Driving support device

Abstract

To provide a driving support device capable of improving riding comfort of an occupant of a vehicle during execution of driving support.SOLUTION: A driving support device according to an embodiment executes driving support of a vehicle on the basis of surrounding information collected by a plurality of sensors provided in the vehicle. The driving support device includes: a route calculation unit for calculating a movement route of the vehicle to a target position on the basis of the surrounding information from the plurality of sensors; a movement control unit for moving the vehicle along the movement route at a target speed within a speed limit value according to each situation of the vehicle; and an acceleration determination unit for determining acceleration for allowing the vehicle to reach the target speed on the basis of a predetermined acceleration time and the speed limit value.SELECTED DRAWING: Figure 3

Description

[Technical field]

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

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

[0003] For example, in the technology of Patent Document 1, an acceleration profile, which is a time change of a target value of acceleration when the vehicle is decelerating, 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 occurrence of an unexpected acceleration state can be suppressed by limiting the acceleration of the vehicle to within an upper limit acceleration set according to the speed of the vehicle. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] International Publication No. 2020 / 066331 [Patent Document 2] Patent No. 5257647 Summary of the Invention [Problem to be solved by the invention]

[0005] However, in the technology of Patent Document 1, depending on the distance to the target position, a situation may occur where the vehicle occupant feels sudden acceleration. Also, in the technology of Patent Document 2, even if the occurrence of unexpected acceleration is suppressed and a safe driving state is maintained, the occupant may feel sudden acceleration.

[0006] The present invention has been made in consideration of the above, and provides a driving assistance device that can improve the riding comfort of vehicle occupants while driving assistance is being performed. [Means for solving the problem]

[0007] In order to solve the above-mentioned problems and achieve the objective, a driving assistance device of an embodiment is a driving assistance device that provides driving assistance for a vehicle based on peripheral information collected by a plurality of sensors provided in the vehicle, and includes a route calculation unit that calculates a movement route of the vehicle to a target position based on the peripheral information from the plurality of sensors, a movement control unit that moves the vehicle along the movement route at a target speed within a speed limit value according to the vehicle's current situation, and an acceleration determination unit that determines an acceleration for causing the vehicle to reach the target speed based on a predetermined acceleration time and the speed limit value. Effect of the Invention

[0008] The driving assistance device according to the embodiment can improve the riding comfort of the vehicle occupants while driving assistance is being performed. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a top view of a vehicle equipped with a driving support device according to an embodiment. [Diagram 2] FIG. 2 is a block diagram illustrating an example of an overall configuration of the driving assistance system according to the embodiment. [Diagram 3] FIG. 3 is a block diagram illustrating an example of a functional configuration of the driving assistance device according to the embodiment. [Figure 4] FIG. 4 is a graph showing an example of an acceleration time when the vehicle moves forward, determined by the driving assistance device according to the embodiment. [Diagram 5] FIG. 5 is a graph showing an example of an acceleration time when a vehicle is moving backward, which is determined by the driving assistance device according to the embodiment. [Figure 6] FIG. 6 is a schematic diagram illustrating an example of the driving assistance operation performed by the driving assistance device according to the embodiment. [Figure 7] FIG. 7 is a schematic diagram illustrating an example of the driving assistance operation performed by the driving assistance device according to the embodiment. [Figure 8] FIG. 8 is a schematic diagram illustrating an example of the driving assistance operation performed by the driving assistance device according to the embodiment. [Figure 9] FIG. 9 is a flow diagram illustrating an example of a procedure of a driving assistance process performed by the driving assistance device according to the embodiment. [Figure 10] FIG. 10 is a graph showing an example of an acceleration time determined by a driving assistance device according to a comparative example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Similar components in the following exemplary embodiments are given the same reference numerals, and duplicated descriptions will be omitted as appropriate.

[0011] (Vehicle configuration example) Fig. 1 is a top view of a vehicle 10 equipped with a driving support device 20 according to an embodiment. The front, rear, left and right of the vehicle 10 in Fig. 1 indicate directions when viewed from the driver's seat of the vehicle 10.

[0012] The vehicle 10 of the embodiment may be, for example, an internal combustion engine vehicle using an internal combustion engine as a power source, an electric vehicle or a fuel cell vehicle using an electric motor as a power source, or a hybrid vehicle using both of these as a power source.

[0013] The vehicle 10 can be equipped with various transmissions and various systems, parts, and other devices required to drive the internal combustion engine or electric motor. The type, number, layout, and other aspects of the devices related to the drive of the wheels 13 of the vehicle 10 can be set in various ways.

[0014] 1, the vehicle 10 includes a vehicle body 12, a plurality of wheels 13, a plurality of distance measuring units 14a-14l, and a plurality of imaging units 16a-16d. When it is not necessary to distinguish between the distance measuring units 14a-14l, they will be simply referred to as distance measuring unit 14. When it is not necessary to distinguish between the imaging units 16a-16d, they will be simply referred to as imaging unit 16. The distance measuring units 14a-14l and imaging units 16a-16d are examples of sensors that collect information about the surroundings of the vehicle 10.

[0015] The vehicle body 12 constitutes a vehicle cabin in which passengers ride. A plurality of wheels 13, a plurality of distance measuring units 14, and a plurality of imaging units 16 are attached to the vehicle body 12. 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 attached to the vehicle body 12 is arbitrary.

[0016] The four wheels 13 are provided on the front, rear, left and right sides of the vehicle body 12. The two front wheels 13 function, for example, as steering wheels, and the two rear wheels 13 function, for example, as driving wheels.

[0017] The distance measuring unit 14 is, for example, a sonar provided on the outer periphery of the vehicle 10, which transmits sound waves such as ultrasonic waves as detection waves and captures the detection waves reflected by objects such as obstacles present around the vehicle 10. The distance measuring unit 14 may be a radar that transmits detection waves such as laser light, a millimeter wave radar, or the like.

[0018] The distance measuring unit 14 collects surrounding information indicating the situation around the vehicle 10 and outputs it to the driving assistance device 20. The distance measuring unit 14 collects, for example, a response time, which is the time from transmitting a detection wave to receiving it, as surrounding information for identifying the distance between an object and the vehicle 10. Based on the surrounding information collected by the distance measuring unit 14, the driving assistance device 20 can detect the presence or absence of an obstacle or the like around the vehicle 10 and the distance to the obstacle.

[0019] In addition, when the distance measuring unit 14 receives multiple detection waves reflected from multiple points on the object in response to a single transmission of a detection wave, the distance measuring unit 14 may include only the response time of the earliest received detection wave in the surrounding information.

[0020] The distance measuring units 14a to 14d are provided at the front of the vehicle body 12. Of these distance measuring units 14a to 14d, the distance measuring units 14b and 14c 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. The distance measuring units 14a and 14d are also called corner sonars, and are provided at the corners of the front of the vehicle 10. The distance measuring units 14a and 14d detect objects on the outside in front of the vehicle 10 and collect peripheral information on the outside in front of the vehicle 10.

[0021] The distance measuring units 14e to 14h are provided at the rear of the vehicle body 12. Of these distance measuring units 14e to 14h, the distance measuring units 14f and 14g 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. 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 on the outside behind the vehicle 10 and collect peripheral information behind the vehicle 10.

[0022] The distance measuring units 14i to 14l are also called side sonars, and are provided on the sides of the vehicle body 12. Of the distance measuring units 14i to 14l, the distance measuring units 14i and 14j are provided on the front sides of the vehicle 10. The distance measuring units 14k and 14l are provided on the rear sides of the vehicle 10. The distance measuring units 14i to 14l detect objects on the sides of the vehicle 10 and collect peripheral information on the sides of the vehicle 10.

[0023] The imaging unit 16 is a digital camera incorporating an imaging element such as a CCD (Charge Coupled Device) or a CIS (CMOS Image Sensor), etc. The imaging unit 16 generates a moving image including a plurality of frame images captured at a predetermined frame rate, or a still image.

[0024] The imaging units 16 are provided on the outer periphery of the vehicle body 12, each having 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 set to face diagonally downward.

[0025] As a result, the imaging unit 16 collects surrounding information obtained by capturing an image of the surroundings of the vehicle 10, including the road surface, and outputs the collected information to the driving assistance device 20. The driving assistance device 20 can detect the presence or absence of obstacles, etc., around the vehicle 10 and the positions of the obstacles, based on the surrounding information collected by the imaging unit 16. The driving assistance device 20 can also 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.

[0026] The imaging unit 16a is provided in the center in the front-rear direction of the left end of the vehicle body 12, for example, on the underside of the left side mirror. The imaging unit 16a collects captured images of the area to the left below the vehicle 10 as peripheral information. The imaging unit 16b is provided in the center in the front-rear direction of the right end of the vehicle body 12, for example, on the underside of the right side mirror. The imaging unit 16b collects captured images of the area to the right below the vehicle 10 as peripheral information.

[0027] The imaging unit 16c is provided in the center in the left-right direction of the front end of the vehicle body 12, for example, on the front bumper. The imaging unit 16c collects captured images of the area in front of the vehicle 10 as peripheral information. The imaging unit 16d is provided in the center in the left-right direction of the rear end of the vehicle body 12, for example, on the rear bumper. The imaging unit 16d collects captured images of the area behind the vehicle 10 as peripheral information.

[0028] (Example of a driving assistance system configuration) 2 is a block diagram showing an example of an overall configuration of a driving assistance system 200 according to an embodiment. The driving assistance system 200 is mounted on, for example, a vehicle 10, and performs driving assistance such as parking the vehicle 10 in a parking area or exiting the parking area.

[0029] 2, the driving assistance system 200 includes a driving assistance device 20, a monitor device 30, a braking system 40, an acceleration system 50, a steering system 60, a gear shift system 70, a vehicle speed sensor 83, a distance measurement unit 14, and an imaging unit 16. These components are connected to each other via an in-vehicle network NT so as to be able to transmit and receive information to and from each other.

[0030] The in-vehicle network NT includes, for example, a Controller Area Network (CAN) and a Local Interconnect Network (LIN), etc. The in-vehicle network NT may be included as a part of the driving assistance system 200.

[0031] 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.

[0032] The driving assistance device 20 includes a CPU (Central Processing Unit) 21, a display control circuit 23, a Solid State Drive (SSD) 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.

[0033] The CPU 21 is an example of a hardware processor, which reads out a program stored in a non-volatile storage device such as the ROM 25, and executes various types of arithmetic processing and control in accordance with the program.

[0034] The ROM 25 stores various programs and parameters necessary for executing the programs. The RAM 26 temporarily stores various data used in the calculations by the CPU 21. The SSD 24 is a rewritable non-volatile storage device, and maintains data even when the power of the driving support device 20 is turned off.

[0035] Among the computational processes performed by the driving assistance device 20, the display control circuit 23 mainly performs image processing of images obtained by the imaging unit 16 and data conversion of images to be displayed on a display unit 31 (described later) provided in the monitor device 30.

[0036] The braking system 40 has a braking unit 41 , a braking control unit 42 , and a braking unit sensor 43 , and controls the deceleration of the vehicle 10 .

[0037] The braking unit 41 is, for example, a device including a brake and a brake pedal, and decelerates the vehicle 10. The braking control unit 42 is, for example, a microcomputer having a hardware processor such as a CPU. The braking control unit 42 controls the braking unit 41 based on an instruction from the driving support device 20 to control the deceleration of the vehicle 10. The braking unit sensor 43 is, for example, a position sensor, and detects the position of a brake pedal included in the braking unit 41. The braking unit sensor 43 outputs the detected brake pedal position to the in-vehicle network NT.

[0038] The acceleration system 50 has an acceleration unit 51 , an acceleration control unit 52 , and an acceleration sensor 53 , and controls the acceleration of the vehicle 10 .

[0039] The acceleration unit 51 is a device including, for example, an accelerator pedal and the like, and accelerates the vehicle 10. The acceleration control unit 52 is a microcomputer having 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 sensor 53 is, for example, a position sensor, and detects the position of the accelerator pedal included in the acceleration unit 51. The acceleration sensor 53 outputs the detected position of the accelerator pedal to the in-vehicle network NT.

[0040] The steering system 60 has a steering section 61, a steering control section 62, and a steering section sensor 63, and controls the direction of travel of the vehicle 10.

[0041] The steering unit 61 is a device including, for example, a steering wheel, and steers the steered wheels of the vehicle 10 to steer the traveling direction of the vehicle 10. The steering control unit 62 is a microcomputer including, for example, a hardware processor such as a CPU. The steering control unit 62 controls the steering unit 61 based on instructions from the driving support device 20 to control the traveling direction of the vehicle 10. The steering unit sensor 63 is an angle sensor including, for example, a Hall element, and detects the steering angle, which is the rotation angle of the steering unit 61. The steering unit sensor 63 outputs the detected steering angle of the steering unit 61 to the in-vehicle network NT.

[0042] The transmission system 70 has a transmission section 71, a transmission control section 72, and a transmission section sensor 73, and controls the gear ratio of the vehicle 10.

[0043] The transmission unit 71 is a device including, for example, a shift lever and the like, and changes the gear ratio of the vehicle 10. The transmission control unit 72 is a microcomputer having a hardware processor such as a CPU. The transmission control unit 72 controls the transmission unit 71 based on instructions from the driving assistance device 20 to control the gear ratio of the vehicle 10. The transmission unit sensor 73 is, for example, a position sensor, and detects the position of a shift lever included in the transmission unit 71. The transmission sensor 73 outputs the detected position of the shift lever to the in-vehicle network NT.

[0044] The vehicle speed sensor 83 has, for example, a Hall element provided near the wheel 13 of the vehicle 10, and detects the amount of rotation or the number of rotations per unit time of the wheel 13. The vehicle speed sensor 83 outputs the number of wheel speed pulses indicating the detected amount of rotation or number of rotations 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, movement amount, etc. of the vehicle 10 based on the sensor value acquired from the vehicle speed sensor 83.

[0045] The monitor device 30 is provided on a dashboard or the like inside the passenger compartment of the vehicle 10 , and has a display unit 31 and an input unit 32 .

[0046] The display unit 31 is a display device such as a liquid crystal display (LCD) or an organic electroluminescent display (OLED). The display unit 31 displays, for example, an image based on image data transmitted by the driving assistance device 20, an image for receiving an operation instruction for switching between automatic driving and manual driving, and the like.

[0047] 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 transparent to the contents displayed on the display screen of the display unit 31. This allows the input unit 32 to allow the occupant to visually recognize the display contents of the display unit 31.

[0048] 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. Note that the input unit 32 is not limited to a touch panel, and may be a hard switch such as a push button.

[0049] 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 support device 20 includes a display control unit 201, an acquisition unit 202, a detection unit 203, a route calculation unit 204, an acceleration determination unit 205, a movement control unit 206, and a storage unit 207 as functional units.

[0050] These functional units are realized, for example, by the above-mentioned CPU 21 reading and executing a program stored in a storage device such as the ROM 25. Alternatively, they are realized by the display control circuit 23, the SSD 24, the ROM 25, the RAM 26, and the like operating under the control of the CPU 21 according to the program.

[0051] Some or all of these functional units may be configured by hardware such as a circuit including an ASIC (Application Specific Integrated Circuit).

[0052] The display control unit 201 generates contents to be displayed on the display unit 31 of the monitor device 30, and causes the contents to be displayed on the display unit 31. That is, the display control unit 201 causes the display unit 31 to display, for example, a notification screen that a parking area in which the vehicle 10 can be parked has been detected, a selection screen for starting, pausing, or canceling driving assistance, an image of the surroundings of the vehicle 10 during driving assistance, and the like.

[0053] The acquisition unit 202 acquires, as information about the surroundings of the vehicle 10, information about transmitted and received sound waves from the distance measurement unit 14 and captured images of the surroundings of the vehicle 10 from the imaging unit 16.

[0054] 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 .

[0055] The obstacle may be, for example, a variety of objects such as other vehicles, walls, pillars, fences, projections, steps, wheel stops, etc. Furthermore, the obstacle may be, for example, a person walking in the parking lot.

[0056] A parking space is an area provided for parking the vehicle 10, and is partitioned by, for example, a partition line, a frame line, a straight line, a strip, a step, etc. A parking area is a parking space where the vehicle 10 can be parked, that is, a parking space where there are no obstacles such as other vehicles that would impede parking of the vehicle 10. The above partition lines, frame lines, straight lines, strips, steps, etc. are examples of objects that indicate a parking area, and serve as targets when the driving assistance device 20 assists the vehicle 10 in entering and exiting the parking area, and causes the vehicle 10 to enter and exit the parking area.

[0057] When a command to start driving assistance is given by the driver of the vehicle 10 or the like, the detection unit 203 detects the presence or absence of an obstacle, the distance from the vehicle 10 to the obstacle, and the like, based on, for example, the detection result of the distance measuring unit 14. In addition, the detection unit 203 detects the presence or absence of an obstacle, a parking space, and the positions (orientations) of these relative to the vehicle 10, as well as the shapes, sizes, heights, and the like, for example, by image processing based on an image captured by the imaging unit 16.

[0058] By combining these detection results, the detection unit 203 extracts information such as whether there is an obstacle around the vehicle 10, whether the obstacle may interfere with the driving of the vehicle 10, whether there is a parking space around the vehicle 10, whether it is possible to park the vehicle 10 in the parking space, i.e., whether it can be used as a parking area.

[0059] The route calculation unit 204 calculates a target position to which the vehicle 10 is to be guided based on the detection result by the detection unit 203, and calculates a travel route along which the vehicle 10 is to move to the target position.

[0060] When parking the vehicle 10, the target position is the parking area detected by the detection unit 203. When departing the vehicle 10, the target position is a predetermined location from which the vehicle 10 can safely start traveling, such as an aisle between multiple parking spaces.

[0061] In addition, the route calculation unit 204 may calculate a turning position as necessary. One or more turning positions are set when parking or exiting the vehicle is difficult after a single back or forward movement.

[0062] The route calculation unit 204 calculates a travel route of the vehicle 10 from the current position of the vehicle 10 to the target position so as to guide the vehicle 10 to the target position calculated as described above. The travel route may include a turning point as described above. In this case, the route calculation unit 204 calculates a travel route from the current position of the vehicle 10 to the target position via the turning point.

[0063] In this manner, the route calculation unit 204 calculates a movement route for parking, such as reverse parking or forward parking. Also, the route calculation unit 204 calculates a movement route for exiting, such as forward exiting or backward exiting.

[0064] When assisting the driving of the vehicle 10, the movement control unit 206 controls each unit of the vehicle 10 to move the vehicle 10. Specifically, the movement control unit 206 controls all or part of the braking system 40, the acceleration system 50, the steering system 60, and the gear shifting system 70 to move the vehicle 10 to the target position according to the above-mentioned movement path. At this time, the movement control unit 206 moves the vehicle 10 while receiving feedback from each sensor such as the braking unit sensor 43, the acceleration unit sensor 53, the steering unit sensor 63, the gear shifting unit sensor 73, and the vehicle speed sensor 83.

[0065] Further, the driving assistance device 20 has an appropriate speed limit value preset according to the situation of the vehicle 10 during the execution of driving assistance. More specifically, the speed limit value is a speed value that allows the vehicle 10 to move safely under the situation at the time, depending on, for example, whether 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 speed limit value setting is stored in, for example, the storage unit 207.

[0066] The movement control unit 206 refers to the data in the storage unit 207, selects a speed limit value according to the situation 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 exclusively at a speed equal to the speed limit value. In this case, it can be said that the speed limit value is also the target speed of the vehicle 10.

[0067] In this way, by moving the vehicle 10 at the highest possible speed within the speed limit at that time, the vehicle 10 can be parked and departed in a short time while ensuring safe driving of the vehicle 10.

[0068] Even after the movement control unit 206 starts moving the vehicle 10, the detection unit 203 continues to acquire surrounding information from the distance measurement unit 14 and the imaging unit 16. The above-mentioned route calculation unit 204 appropriately recalculates the movement route based on the detection result by the detection unit 203. When the movement route is recalculated, the movement control unit 206 continues the movement of the vehicle 10 so as to finely adjust the position of the vehicle 10 accordingly.

[0069] The acceleration determination unit 205 appropriately determines the acceleration of the vehicle 10 based on a predetermined acceleration time and a speed limit value selected by the movement control unit 206 from time to time. The acceleration time is set, for example, for when the vehicle 10 moves forward and when it moves backward, and these settings are stored, for example, in the storage unit 207. The acceleration time when the vehicle 10 moves forward is an example of a first acceleration time. The acceleration time when the vehicle 10 moves backward is an example of a second acceleration time.

[0070] The above-mentioned movement control unit 206 selects a speed limit value according to the current situation of the vehicle 10, and accelerates the vehicle 10 at the acceleration determined by the acceleration determination unit 205, thereby controlling the vehicle 10 so that the speed of the vehicle 10 becomes the selected speed limit value.

[0071] The storage unit 207 stores, for example, a program executed by the CPU 21 of the driving support device 20, and various control parameters necessary for the operation of the driving support device 20. In addition, as described above, the storage unit 207 stores settings such as a speed limit value according to the situation of the vehicle 10 at each time, and acceleration times when moving forward and backward.

[0072] (Example of determining acceleration time) Next, an example of the acceleration time determined by the driving assistance device 20 of the embodiment will be described with reference to FIG. 4 and FIG.

[0073] Fig. 4 is a graph showing an example of an acceleration time AD when the vehicle 10 is moving forward, determined by the driving support device 20 according to the embodiment. Fig. 5 is a graph showing an example of an acceleration time RT when the vehicle 10 is moving backward, determined by the driving support device 20 according to the embodiment.

[0074] In addition, the horizontal axis of the graphs in FIG. 4 and FIG. 5 represents time (s), and the vertical axis represents target speed (m / s).

[0075] 4 and 5, when performing, for example, movement control of the vehicle 10, the driving support device 20 of the embodiment controls the vehicle 10 so that it reaches a target speed in a predetermined acceleration time AD or acceleration time RT. That is, whether the target speed is set to speed limit value A or to speed limit value B lower than speed limit value A, the driving support device 20 controls the vehicle 10 so that it reaches the respective target speed in a constant fixed acceleration time AD or acceleration time RT depending on the traveling direction of the vehicle 10, such as forward or backward.

[0076] Therefore, when speed limit value B, which is lower than speed limit value A, is set as the target speed, the acceleration of the vehicle 10 will be smaller than when speed limit value A is set as the target speed.

[0077] Of these acceleration times AD and RT, the acceleration time AD is set by the acceleration determination unit 205 when the movement control unit 206 is moving the vehicle 10 forward. The acceleration time RT is set by the acceleration determination unit 205 when the movement control unit 206 is moving the vehicle 10 backward.

[0078] In addition, the acceleration time RT when the vehicle 10 is reversing is set to be longer than the acceleration time AD when the vehicle 10 is moving forward. Therefore, if the target speed is the same, the acceleration of the vehicle 10 when reversing, shown by the solid line in Fig. 5, is smaller than the acceleration when moving forward, shown by the dashed line in Fig. 5.

[0079] (Example of operation of driving support device) Next, an example of the operation of the driving support device 20 according to the embodiment will be described with reference to FIGS.

[0080] 6 to 8 are schematic diagrams illustrating an example of the driving assistance operation by the driving assistance device 20 according to the embodiment. In Fig. 6 to Fig. 8, an example in which the vehicle 10 is reverse-parked will be described.

[0081] As shown in FIG. 6, in a parking lot or the like where a number of parking spaces are arranged, it is assumed that one parking space is vacant, sandwiched between parking spaces in which another vehicle 91 is parked.

[0082] When the vehicle 10 is parked at a predetermined position, such as being parked next to an empty parking space, the detection unit 203 of the driving support device 20 mounted on the vehicle 10 detects, from among multiple parking spaces, for example, this empty parking space as a parking area PA in which the vehicle 10 can be parked. The display control unit 201 of the driving support device 20 causes the display unit 31 of the monitor device 30 to display the detected parking area PA.

[0083] When parking in the parking area PA is desired, the driver of the vehicle 10 or the like can instruct the driving assistance device 20 to execute driving assistance using the input unit 32 (see FIG. 2 ) or the like of the monitor device 30. This causes the driving assistance device 20 to start parking assistance for the vehicle 10.

[0084] 7, the route calculation unit 204 of the driving support device 20 calculates a travel route TR. The travel route TR extends from, for example, a stopping position PP of the vehicle 10 parked alongside the parking area PA, through a turning position SP in the forward direction of the vehicle 10, to a target position DP located within the parking area PA in the backward direction of the vehicle 10 at the turning position SP.

[0085] The movement control unit 206 of the driving support device 20 starts the movement of the vehicle 10 on the movement route TR according to the calculation result of the route calculation unit 204.

[0086] Initially, the movement control unit 206 moves the vehicle 10 forward from the stop position PP toward the switching position SP. At this time, the movement control unit 206 selects a speed limit value according to the situation of the vehicle 10 at this time.

[0087] In the example of Fig. 7, at this point, the vehicle 10 is outside the parking area PA, and the movement control unit 206 is moving the vehicle 10 forward. It is also assumed that there are no obstacles within a predetermined range around the vehicle 10. The movement control unit 206 selects a speed limit value according to such a situation of the vehicle 10.

[0088] The acceleration determination unit 205 calculates an acceleration for causing the vehicle 10 to reach the speed of the speed limit value selected by the movement control unit 206 within the acceleration time for forward movement, based on the speed limit value selected by the movement control unit 206 and the acceleration time for forward movement previously stored in the storage unit 207. Such an acceleration is calculated, for example, by the following formula (1).

[0089] Acceleration (m / s 2 ) = speed limit (m / s) / acceleration time (s) (1)

[0090] The movement control unit 206 moves the vehicle 10 forward at an acceleration determined by the acceleration determination unit 205, for example, using the selected speed limit value as a target speed, and moves the vehicle 10 from the stopping position PP to the turning position SP while maintaining the speed of the vehicle 10 within the speed limit value.

[0091] Next, the movement control unit 206 reverses the vehicle 10 from the turning position SP toward the target position DP. At this time, the movement control unit 206 selects a speed limit value according to the situation of the vehicle 10 at this time.

[0092] On the movement route TR from the turning position SP to the target position DP, which is indicated by a solid line in Fig. 7, the vehicle 10 is still outside the parking area PA, and the movement control unit 206 is trying to move the vehicle 10 backward. It is also assumed that there are no obstacles within a predetermined range around the vehicle 10. The movement control unit 206 selects a speed limit value according to such a situation of the vehicle 10.

[0093] The acceleration determination unit 205 calculates, based on the speed limit value selected by the movement control unit 206 and the acceleration time during reversing that is pre-stored in the memory unit 207, an acceleration for causing the vehicle 10 to reach the speed of the speed limit value selected by the movement control unit 206 within the acceleration time during reversing, for example according to the above formula (1).

[0094] The movement control unit 206 reverses the vehicle 10 at an acceleration determined by the acceleration determination unit 205, for example, using the selected speed limit value as the target speed, and moves the vehicle 10 from the turning position SP to the target position DP while maintaining the speed of the vehicle 10 within the speed limit value.

[0095] 8, the movement control unit 206 is still in the process of backing up the vehicle 10 toward the target position DP. At this time, the movement control unit 206 selects a speed limit value according to the situation of the vehicle 10 at this time.

[0096] In the example of Fig. 8, the vehicle 10 has entered the parking area PA, and the movement control unit 206 is trying to move the vehicle 10 further backward. Also, it is assumed that an obstacle such as another vehicle 91 is present within a predetermined range around the vehicle 10. The movement control unit 206 selects a speed limit value according to such a situation of the vehicle 10.

[0097] The acceleration determination unit 205 calculates, based on the speed limit value selected by the movement control unit 206 and the acceleration time during reversing that is pre-stored in the memory unit 207, an acceleration for causing the vehicle 10 to reach the speed of the speed limit value selected by the movement control unit 206 within the acceleration time during reversing, for example according to the above formula (1).

[0098] The movement control unit 206 reverses the vehicle 10 at an acceleration determined by the acceleration determination unit 205, for example, using the selected speed limit value as the target speed, and moves the vehicle 10 toward the target position DP while maintaining the speed of the vehicle 10 within the speed limit value.

[0099] By the above-mentioned control of the driving assistance device 20, the vehicle 10 is parked at the target position DP within the parking area PA, and the parking assistance by the driving assistance device 20 ends.

[0100] 6 to 8, the selection of the speed limit value and the acceleration time and the calculation of the acceleration are performed a total of three times on the travel route TR. However, the above explanation is merely for convenience, and the situation of the vehicle 10 on the travel route TR may change from moment to moment. For this reason, in actual control, the travel control unit 206 and the acceleration determination unit 205 may repeat the above process at short time intervals, for example, on the order of microseconds.

[0101] 6 to 8 have been described with reference to an example in which the vehicle 10 is parked backward in a parallel parking lot. However, the driving support device 20 controls the vehicle 10 in the same manner not only in the case of parallel backward parking, but also in the case of parallel forward parking, parallel forward / backward exit, or parallel parking / exit, etc.

[0102] (Example of processing by driving support device) Next, an example of driving support processing by the driving support device 20 according to the embodiment will be described with reference to Fig. 9. Fig. 9 is a flow diagram showing an example of a procedure of the driving support processing by the driving support device 20 according to the embodiment.

[0103] 9, when an instruction to start driving assistance is received from the driver or the like of the vehicle 10, control by the driving assistance device 20 is started (step S101). The route calculation unit 204 calculates a movement route from the stopping position of the vehicle 10 at that time to the target position (step S102).

[0104] The acceleration determination unit 205 refers to the detection result of the transmission sensor 73 (see FIG. 2) included in the transmission system 70 and determines whether the shift lever position of the vehicle 10 at that time is drive or not (step S103). If the shift lever position is drive (step S103: Yes), the acceleration determination unit 205 sets a forward acceleration time (step S104), and if the shift lever position is a position other than drive, such as reverse (step S103: No), the acceleration determination unit 205 sets a reverse acceleration time (step S105).

[0105] On the other hand, the movement control unit 206 sets a speed limit value according to the situation of the vehicle 10 at that time (step S106). The acceleration determination unit 205 calculates the acceleration required for the speed of the vehicle 10 to reach the speed limit value, based on the acceleration time set in the processing of step S104 or step S105 and the speed limit value set by the movement control unit 206 in the processing of step S106 (step S107).

[0106] The acceleration determination unit 205 performs movement control of the vehicle 10 by accelerating the vehicle 10 at the acceleration calculated by the acceleration determination unit 205 in the process of step S107, for example, with the speed limit value set in the process of step S106 as the target speed (step S108).

[0107] The movement control unit 206 determines whether the driving assistance process has ended, for example, when the vehicle 10 reaches a target position (step S109). If the driving assistance process is ongoing (step S109: No), the process from step S103 is repeated until the driving assistance process ends (step S109: Yes).

[0108] This ends the driving assistance process by the driving assistance device 20 of the embodiment.

[0109] (Overview) The driving assistance device performs driving assistance for the vehicle based on information about the surroundings of the vehicle from various sensors such as a distance measuring unit and an image capturing unit. However, under certain circumstances during driving assistance, the vehicle occupants, including the driver, may feel uncomfortable riding in the vehicle. This point will be described with reference to FIG. 10.

[0110] Fig. 10 is a graph showing an example of an acceleration time determined by a driving support device according to a comparative example, in which the horizontal axis represents time (s) and the vertical axis represents a target speed (m / s).

[0111] As shown in FIG. 10, the driving assistance device of the comparative example accelerates the vehicle at, for example, the same acceleration within a predetermined acceleration range, regardless of whether the target speed of the vehicle is speed limit value A or speed limit value B which is lower than speed limit value A, so that the vehicle speed reaches either speed limit value A or B.

[0112] Therefore, when speed limit value B, which is lower than speed limit value A, 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.

[0113] Moreover, the above control of the driving support device of the comparative example is the same whether 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 whether the vehicle is moving forward or backward, and the acceleration time B' required to reach the speed limit value B is the same whether the vehicle is moving forward or backward.

[0114] For example, when the speed limit is low and the acceleration time is short, the passengers may feel as if the vehicle is suddenly starting, resulting in an uncomfortable ride. This feeling tends to be even stronger when the vehicle is moving backwards.

[0115] According to the driving assistance device 20 of the embodiment, the acceleration for making the vehicle 10 reach the target speed is determined based on the predetermined acceleration time and the speed limit value selected by the movement control unit 206.

[0116] In this way, since the acceleration time is determined in advance regardless of the speed limit value, it is possible to improve the ride comfort of the passengers even when the speed limit value is low, for example. Also, since the acceleration time is determined in advance, it is possible to prevent unnecessary time from being required for parking or exiting the vehicle while improving the ride comfort of the passengers, and to quickly complete the process.

[0117] According to the driving support device 20 of the embodiment, a forward acceleration time is used when moving the vehicle 10 forward, and a backward acceleration time is used when moving the vehicle 10 backward. In this way, by setting different acceleration times when the vehicle 10 is moving forward and backward, which are different sensations felt by the occupants even when the vehicle 10 is moving forward and backward, more detailed control is possible.

[0118] According to the driving support device 20 of the embodiment, the acceleration time when the vehicle 10 is reversing is set to be longer than the acceleration time when the vehicle is moving forward. This makes it possible to improve the ride comfort of the occupants even when the vehicle 10 is reversing, which tends to give the occupants the impression that the vehicle 10 is accelerating rapidly.

[0119] According to the driving support device 20 of the embodiment, the acceleration times for forward and reverse are fixed. In this manner, by setting the acceleration times exclusively for forward and reverse, it is possible to prevent the control from becoming complicated due to the setting of a large number of acceleration times.

[0120] In the above embodiment, the driving assistance device 20 is mounted on the vehicle 10, but the driving assistance device 20 does not necessarily have to be mounted on the vehicle 10. For example, the driving assistance device may acquire peripheral information about the vehicle from various sensors at a location away from the vehicle, and perform driving assistance for the vehicle by remote control. [Explanation of symbols]

[0121] 10…Vehicle 14...Distance measurement section 16…Imaging unit 20...Driving assistance device 200…Driving assistance system 201...Display control unit 202…Acquisition Department 203…Detection unit 204...Route calculation unit 205...Acceleration determining section 206...Movement control unit 207...Storage section

Claims

1. A driving assistance device that provides driving assistance for a vehicle based on peripheral information collected by a plurality of sensors provided in the vehicle, a route calculation unit that calculates a movement route of the vehicle to a target position based on 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 according to the situation of the vehicle at the time; and an acceleration determination unit that determines an acceleration for causing the vehicle to reach the target speed based on a predetermined acceleration time and the speed limit value. Driving assistance device.

2. The acceleration determination unit a first acceleration time is used when moving the vehicle forward; a second acceleration time is used when the vehicle is reversed; The driving assistance device according to claim 1 .

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

4. The first and second acceleration times are each a fixed time. The driving assistance device according to claim 2 or 3.

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