 and a steering unit sensor 63 and controls a direction of travel of the vehicle 10.

[0040] The steering unit 61 is a device that includes, for example, a steering wheel and steers the traveling direction of the vehicle 10 by turning the steered wheels of the vehicle 10. The steering control unit 62 is, for example, a microcomputer that includes a hardware processor such as a CPU. The steering control unit 62 controls the steering unit 61 based on an instruction from the driving support device 20 to control the traveling direction of the vehicle 10. The steering unit sensor 63 is, for example, an angle sensor that includes a Hall element and detects a steering angle, which is a rotation angle of the steering unit 61. The steering unit sensor 63 outputs the detected steering angle of the steering unit 61 to the on-board network NT.

[0041] The switching system 70 includes a switching unit 71, a switching control unit 72, and a switching unit sensor 73, and controls a switching ratio of the vehicle 10.

[0042] The switching unit 71 is a device that includes, for example, a shift lever, and changes the shift ratio of the vehicle 10. The shift control unit 72 is, for example, a microcomputer that includes a hardware processor such as a CPU. The shift control unit 72 controls the switching unit 71 based on an instruction from the driving support device 20 to control the shift ratio of the vehicle 10. The switching unit sensor 73 is, for example, a position sensor and detects the position of the shift lever included in the switching unit 71. The switching unit sensor 73 outputs the detected shift lever position to the on-board network NT.

[0043] The vehicle speed sensor 83 includes, for example, a Hall element provided near the wheel 13 of the vehicle 10 and detects a rotation amount or rotation speed per unit time of the wheel 13. The vehicle speed sensor 83 outputs a wheel speed pulse number indicating the detected rotation amount or rotation speed to the on-board network NT as a sensor value for calculating the speed (vehicle speed) of the vehicle 10. The driving support device 20 can calculate the speed, movement amount, and the like of the vehicle 10 based on the sensor value acquired from the vehicle speed sensor 83.

[0044] The monitor device 30 is provided on a dashboard or the like in the vehicle interior of the vehicle 10 and includes the display unit 31 and an input unit 32.

[0045] The display unit 31 is a device such as a liquid crystal display (LCD) or an organic electroluminescent display (OELD). The display unit 31 displays, for example, an image based on image data transmitted from the driving support device 20 and an image for receiving an operation instruction instructing switching between automatic and manual driving.

[0046] The input unit 32 is, for example, a touch panel provided on a screen of the display unit 31. The input unit 32 is configured to enable the transmission of content displayed on the screen by the display unit 31. As a result, the input unit 32 enables an occupant to visually recognize the display content of the display unit 31.

[0047] The input unit 32 receives an instruction input by the occupant touching a position corresponding to the display contents of the display unit 31, and transmits the instruction to the driving support device 20 via the on-board network NT. Note that the input unit 32 is not limited to the touch panel, but may also be a push button switch or the like.

[0048] Fig. 3 is a block diagram showing an example of a functional configuration of the driving support device 20 according to the embodiment. As shown in Fig. 3, the driving assistance device 20 comprises, as functional units, a display control unit 201, an acquisition unit 202, a detection unit 203, a route calculation unit 204, an acceleration determination unit 205, a motion control unit 206, and a storage unit 207.

[0049] These functional units are realized, for example, by the above-described CPU 21 reading and executing a program stored in a device such as the ROM 25. Alternatively, these functional units are realized by the display control circuit 23, the SSD 24, the ROM 25, the RAM 26, and the like, which operate according to the program under the control of the CPU 21.

[0050] It should be noted that some or all of these functional units may be configured by hardware, e.g., by a circuit comprising an application-specific integrated circuit (ASIC).

[0051] The display control unit 201 generates content to be displayed on the display unit 31 of the monitor device 30 and causes the display unit 31 to display the content. That is, the display control unit 201 causes the display unit 31 to display, for example, a notification screen indicating that a parking space in which the vehicle 10 can be parked has been detected, a selection screen for starting, pausing, or canceling the driving assistance, or an environmental image of the vehicle 10 during the driving assistance.

[0052] The acquisition unit 202 acquires, as the surroundings information of the vehicle 10, the transmission / reception information of a sound wave from the distance measuring unit 14 and a captured image of the surroundings of the vehicle 10 from the imaging unit 16.

[0053] The detection unit 203 detects an obstacle, a parking section, a parking space and the like around the vehicle 10 based on the environmental information acquired by the acquisition unit 202.

[0054] The obstacle can be various objects, such as another vehicle, a wall, a pillar, a fence, a ledge, a step, or a wheel stop. The obstacle can also be a person or something similar walking in a parking lot.

[0055] The parking section is intended for parking the vehicle 10 and is an area divided by, for example, a dividing line, a frame line, a straight line, a band, or a step. The parking space is a parking section in which the vehicle 10 can be parked, that is, a parking section in which there is no obstacle, such as another vehicle, to the parking of the vehicle 10. The dividing line, frame line, straight line, band, step, or the like as described above is an example of an object indicating the parking space, and becomes a target used when the driving support device 20 causes the vehicle 10 to enter or exit the parking space, in assisting the vehicle 10 to enter or exit the parking space.

[0056] Upon receiving an instruction to start driving assistance from a driver or the like of the vehicle 10, the detection unit 203 detects, for example, the presence or absence of an obstacle, a distance between the vehicle 10 and the obstacle, and the like based on a detection result of the detection unit 14. Furthermore, the detection unit 203 detects the presence or absence of an obstacle, a parking section, the positions (orientations) of the obstacle and the parking section with respect to the vehicle 10, and the shapes, sizes, heights, and the like of the obstacle and the parking section through image processing based on an image acquired by, for example, the imaging unit 16.

[0057] By combining these detection results, the detection unit 203 extracts information about whether or not there is an obstacle around the vehicle 10, whether or not the obstacle can hinder the travel of the vehicle 10, whether or not there is a parking section around the vehicle 10, whether or not it is possible to park the vehicle 10 in the parking section, that is, whether or not the parking section can be used as a parking space, or the like.

[0058] The route calculation unit 204 calculates a target position to which the vehicle 10 is to be guided based on the detection result of the detection unit 203 and calculates a movement route along which the vehicle 10 is to be moved to the target position.

[0059] When the vehicle 10 is parking, the target position is a parking space detected by the detection unit 203. When the vehicle 10 is exiting, the target position is a predetermined location from which the vehicle 10 can safely depart, such as a path provided between several parking sections.

[0060] Furthermore, the route calculation unit 204 can calculate a steering wheel reversal position if necessary. In a case where it is difficult to park or exit the vehicle 10 by only moving backward or forward, one or more steering wheel reversal positions are set.

[0061] The route calculation unit 204 calculates the movement route of the vehicle 10 from the current position of the vehicle 10 to the target position calculated as described above, in order to guide the vehicle 10 to the target position. As described above, the movement route may include the steering wheel reversal position. In this case, the route calculation unit 204 calculates the movement route from the current position of the vehicle 10 to the target position via the steering wheel reversal position.

[0062] In this way, the route calculation unit 204 calculates the movement route for parking, e.g., reversing into a parking space or forward parking. Furthermore, the route calculation unit 204 calculates the movement route for exiting a parking space, e.g., reversing out of a parking space or forward exit of a parking space.

[0063] The motion control unit 206 controls each unit of the vehicle 10 to move the vehicle 10 during the driving assistance of the vehicle 10. Specifically, the motion control unit 206 controls all or part of the braking system 40, the accelerator system 50, the steering system 60, and the shifting system 70 to move the vehicle 10 to the target position according to the above movement route. At this time, the motion control unit 206 moves the vehicle 10 while receiving feedback from the respective sensors such as the braking unit sensor 43, the accelerator unit sensor 53, the steering unit sensor 63, the shifting unit sensor 73, and the vehicle speed sensor 83.

[0064] Furthermore, in the driving assistance device 20, a suitable speed limit is set in advance according to a current situation of the vehicle 10 subject to driving assistance. More specifically, the speed limit is a speed value at which the vehicle 10 can be safely moved in a current situation, for example, depending on whether the vehicle 10 is currently inside or outside a parking space, whether the vehicle 10 is moving forward or backward, and whether an obstacle is within a predetermined range of the vehicle 10. The storage unit 207 stores, for example, the settings of the speed limit.

[0065] The motion control unit 206 refers to the data in the storage unit 207, selects the speed limit according to the current situation of the vehicle 10, and moves the vehicle 10 within the speed limit. At this time, the motion control unit 206 could only move the vehicle 10 at a speed corresponding to the speed limit. In this case, the speed limit can also be said to be a target speed of the vehicle 10.

[0066] As described above, it is possible to complete the parking and reversing of the vehicle 10 in a short time and at the same time ensure safe travel of the vehicle 10 by moving the vehicle 10 at the highest possible speed within the current speed limit.

[0067] Note that the detection unit 203 continues to acquire the surrounding information from the distance measuring unit 14 and the imaging unit 16 even after the motion control unit 206 has started the movement of the vehicle 10. The route calculation unit 204 described above appropriately recalculates the movement route based on the detection result of the detection unit 203. After the movement route is recalculated, the motion control unit 206 continues the movement of the vehicle 10 to finely adjust the position of the vehicle 10 accordingly.

[0068] The acceleration determination unit 205 appropriately determines the acceleration of the vehicle 10 based on a predetermined acceleration time and the speed limit currently selected by the motion control unit 206. The acceleration time is set, for example, for each of the forward and backward movements of the vehicle 10, and these settings are stored, for example, in the storage unit 207. The acceleration time at the time of the forward movement of the vehicle 10 is an example of a first acceleration time. The acceleration time at the time of the backward movement of the vehicle 10 is an example of a second acceleration time.

[0069] After selecting the speed limit according to the current situation of the vehicle 10, the above-described motion control unit 206 accelerates the vehicle 10 with the acceleration determined by the acceleration determination unit 205 and controls the vehicle 10 so that the speed of the vehicle 10 reaches the selected speed limit.

[0070] The storage unit 207 stores, for example, a program executed by the CPU 21 of the driving assistance device 20 and various control parameters required for the operation of the driving assistance device 20. Furthermore, as described above, the storage unit 207 stores the speed limit settings according to the current situation of the vehicle 10, the acceleration time at the time of forward movement and the acceleration time at the time of reverse movement, and the like. (Example for determining the acceleration time)

[0071] Next, an example of the acceleration time determined by the driving support device 20 of the embodiment will be explained with reference to FIG. Fig. 4 and Fig. 5 described.

[0072] Fig. 4 is a diagram illustrating an example of an acceleration time AD at the time of forward movement of the vehicle 10 determined by the driving support device 20 according to the embodiment. Fig. 5 is a diagram illustrating an example of an acceleration time RT at the time of backward movement of the vehicle 10 determined by the driving support device 20 according to the embodiment.

[0073] In the diagrams of the Fig. 4 and Fig. 5 the horizontal axis represents time (s) and the vertical axis represents the target speed (m / s).

[0074] As in the Fig. 4 and Fig. For example, as shown in FIG. 5, when performing motion control of the vehicle 10, the driving support device 20 of the embodiment controls the vehicle 10 to reach a target speed within the acceleration time AD or the acceleration time RT determined in advance. That is, in either case where a speed limit value A is set as the target speed or a speed limit value B lower than the speed limit value A is set as the target speed, the vehicle 10 is controlled to reach each target speed within the acceleration time AD or the acceleration time RT determined to be constant according to the traveling direction of the vehicle 10, such as forward movement or backward movement.

[0075] Therefore, when the speed limit B, which is lower than the speed limit A, is set as the target speed, the acceleration of the vehicle 10 becomes lower than when the speed limit A is set as the target speed.

[0076] Among these acceleration times AD and RT, the acceleration control unit 205 sets the acceleration time AD for the case where the motion control unit 206 should move the vehicle 10 forward. The acceleration control unit 205 sets the acceleration time RT for the case where the motion control unit 206 should move the vehicle 10 backward.

[0077] In addition, the acceleration time RT during the backward movement of the vehicle 10 is set longer than the acceleration time AD during the forward movement of the vehicle 10. Therefore, at the same target speed, the acceleration of the vehicle 10 at the time of the backward movement, which is shown by the solid line in Fig. 5 is smaller than the acceleration at the time of forward movement, which is shown by the dashed line in Fig. 5 is displayed. (Operation example of a driving assistance device)

[0078] Next, an operation example of the driving support device 20 of the embodiment will be described with reference to Fig. 6 to 8 described.

[0079] Fig. 6 to 8 are schematic views illustrating examples of a driving support operation by the driving support device 20 according to the embodiment. Fig. 6 to 8 describe an example in which the vehicle 10 is parked backwards.

[0080] As in Fig. 6, in a parking lot or the like in which a plurality of parking sections are arranged, it is assumed that a parking section is free while it is located between parking sections in which other vehicles 91 are parked.

[0081] When the vehicle 10 is stopped at a predetermined position, for example, near the free parking section, the detection unit 203 of the driving assistance device 20 mounted on the vehicle 10 detects, for example, this free parking section from the plurality of parking sections as a parking space PA in which the vehicle 10 can be parked. The display unit 201 of the driving assistance device 20 causes the display unit 31 of the monitor device 30 to display the detected parking space PA.

[0082] When it is desired to park the vehicle 10 in the parking space PA, the driver or the like of the vehicle 10 can control the driving support device 20 via the input unit 32 (see Fig. 2) instruct the monitor device 30 or the like to perform the driving assistance. The driving assistance device 20 then starts the driving assistance of the vehicle 10.

[0083] As in Fig. As shown in Figure 7, the route calculation unit 204 of the driving assistance device 20 calculates a movement route TR. The movement route TR runs, for example, from a stop position PP of the vehicle 10 stopped near the parking space PA via a steering wheel reversal position SP in a forward movement direction of the vehicle 10 to a target position DP located in the parking space PA in a backward movement direction of the vehicle 10 from the steering wheel reversal position SP.

[0084] The movement control unit 206 of the driving support device 20 starts moving the vehicle 10 along the movement route TR according to the calculation result of the route calculation unit 204.

[0085] First, the motion control unit 206 moves the vehicle 10 forward from the stop position PP toward the steering wheel reversal position SP. At this time, the motion control unit 206 selects the speed limit according to the current situation of the vehicle 10.

[0086] In the example of Fig. 7, the vehicle 10 is outside the parking space PA at this time, and the motion control unit 206 is to move the vehicle 10 forward. Furthermore, it is assumed that there is no obstacle within a predetermined area around the vehicle 10. The motion control unit 206 selects the speed limit according to such a situation of the vehicle 10.

[0087] The acceleration determination unit 205 calculates the acceleration at which the vehicle 10 reaches the speed of the speed threshold selected by the motion control unit 206 within the acceleration time at the time of forward movement, based on the speed threshold selected by the motion control unit 206 and the acceleration time at the time of forward movement stored in advance in the storage unit 207. Such an acceleration is calculated, for example, by equation (1) described below. Acceleration(m / s2)=Speed ​​limit(m / s) / Acceleration time(s)

[0088] For example, the motion control unit 206 moves the vehicle 10 forward with the selected speed limit as the target speed at the acceleration determined by the acceleration determination unit 205 and moves the vehicle 10 from the stop position PP to the steering wheel reversal position SP while maintaining the speed of the vehicle 10 within the speed limit.

[0089] Next, the motion control unit 206 moves the vehicle 10 backward from the steering wheel reversal position SP toward the target position DP. At this time, the motion control unit 206 selects the speed limit according to the current situation of the vehicle 10.

[0090] On the line marked by the solid line in Fig. 7, the vehicle 10 is still outside the parking space PA, and the motion control unit 206 is to move the vehicle 10 backward. Furthermore, it is assumed that there is no obstacle within a predetermined area around the vehicle 10. The motion control unit 206 selects the speed limit according to such a situation of the vehicle 10.

[0091] The acceleration determination unit 205 calculates the acceleration at which the vehicle 10 reaches the speed of the speed limit selected by the motion control unit 206 within the acceleration time at the time of backward movement, for example, according to the equation (1) described above based on the speed limit selected by the motion control unit 206 and the acceleration time at the time of backward movement stored in advance in the storage unit 207.

[0092] For example, the motion control unit 206 moves the vehicle 10 backward with the acceleration determined by the acceleration determination unit 205 and moves the vehicle 10 from the steering wheel reversal position SP to the target position DP while maintaining the speed of the vehicle 10 within the speed limit.

[0093] As in Fig. As shown in Figure 8, the motion control unit 206 continues to move the vehicle 10 backward toward the target position DP. At this time, the motion control unit 206 selects the speed limit according to the current situation of the vehicle 10.

[0094] In the example of Fig. 8, the vehicle 10 has entered the parking space PA, and the motion control unit 206 is to continue moving the vehicle 10 backward. Furthermore, it is assumed that an obstacle, such as another vehicle 91, is located within a predetermined area around the vehicle 10. The motion control unit 206 selects the speed limit according to such a situation of the vehicle 10.

[0095] The acceleration determination unit 205 calculates the acceleration at which the vehicle 10 reaches the speed of the speed limit selected by the motion control unit 206 within the acceleration time at the time of backward movement, for example, according to the equation (1) described above based on the speed limit selected by the motion control unit 206 and the acceleration time at the time of backward movement stored in advance in the storage unit 207.

[0096] For example, the motion control unit 206 moves the vehicle 10 backward with the selected speed limit as the target speed at the acceleration determined by the acceleration determination unit 205 and moves the vehicle 10 to the target position DP while maintaining the speed of the vehicle 10 within the speed limit.

[0097] Under the control of the driving support device 20 as described above, the vehicle 10 is parked at the target position DP in the parking space PA, and the driving support by the driving support device 20 is completed.

[0098] As described above, in the examples of Fig. 6 to 8, the selection of the speed limit and acceleration time, as well as the calculation of the acceleration, are performed a total of three times on the movement route TR. However, the above description is for convenience only, and the current situation of the vehicle 10 on the movement route TR may change from time to time. Therefore, in actual control, the movement control unit 206 and the acceleration determination unit 205 may repeat the above processing at short time intervals on the order of, for example, microseconds.

[0099] In addition, the Fig. 6 to 8, an example is described in which the vehicle 10 is reverse-parked in a vertical parking space. However, the driving support device 20 similarly controls the vehicle 10 not only during vertical reverse parking, but also during vertical forward parking, vertical forward / backward parking, parallel parking, or the like. (Processing example of a driving assistance device)

[0100] Hereinafter, an example of a driving support process by the driving support device 20 of the embodiment will be described with reference to Fig. 9 described. Fig. 9 is a flowchart illustrating a process example of the driving support process by the driving support device 20 according to the embodiment.

[0101] As in Fig. As shown in Figure 9, the driving assistance device 20 begins control when a command to start driving assistance is received from a driver or the like of the vehicle 10 (step S101). The route calculation unit 204 calculates the movement route from the stop position to the target position of the vehicle 10 at that time (step S102).

[0102] The acceleration determination unit 205 refers to the detection result or the like of the switching unit sensor 73 included in the switching system 70 (see Fig. 2) Reference and determines whether the shift lever position of the vehicle 10 at that time is a drive position or not (step S103). In a case where the shift lever position is the drive position (step S103: Yes), the acceleration determination unit 205 sets the acceleration time for forward movement (step S104). In a case where the shift lever position is a position other than the drive position, such as a reverse position (step S103: No), the acceleration determination unit 205 sets the acceleration time for reverse movement (step S105).

[0103] On the other hand, the motion control unit 206 sets the speed threshold according to the situation of the vehicle 10 at that time (step S106). The acceleration determination unit 205 calculates the acceleration at which the speed of the vehicle 10 reaches the speed threshold based on the acceleration time set in the processing of step S104 or step S105 and the speed threshold set in the processing of step S106 by the motion control unit 206 (step S107).

[0104] The acceleration determination unit 205 accelerates the vehicle 10 with acceleration calculated by the acceleration determination unit 205 in the processing of step S107, using the speed limit value set in the processing of step S106 as a target speed, and performs the motion control of the vehicle 10 (step S108).

[0105] The motion control unit 206 determines whether the driving assistance process is completed by the vehicle 10 reaching the target position or the like (step S109). If the driving assistance process continues (step S109: No), the processing from step S103 is repeated until the driving assistance process is completed (step S109: Yes).

[0106] The driving support process by the driving support device 20 of the embodiment ends in this way. (Overview)

[0107] The driving assistance device performs driving assistance of the vehicle based on the vehicle's surrounding information from various sensors such as the distance measuring unit and the imaging unit. However, a vehicle occupant, including a driver, may feel uncomfortable in a predetermined situation during driving assistance. This point will be discussed with reference to Fig. 10 described.

[0108] Fig. 10 is a diagram illustrating an example of an acceleration time determined by a driving support device according to a comparative example. In the diagram of Fig. 10 the horizontal axis represents time (s) and the vertical axis represents the target speed (m / s).

[0109] As in Fig.10, the driving support device of the comparative example accelerates the vehicle within a predetermined acceleration range, e.g., at the same acceleration regardless of which of the speed limit A and the speed limit B lower than the speed limit A is the target speed of the vehicle, and causes the speed of the vehicle to reach either the speed limit A or B.

[0110] Therefore, when speed limit B, which is lower than speed limit A, is set as the target speed, the speed reaches the target speed faster than when speed limit A is set as the target speed. That is, the acceleration time B' required to reach speed limit B is shorter than the acceleration time A' required to reach speed limit A.

[0111] Furthermore, the above control by the driving assistance device of the comparative example does not change between the forward and backward movement of the vehicle. That is, the acceleration time A' required to reach the speed limit A can be the same between the forward and backward movement of the vehicle, and the acceleration time B' required to reach the speed limit B can be the same between the forward and backward movement of the vehicle.

[0112] For example, if the speed limit is low and the acceleration time is short, the occupant will feel as if the vehicle is starting suddenly, and the occupant may feel uncomfortable. When the vehicle is moving backward, this feeling tends to be further amplified.

[0113] According to the driving assistance device 20 of the embodiment, the acceleration at which the vehicle 10 reaches the target speed is determined based on the predetermined acceleration time and the speed limit value selected by the motion control unit 206.

[0114] As described above, since the acceleration time is determined in advance regardless of the speed limit, it is possible to improve the ride comfort for the occupant, even when the speed limit is low, for example. Furthermore, since the acceleration time is determined in advance, it is possible to reduce unnecessary time for parking and reversing, while improving the ride comfort for the occupant, and to complete the process quickly.

[0115] According to the driving assistance device 20 of the embodiment, the acceleration time for forward movement is used when the vehicle 10 is moving forward, and the acceleration time for reverse movement is used when the vehicle 10 is moving backward. In this way, different acceleration times are set between the forward movement and the reverse movement of the vehicle 10, at which the occupant has a different feeling even with the same acceleration, so that finer control can be achieved.

[0116] According to the driving assistance device 20 of the embodiment, the acceleration time at the time of reversing the vehicle 10 is set longer than the acceleration time at the time of forward movement. This makes it possible to improve the ride comfort for the occupant even at the time of reversing the vehicle 10, which tends to give the occupant the impression that the vehicle 10 has accelerated suddenly.

[0117] According to the driving support device 20 of the embodiment, the acceleration time at the time of forward movement and the acceleration time at the time of reverse movement are fixed times. Thus, the acceleration time is set exclusively for the forward movement and the reverse movement, which can prevent the control from becoming complicated by setting a large number of acceleration times or the like.

[0118] In the above embodiment, the driving assistance device 20 is mounted on the vehicle 10. However, the driving assistance device 20 does not necessarily have to be mounted on the vehicle 10. For example, the driving assistance device may acquire the vehicle's surrounding information from various sensors located remotely from the vehicle and perform driving assistance of the vehicle remotely. QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] WO 2020 / 066 331 A [0003, 0004] JP 5 257 647 B2 [0003, 0004]

Claims

[1] A driving assistance device (20) that performs driving assistance of a vehicle (10) based on environmental information collected by a plurality of sensors (14a to 14l, 16a to 16d) provided in the vehicle (10), the driving assistance device (20) comprising: a route calculation unit (204) configured to calculate a movement route (TR) of the vehicle (10) to a target position (DP) based on the environmental information from the plurality of sensors (14a to 14l, 16a to 16d); a movement control unit (206) configured to move the vehicle (10) along the movement route (TR) at a target speed within a speed limit value (A, B) according to a current situation of the vehicle (10); and an acceleration determination unit (205) configured to determine the acceleration at which the vehicle (10) reaches the target speed based on a predetermined acceleration time (AD, RT) and the speed limit value (A, B). [2] The driving support device (20) according to claim 1, wherein the acceleration determination unit (205) uses a first acceleration time (AD) to move the vehicle (10) forward, and a second acceleration time (RT) is used to move the vehicle (10) backward. [3] The driving support device (20) according to claim 2, wherein the second acceleration time (RT) is set to a time longer than the first acceleration time (AD). [4] The driving support device (20) according to claim 2 or 3, wherein each of the first and second acceleration times (AD, RT) is a fixed time.

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