Driving support device, driving support method, and program

Abstract

To provide a driving support device capable of improving convenience, a driving support method, and a program.SOLUTION: A driving support device comprises: a determination section for determining a target speed with respect to another vehicle travelling on a movement destination lane, which is a confluence destination or a lane change destination, in order to enter the movement destination lane based on a detection result of the other vehicle; and a notification control section for outputting from a speaker a notification sound which is different in a case where an own vehicle requires acceleration and in a case where speed reduction is required in order to perform speed matching in a direction of vehicle travel to the target speed which is determined by the determination section.SELECTED DRAWING: Figure 5

Description

Technical Field

[0001] The present invention relates to a driving support device, a driving support method, and a program.

Background Art

[0002] When it is determined that the target acceleration / deceleration speed has reached the limit value, there is known a vehicle that uses a buzzer to notify that the target acceleration / deceleration speed has reached the limit value (Patent Document 1). Further, there is known a vehicle that notifies the start of the braking operation by a buzzer sound when the host vehicle reaches the braking operation start point, decreases the buzzer sound as the vehicle speed decreases, and notifies the speed difference with respect to the deceleration target by the volume of the buzzer sound (Patent Document 2).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the above conventional technology, there are cases where the convenience is not sufficient depending on the driving scene.

[0005] The present invention has been made in consideration of such circumstances, and one of the objects is to provide a driving support device, a driving support method, and a program that can improve convenience.

Means for Solving the Problems

[0006] The driving support device, the driving support method, and the program according to the present invention employ the following configuration. (1): The driving support device according to one aspect of the present invention includes a determination unit that determines a target speed for another vehicle to enter the destination lane based on a detection result of another vehicle traveling in the destination lane which is a merging destination or a lane change destination, and a notification control unit that outputs different notification sounds from a speaker when the host vehicle needs to accelerate and when it needs to decelerate in order to match the speed in the vehicle traveling direction with the target speed determined by the determination unit.

[0007] (2): In the aspect of (1) above, the notification control unit varies the pitch of the notification sound when acceleration is required and when deceleration is required.

[0008] (3): In the aspect of (1) or (2) above, the notification control unit outputs the notification sound having a higher pitch when acceleration is required than when deceleration is required.

[0009] (4): In any of the aspects from (1) to (3) above, the notification control unit varies the timbre of the notification sound when acceleration is required and when deceleration is required.

[0010] (5): In any of the aspects from (1) to (4) above, the notification control unit varies the interval of the notification sound according to the degree of speed change of the host vehicle required to perform the speed matching.

[0011] (6): In the aspect of (5) above, the notification control unit shortens the interval as the required acceleration as the degree of speed change is larger, and shortens the interval as the required deceleration as the degree of speed change is larger.

[0012] (7): In any of the aspects from (1) to (6) above, the notification control unit varies the pitch, volume, or timbre of the notification sound according to the degree of speed change of the host vehicle required to perform the speed matching.

[0013] (8) In the aspect of (7) above, the notification control unit increases the pitch of the notification sound as the required acceleration as the degree of speed change is greater, and decreases the pitch of the notification sound as the required deceleration as the degree of speed change is greater.

[0014] (9) In the aspect of (7) or (8) above, the notification control unit increases the volume as the required acceleration as the degree of speed change is greater, and increases the volume as the required deceleration as the degree of speed change is greater.

[0015] (10) In any of the aspects of (1) to (9) above, the notification control unit changes one or more elements among the pitch, volume, timbre, or interval of the notification sound according to whether the host vehicle needs to accelerate or decelerate to perform the speed adjustment, and changes one or more other elements among the pitch, volume, timbre, or interval of the notification sound according to the degree of speed change of the host vehicle required to perform the position adjustment.

[0016] (11) In any of the aspects of (1) to (10) above, the determination unit determines the target relative position with respect to the other vehicle for merging or lane change, and the notification control unit determines the notification sound based on the driving force that simultaneously converges the position and speed of the host vehicle with respect to the target relative position and the target speed determined by the determination unit, and outputs the determined notification sound from the speaker.

[0017] (12) In the aspect of (11) above, it further includes a derivation unit that derives the driving force that simultaneously converges the position and speed of the host vehicle with respect to the target relative position and the target speed determined by the determination unit based on response-specified type control, and the notification control unit determines the notification sound based on the driving force derived by the derivation unit, and outputs the determined notification sound from the speaker.

[0018] (13): In the aspect of the above (12), the derivation unit derives the driving force so as to bring the position deviation, which is the deviation between the target relative position and the position of the host vehicle, and the speed deviation, which is the deviation between the target speed and the speed of the host vehicle, closer to zero while approaching a switching function obtained by linearly combining the position deviation and the speed deviation to zero.

[0019] (14): In the aspect of the above (12), the derivation unit determines a correction amount for the target speed so as to bring a first switching function obtained by linearly combining the position deviation, which is the deviation between the target relative position and the position of the host vehicle, and the past value of the position deviation closer to zero while bringing the position deviation and the past value of the position deviation closer to zero, determines the target speed by correcting a provisional target speed based on the speed of the other vehicle with the correction amount, and derives the driving force so as to bring a second switching function obtained by linearly combining the speed deviation, which is the deviation between the target speed and the speed of the host vehicle, and the past value of the speed deviation closer to zero while bringing the speed deviation and the past value of the speed deviation closer to zero.

[0020] (15): In any of the aspects from the above (1) to (14), the notification control unit changes the notification sound according to the depression characteristics of each driver with respect to the accelerator pedal.

[0021] (16): In any of the aspects from the above (1) to (15), the notification control unit changes the notification sound according to the distance available for merging or lane change.

[0022] (17): In any of the aspects from the above (1) to (16), the vehicle further includes a steering determination unit that determines the steering timing for entering the destination lane, and the notification control unit outputs a steering instruction sound different from the notification sound from the speaker at the steering timing determined by the steering determination unit.

[0023] (18): In any one of the aspects (1) to (17) above, the determination unit determines a target relative position with respect to the other vehicle for entering the target lane, and the notification control unit, with respect to the vehicle traveling direction, starts outputting the notification sound in response to the host vehicle entering an induction start range that is between the front part of a preceding vehicle traveling immediately before the target relative position in the target lane and the rear part of a following vehicle traveling immediately after the target relative position in the target lane.

[0024] (19): In the aspect (18) above, when the host vehicle enters the induction start range, the notification control unit causes the speaker to output an induction start notification sound different from the notification sound prior to starting the output of the notification sound.

[0025] (20): In any one of the aspects (1) to (19) above, the apparatus further includes an entry determination unit that determines whether entry into the target lane is possible, and when the entry determination unit determines that entry into the target lane is impossible after the notification control unit starts outputting the notification sound, the notification control unit causes the speaker to output an induction cancellation notification sound different from the notification sound.

[0026] (21): In any one of the aspects (1) to (20) above, when acceleration and deceleration are not required to perform the speed adjustment, the notification control unit does not output the notification sound from the speaker.

[0027] (22): A driving support apparatus according to another aspect of the present invention includes a determination unit that determines a target speed with respect to the other vehicle for entering the target lane based on a detection result of the other vehicle traveling in the target lane which is a merging destination or a lane change destination, and a notification control unit that causes the speaker to output a notification sound having different pitch, volume, timbre, or interval according to a degree of speed change required by the host vehicle to perform speed adjustment in the vehicle traveling direction with respect to the target speed determined by the determination unit.

[0028] (23): The driving support method according to another aspect of the present invention is such that a computer determines a target speed for another vehicle to enter the destination lane based on a detection result of another vehicle traveling in the destination lane which is the merging destination or the lane change destination, and outputs different notification sounds from a speaker depending on whether the host vehicle needs to accelerate or decelerate to match the speed in the vehicle traveling direction with respect to the determined target speed.

[0029] (24): The program according to another aspect of the present invention causes a computer to determine a target speed for another vehicle to enter the destination lane based on a detection result of another vehicle traveling in the destination lane which is the merging destination or the lane change destination, and causes different notification sounds to be output from a speaker depending on whether the host vehicle needs to accelerate or decelerate to match the speed in the vehicle traveling direction with respect to the determined target speed.

Effect of the Invention

[0030] According to the aspects (1) to (24) above, convenience can be improved.

Brief Description of the Drawings

[0031]

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BEST MODE FOR CARRYING OUT THE INVENTION

[0032] Hereinafter, with reference to the drawings, embodiments of the driving support device, driving support method, and program of the present invention will be described. In the following description, components having the same or similar functions are denoted by the same reference numerals. And redundant descriptions of these components may be omitted. "Based on XX" means "based on at least XX", and may include cases based on another element in addition to XX. "Based on XX" is not limited to the case of directly using XX, and may include cases based on something obtained by performing additional calculations or processing on XX. "XX or YY" is not limited to either one of XX and YY, and may include both cases of XX and YY. This is the same when there are three or more selectable elements. "XX" and "YY" are arbitrary elements (for example, arbitrary information).

[0033] <First Embodiment> [1. Vehicle Configuration] FIG. 1 is a plan view showing a vehicle M (hereinafter sometimes referred to as "own vehicle M") equipped with the driving support device 100 according to the first embodiment. The vehicle M is, for example, an automobile such as a two-wheeled, three-wheeled, or four-wheeled vehicle, an automobile having an internal combustion engine such as a diesel engine or a gasoline engine as a power source, an electric vehicle having an electric motor as a power source, or a hybrid vehicle having both an internal combustion engine and an electric motor. The electric vehicle is driven using electric power discharged from a battery such as a secondary battery, a hydrogen fuel cell, a metal fuel cell, or an alcohol fuel cell, for example.

[0034] As shown in FIG. 1, the vehicle M includes, for example, a front camera 10 (hereinafter sometimes referred to as "camera 10"), a plurality of radars 20, and a driving support device 100.

[0035] The camera 10 is provided, for example, at the front of the vehicle M and can capture the front of the vehicle M. The imaging range of the camera 10 shown in FIG. 1 is conceptual. The camera 10 can capture other vehicles traveling relatively far ahead (for example, it can capture the front vehicle Mf at the position (a) in FIG. 15). The radar 20 is provided, for example, at the four corners of the vehicle M and can monitor the front both sides and the rear both sides of the vehicle M. The radar 20 is, for example, a millimeter-wave radar, but is not limited thereto.

[0036] The vehicle M of the present embodiment is a vehicle premised on being driven by an occupant, and has a simple monitoring sensor group (camera 10 and radar 20) compared to a so-called autonomous vehicle (autonomous vehicle of level 3 or higher). For this reason, a blind spot area DA that cannot be detected by the monitoring sensor group may exist on the side of the vehicle M. However, the vehicle M may have a monitoring sensor group that can monitor 360 degrees around the vehicle M, similar to an autonomous vehicle of level 3 or higher.

[0037] The driving support device 100 is a device that can assist in smoothly merging into or changing lanes on the main line lane, and supports the driving by the occupant (driver) by outputting a guiding notification sound from the speaker 60 described later. The driving support device 100 will be described in detail later.

[0038] In addition to the above-described configuration, the vehicle M has, as components of a general vehicle, a power source (drive source) of the vehicle M, various operation devices, and various operation detection sensors. The power source includes, for example, an internal combustion engine such as an engine and / or an electric motor. The various operation devices include, for example, an accelerator pedal 31 (see FIG. 5), a steering wheel, a brake pedal, and a shift lever. The various operation detection sensors include an accelerator opening sensor 32 (see FIG. 5), a steering torque sensor, a brake sensor, a shift position sensor, and the like. The accelerator opening sensor 32 detects the accelerator opening Qap according to the amount of depression of the accelerator pedal 31 by the driver.

[0039] [2. Scenario examples of merging / lane change] Next, with reference to FIGS. 2 to 4, the difficulty of driving during merging / lane changing will be described. Hereinafter, the term "merging" is used in a meaning that includes both "merging into the main lane" and "lane changing".

[0040] FIG. 2 is a graph showing the relationship between the vehicle speed Ve of the host vehicle M and the driving force (accelerator opening Qap) of the host vehicle M. As shown in FIG. 2, the running resistance Rd increases exponentially as the vehicle speed Ve increases. The region where the driving force of the host vehicle M with respect to the vehicle speed Ve is higher than the running resistance Rd is the acceleration region for accelerating the vehicle M. The region where the driving force of the host vehicle M with respect to the vehicle speed Ve is lower than the running resistance Rd is the deceleration region for decelerating the vehicle M.

[0041] FIG. 3 is a diagram showing several scenarios (Cases 1 to 4) related to merging. Cases 1 to 4 are classifications focusing on the difference in the speed relationship between the host vehicle M and other vehicles. Hereinafter, among the other vehicles traveling in the lane (destination lane, adjacent lane) where the host vehicle M merges, the other vehicle traveling immediately before the merging target position is referred to as "front vehicle Mf", and the other vehicle traveling immediately after the merging target position is referred to as "rear vehicle Mb". Also hereinafter, the speed of the front vehicle Mf is defined as "speed Vof", the speed of the rear vehicle Mb is defined as "speed Vob", the set target merging relative position between the front vehicle Mf and the rear vehicle Mb is defined as "target merging relative position Pmt", and the position error of the host vehicle M with respect to the target merging relative position Pmt is defined as "relative position error Epm". The target merging relative position Pmt is set, for example, at the central position between the front vehicle Mf and the rear vehicle Mb in the vehicle traveling direction, or at a position slightly closer to the front than the above central position. In the right graph in FIG. 3, the white star mark indicates the "driving force at the start of merging", and the hatched star mark indicates the "driving force during merging".

[0042] Case 1 is a situation where the speed of the host vehicle Ve is approximately the same as the speed of the leading vehicle Mf, Vof, and the speed of the trailing vehicle Mb, Vob (the relative speed is approximately zero), and the host vehicle M is located slightly in front compared to the target merging relative position Pmt. In this case, the driver needs to slightly release the accelerator pedal 31 to decelerate, and then step on the accelerator pedal 31 again to return to the original accelerator opening.

[0043] Case 2 is a situation where the speed of the host vehicle Ve is slightly faster than the speed of the leading vehicle Mf, Vof, and the speed of the trailing vehicle Mb, Vob, and the host vehicle M is located slightly in front compared to the target merging relative position Pmt. In this case, the driver needs to return the accelerator pedal 31 to an appropriate value to decelerate, and then step on the accelerator pedal 31 again to set it to an appropriate accelerator opening lower than the original accelerator opening.

[0044] Case 3 is a situation where the speed of the host vehicle Ve is excessively faster than the speed of the leading vehicle Mf, Vof, and the speed of the trailing vehicle Mb, Vob, and the host vehicle M is located slightly in front compared to the target merging relative position Pmt. In this case, the driver needs to significantly release the accelerator pedal 31 to decelerate in order to suppress the excessive speed, and then step on the accelerator pedal 31 again to set it to an appropriate accelerator opening lower than the original accelerator opening.

[0045] Case 4 is a situation where the speed of the host vehicle Ve is excessively slower than the speed of the leading vehicle Mf, Vof, and the speed of the trailing vehicle Mb, Vob, and the host vehicle M is located slightly in front compared to the target merging relative position Pmt. In this case, the driver needs to step on the accelerator pedal 31 deeply to accelerate, and then gradually release the accelerator pedal 31 to set it to an appropriate accelerator opening higher than the original accelerator opening.

[0046] As described above, even when the relative positions of the host vehicle M and other vehicles are the same, the time-series movements of the required accelerator openings are completely different due to differences in relative speeds. The driver needs to align the position of the host vehicle M with an appropriate position relative to other vehicles during merging and also make the relative speed to other vehicles almost zero. That is, the driver must adjust two elements (position and speed) simultaneously. For this reason, merging can be a particularly difficult operation for novice drivers or those who are not good at driving.

[0047] FIG. 4 is a diagram showing some scenarios (Cases 5 to 8) from another perspective regarding merging. Cases 5 to 8 are classifications focusing on differences in the positional relationships between the host vehicle M and other vehicles.

[0048] Case 5 is the same as Case 1, where the host vehicle speed Ve is approximately the same as the speed Vof of the leading vehicle Mf and the speed Vob of the trailing vehicle Mb (the relative speed is approximately zero), and the host vehicle M is positioned slightly in front compared to the target merging relative position Pmt. In this case, the driver needs to slightly release the accelerator pedal 31 to decelerate, and then step on the accelerator pedal 31 again to return to the original accelerator opening.

[0049] Case 6 is a situation where the host vehicle speed Ve is approximately the same as the speed Vof of the leading vehicle Mf and the speed Vob of the trailing vehicle Mb (the relative speed is approximately zero), and the host vehicle M is positioned significantly in front compared to the target merging relative position Pmt. In this case, the driver needs to significantly release the accelerator pedal 31 to decelerate, let the leading vehicle Mf go ahead, and then step on the accelerator pedal 31 again to return to the original accelerator opening.

[0050] Case 7 is a situation where the host vehicle speed Ve is approximately the same as the speed Vof of the leading vehicle Mf and the speed Vob of the trailing vehicle Mb (the relative speed is approximately zero), and the host vehicle M is positioned significantly behind compared to the target merging relative position Pmt. In this case, the driver needs to step on the accelerator pedal 31 to accelerate, and then gradually release the accelerator pedal 31 to return to the original accelerator opening.

[0051] Case 8 is a situation where the speed Ve of the host vehicle is excessively faster than the speed Vof of the leading vehicle Mf and the speed Vob of the trailing vehicle Mb, and the host vehicle M is located significantly behind the target merging relative position Pmt. In this case, although the position of the host vehicle is behind the target merging relative position Pmt, in order to suppress the excessive speed, the driver needs to adjust the position of the host vehicle to the target merging relative position Pmt while returning the accelerator pedal 31, and set the accelerator opening to be higher than the original accelerator opening.

[0052] As described above, even when the relative speeds of the host vehicle M and other vehicles are the same, the time-series movement of the required accelerator opening varies significantly depending on the difference in relative position. In this case as well, the driver needs to adjust the position of the host vehicle M to an appropriate position relative to other vehicles during merging and also make the relative speed with respect to other vehicles approximately zero. For example, even when the host vehicle M is located behind the target merging relative position Pmt as in Case 8, there may be cases where the accelerator pedal 31 needs to be returned against the sense of position control. From this perspective as well, merging can be a particularly difficult operation for novice drivers or those who are not good at driving.

[0053] [3. Configuration of Driving Support Device] FIG. 5 is a configuration diagram showing the driving support device 100. In addition to the above-described configuration, the vehicle M includes a GNSS receiver 40, an in-vehicle camera 50, a speaker 60, and a display device 70.

[0054] The GNSS receiver 40 measures the position of the host vehicle M based on radio waves arriving from GNSS satellites (e.g., GPS satellites). The GNSS receiver 40 outputs the positioning result to the driving support device 100.

[0055] The in-vehicle camera 50 is provided inside the vehicle cabin of the vehicle M and can photograph the driver. The in-vehicle camera 50 is an example of a "driver information detection device" that detects information for identifying the driver. The "driver information detection device" may be, instead of or in addition to the in-vehicle camera 50, a microphone that picks up the driver's voice, a device that detects the driver's biometric information (e.g., fingerprint), etc.

[0056] The speaker 60 is provided inside the passenger compartment of the vehicle M, and can output, for example, a guidance notification sound directed at the driver. The display device 70 is a display unit provided in the meter or a head-up display (HUD), and can display predetermined information to the driver. These details will be described later in detail.

[0057] As shown in FIG. 5, the driving support device 100 includes an information processing unit 100a and a storage unit 100b. The information processing unit 100a includes, for example, a detection unit 101, a target position speed calculation unit 102, a relative position deviation calculation unit 103, a guidance parameter setting unit 104, a merging guidance control unit 105, a target driving force calculation unit 106, a driver required driving force calculation unit 107, a feedforward driving force calculation unit 108, a driver determination unit 109, a notification control unit 110, a steering determination unit 111, and an entry permission determination unit 112. These components are realized, for example, by a hardware processor such as a CPU (Central Processing Unit) executing a program (software). Some or all of these components may be realized by hardware (including a circuit unit; circuitry) such as an LSI (Large Scale Integration), an ASIC (Application Specific Integrated Circuit), an FPGA (Field-Programmable Gate Array), or a GPU (Graphics Processing Unit), or may be realized by the cooperation of software and hardware. The program may be stored in advance in a storage device (a storage device having a non-transitory storage medium) such as an HDD or a flash memory, or may be stored in a removable storage medium (a non-transitory storage medium) such as a DVD or a CD-ROM, and may be installed in the storage device by mounting the storage medium on a drive device.

[0058] The storage unit 100b is, for example, an HDD, a flash memory, a ROM, a RAM (Random Access Memory), etc. The storage unit 100b stores map information 151, guidance parameter information 152, running resistance information (running resistance table) 153, driver information 154, notification sound information (sound table) 155, and driver characteristic information 156.

[0059] [4. Recommendation of merging position] Next, the process performed before the output of the guidance notification sound described later will be explained. When the driving support device 100 of the present embodiment receives an input from a user who desires guidance for merging (for example, an audio input such as "Start the merging guidance" to an in-vehicle microphone), the following process is performed. First, the driving support device 100 identifies a mergeable position based on the detection result of other vehicles detected by the detection unit 101 described later, and notifies the driver of the identified mergeable position. The notification to the driver is performed, for example, by displaying the mergeable position on the display device 70, but other means may be used. Thereafter, the driver enters the host vehicle M into the guidance start range GR (see FIG. 15) by his / her own driving. When the host vehicle M enters the guidance start range GR, the driving support device 100 starts the guidance by the guidance notification sound described below.

[0060] [4. Guidance by guidance notification sound] [4.1 Basic process regarding guidance notification sound] FIG. 6 is a block diagram showing the flow of the process regarding the guidance notification sound. The process described below is repeatedly executed at a predetermined control cycle (for example, 50 [msec] to 300 [msec]). "k" in the formula means the value at the control time k.

[0061] The detection unit 101 acquires the detection results of the camera 10 and the radar 20. The detection results of the camera 10 and the radar 20 include the detection results of other vehicles (front vehicle Mf and rear vehicle Mb) traveling in the destination lane, which is the merging destination or the lane change destination. Based on the detection results of the camera 10 and the radar 20, the detection unit 101 detects the relative position Pof of the front vehicle Mf with respect to the host vehicle M, the relative position Pob of the rear vehicle Mb with respect to the host vehicle M, the speed Vof of the front vehicle Mf, and the speed Vob of the rear vehicle Mb, and outputs the detected relative positions Pof, Pob and speeds Vof, Vob to the target position speed calculation unit 102. The relative positions Pof, Pob are specified, for example, in a relative coordinate system based on the host vehicle M. Further, the detection unit 101 detects the host vehicle speed Ve based on the detection results of sensors provided in the traveling device of the host vehicle M or the like. The detection unit 101 outputs the detected host vehicle speed Ve to the target position speed calculation unit 102 and the merging guidance control unit 105.

[0062] In the present embodiment, the detection unit 101 derives the road information RI based on the detection result of the camera 10 (for example, the image data acquired by the camera 10), and outputs the derived road information RI to the guidance parameter setting unit 104. The road information RI is information indicating the shape of the lane in which the host vehicle M travels, and includes information indicating the distance available for merging. Note that the detection unit 101 may derive the road information RI based on the detection result of the GNSS receiver 40 and the map information 151 stored in the storage unit 10b in addition to / instead of the detection result of the camera 10. The map information 151 is information indicating the lane type of the lane (types such as the main line lane, the merging lane, the overtaking lane, the boarding lane, etc.) and the distance of each lane (such as the length of the merging lane).

[0063] The target position speed calculation unit 102 calculates a target merging relative position Pmt based on the relative positions Pof and Pob. For example, the target position speed calculation unit 102 calculates the central position between the relative position Pof and the relative position Pob in the vehicle traveling direction as the target merging relative position Pmt. Alternatively, the target position speed calculation unit 102 may calculate, as the target merging relative position Pmt, a position on the front side by a predetermined amount (or a predetermined ratio) with respect to the central position between the relative position Pof and the relative position Pob in the vehicle traveling direction. The target merging relative position Pmt is the target relative position with respect to another vehicle (for example, the vehicle Mf ahead) for entering the destination lane. The target merging relative position Pmt is calculated, for example, in a relative coordinate system based on the host vehicle M. The target position speed calculation unit 102 outputs the calculated target merging relative position Pmt to the relative position deviation calculation unit 103.

[0064] Furthermore, the target position speed calculation unit 102 calculates a target merging speed Vmt, which is the target speed for merging, based on the speeds Vof and Vob. For example, the target position speed calculation unit 102 calculates the same speed as the speed Vof of the vehicle Mf ahead as the target merging speed Vmt. Alternatively, when the speed Vob of the vehicle Mb behind is greater than the speed Vof of the vehicle Mf ahead, the target position speed calculation unit 102 may calculate the median value between the speeds Vof and Vob as the target merging speed Vmt. The target position speed calculation unit 102 outputs the calculated target merging speed Vmt to the target driving force calculation unit 106. The target position speed calculation unit 102 is an example of a "determination unit" that determines the target merging relative position Pmt and the target merging speed Vmt.

[0065] The relative position deviation calculation unit 103 calculates a relative position deviation Ept based on the target merging relative position Pmt. The relative position deviation Ept has substantially the same meaning as the relative position error Epm described above. The relative position deviation Ept is calculated, for example, in a relative coordinate system with the host vehicle M as a reference. In this case, the relative position deviation Ept is calculated by multiplying the target merging relative position Pmt by "-1". That is, the relative position deviation calculation unit 103 calculates the relative position deviation Ept based on the following formula (1). The relative position deviation calculation unit 103 outputs the calculated relative position deviation Ept to the merging guidance control unit 105.

Number

[0066] The guidance parameter setting unit 104 sets a merging guidance parameter S (0 < S) for each merging scenario based on the lane information RI and the guidance parameter information 152 stored in the storage unit 100b. The guidance parameter information 152 is information indicating the correspondence between the available distance for merging and the merging guidance parameter S. The merging guidance parameter S is a parameter used in the calculation of the guidance feedback driving force Ffb in the merging guidance control unit 105 described later. The larger the merging guidance parameter S, the greater the allowable acceleration and deceleration during merging. By calculating the guidance feedback driving force Ffb considering the merging guidance parameter S, the guidance notification sound is changed according to the available distance for merging.

[0067] FIG. 7 is a diagram conceptually showing the setting of the merging guidance parameter S. The guidance parameter setting unit 104 sets a larger merging guidance parameter S as the distance available for merging is longer based on the lane information RI. On the other hand, it sets a smaller merging guidance parameter S as the distance available for merging is shorter. The guidance parameter setting unit 104 outputs the set merging guidance parameter S to the merging guidance control unit 105. The merging guidance parameter S is a parameter such that the smaller it is, the greater the allowable acceleration and deceleration during merging. That is, the smaller the merging guidance parameter S, the steeper the slope of the switching function σ (FIG. 8) described later, and the position of the host vehicle M is adjusted to the target merging position in a short time while leaving a large deviation between the target merging speed and the speed of the host vehicle M.

[0068] Next, returning to FIG. 6, the merging guidance control unit (guidance feedback driving force calculation unit) 105 will be described. The merging guidance control unit 105 calculates a guidance feedback driving force Ffb based on the target merging speed Vmt, the relative position deviation Ept, the host vehicle speed Ve, and the merging guidance parameter S.

[0069] FIG. 8 is a diagram conceptually showing the calculation by the merging guidance control unit 105. The merging guidance control unit 105 first calculates a target speed deviation Evt based on the target merging speed Vmt and the host vehicle speed Ve. Specifically, the target speed deviation Evt is calculated based on the following formula (2).

Equation

[0070] Then, the merging guidance control unit 105 calculates a guidance feedback driving force Ffb for simultaneously converging both the relative position deviation Ept and the target speed deviation Evt to zero. The merging guidance control unit 105 of the present embodiment calculates a guidance feedback driving force Ffb for simultaneously converging both the relative position deviation Ept and the target speed deviation Evt to zero based on response-specified control (pole-assignment control, for example, sliding mode control, backstepping control, etc.). That is, the merging guidance control unit 105 calculates a guidance feedback driving force Ffb that simultaneously approaches both the relative position deviation Ept and the target speed deviation Evt to a straight line L where the switching function σ = Evt + S × Ept is zero (for example, approaching with exponential decay).

[0071] Specifically, the guidance feedback driving force Ffb is calculated based on the following equations (3) to (6). S is a merging guidance parameter, Ept is a target position deviation, Evt is a target speed deviation, Ve is the vehicle speed, Vmt is the target merging speed, Pmt is the target relative merging position, k is the control time (control cycle), Ffb is the guidance feedback driving force, Ffb_rch is the reaching-side input, Ffb_adp is the adaptation-side input, and Krch and Kadp are feedback gains, respectively.

Equation

Equation

Equation

Equation

[0072] FIG. 9 conceptually shows a case where response-specified control is used for the above-described Cases 1 to 8. By using the response-specified control, the ideal acceleration / deceleration behavior of the vehicle M can be expressed in any merging scenario. Note that the calculation of the driving force at the time of merging is not limited to the response-specified control, and other control methods such as cascade control may be used.

[0073] Next, returning to FIG. 6, the remaining configuration will be described. The target driving force calculation unit 106 calculates the target driving force Fdt at the time of merging of the host vehicle M based on the target merging speed Vmt and the running resistance information 153 stored in the storage unit 101b. That is, the target driving force calculation unit 106 refers to the running resistance information 153 and calculates the driving force at the time of merging required to achieve the target merging speed Vmt as the target driving force Fdt at the time of merging. The running resistance information 153 is information indicating the correspondence between the host vehicle speed Ve and the driving force (accelerator opening Qap) required to achieve the host vehicle speed Ve as shown in FIG. 2. The target driving force calculation unit 106 outputs the calculated target driving force Fdt at the time of merging to the feedforward driving force calculation unit 108.

[0074] The accelerator opening Qap, which is the detection result of the accelerator opening sensor 32, is input to the driver request driving force calculation unit 107. The driver request driving force calculation unit 107 calculates the driving force Fdrv of the host vehicle M corresponding to the input accelerator opening Qap (hereinafter referred to as the "driver request driving force Fdrv") based on the input accelerator opening Qap and, for example, a previously registered conversion formula. The driver request driving force calculation unit 107 outputs the calculated driver request driving force Fdrv to the feedforward driving force calculation unit 108.

[0075] The feedforward driving force calculation unit 108 calculates the feedforward driving force Fff based on the driver request driving force Fdrv and the target driving force Fdt at the time of merging. The feedforward driving force calculation unit 108 calculates the feedforward driving force Fff based on, for example, a model that smoothly connects (connects with a ramp) the driver request driving force Fdrv and the target driving force Fdt at the time of merging.

[0076] The feedforward driving force Fff calculated by the feedforward driving force calculation unit 108 is added to the guiding feedback driving force Ffb calculated by the merging guidance control unit 105. Thereby, the required driving force Frq is calculated. Then, the target merging driving force Fdt is subtracted from the required driving force Frq, whereby the guiding parameter (guiding driving force) Flead is calculated. That is, the guiding parameter Flead is calculated as the difference from the driving force that reaches the target merging speed at the time of merging. When the host vehicle M is maintained at the target speed, the guiding parameter Flead becomes zero. The calculated guiding parameter Flead is output to the notification control unit 110.

[0077] As described above, in the present embodiment, an example of the "derivation unit DU" is formed by the merging guidance control unit 105, the target driving force calculation unit 106, the driver required driving force calculation unit 107, and the feedforward driving force calculation unit 108. The derivation unit DU derives, based on the response-specified type control, the driving force that simultaneously converges the position and speed of the host vehicle M with respect to the target merging relative position Pmt and the target merging speed Vmt. Here, "derivation" in this specification includes not only calculation but also cases where a value is obtained by referring to a table or the like. In other words, in the description of each functional unit, the term "calculation" may be appropriately read as "derivation".

[0078] The detection result (imaging result) of the in-vehicle camera 50 is input to the driver determination unit 109. The driver determination unit 109 determines the driver who drives the host vehicle M based on the detection result of the in-vehicle camera 50 and the driver information 154 stored in the storage unit 101b. The driver information 154 is information for determining (identifying) the driver based on the detection result of the in-vehicle camera 50. For example, the driver information 154 is information indicating the correspondence between the detection result of the in-vehicle camera 50 and the identification ID of the driver. The information (driver ID) indicating the determined driver is output to the notification control unit 110.

[0079] The notification control unit 110 specifies (determines) the type (pitch, timbre, volume, interval, etc.) of the guidance notification sound for guiding the driver at the time of merging based on the guidance parameter Flead, and causes the specified (determined) guidance notification sound to be output from the speaker 60. The guidance notification sound is a notification sound that assists the driver in aligning the position of the host vehicle M in the vehicle traveling direction with respect to the target merging relative position Pmt while matching the speed of the host vehicle M to the target merging speed Vmt.

[0080] FIG. 10 is a diagram conceptually showing the guidance notification sound output by the notification control unit 110. In the present embodiment, the notification control unit 110 causes different guidance notification sounds to be output from the speaker 60 when the host vehicle M needs to accelerate and when it needs to decelerate in order to align the position in the vehicle traveling direction with respect to the target merging relative position Pmt.

[0081] For example, the notification control unit 110 causes the speaker 60 to output notification sounds with different pitches when the host vehicle M needs to accelerate and when it needs to decelerate. In the present embodiment, the notification control unit 110 causes the speaker 60 to output a guidance notification sound with a higher pitch when the host vehicle M needs to accelerate than when it needs to decelerate. That is, the notification control unit 110 outputs a notification sound with a high pitch (e.g., "tut tut tut") when the host vehicle M needs to accelerate, and outputs a notification sound with a low pitch (e.g., "dod dod dod") when the host vehicle M needs to decelerate.

[0082] In the present embodiment, the notification control unit 110 varies the interval (the cycle of sounding the notification sound) of the guidance notification sound according to the degree of speed change (required acceleration / required deceleration) required by the host vehicle M to perform the above alignment. For example, the notification control unit 110 shortens the interval of the guidance notification sound as the required acceleration as the degree of speed change is larger, and shortens the interval of the guidance notification sound as the required deceleration as the degree of speed change is larger.

[0083] Instead of or in addition to the interval of the guidance notification sound, the notification control unit 110 may vary the pitch, volume, or timbre of the guidance notification sound according to the degree of speed change required by the host vehicle M to perform the above alignment. For example, the notification control unit 110 may increase the pitch of the guidance notification sound as the required acceleration as the degree of speed change increases, and decrease the pitch of the guidance notification sound as the required deceleration as the degree of speed change increases. For example, the notification control unit 110 may increase the volume of the guidance notification sound as the required acceleration as the degree of speed change increases, and increase the volume of the guidance notification sound as the required deceleration as the degree of speed change increases.

[0084] In other words, the notification control unit 110 of the present embodiment changes one or more of the pitch, volume, timbre, or interval of the guidance notification sound according to whether the host vehicle M needs to accelerate or decelerate to perform the above alignment, and changes one or more of the other pitch, volume, timbre, or interval of the guidance notification sound according to the degree of speed change required by the host vehicle M to perform the above alignment.

[0085] In the present embodiment, when acceleration and deceleration are not required to perform the above alignment, the notification control unit 110 causes the speaker 60 to output a guidance notification sound (neutral guidance notification sound) indicating that acceleration and deceleration are not required. The pitch of the neutral guidance notification sound is set, for example, between the pitch of the guidance notification sound when acceleration is required and the pitch of the guidance notification sound when deceleration is required. The interval of the neutral guidance notification sound is set, for example, longer than the interval of the guidance notification sound when acceleration is required and longer than the interval of the guidance notification sound when deceleration is required. Alternatively, the notification control unit 110 may prevent the guidance notification sound from being output from the speaker 60 when acceleration and deceleration are not required to perform the above alignment.

[0086] More specifically, the notification control unit 110 of the present embodiment performs the following processing. That is, the notification control unit 110 specifies the sound parameter Psound based on the guidance parameter Flead and a driver characteristic parameter (hereinafter referred to as "slope α" for convenience of explanation) described later. The specification of the sound parameter Psound is performed using, for example, a preset conversion formula or table. Then, the notification control unit 110 refers to the notification sound information 155 and specifies the components (pitch, volume, timbre, and interval) of the guidance notification sound corresponding to the specified sound parameter Psound. Then, the notification control unit 110 controls the speaker 60 based on the specified components (pitch, volume, timbre, and interval) of the guidance notification sound, so as to output the specified guidance notification sound from the speaker 60.

[0087] In other words, the above-mentioned "outputting different guidance notification sounds from the speaker 60 when the host vehicle M needs to accelerate and when it needs to decelerate" means that without the notification control unit 110 performing the determination process of "whether it is a case where acceleration is required" or "whether it is a case where deceleration is required", the guidance notification sound to be output is specified (for example, selected) based on the input guidance parameter Flead, and the specified guidance notification sound is output from the speaker 60 also includes the case.

[0088] FIG. 11 is a diagram conceptually showing an example of the notification sound information 155. In the notification sound information 155, for example, the sound parameter Psound, the pitch of the guidance notification sound, and the interval (period) of the guidance notification sound are registered in association with each other. The notification control unit 110 refers to the notification sound information 155 to obtain the pitch and period of the guidance notification sound corresponding to the sound parameter Psound. In the example shown in FIG. 11, the pitch is set in three levels: "when acceleration is required", "when neither acceleration nor deceleration is required", and "when deceleration is required". On the other hand, the period of the sound is set such that "when neither acceleration nor deceleration is required" is the longest, and it becomes shorter as the required acceleration or the required deceleration increases.

[0089] FIG. 12 conceptually shows another example of the notification sound information 155. In the example shown in FIG. 12, the pitch is registered such that, centered around "when neither acceleration nor deceleration is required", it increases as the required acceleration increases and decreases as the required deceleration increases.

[0090] [4.2 Change of the slope α according to the driver characteristics] Next, the change of the slope α according to the driver characteristics will be described. For example, even when the same guidance notification sound is heard, the amount of depression of the accelerator pedal 31 may vary greatly depending on the driver. Therefore, the notification control unit 110 changes (adjusts) the guidance notification sound according to the depression characteristics for each driver with respect to the accelerator pedal 31. That is, the notification control unit 110 changes the setting of the slope α for each driver so that the driver depresses the accelerator pedal 31 to the amount of depression at which the required driving force can be obtained.

[0091] FIG. 13 conceptually shows the change of the slope α. The notification control unit 110 first specifies the sound parameter Psound based on the currently calculated value (for example, the initial value) of the guidance parameter Flead, and outputs the guidance notification sound corresponding to the specified sound parameter Psound. As a result, the driver displaces the accelerator pedal 31 in response to the guidance notification sound.

[0092] Next, the driver required driving force calculation unit 107 calculates the driver required driving force Fdrv after reacting to the guidance notification sound based on the most recent accelerator opening Qap of the accelerator pedal 31, and outputs the calculated driver required driving force Fdrv to the notification control unit 110. Then, the notification control unit 110 compares the difference between the received driver required driving force Fdrv and the target merging driving force Fdt with the guidance parameter Flead, and determines whether there is a driving force deviation Ef (= Fdrv - Fdt - Flead), which is the difference of the guidance parameter Flead with respect to the difference between the driver required driving force Fdrv and the target merging driving force Fdt.

[0093] When there is a driving force deviation Ef, the notification control unit 110 changes the inclination α so as to eliminate the driving force deviation Ef. For example, when the driver required driving force Fdrv is small with respect to the currently calculated value of the induction parameter Flead, the inclination α is changed so that the interval of the induction notification sound becomes shorter (that is, the induction notification sound that requires a higher driving force) even when the same induction parameter Flead is input. The notification control unit 110 repeats the above-described inclination α change process (adjustment process) at a predetermined cycle. Thereby, an appropriate inclination α is obtained for each driver. The notification control unit 110 registers the inclination α obtained for each driver in the driver characteristic information 156 and uses it after the next time.

[0094] FIG. 14 is a diagram showing an example of the driver characteristic information 156. In the driver characteristic information 156, the identification ID of the driver and the inclination α obtained for each driver are registered in association with each other. When the inclination α corresponding to the driver ID determined by the driver determination unit 109 is registered in the driver characteristic information 156, the notification control unit 110 reads out the inclination α from the driver characteristic information 156 and calculates the sound parameter Psound using the read inclination α. Thereby, it is possible to output an induction notification sound according to the stepping characteristics for each driver.

[0095] The change process of the inclination α according to the driver characteristics described above is performed based on, for example, the following formulas (7) to (9). Psound is the sound parameter, α is the inclination of the sound parameter, Ef is the driving force deviation, and Ksnd is the sound parameter adaptation gain (0 < ksnd). [Equation] [Equation] [Equation]

[0096] [5. Other processes related to the induction notification sound] [5.1 Induction start range by the induction notification sound] FIG. 15 is a diagram showing an induction start range GR by an induction notification sound. In the present embodiment, the notification control unit 110 starts outputting the induction notification sound in response to the host vehicle M entering an induction start range GR that is between the front part (for example, the front end) of the front vehicle Mf traveling immediately before the target merging relative position Pmt and the rear part (for example, the rear end) of the rear vehicle Mb traveling immediately after the target merging relative position Pmt with respect to the vehicle traveling direction.

[0097] For example, when the host vehicle M enters the induction start range GR from the rear as shown in (a) in FIG. 15 and when the host vehicle M enters the induction start range GR from the front as shown in (b) in FIG. 15, the notification control unit 110 starts outputting the induction notification sound. This is because when the host vehicle M is located in front of the front part (for example, the front end) of the front vehicle Mf or when the host vehicle M is located behind the rear part of the rear vehicle Mb, the detection unit 101 detects the front vehicle Mf and the rear vehicle Mb in an overlapping state, and the recognition accuracy of the positions and speeds of these front vehicle Mf and rear vehicle Mb decreases.

[0098] On the other hand, when an input is made by a driver who wishes to perform induction of merging while the host vehicle M is located on the side of the target merging relative position Pmt as shown in (c) in FIG. 15, the notification control unit 110 does not start outputting the induction notification sound. In this case, the driving support device 100 notifies the driver that it is necessary to enter the induction start range GR again or takes measures such as changing the target merging relative position Pmt. This is because, as described above, the host vehicle M in the present embodiment may have a blind spot area DA on the side. Note that when the host vehicle M has a monitoring sensor group capable of detecting the situation around 360 degrees, the output of the induction notification sound may be started even from the state shown in (c) in FIG. 15.

[0099] [5.2 Output of Induction Start Notification Sound] In this embodiment, when the host vehicle M enters the guidance start range GR, the notification control unit 110 causes the speaker 60 to output a guidance start notification sound different from the guidance notification sound prior to the start of the output of the guidance notification sound. The guidance start notification sound may be an announcement by voice such as "Start guidance."

[0100] [5.3 Output of steering instruction sound] In this embodiment, the steering determination unit 111 determines the steering timing for entering the target lane. For example, the steering determination unit 111 determines that the steering timing has arrived when the position error of the host vehicle M with respect to the target merging relative position Pmt is within a predetermined range and the speed error of the host vehicle M with respect to the target merging speed Vmt is within a predetermined range.

[0101] The notification control unit 110 causes the speaker 60 to output a steering instruction sound different from the guidance notification sound at the steering timing determined by the steering determination unit 111. The steering instruction sound may be a specific sound output from the speaker 60 (for example, a sound such as "Pon") or an announcement by voice such as "Merging is possible" or "Please turn the steering wheel."

[0102] [5.4 Output of guidance cancellation notification sound] In this embodiment, the entry permission determination unit 112 determines whether entry into the target lane is possible. For example, the entry permission determination unit 112 determines that entry into the target lane is impossible when a predetermined condition is satisfied, such as when the inter-vehicle distance between the preceding vehicle Mf and the following vehicle Mb becomes less than a predetermined value.

[0103] When the entry permission determination unit 112 determines that entry into the target lane is impossible after the notification control unit 110 starts the output of the guidance notification sound, the notification control unit 110 causes the speaker 60 to output a guidance cancellation notification sound different from the guidance notification sound. The guidance cancellation notification sound may be a specific sound output from the speaker 60 (for example, a warning sound such as "Boo") or an announcement by voice such as "Please cancel merging" or "Let's move behind the vehicle behind."

[0104] [6. Control flow] FIG. 16 is a flowchart showing an example of the control flow by the driving support device 100. Here, it is assumed that the driver inputs to start guidance and the host vehicle M has entered the guidance start range GR.

[0105] When the host vehicle M enters the guidance start range GR, the notification control unit 110 outputs a guidance start notification sound prior to the output of the guidance notification sound (S101). Next, the notification control unit 110 calculates a guidance parameter Flead (S102). Then, the notification control unit 110 specifies a sound parameter Psound based on the guidance parameter Flead and outputs a guidance notification sound corresponding to the specified sound parameter Psound (S103).

[0106] Next, the entry permission determination unit 112 determines whether or not merging is possible (S104). When it is determined by the entry permission determination unit 112 that merging is not possible (S104: NO), the notification control unit 110 outputs a guidance cancellation notification sound (S105). Then, the notification control unit 110 stops the output of the guidance notification sound (S109) and ends a series of processes.

[0107] When it is determined by the entry permission determination unit 112 that merging is possible (S104: YES), the steering determination unit 111 determines whether or not the alignment of the host vehicle M with respect to the target merging relative position Pmt has been completed, that is, whether or not it is the steering timing to enter the destination lane (S106). When it is not determined that the alignment of the host vehicle M with respect to the target merging relative position Pmt has been completed (S106: NO), the notification control unit 110 returns to S102 and continues the process. On the other hand, when it is determined that the alignment of the host vehicle M with respect to the target merging relative position Pmt has been completed (S106: YES), the notification control unit 110 outputs a steering instruction sound (S107).

[0108] Next, the notification control unit 110 determines whether the merging has been completed (S108). If the notification control unit 110 determines that the merging has not been completed (for example, when steering is not performed by the driver) (S108: NO), it returns to S102 and continues the process. On the other hand, if the notification control unit 110 determines that the merging has been completed (S108: YES), it stops the output of the guidance notification sound (S109) and ends the series of processes.

[0109] [7. Function] In this embodiment, different guidance notification sounds are output from the speaker 60 when the host vehicle M needs to accelerate and when it needs to decelerate in order to align with the target merging relative position Pmt. According to such a configuration, even if the driver does not accurately grasp the position of the other vehicle, the driver can easily know the appropriate amount of depression of the accelerator pedal 31 from the guidance notification sound. Thereby, the position and speed of the host vehicle M for merging can be adjusted within a shorter time, and the convenience can be improved. Furthermore, for the driver, the burden of looking sideways is reduced, and the frequency of looking forward increases. Therefore, the driver's sense of security can also be improved.

[0110] In this embodiment, guidance notification sounds with different pitches and periods are output according to the required degree of speed change (required acceleration / required deceleration) of the host vehicle M. Thereby, the driver can know the appropriate driving force (accelerator opening Qap). That is, the driver can easily know how much to depress the accelerator pedal 31 without searching for the appropriate accelerator opening by himself / herself. Furthermore, it can be said that the driver can appropriately know the accelerator operation whose change direction changes in time series. Thereby, the driver can easily perform a continuous variable operation of the accelerator, and a smoother merging can be realized. Thereby, the convenience can be further enhanced.

[0111] (First Modification Example) Next, a first modification example of the first embodiment will be described. In the first embodiment, the notification control unit 110 outputs a guiding notification sound with a different pitch from the speaker 60 depending on whether acceleration is required or deceleration is required. On the other hand, instead of / in addition to the above, the notification control unit 110 of the first modification example outputs a guiding notification sound with a different timbre from the speaker 60 depending on whether acceleration is required or deceleration is required. Even with such a configuration, it is possible to guide the driver to an appropriate depression amount of the accelerator pedal 31 at the time of merging, and the convenience can be improved.

[0112] (Second modification example) Next, a second modification example of the first embodiment will be described. The second modification example is an example of calculating the guiding parameter Flead using a simpler calculation model. For example, in the first embodiment, the merging guiding control unit 105 calculates a guiding feedback driving force Ffb based on response-specified type control. On the other hand, the merging guiding control unit 105 of the second modification example calculates a guiding feedback driving force Ffb based on a model different from the response-specified type control (for example, a simpler model). Even with such a configuration, it is possible to guide the driver to the depression amount of the accelerator pedal 31 at the time of merging, and the convenience can be improved.

[0113] <Second embodiment> Next, the second embodiment will be described. This embodiment is different from the first embodiment in that the sound parameter Psound´ is specified based on the relative position deviation Ept instead of the guiding parameter Flead. The configuration other than that described below is the same as that of the first embodiment.

[0114] FIG. 17 is a diagram conceptually showing the guidance notification sound output by the notification control unit 110 of the second embodiment. In the present embodiment, the notification control unit 110 specifies (determines) the type (pitch, sound quality, volume, interval, etc.) of the guidance notification sound for guiding the driver at the time of merging based on the relative position deviation Ept, and causes the speaker 60 to output the specified (determined) guidance notification sound. The guidance notification sound of the second embodiment is a notification sound that assists the driver in aligning the position of the host vehicle M in the vehicle traveling direction with respect to the target merging relative position Pmt. That is, in the second embodiment, the adjustment of the speed is left to the driver, and it is a simple one that notifies the position (for example, too far forward / too far backward) with respect to the target merging relative position Pmt by the guidance notification sound.

[0115] For example, when the notification control unit 110 is too far behind with respect to the target merging relative position Pmt (that is, when acceleration is required) and when it is too far ahead with respect to the target merging relative position Pmt (that is, when deceleration is required), the notification control unit 110 causes the speaker 60 to output notification sounds with different pitches. In the present embodiment, when the notification control unit 110 is too far behind with respect to the target merging relative position Pmt, the notification control unit 110 causes the speaker 60 to output a guidance notification sound with a higher pitch than when it is too far ahead with respect to the target merging relative position Pmt. That is, when the notification control unit 110 is too far behind with respect to the target merging relative position Pmt, it outputs a notification sound with a high pitch (for example, "tut tut tut"), and when it is too far ahead with respect to the target merging relative position Pmt, it outputs a notification sound with a low pitch (for example, "dod dod dod").

[0116] In the present embodiment, the notification control unit 110 varies the interval (the cycle of sounding the notification sound) of the guidance notification sound according to the degree of speed change (required acceleration / required deceleration) required by the host vehicle M to perform the above alignment. For example, the notification control unit 110 shortens the interval of the guidance notification sound as it is more behind with respect to the target merging relative position Pmt (that is, the greater the required acceleration), and shortens the interval of the guidance notification sound as it is more ahead with respect to the target merging relative position Pmt (that is, the greater the required deceleration).

[0117] The notification control unit 110 may vary the pitch, volume, or timbre of the guidance notification sound according to the magnitude of the relative position deviation Ept, instead of or in addition to the interval of the guidance notification sound. For example, the notification control unit 110 may increase the pitch of the guidance notification sound as the vehicle moves further behind the target merging relative position Pmt, and decrease the pitch of the guidance notification sound as the vehicle moves too far in front of the target merging relative position Pmt. For example, the notification control unit 110 may increase the volume of the guidance notification sound as the vehicle moves further behind the target merging relative position Pmt, and increase the volume of the guidance notification sound as the vehicle moves too far in front of the target merging relative position Pmt.

[0118] In this embodiment, the sound characteristic parameter (hereinafter referred to as "slope β" for convenience of explanation) is changed according to the host vehicle speed Ve. The change process of the slope β is performed based on, for example, the following formulas (10) to (12). Psound´ is the sound parameter, β is the slope of the sound parameter, Δ is the target position deviation (= Ept), Flead´ is the virtual guidance parameter, Ef´ is the driving force deviation, and Ksnd´ is the sound parameter adaptation gain (0 < ksnd´). The virtual guidance parameter Flead´ is derived based on the table shown in FIG. 18.

Equation

Equation

Equation

[0119] FIG. 18 is a diagram conceptually showing the relationship between the target position deviation Δ (= Ept), the virtual guidance parameter Flead´, and the host vehicle speed Ve. As shown in FIG. 18, as the host vehicle speed Ve increases, a larger virtual guidance parameter Flead´ is derived even for the same target position deviation Δ. Thereby, the guidance notification sound can be changed reflecting the magnitude of the speed of the host vehicle M.

[0120] Even with such a configuration, it is possible to guide the driver to the amount of depression of the accelerator pedal 31 at the time of merging, and the convenience can be improved.

[0121] <Third Embodiment> FIG. 19 is a diagram schematically showing the functions of the merging guidance control unit 105 and the guidance parameter setting unit 104 of the third embodiment. The merging guidance control unit 105 includes a primary controller 105a and a secondary controller 105b. The primary controller 105a functions as a position controller, and the secondary controller 105b functions as a speed controller.

[0122] The primary controller 105a determines the correction amount Ufb of the target merging speed Vmt of the host vehicle M so as to approximate the first switching function σp(k), which is a linear combination of the relative position deviation Ept(k) and the past value Ept(k-n) of the relative position deviation, to zero while approximating the relative position deviation Ept(k) and the past value Ept(k-n) of the relative position deviation to zero. n is a natural number. Therefore, Ept(k-n) means the value n cycles before the control cycle k. The first switching function σp(k) is represented by Equation (13). Sp(k) is a first guidance parameter and is set in the range of -1 < Sp(k) < 0.

[0123]

Equation

[0124] The primary controller 105a calculates the correction amount Ufb based on, for example, Equations (14) to (16). In the equations, Urch(k) is the reaching law input for position control, Uadp(k) is the adaptation law input for position control, and Krch_p and Kadp_p are feedback gains, respectively.

[0125]

Equation

Equation

Number

[0126] The merging guidance control unit 105 corrects the provisional target merging speed Vmt# based on either or both of the speed Vof of the leading vehicle Mf and the speed Vob of the trailing vehicle Mb with the correction amount Ufb(k) to determine the target merging speed Vmt. The target speed deviation Evt(k) in the third embodiment is the difference between the corrected target merging speed Vmt and the host vehicle speed Ve.

[0127] The secondary controller 105b calculates the guidance feedback driving force Ffb(k) so as to approximate the second switching function σv(k), which is a linear combination of the target speed deviation Evt(k) and the past value Evt(k - m) of the target speed deviation, to zero while approximating the target speed deviation Evt(k) and the past value Evt(k - m) of the target speed deviation to zero. m is a natural number. Therefore, Evt(k - m) means the value m cycles before the control cycle k. The second switching function σv(k) is represented by Equation (17). Sv(k) is the second guidance parameter and is set in the range of -1 < Sv(k) < 0. Here, n and m may be set to the same value, but by setting n > m, it is possible to adjust so that the convergence speed of the speed control is faster than the convergence speed of the position control.

[0128]

Number

[0129] The secondary controller 105b calculates the guidance feedback driving force Ffb, for example, based on Equations (18) to (20). In the equations, Frch(k) is the reach law input for speed control, Fadp(k) is the adaptation law input for speed control, and Krch_v and Kadp_v are feedback gains, respectively.

[0130]

Number

Number

Number

[0131] The induction feedback driving force Ffb is added to the forward driving force Fff and output to the notification control unit 110 as the induction parameter Flead. By calculating the induction feedback driving force Ffb as described above, the relative position deviation Ept and the target speed deviation Evt can be made to approach zero almost simultaneously as in the first embodiment. However, compared with the first embodiment, the relative position deviation Ept approaches zero slightly earlier, and as a result, a slight target speed deviation Evt remains at that time. For this reason, it is possible to reach the vicinity of the target merging relative position Pmt with the host vehicle M more quickly than in the first embodiment, but the acceleration and deceleration felt by the occupant increases. Also, since the control does not oscillate even if the feedback gain is increased in the third embodiment compared to the first embodiment, the host vehicle M can similarly reach the vicinity of the target merging relative position Pmt more quickly than in the first embodiment.

[0132] The induction parameter setting unit 104 sets at least the first induction parameter Sp(k) based on the driving environment of the host vehicle M. For example, similar to the first embodiment, the induction parameter setting unit 104 acquires the road information RI from the detection unit 101, and the absolute value of the first induction parameter Sp(k) increases as the available merging distance included in the road information RI becomes longer, and the absolute value of the first induction parameter Sp(k) becomes smaller as the available merging distance becomes shorter. Thus, when the remaining distance to the merge is short, the relative position deviation Ept(k) can be preferentially set to zero, and a rapid merge can be realized. On the other hand, when the available merging distance is sufficiently long, by increasing the absolute value of the first induction parameter Sp(k), a merge control that prioritizes ride comfort with suppressed acceleration and deceleration is performed.

[0133] The induction parameter setting unit 104 may set the second induction parameter Sv(k) to a fixed value, or may set it to a variable value that varies according to the change in the first induction parameter Sp(k).

[0134] According to the third embodiment described above, smoother speed adjustment can be performed, and control prioritizing alignment can be performed as compared with the first embodiment.

[0135] <Modification Example of the Third Embodiment> In the third embodiment, the secondary controller 105b may perform control using an equivalent control input. Assume that the function of the primary controller 105a is the same as that in the third embodiment. The secondary controller 105b in the modification example of the third embodiment calculates the induction feedback driving force Ffb based on, for example, the aforementioned equations (18), (19), and (21). Frch(k) in equation (21) is the reaching law input for speed control, Fadp(k) is the adaptation law input for speed control, and Feq(k) is the equivalent control input. The equivalent control input Feq(k) is represented by equation (22) using the temporary target merging speed Vmt#. The equivalent control input Feq(k) acts to constrain the switching function σv(k) to zero after the switching function σv(k) becomes zero (in other words, to constrain the target speed deviation Evt(k - m) and the target speed deviation Evt(k) to the control line where the switching function σv(k) is zero). By including the equivalent control input Feq(k) in the calculation, the feedback gain can be increased, and as a result, a faster merge can be realized. M in equation (22) is the vehicle weight of the host vehicle M, and ΔT is the control period (for example, on the order of several tens [ms] to several hundreds [ms]).

[0136]

Number

Number

[0137] The principle of determining the equivalent control input Feq(k) as described above will be explained. In Feq(k), in principle, the target merging speed Vmt(k + 1) in the future of one control cycle is required. However, since it cannot be calculated, it is necessary to delay the target merging speed Vmt used for calculating the target speed deviation Evt(k) and calculating the equivalent control input Feq(k) by one control cycle. Also, ideally, the target merging speed Vmt used for calculating the equivalent control input Feq(k) should be the target merging speed Vmt obtained by correcting the provisional target merging speed Vmt# by the correction amount Ufb(k) by the primary controller 105a.

[0138] When determining the equivalent control input Feq(k) using the target merging speed Vmt(k + 1) in the future of one control cycle, based on Equation (23), it becomes as shown in Equation (24). When shifting one control cycle earlier to eliminate the target merging speed Vmt(k + 1) in the future of one control cycle from this equation, it becomes as shown in Equation (25).

[0139]

Equation

Equation

Equation

[0140] However, when performing merging control using the equivalent control input Feq(k) obtained by Equation (25), the primary controller 105a and the secondary controller 105b resonate due to the delay of the merging speed target value Vmt and the influence of the feedforward control action force change by the equivalent control input Feq(k), and the control of position and speed diverges.

[0141] Therefore, on the premise of Equation (26) in which the one control cycle delay of the target merging speed Vmt is eliminated when calculating the target speed deviation Evt(k), the predicted value Vmt#(k + 1) of the aforementioned temporary merging target speed Vmt# is used as the future merging target speed, and the equivalent control input Feq(k) is determined by Equation (27).

[0142]

Number

Number

[0143] Here, when the predicted value Vmt#(k + 1) of the temporary merging target speed Vmt# is defined as ΔVmt#(k) = Vmt#(k) - Vmt#(k - 1), it is expressed as Vmt#(k) + ΔVmt#(k + 1), which can be approximated as Vmt#(k) + ΔVmt#(k). According to this relationship, Vmt#(k + 1) = 2 × Vmt#(k) - Vmt#(k - 1). Using this to rearrange Equation (27), the aforementioned Equation (22) is obtained.

[0144] Thus, according to the modification of the third embodiment, by determining the equivalent control input using the temporary merging target speed Vm# before being corrected by the primary controller 105a, it is possible to more quickly perform speed adjustment and alignment while preventing divergence of control.

[0145] The above-described embodiments can be expressed as follows. A storage device storing a program, A hardware processor, and by the hardware processor executing the program, Based on the detection result of other vehicles traveling in the destination lane, which is the merging destination or the lane change destination, the target relative position with respect to the other vehicles for entering the destination lane is derived, When the host vehicle needs to accelerate or decelerate in order to align with the traveling direction of the vehicle with respect to the derived target relative position, different notification sounds are output from the speaker. A driving assistance device configured as described above.

[0146] As described above, the embodiments for carrying out the present invention have been described using the embodiments. However, the present invention is not limited to such embodiments, and various modifications and substitutions can be made without departing from the gist of the present invention.

Explanation of Reference Numerals

[0147] 60 Speaker 100 Driving assistance device 101 Detection unit 102 Target position speed calculation unit (decision unit) 103 Relative position deviation calculation unit 104 Induction parameter setting unit 105 Merging induction control unit 106 Target driving force calculation unit 107 Driver required driving force calculation unit 108 Feedforward driving force calculation unit 109 Driver determination unit 110 Notification control unit 111 Steering determination unit 112 Entry permission determination unit DU Derivation unit M Vehicle (host vehicle) Mf Leading vehicle Mb Rear vehicle

Claims

1. A determination unit that determines a target speed for the other vehicle to enter the destination lane based on a detection result of the other vehicle traveling in the destination lane where the vehicle will merge or change lanes; a derivation unit that derives a difference with respect to a required driving force as an induction parameter based on a driving force required for the host vehicle to reach the target speed determined by the determination unit and a detection result of an accelerator opening sensor that detects an accelerator opening of the host vehicle; a notification control unit that outputs different notification sounds from a speaker depending on whether the host vehicle needs to accelerate or decelerate in order to match the speed in the vehicle traveling direction to the target speed determined by the determination unit, and changes a pitch, volume, tone, or interval of the notification sound from a reference value to a greater extent as the magnitude of the induction parameter derived by the derivation unit increases; A driving assistance device equipped with the above.

2. The notification control unit changes the pitch of the notification sound depending on whether acceleration is required or deceleration is required. The driving assistance device according to claim 1.

3. The notification control unit outputs the notification sound having a higher pitch when acceleration is required compared to when deceleration is required. The driving assistance device according to claim 1 or 2.

4. The notification control unit changes the tone of the notification sound depending on whether acceleration is required or deceleration is required. The driving assistance device according to claim 1 or 2.

5. The notification control unit varies an interval of the notification sound depending on a speed change rate of the host vehicle required for performing the speed matching. The driving assistance device according to claim 1 or 2.

6. the notification control unit shortens the interval as a required acceleration as the speed change rate increases, and shortens the interval as a required deceleration as the speed change rate increases. The driving assistance device according to claim 5.

7. The notification control unit varies a pitch, a volume, or a tone of the notification sound depending on a speed change rate of the host vehicle required to perform the speed matching. The driving assistance device according to claim 1 or 2.

8. The notification control unit increases the pitch as the required acceleration as the speed change rate increases, and decreases the pitch as the required deceleration as the speed change rate increases. The driving assistance device according to claim 7.

9. The notification control unit increases the volume as a required acceleration as the speed change rate increases, and increases the volume as a required deceleration as the speed change rate increases. The driving assistance device according to claim 7.

10. The notification control unit changes one or more elements of the pitch, volume, tone, or interval of the notification sound depending on whether the host vehicle needs to accelerate or decelerate in order to perform the speed matching, and changes one or more other elements of the pitch, volume, tone, or interval of the notification sound depending on a speed change degree of the host vehicle required to perform the speed matching. The driving assistance device according to claim 1 or 2.

11. The notification control unit changes the notification sound in accordance with the depression characteristics of an accelerator pedal for each driver. The driving assistance device according to claim 1 or 2.

12. The notification control unit changes the notification sound depending on a distance available for merging or changing lanes. The driving assistance device according to claim 1 or 2.

13. A steering determination unit that determines a steering timing for entering the destination lane, The notification control unit outputs a steering instruction sound different from the notification sound from the speaker at the steering timing determined by the steering determination unit. The driving assistance device according to claim 1 or 2.

14. The determination unit determines a target relative position with respect to the other vehicle for entering the destination lane, the notification control unit starts outputting the notification sound in response to the host vehicle entering a guidance start range that is between a front part of a leading vehicle traveling just before the target relative position on the destination lane and a rear part of a trailing vehicle traveling just after the target relative position on the destination lane with respect to the vehicle traveling direction. The driving assistance device according to claim 1 or 2.

15. When the host vehicle enters the guiding start range, the notification control unit outputs a guiding start notification sound, which is different from the notification sound, from the speaker prior to starting output of the notification sound. A driving assistance device according to claim 14.

16. An entry possibility determination unit that determines whether or not the vehicle is allowed to enter the destination lane, When the entry possibility determination unit determines that entry into the destination lane is impossible after starting output of the notification sound, the notification control unit outputs a guidance stop notification sound different from the notification sound from the speaker. The driving assistance device according to claim 1 or 2.

17. The notification control unit, when acceleration and deceleration are not necessary to perform the speed matching, does not output the notification sound from the speaker. The driving assistance device according to claim 1 or 2.

18. A determination unit that determines a target speed for the other vehicle to enter the destination lane based on a detection result of the other vehicle traveling in the destination lane where the vehicle will merge or change lanes; a derivation unit that derives a difference with respect to a required driving force as an induction parameter based on a driving force required for the host vehicle to reach the target speed determined by the determination unit and a detection result of an accelerator opening sensor that detects an accelerator opening of the host vehicle; a notification control unit that outputs, from a speaker, a notification sound for adjusting the speed in the vehicle traveling direction to the target speed determined by the determination unit, and changes a pitch, a volume, a tone, or an interval of the notification sound from a reference value to a greater extent as the magnitude of the induction parameter derived by the derivation unit increases; A driving assistance device equipped with the above.

19. The computer Based on a detection result of another vehicle traveling in a destination lane where the vehicle will merge or change lanes, a target speed for the other vehicle to enter the destination lane is determined; deriving a difference between a driving force required for the host vehicle to reach the determined target speed and an accelerator pedal depression sensor of the host vehicle to detect an accelerator pedal depression of the host vehicle as a derived parameter; outputting a notification sound from a speaker to adjust the speed in the vehicle travel direction to the determined target speed, and changing a pitch, a volume, a tone, or an interval of the notification sound from a reference value to a greater extent as the magnitude of the derived induction parameter increases; Driving assistance methods.

20. On the computer, Based on a detection result of another vehicle traveling in a destination lane where the vehicle will merge or change lanes, a target speed for the other vehicle to enter the destination lane is determined; deriving a difference between a driving force required for the host vehicle to reach the determined target speed and an accelerator pedal depression sensor of the host vehicle to detect an accelerator pedal depression of the host vehicle as a derived parameter; outputting a notification sound from a speaker to adjust the speed in the vehicle travel direction to the determined target speed, and changing a pitch, volume, tone, or interval of the notification sound from a reference value to a greater extent as the magnitude of the derived induction parameter increases; program.

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