Driving assistance device

Abstract

Provided is a driving assistance device capable of improving riding comfort of an occupant of a vehicle during execution of driving assistance. A driving assistance device according to an embodiment performs driving assistance of a vehicle on the basis of peripheral information collected by a plurality of sensors provided in the vehicle, the driving assistance device being provided with: a route calculation unit that calculates a movement route of the vehicle to a target position on the basis of the peripheral information from the plurality of sensors; a movement control unit that moves the vehicle along the movement path at a target speed within a speed limit value corresponding to the condition of the vehicle at each time; and an acceleration determination unit that determines an acceleration for causing the vehicle to reach the target speed on the basis of a predetermined acceleration time and the speed limit value.

Description

Technical Field

[0001] The present invention relates to a driving assistance device. Background Art

[0002] There is a driving assistance device that automatically parks and moves a vehicle to a parking area. During the driving assistance, a speed limit value is set according to the vehicle's condition at each time. The driving assistance device accelerates the vehicle at an acceleration within a predetermined range, brings the vehicle speed to, for example, the set speed limit value, and moves the vehicle to a target position.

[0003] For example, in the technology of Patent Document 1, the time variation of the target value of acceleration when the vehicle decelerates, i.e., the acceleration curve, is set according to the distance to the target position, so that the vehicle can be stopped at the target position. In addition, in the technology of Patent Document 2, the acceleration of the vehicle is limited to within the acceleration of the upper limit set according to the speed of the vehicle, so that the occurrence of an unexpected acceleration state can be suppressed.

[0004] Patent Document 1: International Publication No. 2020 / 066331

[0005] Patent Document 2: Japanese Patent No. 5257647

[0006] However, in the technology of Patent Document 1, due to the difference in distance to the target position, the occupant of the vehicle may feel a sudden acceleration. In addition, in the technology of Patent Document 2, even if the unexpected acceleration state is suppressed and the safe driving state is maintained, the occupant may feel a sudden acceleration. Summary of the invention

[0007] The present invention has been made in view of the above circumstances, and provides a driving assistance device capable of improving the riding comfort of a vehicle occupant while driving assistance is being performed.

[0008] In order to solve the above-mentioned problems and achieve the purpose, a driving assistance device of an embodiment performs driving assistance for the above-mentioned vehicle based on surrounding information collected by multiple sensors installed in the vehicle, and the above-mentioned driving assistance device includes: a path calculation unit, which calculates a movement path of the above-mentioned vehicle to a target position based on the above-mentioned surrounding information from the above-mentioned multiple sensors; a movement control unit, which makes the above-mentioned vehicle move along the above-mentioned movement path at a target speed within a speed limit value corresponding to the condition of the above-mentioned vehicle at each time; and an acceleration determination unit, which determines the acceleration for making the above-mentioned vehicle reach the above-mentioned target speed based on a predetermined acceleration time and the above-mentioned speed limit value.

[0009] The driving assistance device of the embodiment can improve the riding comfort of the occupant of the vehicle during the execution of driving assistance. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 It is a plan view of a vehicle equipped with the driving assistance device according to the embodiment.

[0011] Figure 2 This is a block diagram showing an example of the overall configuration of a driving assistance system according to the embodiment.

[0012] Figure 3 This is a block diagram showing an example of a functional configuration of a driving assistance device according to an embodiment.

[0013] Figure 4 This is a graph showing an example of the acceleration time of the vehicle when moving forward determined by the driving assistance device according to the embodiment.

[0014] Figure 5 This is a graph showing an example of the acceleration time of the vehicle during reverse movement determined by the driving assistance device according to the embodiment.

[0015] Figure 6 This is a schematic diagram for explaining an example of a driving assistance operation performed by the driving assistance device according to the embodiment.

[0016] Figure 7 This is a schematic diagram for explaining an example of a driving assistance operation performed by the driving assistance device according to the embodiment.

[0017] Figure 8 This is a schematic diagram for explaining an example of a driving assistance operation performed by the driving assistance device according to the embodiment.

[0018] Fig. 9 This is a flowchart showing an example of a procedure of a driving assistance process performed by the driving assistance device according to the embodiment.

[0019] Fig.10 This is a graph showing an example of the acceleration time determined by the driving assistance device according to the comparative example.

[0020] Description of Reference Numerals

[0021] 10... vehicle; 14... distance measuring unit; 16... photographing unit; 20... driving assistance device; 200... driving assistance system; 201... display control unit; 202... acquisition unit; 203... detection unit; 204... path calculation unit; 205... acceleration determination unit; 206... movement control unit; 207... storage unit. DETAILED DESCRIPTION

[0022] The same components in the following exemplary embodiments and the like are denoted by common reference numerals, and duplicate descriptions are omitted as appropriate.

[0023] (Example of vehicle structure)

[0024] Figure 1 It is a plan view of a vehicle 10 equipped with a driving assistance device 20 according to the embodiment. Figure 1 The front, rear, left, and right of the vehicle 10 in FIG. 1 represent directions when viewed from a driver's seat of the vehicle 10 .

[0025] The vehicle 10 of the embodiment may be, for example, an internal combustion engine vehicle using an internal combustion engine as a driving source, an electric vehicle or a fuel cell vehicle using an electric motor as a driving source, or a hybrid vehicle using both of them as driving sources.

[0026] In addition, the vehicle 10 can be equipped with various transmission devices and various systems, components and other devices required to drive the internal combustion engine or the electric motor. In addition, the installation method, number and layout of the devices related to the driving of the wheels 13 in the vehicle 10 can be set in various ways.

[0027] like Figure 1 As shown, 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 addition, when it is not necessary to distinguish the distance measuring units 14a to 14l, only the distance measuring unit 14 is recorded. In addition, when it is not necessary to distinguish the imaging units 16a to 16d, only the imaging unit 16 is recorded. These distance measuring units 14a to 14l and the imaging units 16a to 16d are examples of sensors that collect information about the surroundings of the vehicle 10.

[0028] The vehicle body 12 constitutes a vehicle room for passengers to sit in. A plurality of wheels 13 , a plurality of distance measuring units 14 , and a plurality of imaging units 16 are mounted on the vehicle body 12 . Figure 1 In the example of FIG. 1 , the vehicle body 12 includes 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 mounted on the vehicle body 12 is arbitrary.

[0029] The four wheels 13 are provided at the front, rear, left, and right of the vehicle body 12. The two front wheels 13 function as, for example, steering wheels, and the two rear wheels 13 function as, for example, drive wheels.

[0030] The distance measuring unit 14 is, for example, a sonar that is provided at the outer periphery of the vehicle 10, transmits sound waves such as ultrasonic waves as detection waves, and captures the detection waves reflected by objects such as obstacles existing around the vehicle 10. Alternatively, the distance measuring unit 14 may be a radar or millimeter wave radar that transmits detection waves such as lasers.

[0031] The distance measuring unit 14 collects surrounding information indicating the conditions around the vehicle 10 and outputs it to the driving assistance device 20. For example, the distance measuring unit 14 collects the response time, which is the time from the transmission of the detection wave to the reception of the detection wave, as surrounding information for specifying the distance between the object and the vehicle 10. The driving assistance device 20 can detect the presence or absence of obstacles and the like around the vehicle 10 and the distance to the obstacles based on the surrounding information collected by the distance measuring unit 14.

[0032] Furthermore, when the distance measuring unit 14 receives a plurality of detection waves reflected from a plurality of positions of the object with respect to one transmission of a detection wave, it may include only the response time of the earliest received detection wave in the surrounding information.

[0033] The distance measuring units 14a to 14d are provided at the front of the vehicle body 12. The distance measuring units 14b and 14c of the distance measuring units 14a to 14d are also called front sonars and are provided at the front end of the vehicle 10. The distance measuring units 14b and 14c detect objects in front of the vehicle 10 and collect peripheral information in front of the vehicle 10. In addition, the distance measuring units 14a and 14d are also called corner sonars and are provided at the corner portion of the front of the vehicle 10. The distance measuring units 14a and 14d detect objects outside the front of the vehicle 10 and collect peripheral information outside the front of the vehicle 10.

[0034] The distance measuring units 14e to 14h are provided at the rear of the vehicle body 12. The distance measuring units 14f and 14g of the distance measuring units 14e to 14h are also called rear sonars and are provided at the rear end of the vehicle 10. The distance measuring units 14f and 14g detect objects behind the vehicle 10 and collect peripheral information behind the vehicle 10. In addition, the distance measuring units 14e and 14h are also called corner sonars and are provided at the corners of the rear of the vehicle 10. The distance measuring units 14e and 14h detect objects outside the rear of the vehicle 10 and collect peripheral information outside the rear of the vehicle 10.

[0035] The distance measuring units 14i to 14l are also called side sonars, and are provided on the side of the vehicle body 12. The distance measuring units 14i and 14j of the distance measuring units 14i to 14l are provided on the side of the front of the vehicle 10. The distance measuring units 14k and 14l are provided on the side of the rear of the vehicle 10. The distance measuring units 14i to 14l detect objects on the side of the vehicle 10 and collect peripheral information on the side of the vehicle 10.

[0036] The imaging unit 16 is a digital camera having an imaging element such as a CCD (Charge Coupled Device) or a CIS (CMOS Image Sensor) built in. The imaging unit 16 generates a captured image including a moving image or a still image of a plurality of frame images captured at a predetermined frame rate.

[0037] The imaging unit 16 is provided at the outer periphery of the vehicle body 12 and each has a wide-angle lens or a fish-eye lens, and can capture, for example, a range of 140° to 190° in the horizontal direction. The optical axis of the imaging unit 16 is set to face obliquely downward.

[0038] Thus, the imaging unit 16 collects surrounding information obtained by imaging the surroundings of the vehicle 10 including the road surface and outputs it to the driving assistance device 20. The driving assistance device 20 can detect the presence or absence of obstacles and the like around the vehicle 10 and the positions of the obstacles based on the surrounding information collected by the imaging unit 16. In addition, the driving assistance device 20 can detect parking areas around the vehicle 10 and the positions of the parking areas based on the surrounding information collected by the imaging unit 16.

[0039] The imaging unit 16c is provided at the center of the front-to-back direction of the left end of the vehicle body 12, for example, the lower surface of the left rearview mirror. The imaging unit 16c collects the captured image obtained by capturing the lower left side of the vehicle 10 as the surrounding information. The imaging unit 16d is provided at the center of the front-to-back direction of the right end of the vehicle body 12, for example, the lower surface of the right rearview mirror. The imaging unit 16d collects the captured image obtained by capturing the surrounding area of ​​the lower right side of the vehicle 10 as the surrounding information.

[0040] The imaging unit 16a is provided at the center of the front end of the vehicle body 12 in the left-right direction, such as the front bumper. The imaging unit 16a collects the captured images obtained by capturing the front of the vehicle 10 as the surrounding information. The imaging unit 16b is provided at the center of the rear end of the vehicle body 12 in the left-right direction, such as the rear bumper. The imaging unit 16b collects the captured images obtained by capturing the rear of the vehicle 10 as the surrounding information.

[0041] (Configuration example of driving assistance system)

[0042] Figure 2 2 is a block diagram showing an example of the overall configuration of the driving assistance system 200 according to the embodiment. The driving assistance system 200 is mounted on the vehicle 10, for example, and performs driving assistance such as parking the vehicle 10 in a parking area or exiting the vehicle 10 from a parking area.

[0043] like Figure 2 As shown, the driving assistance system 200 includes a driving assistance device 20, a monitoring device 30, a braking system 40, an acceleration system 50, a steering system 60, a transmission system 70, a vehicle speed sensor 83, a distance measuring unit 14, and a camera 16. These components are connected in a manner that can transmit and receive information to each other through an in-vehicle network NT.

[0044] The in-vehicle network NT is configured by including, for example, CAN (Controller Area Network) and LIN (Local Interconnect Network), etc. The in-vehicle network NT may be included in a part of the driving support system 200 .

[0045] The driving assistance device 20 is configured as a microcomputer such as an ECU (Electronic Control Unit), and performs driving assistance for the vehicle 10 .

[0046] The driving support device 20 includes a CPU (Central Processing Unit) 21, a display control circuit 23, an SSD (Solid State Drive) 24, a ROM (Read Only Memory) 25, and a RAM (Random Access Memory) 26. The CPU 21, the ROM 25, and the RAM 26 may be integrated in the same package.

[0047] The CPU 21 is an example of a hardware processor, and reads out a program stored in a nonvolatile storage device such as the ROM 25 , and executes various calculation processes and controls according to the program.

[0048] The ROM 25 stores various programs and parameters necessary for executing the programs, etc. The RAM 26 temporarily stores various data used in calculations of the CPU 21. The SSD 24 is a rewritable nonvolatile storage device and maintains data even when the power of the driving assistance device 20 is turned off.

[0049] Among the calculation processes performed by the driving assistance device 20 , the display control circuit 23 mainly performs image processing of images acquired by the imaging unit 16 , data conversion of images for display displayed on a display unit 31 included in the monitoring device 30 and described later, and the like.

[0050] The brake system 40 includes a brake unit 41 , a brake control unit 42 , and a brake unit sensor 43 , and controls deceleration of the vehicle 10 .

[0051] The brake unit 41 is a device including, for example, a brake and a brake pedal, and decelerates the vehicle 10. The brake control unit 42 is, for example, a microcomputer having a hardware processor such as a CPU. The brake control unit 42 controls the brake unit 41 based on an instruction from the driving assistance 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 in-vehicle network NT.

[0052] The acceleration system 50 includes an acceleration unit 51 , an acceleration control unit 52 , and an acceleration unit sensor 53 , and controls acceleration of the vehicle 10 .

[0053] 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 assistance device 20, thereby controlling 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 position of the accelerator pedal to the in-vehicle network NT.

[0054] The steering system 60 includes a steering unit 61 , a steering control unit 62 , and a steering unit sensor 63 , and controls the traveling direction of the vehicle 10 .

[0055] The steering control unit 61 is a device including, for example, a steering wheel or a steering wheel, and steers the steering wheel of the vehicle 10 to steer the direction of travel of the vehicle 10. The steering control unit 62 is, for example, a microcomputer including a hardware processor such as a CPU. The steering control unit 62 controls the steering control unit 61 based on instructions from the driving assistance device 20, thereby controlling the direction of travel of the vehicle 10. The steering control unit sensor 63 is, for example, an angle sensor including a Hall element, and detects the rotation angle of the steering control unit 61, that is, the steering angle. The steering control unit sensor 63 outputs the detected steering angle of the steering control unit 61 to the in-vehicle network NT.

[0056] The transmission system 70 includes a transmission unit 71 , a transmission control unit 72 , and a transmission unit sensor 73 , and controls the transmission ratio of the vehicle 10 .

[0057] The speed change unit 71 is a device including a shift lever, etc., for example, and changes the speed ratio of the vehicle 10. The speed change control unit 72 is a microcomputer including a hardware processor such as a CPU, for example. The speed change control unit 72 controls the speed change unit 71 based on instructions from the driving assistance device 20, thereby controlling the speed ratio of the vehicle 10. The speed change unit sensor 73 is, for example, a position sensor, and detects the position of the shift lever included in the speed change unit 71. The speed change unit sensor 73 outputs the detected position of the shift lever to the in-vehicle network NT.

[0058] The vehicle speed sensor 83 has, for example, a Hall element provided near the wheel 13 of the vehicle 10, and detects the rotation amount or the rotation speed per unit time of the wheel 13. The vehicle speed sensor 83 outputs the number of wheel speed pulses indicating the detected rotation amount or rotation speed to the in-vehicle network NT as a sensor value for calculating the speed (vehicle speed) of the vehicle 10. The driving assistance device 20 can calculate the speed and movement amount of the vehicle 10 based on the sensor value obtained from the vehicle speed sensor 83.

[0059] The monitoring device 30 is installed on a dashboard or the like in the interior of the vehicle 10 , and includes a display unit 31 and an input unit 32 .

[0060] The display unit 31 is a display device such as a liquid crystal display (LCD) or an organic EL display (OELD). The display unit 31 displays images based on image data sent from the driving assistance device 20 and images receiving operation instructions for switching between automatic driving and manual driving.

[0061] The input unit 32 is, for example, a touch panel provided on the display screen of the display unit 31. The input unit 32 is configured to be able to see through the content displayed on the display screen of the display unit 31. Thus, the input unit 32 can allow the passenger to visually recognize the display content of the display unit 31.

[0062] The input unit 32 receives instructions input by the occupant touching a position corresponding to the display content of the display unit 31, and transmits the instructions to the driving support device 20 via the in-vehicle network NT. The input unit 32 is not limited to a touch panel, and may be a hard switch such as a push button.

[0063] Figure 3 2 is a block diagram showing an example of the functional structure of the driving assistance device 20 according to the embodiment. Figure 3 As shown, the driving assistance device 20 includes a display control unit 201 , an acquisition unit 202 , a detection unit 203 , a path calculation unit 204 , an acceleration determination unit 205 , a movement control unit 206 , and a storage unit 207 as functional units.

[0064] These functional units are realized by, for example, the CPU 21 reading a program stored in a storage device such as the ROM 25 and executing the program. Alternatively, they are realized by the display control circuit 23, SSD 24, ROM 25, RAM 26, etc. operating under the control of the CPU 21 according to the program.

[0065] Furthermore, part or all of these functional units may be configured by hardware such as a circuit including an ASIC (Application Specific Integrated Circuit).

[0066] The display control unit 201 generates content to be displayed on the display unit 31 of the monitoring device 30, and displays it on the display unit 31. In other words, the display control unit 201 displays, on the display unit 31, for example, a notification screen that a parking area where the vehicle 10 can park has been detected, a selection screen for starting, interrupting, or stopping driving assistance, and an image of the surroundings of the vehicle 10 during driving assistance.

[0067] The acquisition unit 202 acquires the transmission and reception information of the sound wave from the distance measuring unit 14 and acquires the captured image of the periphery of the vehicle 10 from the imaging unit 16 as the periphery information of the vehicle 10 .

[0068] The detection unit 203 detects obstacles, parking spaces, parking areas, and the like around the vehicle 10 based on the surrounding information acquired by the acquisition unit 202 .

[0069] Obstacles are various objects such as other vehicles, walls, pillars, fences, protrusions, steps, wheel chocks, etc. In addition, obstacles may be, for example, people walking in the parking lot.

[0070] The parking space is an area provided for parking the vehicle 10 and divided by, for example, a dividing line, a frame line, a straight line, a belt, a step, etc. The parking area is a parking space where the vehicle 10 can park, in other words, a parking space where there are no obstacles such as other vehicles that hinder the parking of the vehicle 10. The dividing line, frame line, straight line, belt, step, etc. mentioned above are examples of objects indicating the parking area, and when the driving assistance device 20 assists the vehicle 10 in entering or exiting the parking area, they become the target objects when the vehicle 10 enters or exits the parking area.

[0071] If there is an instruction to start driving assistance from the driver of the vehicle 10, the detection unit 203 detects the presence of an obstacle, the distance from the vehicle 10 to the obstacle, etc. based on the detection result of the distance measuring unit 14, for example. In addition, the detection unit 203 detects the presence of obstacles and parking spaces, their positions (orientations) relative to the vehicle 10, and their shapes, sizes, heights, etc., by image processing based on images captured by the imaging unit 16, for example.

[0072] The detection unit 203 combines these detection results to extract information such as whether there are obstacles around the vehicle 10, whether the obstacles can hinder the driving of the vehicle 10, whether there are parking spaces around the vehicle 10, whether the vehicle 10 can be parked in the parking space, in other words, whether it can be used as a parking area.

[0073] The path calculation unit 204 calculates a target position for guiding the vehicle 10 based on the detection result of the detection unit 203 , and calculates a movement path for moving the vehicle 10 to the target position.

[0074] If the vehicle 10 is parked, the parking area detected by the detection unit 203 becomes the target position. If the vehicle 10 is driven away, a predetermined place such as an aisle between a plurality of parking spaces where the vehicle 10 can start to drive safely becomes the target position.

[0075] In addition, the path calculation unit 204 may calculate the turning position as needed. In a case where it is difficult to park or move the vehicle with one reverse or one forward movement, one or more turning positions are set.

[0076] The path calculation unit 204 calculates the movement path of the vehicle 10 from the current position of the vehicle 10 to the target position in order to guide the vehicle 10 to the target position calculated as described above. The movement path may also include a turning position as described above. In this case, the path calculation unit 204 calculates the movement path from the current position of the vehicle 10 to the target position via the turning position.

[0077] Thus, the movement path for parking such as reverse parking or forward parking is calculated by the path calculation unit 204. In addition, the movement path for exiting the vehicle such as forward exiting or backward exiting is calculated by the path calculation unit 204.

[0078] The movement control unit 206 controls various parts of the vehicle 10 to move the vehicle 10 during driving assistance of the vehicle 10. Specifically, the movement control unit 206 moves the vehicle 10 to the target position according to the above-mentioned movement path by controlling all or part of the brake system 40, the acceleration system 50, the steering system 60, and the transmission system 70. At this time, the movement control unit 206 moves the vehicle 10 while receiving feedback from various sensors such as the brake sensor 43, the acceleration sensor 53, the steering sensor 63, the transmission sensor 73, and the vehicle speed sensor 83.

[0079] In addition, the driving assistance device 20 pre-sets an appropriate speed limit value according to the conditions of the vehicle 10 at each time when the driving assistance is being performed. More specifically, the speed limit value is a speed value that enables the vehicle 10 to move safely under the conditions at each time, for example, where the vehicle 10 is located inside or outside the parking area at that time, whether the vehicle 10 is moving forward or backward, whether there is an obstacle within a predetermined range from the vehicle 10, etc. The setting of the speed limit value is stored in the storage unit 207, for example.

[0080] The movement control unit 206 refers to the data of the storage unit 207, selects a speed limit value corresponding to the status of the vehicle 10 at each time, and moves the vehicle 10 within the speed limit value. At this time, the movement control unit 206 may move the vehicle 10 only at a speed equal to the speed limit value. In this case, it can also be said that the speed limit value is the target speed of the vehicle 10.

[0081] In this way, by moving the vehicle 10 at an extremely high speed within the speed limit value at each time, it is possible to ensure safe travel of the vehicle 10 and complete parking and exiting of the vehicle 10 in a short time.

[0082] In addition, after the movement control unit 206 starts the movement of the vehicle 10, the detection unit 203 continues to obtain the surrounding information from the distance measuring unit 14 and the imaging unit 16. The above-mentioned path calculation unit 204 appropriately recalculates the movement path based on the detection result of the detection unit 203. The movement control unit 206 continues the movement of the vehicle 10 in such a way that if the movement path is recalculated, the position of the vehicle 10 is finely adjusted accordingly.

[0083] The acceleration determination unit 205 appropriately determines the acceleration of the vehicle 10 based on the predetermined acceleration time and the speed limit value selected at each time by the movement control unit 206. The acceleration time is set for, for example, the forward movement of the vehicle 10 and the backward movement of the vehicle 10, respectively, and these settings are stored in, for example, the storage unit 207. The acceleration time when the vehicle 10 is moving forward is an example of the first acceleration time. The acceleration time when the vehicle 10 is moving backward is an example of the second acceleration time.

[0084] The movement control unit 206 controls the vehicle 10 so that, if a speed limit value is selected according to the status of the vehicle 10 at each time, the vehicle 10 is accelerated at the acceleration determined by the acceleration determination unit 205 and the speed of the vehicle 10 becomes the selected speed limit value.

[0085] The storage unit 207 stores, for example, programs 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. In addition, the storage unit 207 stores settings such as speed limit values ​​corresponding to the conditions of the vehicle 10 at each time and acceleration times when moving forward and backward, as described above.

[0086] (Example of determining acceleration time)

[0087] Next, use Figure 4 and Figure 5 , an example of the acceleration time determined by the driving assistance device 20 according to the embodiment is described.

[0088] Figure 4: is a graph showing an example of the acceleration time AD when the vehicle 10 is moving forward, which is determined by the driving assistance device 20 according to the embodiment. Figure 5 : is a graph showing an example of the acceleration time RT during reverse movement of the vehicle 10 determined by the driving assistance device 20 according to the embodiment.

[0089] in addition, Figure 4 and Figure 5 The horizontal axis of the coordinate graph is time (s), and the vertical axis is target speed (m / s).

[0090] like Figure 4 and Figure 5 As shown, the driving assistance device 20 of the embodiment controls the vehicle 10 so that, for example, the target speed is reached in a predetermined acceleration time AD or acceleration time RT when the movement control of the vehicle 10 is performed. That is, whether the speed limit value A is set as the target speed or the speed limit value B lower than the speed limit value A is set as the target speed, the vehicle 10 is controlled so that the respective target speeds are reached in a constant and fixed acceleration time AD or acceleration time RT according to the traveling direction of the vehicle 10 in the forward or reverse motion, etc.

[0091] Therefore, compared with the case where the speed limit value A is set as the target speed, when the speed limit value B lower than the speed limit value A is set as the target speed, the acceleration of the vehicle 10 becomes smaller.

[0092] When the movement control unit 206 intends to move the vehicle 10 forward, the acceleration time AD of the acceleration times AD and RT is set by the acceleration determination unit 205. When the movement control unit 206 intends to move the vehicle 10 backward, the acceleration determination unit 205 sets the acceleration time RT.

[0093] In addition, the acceleration time RT when the vehicle 10 moves backward is set to be longer than the acceleration time AD when the vehicle 10 moves forward. Therefore, if the target speeds are the same, Figure 5 The acceleration ratio of the vehicle 10 when moving backward is shown by the solid line. Figure 5 The acceleration during forward movement shown by the middle dotted line is small.

[0094] (Operation example of driving assistance device)

[0095] Next, use Figure 6 to Figure 8 An operation example of the driving assistance device 20 according to the embodiment will be described.

[0096] Figure 6 to Figure 8 This is a schematic diagram for explaining an example of a driving assistance operation performed by the driving assistance device 20 according to the embodiment. Figure 6 to Figure 8In the following, an example in which the vehicle 10 performs reverse parking will be described.

[0097] like Figure 6 As shown, it is assumed that in a parking lot where a plurality of parking spaces are arranged, one parking space is empty between parking spaces where other vehicles 91 are parked.

[0098] When the vehicle 10 is parked at a predetermined position by, for example, pulling into a parking space that is empty of a vehicle, the detection unit 203 of the driving assistance device 20 mounted on the vehicle 10 detects, for example, a parking space that is empty of a vehicle from among a plurality of parking spaces as a parking area PA where the vehicle 10 can park. The display control unit 201 of the driving assistance device 20 causes the detected parking area PA to be displayed on the display unit 31 of the monitoring device 30.

[0099] When the driver of the vehicle 10 wishes to park in the parking area PA, he or she can use the input unit 32 (see FIG. Figure 2 ) and other components instruct the driving assistance device 20 to execute driving assistance. As a result, parking assistance for the vehicle 10 by the driving assistance device 20 starts.

[0100] like Figure 7 As shown, the path calculation unit 204 of the driving assistance device 20 calculates the movement path TR. The movement path TR starts from, for example, the parking position PP of the vehicle 10 parked in the parking area PA, passes through the turning position SP in the forward direction of the vehicle 10, and reaches the target position DP in the parking area PA in the backward direction of the vehicle 10 at the turning position SP.

[0101] The movement control unit 206 of the driving assistance device 20 starts moving the vehicle 10 on the movement path TR based on the calculation result of the path calculation unit 204 .

[0102] First, the movement control unit 206 moves the vehicle 10 forward from the parking position PP toward the turning position SP. At this time, the movement control unit 206 selects a speed limit value corresponding to the situation of the vehicle 10 at that time.

[0103] Figure 7 In the example of FIG. 1 , at this moment, the vehicle 10 is outside the parking area PA, and the movement control unit 206 intends to move the vehicle 10 forward. In addition, it is assumed that there is no obstacle within a predetermined range around the vehicle 10. The movement control unit 206 selects a speed limit value corresponding to such a situation of the vehicle 10.

[0104] The acceleration determination unit 205 calculates an acceleration for causing the vehicle 10 to reach the speed limit selected by the movement control unit 206 in the acceleration time when moving forward, based on the speed limit selected by the movement control unit 206 and the acceleration time when moving forward stored in advance in the storage unit 207. Such acceleration is calculated, for example, by the following formula (1).

[0105] Acceleration (m / s 2 ) = speed limit value (m / s) / acceleration time (s) (1)

[0106] For example, the movement control unit 206 sets the selected speed limit value as the target speed, moves the vehicle 10 forward at the acceleration determined by the acceleration determination unit 205, maintains the speed of the vehicle 10 within the speed limit value, and moves the vehicle 10 from the parking position PP to the turning position SP.

[0107] Next, the movement control unit 206 causes the vehicle 10 to move backward from the turning position SP toward the target position DP. At this time, the movement control unit 206 selects a speed limit value corresponding to the situation of the vehicle 10 at that time.

[0108] On the moving path TR from the reversing position SP to the target position DP, and Figure 7 In the movement path TR shown by the solid line, the vehicle 10 is still outside the parking area PA, and the movement control unit 206 intends to move the vehicle 10 backward. In addition, it is assumed that there is no obstacle within a predetermined range around the vehicle 10. The movement control unit 206 selects a speed limit value corresponding to such a situation of the vehicle 10.

[0109] The acceleration determination unit 205 calculates the acceleration for causing the vehicle 10 to reach the speed limit selected by the movement control unit 206 in the acceleration time for reverse movement based on the speed limit selected by the movement control unit 206 and the acceleration time for reverse movement pre-stored in the storage unit 207, for example, according to the above formula (1).

[0110] The movement control unit 206 sets the selected speed limit value as the target speed, causes the vehicle 10 to move backward at the acceleration determined by the acceleration determination unit 205, maintains the speed of the vehicle 10 within the speed limit value, and moves from the switching position SP to the target position DP.

[0111] like Figure 8 As shown in FIG. 2 , the movement control unit 206 is still in the process of moving the vehicle 10 backward toward the target position DP. At this time, the movement control unit 206 selects a speed limit value corresponding to the situation of the vehicle 10 at this time.

[0112] Figure 8In the example of FIG. 1 , the vehicle 10 enters the parking area PA, and the movement control unit 206 intends to make the vehicle 10 further move backward. In addition, it is assumed that there are obstacles such as other vehicles 91 within a predetermined range around the vehicle 10. The movement control unit 206 selects a speed limit value corresponding to such a situation of the vehicle 10.

[0113] The acceleration determination unit 205 calculates the acceleration for causing the vehicle 10 to reach the speed limit selected by the movement control unit 206 in the acceleration time for reverse movement based on the speed limit selected by the movement control unit 206 and the acceleration time for reverse movement pre-stored in the storage unit 207, for example, according to the above formula (1).

[0114] The movement control unit 206 sets the selected speed limit value as the target speed, causes the vehicle 10 to move backward at the acceleration determined by the acceleration determination unit 205, and moves the vehicle 10 toward the target position DP while maintaining the speed of the vehicle 10 within the speed limit value.

[0115] Through the above-described control by the driving assistance device 20 , the vehicle 10 is parked at the target position DP in the parking area PA, and the parking assistance by the driving assistance device 20 is completed.

[0116] Above, in Figure 6 to Figure 8 In the example, the selection of the speed limit value and the acceleration time and the calculation of the acceleration are performed three times in total on the moving path TR. However, the above description is for the convenience of explanation. The conditions of the vehicle 10 at each moment on the moving path TR may change at any time. Therefore, in actual control, the movement control unit 206 and the acceleration determination unit 205 repeat the above processing at short time intervals such as microseconds.

[0117] In addition, Figure 6 to Figure 8 In the example of reverse parking of the vehicle 10 in a parallel parking lot, the driving assistance device 20 controls the vehicle 10 in the same manner not only in reverse parking but also in front parking, front parking / rear exiting, or parallel parking / exiting.

[0118] (Processing Example of Driving Assistance Device)

[0119] Next, use Fig. 9 , an example of driving assistance processing performed by the driving assistance device 20 according to the embodiment will be described. Fig. 9 1 is a flowchart showing an example of a procedure of a driving assistance process performed by the driving assistance device 20 according to the embodiment.

[0120] like Fig. 9As shown, when receiving an instruction to start driving assistance from the driver of the vehicle 10, the driving assistance device 20 starts control (step S101). The path calculation unit 204 calculates a movement path from the parking position of the vehicle 10 to the target position at that time (step S102).

[0121] The acceleration determination unit 205 refers to the transmission unit sensor 73 (see Figure 2 ) detection result, etc., to determine whether the gear lever position of the vehicle 10 at that moment is in the driving state (step S103). The acceleration determination unit 205 sets the acceleration time for forward movement (step S104) when the gear lever position is in the driving state (step S103: Yes), and sets the acceleration time for reverse movement (step S105) when the gear lever position is in a position other than the driving state such as reverse movement (step S103: No).

[0122] On the other hand, the movement control unit 206 sets the speed limit value according to the state of the vehicle 10 at that moment (step S106). The acceleration determination unit 205 calculates the acceleration required to make the speed of the vehicle 10 reach the speed limit value based on the acceleration time set in the process of step S104 or step S105 and the speed limit value set by the movement control unit 206 in the process of step S106 (step S107).

[0123] The acceleration determination unit 205 uses the speed limit value set in the process of step S106 as the target speed, accelerates the vehicle 10 at the acceleration calculated by the acceleration determination unit 205 in the process of step S107, and controls the movement of the vehicle 10 (step S108).

[0124] The movement control unit 206 determines whether the vehicle 10 has reached the target position and the driving assistance process has ended (step S109). If the driving assistance process is continuing (step S109: No), the process starting from step S103 is repeated until the driving assistance process ends (step S109: Yes).

[0125] According to the above description, the driving assistance process performed by the driving assistance device 20 of the embodiment ends.

[0126] (Summary)

[0127] The driving assistance device provides driving assistance for the vehicle based on the surrounding information of the vehicle obtained from various sensors such as the distance measuring unit and the camera unit. However, there are cases where the vehicle occupants including the driver feel poor riding comfort under the conditions specified in the driving assistance. Fig.10 Provide explanation.

[0128] Fig.10This is a graph showing an example of the acceleration time determined by the driving assistance device according to the comparative example. Fig.10 The horizontal axis of the coordinate graph is time (s), and the vertical axis is target speed (m / s).

[0129] like Fig.10 As shown, the driving assistance device of the comparative example accelerates the vehicle within a predetermined acceleration range, for example, at the same acceleration, so that the vehicle speed reaches either speed limit value A or speed limit value B which is lower than speed limit value A, regardless of which is the target speed of the vehicle.

[0130] Therefore, when speed limit value B is set as the target speed, the target speed is reached faster than when speed limit value A is set as the target speed. In other words, acceleration time B' required to reach speed limit value B is shorter than acceleration time A' required to reach speed limit value A.

[0131] In addition, the above control of the driving assistance device of the comparative example does not change when the vehicle is moving forward or backward. In other words, the acceleration time A' required to reach the speed limit value A is the same when the vehicle is moving forward or backward, and the acceleration time B' required to reach the speed limit value B is the same when the vehicle is moving forward or backward.

[0132] Here, for example, when the speed limit value is low and the acceleration time is short, the occupants may feel that the vehicle has suddenly started, which may cause the passengers to feel that the ride comfort has deteriorated. When the vehicle is moving backward, such an impression tends to be stronger.

[0133] According to the driving assistance device 20 of the embodiment, the acceleration for causing the vehicle 10 to reach the target speed is determined based on the predetermined acceleration time and the speed limit value selected by the movement control unit 206 .

[0134] In this way, the acceleration time is predetermined regardless of the speed limit value, so that, for example, even when the speed limit value is low, the riding comfort of the occupants can be improved. In addition, by predetermining the acceleration time, the riding comfort of the occupants can be improved, and the unnecessary time required for parking or leaving the vehicle can be suppressed and the processing can be quickly completed.

[0135] According to the driving assistance device 20 of the embodiment, the acceleration time for moving forward is used when the vehicle 10 is moved forward, and the acceleration time for moving backward is used when the vehicle 10 is moved backward. In this way, even if the acceleration is the same, the acceleration time is set separately in advance when the vehicle 10 is moving forward and when the vehicle 10 is moving backward, where the passenger's body sensation is different, so that more detailed control can be performed.

[0136] According to the driving assistance device 20 of the embodiment, the acceleration time when the vehicle 10 moves backward is set to be longer than the acceleration time when the vehicle 10 moves forward. Thus, even when the vehicle 10 moves backward, which tends to give the occupants a stronger impression that the vehicle 10 is accelerating suddenly, the riding comfort of the occupants can be improved.

[0137] According to the driving assistance device 20 of the embodiment, the acceleration time when moving forward and when moving backward is fixed. Thus, by setting the acceleration time only when moving forward and when moving backward, it is possible to suppress the situation where the control becomes complicated by setting many acceleration times.

[0138] In addition, in the above-mentioned embodiment, the driving assistance device 20 is mounted on the vehicle 10, but the driving assistance device 20 may not necessarily be mounted on the vehicle 10. For example, the driving assistance device may acquire the surrounding information of the vehicle from various sensors at a position away from the vehicle and perform driving assistance of the vehicle through remote operation.

Claims

1. A driving assistance device for assisting the driving of a vehicle based on surrounding information collected by a plurality of sensors installed in the vehicle. The driving assistance device is characterized by comprising: a path calculation unit that calculates a movement path of the vehicle to a target position based on the peripheral information from the plurality of sensors; a movement control unit configured to move the vehicle along the movement path at a target speed within a speed limit value corresponding to a condition of the vehicle at each time; as well as The acceleration determination unit determines an acceleration for causing the vehicle to reach the target speed based on a predetermined acceleration time and the speed limit value.

2. The driving assistance device according to claim 1, characterized in that: For the acceleration determination unit, When the vehicle is moved forward, a first acceleration time is used, The second acceleration time is used when the vehicle is moved backward.

3. The driving assistance device according to claim 2, characterized in that: The second acceleration time is set to a time longer than the first acceleration time.

4. The driving assistance device according to claim 2 or 3, characterized in that: The first acceleration time and the second acceleration time are each a fixed time.

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