Driving assistance method and driving assistance device

Abstract

The present invention provides a driver assistance method and a driver assistance device that can control acceleration in accordance with the characteristics of the driver's pedal operation in driving situations where slow speed is required. [Solution] A reference characteristic of the vehicle's acceleration gain in relation to the amount of depression of at least one of the vehicle's accelerator pedal and brake pedal is set in advance. When it is determined that the vehicle's driving scene is a predetermined scene in which the vehicle is moving slowly, and the amount of depression of the pedal is less than a predetermined threshold, either a first gain of the reference characteristic or a second gain smaller than the first gain is set based on the operation characteristics of the vehicle driver's pedal operation, which have been learned in advance from operation information regarding the operation of at least one of the accelerator pedal and brake pedal in the predetermined scene.

Description

Technical Field

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

Background Art

[0002] When the vehicle is stopped, if the position of the shift lever is in the non-driving range and a sudden depression of the accelerator pedal is detected, the throttle opening of the engine is restricted. When the position of the shift lever shifts from the non-driving range to the driving range while the accelerator pedal is continuously depressed, acceleration is performed up to a predetermined driving speed through low-speed driving, and a vehicle sudden acceleration suppression device is known (Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the above prior art, when the depression amount of the accelerator pedal is relatively small, the acceleration of the vehicle is not suppressed, so there is a problem that the vehicle may accelerate unnecessarily in a driving scene where slow driving is required.

[0005] The problem to be solved by the present invention is to provide a driving support method and a driving support device capable of controlling acceleration according to the characteristics of the driver's pedal operation of the vehicle in a driving scene where slow driving is required.

Means for Solving the Problems

[0006] The present invention solves the above problem by pre-setting a reference characteristic of the vehicle's acceleration gain in relation to the amount of depression of at least one of the vehicle's accelerator pedal and brake pedal, determining that the vehicle's driving scene is a predetermined scene in which the vehicle is moving slowly, and when the amount of depression of the pedal is less than a predetermined threshold, setting either a first gain of the reference characteristic or a second gain smaller than the first gain based on the operation characteristics of the vehicle driver's pedal operation, which have been learned in advance from operation information regarding the operation of at least one of the accelerator pedal and brake pedal in the predetermined scene. [Effects of the Invention]

[0007] According to the present invention, acceleration can be controlled in accordance with the characteristics of the driver's pedal operation in driving situations where slow speed is required. [Brief explanation of the drawing]

[0008] [Figure 1] This is a block diagram showing one embodiment of the driver assistance system according to the present invention. [Figure 2] Figure 1 is a plan view showing an example of a driving scenario in which driver assistance is performed by the driver assistance system. [Figure 3] This figure shows an example of acceleration set by the driver assistance system in Figure 1. [Figure 4] This figure shows another example of acceleration set by the driver assistance system in Figure 1. [Figure 5] This figure shows another example of acceleration set by the driver assistance system in Figure 1. [Figure 6] Figure 1 is a flowchart showing an example of the processing procedure performed in the driver assistance system. [Figure 7] This flowchart shows another example of the processing steps performed in the driver assistance system shown in Figure 1. [Figure 8] This flowchart shows yet another example of the processing steps performed in the driver assistance system shown in Figure 1. [Figure 9]This flowchart shows yet another example of the processing steps performed in the driver assistance system shown in Figure 1. [Figure 10] This flowchart shows yet another example of the processing steps performed in the driver assistance system shown in Figure 1. [Modes for carrying out the invention]

[0009] Embodiments of the present invention will be described below with reference to the drawings. In the following description, it is assumed that vehicles travel on the left side of the road in countries with left-hand traffic regulations. In countries with right-hand traffic regulations, vehicles travel on the right side of the road, so the terms "right" and "left" in the following description should be interpreted symmetrically.

[0010] [Configuration of the driver assistance system] Figure 1 is a block diagram showing one embodiment of the driver assistance system according to the present invention (hereinafter also referred to as this embodiment). The driver assistance system is an in-vehicle system installed in a vehicle, and assists the driver of the vehicle (hereinafter also referred to as the driver) when the vehicle is traveling from its current location to a destination set by the vehicle's occupants (hereinafter also simply referred to as the destination). In the following description, assisting the driver's driving operations will also be referred to as driver assistance. The driver assistance system may also provide information related to driver assistance to the vehicle's occupants.

[0011] As shown in Figure 1, the driver assistance system 10 of this embodiment includes an imaging device 11, a distance measuring device 12, an in-vehicle sensor 13, a map database 14, a vehicle position detection device 15, a navigation device 16, an actuator 17, a display device 18, and a driver assistance device 20. The devices constituting the driver assistance system 10 are connected to each other via CAN (Controller Area Network) or other in-vehicle LANs and exchange information with each other.

[0012] The imaging device 11 is a camera equipped with an imaging element such as a CCD, which images objects around the vehicle and generates an image including the objects. The imaging device 11 may be an infrared camera, a stereo camera, or the like. Also, in order to suppress the occurrence of blind spots where objects cannot be imaged, a plurality of imaging devices 11 are provided on the front grille, side mirrors, rear bumper, etc. of the vehicle.

[0013] The distance measuring device 12 detects the relative distance and relative speed between the vehicle and the object. The distance measuring device 12 includes a laser radar, a millimeter wave radar, a LiDAR (light detection and ranging) unit, etc. In order to suppress the occurrence of blind spots where objects cannot be detected, a plurality of distance measuring devices 12 are provided on one vehicle.

[0014] The objects detected by the imaging device 11 and the distance measuring device 12 are objects existing on the road and its surroundings, and include road lane boundary lines, center lines, road surface markings, median strips, guardrails, curbs, road signs, traffic signals, crosswalks, etc. Also, the objects include obstacles that can affect the running of the vehicle, such as other automobiles (other vehicles), motorcycles, bicycles, pedestrians, etc.

[0015] The driving support device 20acquires image information from the imaging device 11 and acquires the position information of the object from the distance measuring device 12, and recognizes the objects around the vehicle and the driving environment. The acquisition of information by the driving support device 20 is executed at a predetermined time interval (for example, every 0.1 to 1 millisecond). Note that the driving support device 20 may recognize the driving environment by integrating or synthesizing the information acquired from the imaging device 11 and the distance measuring device 12.

[0016] The vehicle-mounted sensor 13 detects the running state of the vehicle. The vehicle-mounted sensor 13 includes a speed sensor, an acceleration sensor, a yaw rate sensor, a steering angle sensor, etc. As the sensor, known ones can be used without particular limitation, and its arrangement and number can be appropriately set within the range where the running state of the vehicle can be appropriately detected. The driving support device 20 acquires the detection results of each sensor at a predetermined time interval (for example, every 0.1 to 1 millisecond).

[0017] The map database 14 is a storage medium storing map information and is provided inside or outside the vehicle. The driving support device 20 acquires map information from the map database 14 as necessary. The map information includes information on nodes corresponding to specific points (such as intersections) on a road where the traveling direction of the vehicle (hereinafter, also simply referred to as the traveling direction) changes, and links corresponding to road sections connecting the nodes. The information of the nodes includes position information, information regarding entry into and exit from intersections, etc., and the information of the links includes road width, radius of curvature of the road, shoulder structures, road traffic regulations, etc. Note that the map information may be high-precision map information capable of grasping the movement trajectory for each lane.

[0018] The own vehicle position detection device 15 is a positioning system that detects the current position of the vehicle. For example, it calculates the current position of the vehicle from radio waves received from satellites for GPS (Global Positioning System). Further, the own vehicle position detection device 15 may estimate the current position of the vehicle from the traveling speed information and acceleration information acquired from the vehicle-mounted sensor 13, and calculate the current position of the vehicle by collating the estimated current position with the map information. The driving support device 20 acquires information regarding the current position of the vehicle as necessary.

[0019] The navigation device 16 refers to the map information and calculates a traveling route from the current position of the vehicle detected by the own vehicle position detection device 15 to the destination set by the occupant. The traveling route includes at least information on the road on which the vehicle travels, the traveling lane, and the traveling direction, and is displayed linearly, for example. The driving support device 20 acquires information regarding the calculated traveling route as necessary.

[0020] The actuator 17 is a device that converts an electrical control signal input from the driving support device 20 into mechanical work, and includes a servo motor, a hydraulic motor, a hydraulic cylinder, etc. The actuator 17 operates the driving device, braking device, steering device, etc. of the vehicle.

[0021] <000010The display device 18 provides information to the vehicle occupants. The display device 18 is, for example, a projector such as a liquid crystal display or head-up display provided on the instrument panel, and may include an input device for the occupants to input instructions to the driver assistance device 20, and a speaker as an output device.

[0022] The driver assistance device 20 controls and coordinates the devices that constitute the driver assistance system 10 to perform driver assistance. In this embodiment, the driver assistance is performed when the driver operates at least one of the vehicle's accelerator pedal and brake pedal. The operation of the pedal not operated by the driver, and the operation of the vehicle's steering wheel, may be controlled by the driver assistance device 20 or performed manually by the driver. In the following description, the accelerator pedal and brake pedal will be collectively referred to as pedals.

[0023] The control of the pedals and steering wheel by the driver assistance system 20 is performed as part of autonomous driving control. Autonomous driving control is the autonomous control of the vehicle's driving actions, which include all driving actions such as acceleration, deceleration, starting, stopping, and steering. The driver assistance system 20 performs autonomous control of driving actions using devices installed in the vehicle and controls the driving actions within a predetermined range. Driving actions that are not controlled by the driver assistance system 20 are operated manually by the driver. When the driver operates the vehicle manually, the driver assistance system 20 does not perform autonomous control of driving actions, and the vehicle's driving actions are controlled by the driver's operation.

[0024] The driver assistance device 20 is, for example, a computer and includes a CPU (Central Processing Unit) which is a processor, a ROM (Read Only Memory) where programs are stored, and a RAM (Random Access Memory) which functions as an accessible storage device. The CPU is the operating circuit that executes the programs stored in the ROM and realizes the functions of the driver assistance device 20. Alternatively, an MPU (Micro Processing Unit), ASIC (Application Specific Integrated Circuit), etc., may be used instead of or in conjunction with the CPU.

[0025] The vehicle according to this embodiment is equipped with at least one of a throttle-by-wire drive system and a brake-by-wire braking system. In the throttle-by-wire drive system, the accelerator pedal and the actuator 17 of the drive system are electrically connected via a driver assistance device 20, and the driving force of the drive system is electrically controlled in accordance with the driver's operation of the accelerator pedal. Similarly, in the brake-by-wire braking system, the brake pedal and the actuator 17 of the braking system are electrically connected via a driver assistance device 20, and the braking force of the braking system is electrically controlled in accordance with the driver's operation of the brake pedal.

[0026] The vehicle according to this embodiment may be a vehicle equipped with an automatic transmission (hereinafter also referred to as an AT vehicle) or a vehicle equipped with a manual transmission. Furthermore, the vehicle according to this embodiment may be any of the following: a vehicle powered solely by an engine, a hybrid vehicle powered by both an engine and a motor, or an electric vehicle powered solely by a motor.

[0027] [Functions of driver assistance systems] The ROM of the driver assistance device 20 stores a program for assisting the vehicle's operation, and the CPU of the driver assistance device 20 executes this program to provide driver assistance. Figure 1 shows, for convenience, the determination unit 21, the setting unit 22, and the learning unit 23 as functional blocks for performing driver assistance.

[0028] The determination unit 21 acquires information from each device constituting the driver assistance system 10 and recognizes the driving environment around the vehicle (hereinafter also simply referred to as the driving environment) based on the acquired information. The determination unit 21 acquires information such as, for example, information related to images captured by the imaging device 11 (hereinafter also referred to as image information), location information of objects measured by the distance measuring device 12 (hereinafter also simply referred to as location information of objects), information related to the detection results of the on-board sensors 13 (hereinafter also referred to as detection information), map information stored in the map database 14 (hereinafter also simply referred to as map information), information related to the current location of the vehicle detected by the vehicle position detection device 15 (hereinafter also referred to as current location information), and information related to the driving route set by the navigation device 16 (hereinafter also referred to as driving route information).

[0029] The determination unit 21 determines, based on the recognized driving environment, whether the vehicle's driving scene (hereinafter also simply referred to as the driving scene) is a predetermined scene in which the vehicle must proceed slowly. Slow driving means driving at a slow speed (for example, 1 to 10 km / h) that allows the vehicle to stop immediately. A predetermined scene in which the vehicle must proceed slowly (hereinafter also simply referred to as the predetermined scene) is, for example, a scene in which a vehicle that has started from a standstill needs to proceed slowly for a while after starting. A while after starting means, for example, the period until the determination unit 21 determines that the vehicle can accelerate to the road's speed limit without coming into contact with an obstacle.

[0030] Furthermore, a specified scene is, for example, a scene in which a vehicle may stop immediately after it starts moving from a standstill (or immediately after a moving vehicle begins to accelerate). "Immediately after a vehicle starts moving" refers to, for example, the moment when the vehicle's speed becomes a slow speed after it starts moving from a standstill, and "immediately after a vehicle begins to accelerate" refers to, for example, the moment when the vehicle's speed becomes a slow speed after it begins to accelerate.

[0031] Examples of designated scenarios include situations where obstacles around the vehicle are difficult to see due to obstructions, situations where it is necessary to check for obstacles over a relatively wide area, situations where obstacles are located relatively close to the vehicle, situations where the road the vehicle is traveling on is relatively narrow, and situations where the space available for the vehicle to travel is relatively small. Furthermore, specific examples of designated scenarios include the following scenarios 1 through 8.

[0032] The first scene is one in which the vehicle passes through an intersection where a stop line is provided on the near side in the direction of travel (hereinafter also simply referred to as the near side). The determination unit 21 determines that the driving scene is the first scene if, for example, a stop line located ahead in the direction of travel is detected from the image information, and an intersection existing ahead in the direction of travel is detected from the map information. In the first scene, in order for the driver or the determination unit 21 to check (or determine) whether there are other vehicles traveling on the intersecting road (hereinafter also simply referred to as the intersecting road) that intersects the road on which the vehicle is traveling, the vehicle starts from a standstill, passes the stop line, and then stops again before entering the intersection. The vehicle must proceed slowly in the section from when it starts moving until it stops again on the near side of the intersection.

[0033] The second scene is one in which the vehicle passes through an intersection equipped with traffic signals. The determination unit 21 determines that the driving scene is the second scene if, for example, a traffic signal located ahead in the direction of travel is detected from the image information, and an intersection located ahead in the direction of travel is detected from the map information. In the second scene, for example, the driver or the determination unit 21 checks (or determines) whether there are pedestrians entering the crosswalk provided on the intersecting road, so the vehicle starts moving from a standstill and then stops again before passing the crosswalk. The vehicle needs to proceed slowly in the section from when it starts moving until it stops again just before the crosswalk.

[0034] The third scene is a scene in which a vehicle is driving on a road where traffic congestion is occurring. The determination unit 21 determines that the driving scene is the third scene if, for example, a convoy of multiple preceding vehicles is detected from the location information of the object, the vehicle's driving speed is detected to be a slow speed from the detection result of the speed sensor, and traffic congestion is detected on the road in which the vehicle is traveling from the map information. In the third scene, the distance between the vehicle and the preceding vehicle is relatively short and the driving speed is relatively slow, so the vehicle needs to repeatedly slow down and stop.

[0035] The fourth scene is a scene of driving in a parking lot. The determination unit 21 determines, for example, that the vehicle's current location is inside a parking lot based on map information and current location information, and determines that the driving scene is the fourth scene. In the fourth scene, the vehicle needs to drive at a slow speed to avoid contact with parked vehicles and obstacles in the parking lot.

[0036] The fifth scene is one in which a vehicle enters a facility facing a road by passing through a sidewalk. The determination unit 21 determines, for example, that the driving scene is the fifth scene if it determines from map information, current location information, and driving route information that a sidewalk exists between the vehicle's current location and the destination at a location relatively close to the destination. In the fifth scene, in order to avoid contact with pedestrians moving on the sidewalk, the vehicle must travel at a slow speed, at least while passing through the sidewalk. The facility in the fifth scene is not particularly limited, as long as it is a facility that a vehicle can enter.

[0037] The sixth scene is one in which a vehicle enters the roadway from a facility facing the road, passing through a sidewalk. The determination unit 21 determines, for example, that the driving scene is the sixth scene if it determines from map information and current location information that a sidewalk exists between the current location and the roadway. In the sixth scene, in order to avoid contact with pedestrians moving on the sidewalk, the vehicle must travel at a slow speed, at least while passing through the sidewalk. The facility in the sixth scene is not particularly limited, as long as it is a facility that a vehicle can enter.

[0038] The seventh scene is one in which the vehicle drives through a designated school zone, such as a kindergarten or elementary school. The determination unit 21 determines, for example, that the driving scene is the seventh scene if it determines from the map information and current location information that the vehicle's current location is within a school zone. In the seventh scene, in order to avoid contact with students from nearby elementary schools, the vehicle must drive at a slow speed, at least while passing through the school zone.

[0039] The eighth scene is a scene in which a vehicle is driving on a narrow road without lane markings. The determination unit 21 determines that the driving scene is the eighth scene if, for example, the lane boundary lines of the road are not detected from the position information of the object, and the map information is registered to indicate that the road the vehicle is currently traveling on is a road without lane markings. In the eighth scene, the road is narrow, and pedestrians and oncoming vehicles pass relatively close to the vehicle, so the vehicle needs to slow down to avoid contact with obstacles.

[0040] The setting unit 22 sets the gain (hereinafter simply referred to as the gain) of the vehicle's acceleration (hereinafter simply referred to as acceleration) in relation to the amount of depression (hereinafter simply referred to as the depression amount) of at least one of the vehicle's accelerator pedal and brake pedal. Vehicle acceleration is the acceleration that occurs in the vehicle and includes acceleration that accelerates the vehicle (positive acceleration) and acceleration that decelerates the vehicle (negative acceleration). The setting unit 22 obtains the vehicle's acceleration from the acceleration sensor and the depression amount from the pedal stroke sensors provided on the accelerator pedal and brake pedal.

[0041] Gain is the ratio of acceleration to the amount of pedal depression, and determines the characteristics of the acceleration obtained for a given amount of depression. For example, if a small gain is set for the amount of accelerator pedal depression, the vehicle will experience less acceleration than if a large gain is set for the amount of accelerator pedal depression (i.e., the vehicle will not accelerate as easily even if the accelerator pedal is depressed). Similarly, if a large gain is set for the amount of brake pedal depression, the vehicle will experience greater deceleration than if a small gain is set for the amount of brake pedal depression (i.e., the vehicle will decelerate more easily). The setting unit 22 can appropriately set the gain for each amount of depression within a range that satisfies preset upper and lower limits. The upper and lower limits of the gain can be set to appropriate values ​​according to the vehicle's dynamic performance and the comfort of the occupants.

[0042] The setting unit 22 sets the acceleration obtained by multiplying the amount of depression by a gain as the reference acceleration, and generates a control signal to operate the actuator 17 so that the vehicle experiences an acceleration with an absolute value less than or equal to the reference acceleration. The actuator 17 controls at least one of the drive unit and the brake unit according to the control signal input from the driving support device 20 (setting unit 22), and causes the vehicle to experience an acceleration with an absolute value less than or equal to the reference acceleration in order to achieve or maintain the set target driving speed (or target inter-vehicle distance).

[0043] In this embodiment, a reference acceleration, which is a standard acceleration typically generated in a vehicle, is set in advance, and a reference characteristic of the gain corresponding to the reference acceleration (hereinafter also simply referred to as the reference characteristic) is set in advance. By setting the gain of the reference characteristic in the setting unit 22, the reference acceleration corresponding to the amount of pedal depression is set as the reference acceleration. The reference acceleration can be set to an appropriate acceleration within a range that does not impair the ride comfort of the occupants.

[0044] Figure 2 is a plan view showing an example of a driving scene in which driving assistance is performed by the driving assistance system 10 of Figure 1. In the driving scene shown in Figure 2, a road with one lane in each direction extends in the vertical and horizontal directions of the drawing, and an intersection C is provided at the point where the two roads intersect (i.e., the hatched area in the center of Figure 2). Vehicles traveling on the road are allowed to proceed straight, turn left, or turn right at intersection C. Vehicle V shown in Figure 2 is stopped at position P1 in lane L1 and is driven by the driver to a destination Px located ahead in the direction of travel of vehicle V.

[0045] In the driving scene shown in Figure 2, the determination unit 21 detects, for example, a stop line H located in front of the vehicle V in the direction of travel from the image information, and an intersection C located in front of the vehicle V in the direction of travel from the map information. Based on the detection of the stop line H and intersection C, the determination unit 21 determines that the driving scene of vehicle V corresponds to the first scene. The setting unit 22 sets the gain based on the determination result of the determination unit 21.

[0046] In the driving scene shown in Figure 2, the driver of vehicle V starts vehicle V from position P1 and drives vehicle V slowly until it passes the stop line H and stops at position P2 just before intersection C. After stopping vehicle V at position P2, the driver checks whether there are any other vehicles traveling on the intersecting roads extending in the left-right direction in the diagram before entering intersection C. If it is confirmed that there are no other vehicles traveling on the intersecting roads, the driver starts vehicle V from position P2 and enters intersection C, driving to position P3.

[0047] In this case, the driver of vehicle V needs to accurately operate the accelerator pedal within a small range of pedal depression when slowing vehicle V down to position P2. However, accurately operating the pedal within a small range of pedal depression is generally not easy. In particular, if the driver is an elderly person whose leg muscles have weakened with age, or a person with an ankle injury that limits the range of motion of the ankle joint, they may not be able to operate the accelerator pedal accurately, and vehicle V may accelerate unnecessarily.

[0048] Therefore, when the setting unit 22 determines that the driving scene is a predetermined scene, and the amount of pedal depression is less than a predetermined threshold, it sets either a first gain of the reference characteristics or a second gain smaller than the first gain, based on the driver's pedal operation characteristics (hereinafter also simply referred to as operation characteristics). In this case, the learning unit 23 learns operation information (hereinafter also simply referred to as operation information) regarding the operation of at least one of the driver's accelerator pedal and brake pedal in the predetermined scene to understand the characteristics of the driver's pedal operation, and pre-generates operation characteristics corresponding to the understood characteristics for each driver, in order to reliably perform the second gain setting process for drivers for whom setting the second gain is particularly necessary (for example, elderly drivers).

[0049] The predetermined threshold can be set to an appropriate value within a range in which the driver can suppress unnecessary acceleration of the vehicle. For example, the threshold is set to a value such that the pedal depression ratio, which is the ratio of the pedal depression amount to the maximum pedal depression amount, is greater than 0% and less than or equal to 25%. The second gain is set such that, for example, the ratio of the second gain to the first gain (e.g., the ratio of magnitudes) at a certain pedal depression amount is greater than 0 and less than 1. As a result, an acceleration that has the same direction as the reference acceleration and has a smaller absolute value than the reference acceleration (hereinafter also referred to as the suppression acceleration) is set as the reference acceleration.

[0050] The learning unit 23 stores detection results from the in-vehicle sensors 13 and other sources as operation information for each driver and stores them in a storage medium (not shown) such as non-volatile memory. The learning unit 23 identifies the driver using pattern matching and voice analysis from images captured by the in-vehicle camera (not shown) and audio acquired by the microphone (not shown). The timing of the generation of operation characteristics by the learning unit 23 is not particularly limited as long as it is before the timing of the gain setting by the setting unit 22.

[0051] The learning unit 23 may generate operation characteristics using a pre-trained model that has been trained using machine learning. A pre-trained model is a model that has been trained in advance by machine learning so that appropriate output data can be obtained for a given input data, and comprises at least a program that performs calculations from input data to output data, and weighting coefficients (parameters) used in said calculations. When operation information is input as input data, the pre-trained model causes the computer (particularly the processor of the driver assistance device 20) to function so that output data including operation characteristics is output based on the input data.

[0052] The trained model is not particularly limited, but one example is a neural network. A neural network comprises an input layer, a hidden layer, and an output layer, each containing at least one neuron. The input layer receives input data containing operation information and outputs the input data to the hidden layer. The hidden layer extracts characteristics of the driver's pedal operation (average amount of depression, frequency of depression, number of times each pedal is operated, etc.) from the data input from the input layer and outputs data containing information about these characteristics to the output layer. The output layer outputs output data containing operation characteristics corresponding to the data input from the hidden layer (information about the driver's pedal operation characteristics).

[0053] For example, if the learning unit 23 learns from the operation information that the driver operates the accelerator pedal relatively frequently in a predetermined scene, it generates an operation characteristic (hereinafter also referred to as the second operation characteristic) in which the setting unit 22 sets a second gain when the amount of pedal depression is less than a predetermined threshold in the predetermined scene, in order to suppress unnecessary acceleration. As another example, if the learning unit 23 learns from the operation information that the driver operates neither the accelerator pedal nor the brake pedal relatively frequently in a predetermined scene and drives the AT vehicle by creeping, it generates an operation characteristic (hereinafter also referred to as the first operation characteristic) in which the setting unit 22 sets a first gain when the amount of pedal depression is less than a predetermined threshold in the predetermined scene, without suppressing acceleration.

[0054] Figure 3 shows an example of the reference acceleration set by the setting unit 22 in an AT vehicle when the driving scene is determined to be a predetermined scene. In the graph shown in Figure 3, the horizontal axis represents the degree of pedal depression (unit: none), and the vertical axis represents the acceleration generated in the vehicle (unit: m / s²). In the example shown in Figure 3, the vehicle's shift position (hereinafter also simply referred to as the shift position) is in drive range (D range). Note that for the accelerator pedal, the degree of pedal depression on the horizontal axis may be read as the throttle opening.

[0055] The acceleration A1 shown in Figure 3 represents the suppression acceleration relative to the reference acceleration B1, which corresponds to the degree of depression of the accelerator pedal, and the acceleration A2 represents the suppression acceleration relative to the reference acceleration B2, which corresponds to the degree of depression of the brake pedal. Acceleration A1 represents a positive acceleration corresponding to the degree of depression of the accelerator pedal, and acceleration A2 represents a negative acceleration (i.e., deceleration) corresponding to the degree of depression of the brake pedal. Note that the positive acceleration set when the depression rate is 0 in acceleration A1 and reference acceleration B1 corresponds to the maximum acceleration that occurs in the vehicle when the AT vehicle moves forward in creep mode. Note that suppression gains may be set for both the accelerator pedal and the brake pedal separately.

[0056] In the acceleration A1 shown in Figure 3, a predetermined threshold corresponding to the depression rate X1 is set for the accelerator pedal, and a second gain is set in the range from 0 to the predetermined threshold (i.e., the range where the depression rate is 0 to X1). In acceleration A1, the second gain changes continuously in the range from 0 to the predetermined threshold (i.e., the range where the depression rate is 0 to X1), and as a result, the suppression acceleration A1 changes continuously. On the other hand, in the range where the depression rate is greater than the predetermined threshold (i.e., the range where the depression rate is greater than X1), the first gain of the reference characteristic is set.

[0057] Similarly, in acceleration A2 shown in Figure 3, a predetermined threshold corresponding to the depression rate X2 is set for the brake pedal, and a second gain is set in the range from 0 to the predetermined threshold (i.e., the range where the depression rate is 0 to X2). In acceleration A2, the second gain changes continuously in the range from 0 to the predetermined threshold (i.e., the range where the depression rate is 0 to X2), and as a result, the suppression acceleration A2 changes continuously. On the other hand, in the range where the depression rate is greater than the predetermined threshold (i.e., the range where the depression rate is greater than X2), the first gain of the reference characteristic is set.

[0058] For example, when a driver whose first operating characteristics have been set by the learning unit 23 is driving the vehicle, the setting unit 22 sets the first gain even if the amount of pedal depression is less than a predetermined threshold in a predetermined scene. As a result, regardless of the amount of pedal depression, the reference accelerations B1 and B2 shown in Figure 3 are set as the reference accelerations in the predetermined scene. On the other hand, when another driver whose second operating characteristics have been set by the learning unit 23 is driving the vehicle, the setting unit 22 sets the second gain when the amount of accelerator pedal depression is less than a predetermined threshold in a predetermined scene. As a result, when the amount of accelerator pedal depression is less than a predetermined threshold (i.e., when the accelerator pedal depression rate is between 0 and X1), the acceleration A1 shown in Figure 3 is set as the reference acceleration. Furthermore, when another driver is driving the vehicle, the setting unit 22 sets the second gain when the amount of brake pedal depression is less than a predetermined threshold in a predetermined scene. As a result, when the amount of brake pedal depression is less than a predetermined threshold (i.e., when the brake pedal depression rate is between 0 and X2), the acceleration A2 shown in Figure 3 is set as the reference acceleration.

[0059] As shown in the example in Figure 3, by using different gain settings according to the operating characteristics of each driver, it is possible to suppress unnecessary acceleration and deceleration of the vehicle by the driver's operation in the range where the amount of pedal depression is relatively small, while suppressing any discomfort or unpleasant feeling to the driver. Furthermore, in the range where the amount of pedal depression is relatively large, smooth acceleration and deceleration can be performed, reflecting the driver's intentions. In this embodiment, the suppression of acceleration in the range where the amount of pedal depression is relatively small is specified, but the driver assistance device 20 may also suppress acceleration in the range where the amount of pedal depression is relatively large, such as when the driver mistakenly presses the accelerator pedal instead of the brake pedal, as needed.

[0060] Figure 4 shows another example of the reference acceleration set by the setting unit 22 in an AT vehicle when the driving scene is determined to be a predetermined scene. Figure 4 shows an example of the gain set for the accelerator pedal when the shift position is in reverse range (R range).

[0061] The acceleration A3 shown in Figure 4 represents the suppression acceleration relative to the reference acceleration B3, which corresponds to the degree of depression of the accelerator pedal. In the example shown in Figure 4, since the shift position is in reverse range, acceleration A3 represents a negative acceleration corresponding to the degree of depression of the accelerator pedal. Note that the negative acceleration set when the depression rate is 0 in acceleration A3 and reference acceleration B3 corresponds to the maximum acceleration that occurs in the vehicle when an AT vehicle is creeping backward. In acceleration A3 shown in Figure 4, a second gain is set for all amounts of depression (i.e., all degrees of depression) of the accelerator pedal.

[0062] For example, when a driver whose first operating characteristics have been set by the learning unit 23 is operating the vehicle, the setting unit 22 sets the first gain in a predetermined scene. As a result, the reference acceleration B3 shown in Figure 4 is set as the reference acceleration in the predetermined scene. On the other hand, when another driver whose second operating characteristics have been set by the learning unit 23 is operating the vehicle, the setting unit 22 sets the second gain in a predetermined scene. As a result, the acceleration A3 shown in Figure 4 is set as the reference acceleration in the predetermined scene.

[0063] Figure 5 shows an example of the reference acceleration set by the setting unit 22 when the vehicle is determined to be an electric vehicle and the driving scene is a predetermined scene. Figure 5 also shows an example of the gain set for the accelerator pedal when the vehicle is driven in one-pedal mode, where acceleration and deceleration of the vehicle are controlled by operating only the accelerator pedal. Note that the shift position of the vehicle shown in Figure 5 is the drive range.

[0064] The acceleration A4 shown in Figure 5 represents the suppression acceleration relative to the reference acceleration B4, depending on the degree to which the accelerator pedal is depressed. The acceleration A4 shown in Figure 5 exhibits the characteristic that, when the depression rate is less than X3, deceleration occurs due to regenerative braking, resulting in negative acceleration (deceleration), and when the depression rate is X3 or greater, acceleration occurs due to motor acceleration, resulting in positive acceleration. Similarly, the reference acceleration B4 exhibits the characteristic that, when the depression rate is less than X4, negative acceleration occurs, and when the depression rate is X4 or greater, positive acceleration occurs.

[0065] In the acceleration A4 shown in Figure 5, a predetermined threshold corresponding to the depression rate X5 is set, and a second gain is set in the range from 0 to the predetermined threshold (i.e., the range where the depression rate is 0 to X5). In the acceleration A4 shown in Figure 5, the second gain changes continuously in the range from 0 to the predetermined threshold (i.e., the range where the depression rate is 0 to X5), and as a result, the suppression acceleration A4 changes continuously. On the other hand, in the range where the depression rate is greater than the predetermined threshold (i.e., the range where the depression rate is greater than X5), the first gain of the reference characteristic is set.

[0066] For example, when a driver whose first operating characteristics have been set by the learning unit 23 is driving the vehicle, the setting unit 22 sets the first gain even if the amount of pedal depression is less than a predetermined threshold in a predetermined scene. As a result, regardless of the amount of pedal depression, the reference acceleration B4 shown in Figure 5 is set as the reference acceleration in the predetermined scene. On the other hand, when another driver whose second operating characteristics have been set by the learning unit 23 is driving the vehicle, the setting unit 22 sets the second gain when the amount of accelerator pedal depression is less than a predetermined threshold in a predetermined scene. As a result, when the amount of accelerator pedal depression is less than a predetermined threshold (i.e., when the accelerator pedal depression rate is between 0 and X5), the acceleration A4 shown in Figure 5 is set as the reference acceleration.

[0067] The learning unit 23 may change the operating characteristics generated for the driver in accordance with the change in the characteristics of the driver's pedal operation if the characteristics change. For example, the learning unit 23 counts the number of times the throttle opening exceeds a predetermined opening (e.g., 10-15%) while a driver completes driving in a predetermined scene, and repeats this count each time the vehicle drives through the predetermined scene. When the vehicle has completed driving through the predetermined scene a predetermined number of times (e.g., 3-10 times), if the number of times the throttle opening has exceeded the predetermined opening exceeds a certain reference number (e.g., 3-5 times), the learning unit 23 sets a second operating characteristic for the driver, and sets a first operating characteristic for the driver if the number of times the throttle opening has exceeded the predetermined opening is less than or equal to the reference number. Furthermore, as the learning unit 23 repeats the above count, if the ratio of the number of times the throttle opening exceeds a predetermined opening to the number of times the vehicle has completed driving a predetermined scene falls below a certain standard percentage (for example, 50-60%), the learning unit 23 generates a first operating characteristic for a driver instead of a second operating characteristic.

[0068] A predetermined scene may include at least one of the following: a scene in which a vehicle passes a stop line located before an intersection located in the direction of travel of the vehicle (hereinafter also referred to as the forward intersection); and a scene in which a vehicle passes the boundary line (hereinafter simply referred to as the boundary line) that defines the area corresponding to the forward intersection, specifically the boundary line on the side before the forward intersection. The forward intersection is detected in particular from intersections located within a predetermined distance from the current position. That is, the determination unit 21 searches for intersections located within a predetermined distance from the current position using map information and current position information, and extracts the forward intersection from the searched intersections. The predetermined distance may correspond to, for example, the distance at which lane changes are prohibited before the intersection, or the distance from the intersection to the stop line located before the intersection, and may be, for example, 15 to 25 m.

[0069] The stop line is detected by performing pattern matching and other processing on the image captured by the imaging device 11. The boundary line that defines the area corresponding to the intersection ahead is the line that defines the intersection of the road being traveled on and the intersecting road, for example, the four line segments that define the rectangular intersection C shown in Figure 2. The boundary line on the near side of the intersection ahead is the boundary line that a vehicle first passes when passing through the intersection, and in the driving scene shown in Figure 2, boundary line Ca is the boundary line on the near side of the intersection ahead. The determination unit 21 calculates the positions of these boundary lines from the map information. Alternatively, the determination unit 21 may recognize the position of the boundary line on the near side of the intersection ahead as a position half the width of the intersecting road in front of the coordinates of the center position of the intersection, or it may recognize the position of the boundary line on the near side of the intersection ahead as the position where obstacles on both sides of the vehicle (e.g., shoulders) are no longer detected by the imaging device 11 and the distance measuring device 12.

[0070] Furthermore, the predetermined scene may include at least one of the following: a scene in which a vehicle passes through a predetermined range from a stop line set up before the intersection ahead, and a scene in which a vehicle passes through a predetermined range from the boundary line on the side of the boundary line before the intersection ahead. The predetermined range can be set to an appropriate range within a range that can suppress unnecessary acceleration of the vehicle when passing the stop line and when passing the boundary line on the side of the boundary line before the intersection ahead, for example, a range of 20m each on the near and far sides in the direction of travel from the stop line (or the boundary line on the side of the intersection ahead).

[0071] The predetermined scene may include a parking scene from when the shift position is set to the reverse range and the vehicle begins to reverse, until the vehicle completes its movement and stops, and the shift position is set to the parking range. The shift position range is obtained from the shift position sensor. Whether or not the vehicle has started to reverse is determined from the driving speed detected by the speed sensor. Similarly, whether or not the vehicle has completed its movement and stopped is determined from the driving speed detected by the speed sensor.

[0072] The learning unit 23 may calculate the frequency of the driver's accelerator pedal operation in a predetermined scene from the operation information. The accelerator pedal operation frequency is, for example, the number of times the accelerator pedal is operated per unit of time from when the vehicle starts driving in a predetermined scene until it completes the driving (or from when it is determined that the driving scene is a predetermined scene until it is determined that the driving scene is not a predetermined scene). For example, the learning unit 23 counts the number of times the driver operates the accelerator pedal from when they start driving in a predetermined scene until they complete the driving, based on the detection results of the pedal stroke sensor, and calculates the accelerator pedal operation frequency for each driver.

[0073] The learning unit 23 determines whether the frequency of accelerator pedal operation is equal to or greater than a predetermined first frequency. If it is determined that the frequency of accelerator pedal operation is equal to or greater than the first frequency, the learning unit 23 generates an operating characteristic (i.e., a second operating characteristic) for the driver in which a second gain is set in a predetermined scene. On the other hand, if it is determined that the frequency of accelerator pedal operation is less than the first frequency, the learning unit 23 generates a first operating characteristic for the driver. The first frequency can be set to an appropriate value within the range in which the second gain setting process can be executed for drivers for whom setting the second gain is necessary.

[0074] The learning unit 23 may calculate the completion frequency of a predetermined scene in which the driver completes driving in that scene without operating the accelerator pedal, based on the operation information. That is, the learning unit 23 may calculate the frequency of the driver driving the vehicle by creep driving of the AT vehicle from the time it is determined that the driving scene is a predetermined scene until it is determined that the driving scene is not a predetermined scene. The completion frequency is calculated as the ratio of the number of times the driver completed driving in the predetermined scene without operating the accelerator pedal to the number of times the driving scene was determined to be a predetermined scene.

[0075] The learning unit 23 determines whether the completion frequency is equal to or greater than a predetermined second frequency. If it is determined that the completion frequency is equal to or greater than the predetermined second frequency, the learning unit 23 generates an operating characteristic (i.e., a first operating characteristic) for the driver in which the first gain is set in a predetermined scene. On the other hand, if it is determined that the completion frequency is less than the second frequency, the learning unit 23 generates a second operating characteristic for the driver. The second frequency can be set to an appropriate value within the range in which the second gain setting process can be executed for drivers for whom the second gain setting is required.

[0076] The learning unit 23 may calculate from the operation information the number of times the accelerator pedal is pressed to a predetermined degree or more in a predetermined scene. The learning unit 23 counts the number of times the accelerator pedal is pressed to a predetermined degree or more, as detected by the pedal stroke sensor. The predetermined degree can be set to an appropriate value within a range that can suppress unnecessary acceleration of the vehicle in a predetermined scene, for example, a degree of pressing that results in a pressing rate of 5 to 15%.

[0077] The learning unit 23 determines whether the number of times the pedal is pressed is equal to or greater than a predetermined first number. If it is determined that the number of times the pedal is pressed is equal to or greater than the first number, the learning unit 23 generates an operating characteristic (i.e., a second operating characteristic) for the driver in which a second gain is set in a predetermined scene. On the other hand, if it is determined that the number of times the pedal is pressed is less than the first number, the learning unit 23 generates a first operating characteristic for the driver. The first number can be set to an appropriate value within the range that allows the second gain setting process to be executed for drivers who require the setting of the second gain.

[0078] The learning unit 23 may calculate the number of times the vehicle's speed exceeds a predetermined speed in a predetermined scenario (hereinafter also referred to as the number of times the vehicle's speed exceeds a predetermined speed) from the detection results of the speed sensor. The predetermined speed is a slow speed or a speed faster than a slow speed, for example, 15 to 25 km / h.

[0079] The learning unit 23 determines whether the number of times the vehicle has traveled at a given speed is equal to or greater than a predetermined second number. If it is determined that the number of times the vehicle has traveled at a given speed is equal to or greater than the second number, the learning unit 23 generates an operating characteristic (i.e., a second operating characteristic) for the driver in which a second gain is set in a predetermined scene. On the other hand, if it is determined that the number of times the vehicle has traveled at a given speed is less than the second number, the learning unit 23 generates a first operating characteristic for the driver. The second number can be set to an appropriate value within the range in which the second gain setting process can be executed for drivers who require the setting of the second gain.

[0080] The learning unit 23 may calculate from the operation information the number of times (hereinafter also referred to as the "time count") in which the time it takes for the driver to complete driving in a predetermined scene is less than a predetermined time. That is, the learning unit 23 may calculate the number of times the time from when it is determined that a driving scene is a predetermined scene until when it is determined that the driving scene is not a predetermined scene is less than a predetermined time. The predetermined time is the time that it normally takes for the driver to complete driving in a predetermined scene, and is set for each of the 1st to 8th scenes, for example.

[0081] The learning unit 23 determines whether the time count is equal to or greater than a predetermined third count. If it is determined that the time count is equal to or greater than the third count, the learning unit 23 generates an operating characteristic (i.e., a second operating characteristic) for the driver in which the second gain is set in a predetermined scene. On the other hand, if it is determined that the time count is less than the third count, the learning unit 23 generates a first operating characteristic for the driver. The third count can be set to an appropriate value within the range in which the second gain setting process can be executed for drivers who require the setting of the second gain.

[0082] When generating operation characteristics, the learning unit 23 may pre-calculate the average number of times the accelerator pedal is pressed to a predetermined amount or more in a predetermined scene from the operation information, and when the number of times the accelerator pedal is pressed to a predetermined amount or more is equal to or greater than the average number, it may generate operation characteristics in which a second gain is set in the predetermined scene (i.e., second operation characteristics). Furthermore, when generating operation characteristics, the learning unit 23 may pre-calculate the average speed of the vehicle's driving speed in a predetermined scene from the operation information, and when the vehicle's driving speed is equal to or greater than the average speed, it may generate operation characteristics in which a second gain is set in the predetermined scene (i.e., second operation characteristics). In addition, when generating operation characteristics, the learning unit 23 may pre-calculate the average time it takes for the driver to complete driving in a predetermined scene from the operation information, and when the time it takes for the driver to complete driving in a predetermined scene is less than the average time, it may generate operation characteristics in which a second gain is set in the predetermined scene (i.e., second operation characteristics).

[0083] Scenes in which the pedal needs to be pressed relatively hard to reach a destination, or scenes in which the accelerator pedal needs to be pressed relatively hard to pass a specific point, may be excluded from the defined scenes. For example, at least one of the following scenes may be excluded from the defined scenes: a scene in which a vehicle decelerates but does not move slowly, a scene in which a vehicle parks in a parking space where the surrounding road surface has a slope, a scene in which a vehicle parks in a parking space where there is a step around it, and a scene in which a vehicle passes a railroad crossing. Note that the aforementioned slope is, for example, a slope that an automatic transmission vehicle cannot climb by creeping, and the aforementioned step is, for example, a step that an automatic transmission vehicle cannot overcome by creeping.

[0084] Furthermore, the specified scenes do not necessarily have to include scenes in which a vehicle passes through an intersection where there are no obstacles that would hinder the detection of traffic participants entering the intersection. This is because in such scenes, the vehicle may be able to pass through the intersection without slowing down or stopping. Traffic participants are any moving objects other than vehicles (the vehicle itself), and are not particularly limited. Examples of traffic participants include automobiles, pedestrians, bicycles, and motorcycles.

[0085] The vehicle may be provided with a switch to select whether or not to execute the second gain setting process. For example, as shown in Figure 1, the vehicle may be provided with a switch 20a that indicates whether or not to execute the second gain setting process. The learning unit 23 may also provide the driver with information regarding operating characteristics. For example, the learning unit 23 displays information on the driver's frequency of operating the accelerator pedal on the display device 18. Furthermore, the setting unit 22 may notify the driver that the second gain has been set. For example, the setting unit 22 displays an image on the display device 18 indicating that the second gain has been set.

[0086] [Processing in driver assistance systems] Referring to Figures 6-10, the procedure for how the driver assistance system 20 processes information will be explained below. The processes described below are executed, for example, by the processor (CPU) of the driver assistance system 20 at predetermined time intervals (for example, every 0.1 to 1 millisecond).

[0087] Figure 6 is a flowchart showing an example of the processing procedure performed in the driver assistance system 10 shown in Figure 1 when generating operating characteristics.

[0088] First, in step S1, the driver assistance device 20 recognizes the driving environment around the vehicle and determines whether the vehicle's driving scene corresponds to a predetermined scene based on the recognized driving environment. If it is determined that the vehicle's driving scene does not correspond to a predetermined scene, the driver assistance device 20 repeats the process in step S1. On the other hand, if it is determined that the vehicle's driving scene corresponds to a predetermined scene, the process proceeds to step S2.

[0089] In step S2, the driver assistance device 20 determines whether the driver operated the accelerator pedal based on the amount of depression detected by the pedal stroke sensor. If it is determined that the driver did not operate the accelerator pedal, the process proceeds to step S1. On the other hand, if it is determined that the driver operated the accelerator pedal, the process proceeds to step S3.

[0090] In step S3, the driver assistance device 20 calculates the frequency of the driver's accelerator pedal operation from the amount of depression detected by the pedal stroke sensor, and in the following step S4, it determines whether the operation frequency is equal to or greater than a predetermined frequency (first frequency). If it is determined that the operation frequency is equal to or greater than a predetermined frequency (first frequency), the process proceeds to step S5, where the driver assistance device 20 generates an operation characteristic in which a second gain is set when the amount of depression is less than a predetermined threshold in a predetermined scene. On the other hand, if it is determined that the operation frequency is less than a predetermined frequency (first frequency), the process proceeds to step S6, where the driver assistance device 20 generates an operation characteristic in which a first gain is set when the amount of depression is less than a predetermined threshold in a predetermined scene.

[0091] Figure 7 is a flowchart showing another example of the processing steps performed in the driver assistance system 10 of Figure 1 when generating operating characteristics.

[0092] First, in step S11, the driver assistance device 20 determines, based on image information, map information, current location information, etc., whether or not an intersection exists in front of the vehicle in the direction of travel within a predetermined distance from the current location. If it is determined that there is no intersection in front of the vehicle in the direction of travel, the process in step S11 is repeated. On the other hand, if it is determined that there is an intersection in front of the vehicle in the direction of travel, the process proceeds to step S12.

[0093] In step S12, the driver assistance device 20 determines, based on image information, object position information, etc., whether a stop line or boundary line exists in front of the vehicle in the direction of travel, within a predetermined distance from the current position. If it is determined that there is no stop line or boundary line in front of the vehicle in the direction of travel, the process proceeds to step S11. On the other hand, if it is determined that there is a stop line or boundary line in front of the vehicle in the direction of travel, the process proceeds to step S13.

[0094] In step S13, the driver assistance device 20 determines whether the amount of pedal depression detected by the pedal stroke sensor is equal to or greater than a predetermined amount. If it is determined that the amount of depression is less than the predetermined amount, the process proceeds to step S11. On the other hand, if it is determined that the amount of depression is equal to or greater than the predetermined amount, the process proceeds to step S14, where the driver assistance device 20 calculates the number of times the accelerator pedal has been depressed.

[0095] In step S15, the driver assistance device 20 determines whether the number of times the accelerator pedal has been pressed is equal to or greater than a predetermined number (first number). If it is determined that the number of times the pedal has been pressed is equal to or greater than the predetermined number (first number), the process proceeds to step S16, where the driver assistance device 20 generates an operating characteristic in which a second gain is set when the amount of pedal depression is less than a predetermined threshold in a predetermined scene. Conversely, if it is determined that the number of times the pedal has been pressed is less than a predetermined number (first number), the process proceeds to step S17, where the driver assistance device 20 generates an operating characteristic in which a first gain is set when the amount of pedal depression is less than a predetermined threshold in a predetermined scene.

[0096] Figure 8 is a flowchart showing another example of the processing steps performed in the driver assistance system 10 of Figure 1 when generating operating characteristics.

[0097] First, in step S21, the driver assistance device 20 determines, based on image information, map information, current location information, etc., whether or not an intersection exists in front of the vehicle in the direction of travel within a predetermined distance from the current location. If it is determined that there is no intersection in front of the vehicle in the direction of travel, the process in step S21 is repeated. On the other hand, if it is determined that there is an intersection in front of the vehicle in the direction of travel, the process proceeds to step S22.

[0098] In step S22, the driver assistance device 20 determines, based on image information, object position information, etc., whether a stop line or boundary line exists in front of the vehicle in the direction of travel, within a predetermined distance from the current position. If it is determined that there is no stop line or boundary line in front of the vehicle in the direction of travel, the process proceeds to step S21. On the other hand, if it is determined that there is a stop line or boundary line in front of the vehicle in the direction of travel, the process proceeds to step S23.

[0099] In step S23, the driver assistance device 20 determines whether the driving speed detected by the speed sensor is equal to or greater than a predetermined speed. If it is determined that the driving speed is less than the predetermined speed, the process proceeds to step S21. On the other hand, if it is determined that the driving speed is equal to or greater than the predetermined speed, the process proceeds to step S24, where the driver assistance device 20 calculates the number of times the driving speed is equal to or greater than the predetermined speed.

[0100] In step S25, the driver assistance device 20 determines whether the number of times the driving speed has been reached is equal to or greater than a predetermined number (second number). If it is determined that the number of times the driving speed has been reached is equal to or greater than a predetermined number (second number), the process proceeds to step S26, where the driver assistance device 20 generates an operating characteristic in which a second gain is set when the amount of pedal depression is less than a predetermined threshold in a predetermined scene. Conversely, if it is determined that the number of times the driving speed has been reached is less than a predetermined number (second number), the process proceeds to step S27, where the driver assistance device 20 generates an operating characteristic in which a first gain is set when the amount of pedal depression is less than a predetermined threshold in a predetermined scene.

[0101] Figure 9 is a flowchart showing yet another example of the processing steps performed in the driver assistance system 10 of Figure 1 when generating operating characteristics.

[0102] First, in step S31, the driver assistance system 20 determines whether the vehicle is driving in the parking lot based on map information, current location information, etc. If it is determined that the vehicle is not driving in the parking lot, the driver assistance system 20 repeats the process in step S31. On the other hand, if it is determined that the vehicle is driving in the parking lot, the process proceeds to step S32.

[0103] In step S32, the driver assistance device 20 obtains range information from the shift position sensor and determines whether the shift position is in the reverse range. If it is determined that the shift position is not in the reverse range, the process proceeds to step S31. On the other hand, if it is determined that the shift position is in the reverse range, the process proceeds to step S33.

[0104] In step S33, the driver assistance device 20 determines whether the amount of depression of the accelerator pedal detected by the pedal stroke sensor is equal to or greater than a predetermined depression amount. If it is determined that the amount of depression of the accelerator pedal is less than the predetermined depression amount, the process proceeds to step S31. On the other hand, if it is determined that the amount of depression of the accelerator pedal is equal to or greater than the predetermined depression amount, the process proceeds to step S34, where the driver assistance device 20 calculates the number of times the accelerator pedal is depressed to equal or greater than the predetermined depression amount.

[0105] In step S35, the driver assistance device 20 determines whether the number of times the pedal is pressed is equal to or greater than a predetermined number (e.g., the first number). If it is determined that the number of times the pedal is pressed is equal to or greater than a predetermined number (e.g., the first number), the process proceeds to step S36, where the driver assistance device 20 generates an operating characteristic in which a second gain is set when the amount of pedal pressed is less than a predetermined threshold in a predetermined scene. Conversely, if it is determined that the number of times the pedal is pressed is less than a predetermined number (e.g., the first number), the process proceeds to step S37, where the driver assistance device 20 generates an operating characteristic in which a first gain is set when the amount of pedal pressed is less than a predetermined threshold in a predetermined scene.

[0106] Figure 10 is a flowchart showing an example of the processing procedure performed in the driver assistance system 10 shown in Figure 1 when setting the gain.

[0107] First, in step S41, the driver assistance device 20 determines whether the driver has operated the accelerator pedal or the brake pedal based on the amount of depression detected by the pedal stroke sensor. If it is determined that the driver has not operated the accelerator pedal or the brake pedal, the driver assistance device 20 repeats the process in step S41. On the other hand, if it is determined that the driver has operated the accelerator pedal or the brake pedal, the process proceeds to step S42.

[0108] In step S42, the driver assistance device 20 recognizes the driving environment around the vehicle and determines whether the vehicle's driving scene corresponds to a predetermined scene based on the recognized driving environment. If it is determined that the vehicle's driving scene does not correspond to a predetermined scene, the process proceeds to step S47. On the other hand, if it is determined that the vehicle's driving scene corresponds to a predetermined scene, the process proceeds to step S43.

[0109] In step S43, the driver assistance device 20 determines whether the amount of pedal depression detected by the pedal stroke sensor is less than a predetermined threshold. If it is determined that the amount of depression is equal to or greater than the predetermined threshold, the device proceeds to step S47. On the other hand, if it is determined that the amount of depression is less than the predetermined threshold, the device proceeds to step S44.

[0110] In step S44, the driver assistance device 20 determines whether the driving speed detected by the speed sensor is less than a predetermined speed. If it is determined that the driving speed is less than a predetermined speed, the device proceeds to step S45. In step S45, the driver assistance device 20 sets an acceleration gain for the amount of pedal depression based on the learned operating characteristics, and in the following step S46, sets the acceleration corresponding to the set gain as the reference acceleration.

[0111] If it is determined that the driving speed is equal to or greater than a predetermined speed, the process proceeds to step S47. In step S47, the driving support device 20 sets the acceleration gain with respect to the pedal depression amount to the gain of the reference characteristic (first gain), and in the following step S48, sets the reference acceleration to the reference acceleration.

[0112] [Embodiments of the present invention] According to this embodiment, a reference characteristic of the vehicle's acceleration gain for the amount of depression of at least one of the vehicle's accelerator pedal and brake pedal is set in advance, and when it is determined that the vehicle's driving scene is a predetermined scene in which the vehicle is moving slowly, and the amount of depression is less than a predetermined threshold, a driving support method is provided in which either a first gain of the reference characteristic or a second gain smaller than the first gain is set based on the operation characteristics of the vehicle driver's pedal operation, which have been learned in advance from operation information regarding the operation of at least one of the accelerator pedal and brake pedal in the predetermined scene, and a driving support device that executes this driving support method is provided. This makes it possible to control acceleration according to the characteristics of the vehicle driver's pedal operation in driving scenes in which slow driving is required.

[0113] In the driving assistance method and driving assistance device of this embodiment, the predetermined scene includes at least one of the following: a scene in which the vehicle passes a stop line provided on the near side of the direction of travel of an intersection located ahead of the direction of travel of the vehicle; and a scene in which the vehicle passes the boundary line defining the area corresponding to the intersection, on the near side of the direction of travel of the intersection. This improves the efficiency and accuracy of machine learning for generating operating characteristics.

[0114] In the driving assistance method and driving assistance device of this embodiment, the predetermined scene includes at least one of the following: a scene in which the vehicle passes through a predetermined range from a stop line provided on the near side of the direction of travel of an intersection located ahead of the direction of travel of the vehicle; and a scene in which the vehicle passes through a predetermined range from the boundary line defining the area corresponding to the intersection on the near side of the direction of travel of the intersection. This improves the efficiency and accuracy of machine learning for generating operating characteristics.

[0115] In the driving assistance method and driving assistance device of this embodiment, the predetermined scene includes a parking scene from when the vehicle's shift position is in the reverse range and the vehicle begins to reverse, until the vehicle completes its movement and stops and the shift position is in the parking range. This improves the efficiency and accuracy of machine learning for generating operating characteristics.

[0116] In the driving assistance method and driving assistance device of this embodiment, the frequency of the driver's operation of the accelerator pedal in the predetermined scene is calculated from the operation information, and if the operation frequency is equal to or greater than a predetermined first frequency, the operation characteristics are generated in which the second gain is set in the predetermined scene. This makes it possible to suppress unnecessary acceleration in driving scenes where slow speed is required.

[0117] In the driving assistance method and driving assistance device of this embodiment, the completion frequency in which the driver completes driving in the predetermined scene without operating the accelerator pedal is calculated from the operation information, and if the completion frequency is equal to or greater than a predetermined second frequency, the operation characteristics in which the first gain is set in the predetermined scene are generated. This encourages the driver to drive by creeping.

[0118] In the driving assistance method and driving assistance device of this embodiment, the number of times the accelerator pedal is pressed in a predetermined scene is calculated from the operation information, and if the number of presses is equal to or greater than a predetermined first number, the operation characteristics are generated in which the second gain is set in the predetermined scene. This makes it possible to suppress unnecessary acceleration in driving scenes where slow speed is required.

[0119] In the driving assistance method and driving assistance device of this embodiment, the number of times the vehicle's driving speed exceeds a predetermined speed in the predetermined scene is calculated from the operation information, and if the number of times the vehicle's driving speed exceeds a predetermined second number, the operation characteristics are generated in which the second gain is set in the predetermined scene. This makes it possible to suppress unnecessary acceleration in driving scenes where slow speed is required.

[0120] In the driving assistance method and driving assistance device of this embodiment, the number of times the time it takes for the driver to complete driving in the predetermined scene is less than a predetermined time is calculated from the operation information, and if the number of times is a predetermined third time or more, the operation characteristics are generated in which the second gain is set in the predetermined scene. This makes it possible to suppress unnecessary acceleration in driving scenes where slow speed is required.

[0121] In the driving assistance method and driving assistance device of this embodiment, when generating the operation characteristics, the average number of times the amount of depression of the accelerator pedal exceeds a predetermined amount in the predetermined scene is calculated in advance from the operation information, and when the number of times exceeds the average number, the operation characteristics in which the second gain is set in the predetermined scene are generated. This makes it possible to generate operation characteristics in a simple manner.

[0122] In the driving assistance method and driving assistance device of this embodiment, when generating the operation characteristics, the average speed of the vehicle's travel speed in the predetermined scene is calculated in advance from the operation information, and when the travel speed becomes equal to or greater than the average speed, the operation characteristics in which the second gain is set in the predetermined scene are generated. This makes it possible to generate operation characteristics in a simple manner.

[0123] In the driving assistance method and driving assistance device of this embodiment, when generating the operation characteristics, the average time it takes for the driver to complete driving in the predetermined scene is calculated in advance from the operation information, and when the time is less than the average time, the operation characteristics in which the second gain is set in the predetermined scene are generated. This makes it possible to generate operation characteristics in an easy manner.

[0124] In the driving assistance method and driving assistance device of this embodiment, the predetermined scene does not include a scene in which the vehicle decelerates but does not proceed at a slow speed. This improves the efficiency and accuracy of machine learning for generating operating characteristics.

[0125] In the driving assistance method and driving assistance device of this embodiment, the predetermined scene does not include a scene in which the vehicle passes through an intersection where there are no obstacles that would hinder the detection of traffic participants entering the intersection. This improves the efficiency and accuracy of machine learning for generating operating characteristics.

[0126] In the driving assistance method and driving assistance device of this embodiment, the predetermined scene does not include a scene in which the vehicle parks in a parking space where there is a slope on the surrounding road surface, or a scene in which the vehicle parks in a parking space where there is a step on the surrounding surface. This improves the efficiency and accuracy of machine learning for generating operating characteristics.

[0127] In the driving assistance method and driving assistance device of this embodiment, the predetermined scene does not include a scene in which the vehicle passes a level crossing. This improves the efficiency and accuracy of machine learning for generating operating characteristics.

[0128] In the driving assistance method and driving assistance device of this embodiment, the vehicle is provided with a switch that allows the driver to select whether or not to perform the setting process of the second gain. This allows the driver or a dealer's mechanic to select the vehicle's acceleration characteristics according to the driver's attributes.

[0129] In the driving assistance method and driving assistance device of this embodiment, the driving assistance device presents the driver with information regarding the operating characteristics. This makes it possible to suppress the driver's discomfort or unease caused by the suppression of acceleration.

[0130] In the driving assistance method and driving assistance device of this embodiment, the driving assistance device notifies the driver that the second gain has been set. This prevents the driver from feeling discomfort or unease due to an unintended change in acceleration characteristics. [Explanation of symbols]

[0131] 10...Driving assistance system, 11...Imaging device, 12...Distance measuring device, 13...On-board sensor, 14...Map database, 15...Vehicle position detection device, 16...Navigation device, 17...Actuator, 18...Display device, 20...Driving assistance device, 20a...Switch, 21...Determination unit, 22...Setting unit, 23...Learning unit, A1,A2,A3,A4...Acceleration, B1,B2,B3,B4...Reference acceleration, C...Intersection, Ca...Boundary line, L1,L2...Lane, H...Stop line, P1,P2,P3...Position, Px...Destination, V...Vehicle, X1,X2,X3,X4,X5...Pedal pressure

Claims

1. In a driving assistance method performed by a vehicle's driving assistance system, The driving assistance device is a driving assistance method in which a reference characteristic of the vehicle's acceleration gain with respect to the amount of depression of at least one of the vehicle's accelerator pedal and brake pedal is set in advance, and when it is determined that the vehicle's driving scene is a predetermined scene in which the vehicle is moving slowly, and the amount of depression is less than a predetermined threshold, either a first gain of the reference characteristic or a second gain smaller than the first gain is set based on the operation characteristics of the vehicle's driver's pedal operation which have been learned in advance from operation information regarding the operation of at least one of the accelerator pedal and brake pedal in the predetermined scene.

2. The driving assistance method according to claim 1, wherein the predetermined scene includes at least one of the following: a scene in which the vehicle passes a stop line provided on the near side of the direction of travel of an intersection located in front of the direction of travel of the vehicle; and a scene in which the vehicle passes the boundary line that defines the area corresponding to the intersection, on the near side of the direction of travel of the intersection.

3. The driving assistance method according to claim 1, wherein the predetermined scene includes at least one of the following: a scene in which the vehicle passes through a predetermined range from a stop line provided on the near side of the direction of travel of an intersection located in front of the direction of travel of the vehicle; and a scene in which the vehicle passes through a predetermined range from the boundary line defining the area corresponding to the intersection on the near side of the direction of travel of the intersection.

4. The driving assistance method according to any one of claims 1 to 3, wherein the predetermined scene includes a parking scene from when the vehicle's shift position is set to the reverse range and the vehicle begins to move backward until the vehicle completes its movement and stops and the shift position is set to the parking range.

5. The aforementioned driving support device, From the aforementioned operation information, the frequency of the driver's operation of the accelerator pedal in the predetermined scene is calculated. The driving support method according to any one of claims 1 to 3, wherein if the operation frequency is equal to or greater than a predetermined first frequency, the operation characteristics are generated such that the second gain is set in the predetermined scene.

6. The aforementioned driving support device, From the aforementioned operation information, the completion frequency of the predetermined scene in which the driver completes driving in the predetermined scene without operating the accelerator pedal is calculated. The driving support method according to any one of claims 1 to 3, wherein if the completion frequency is equal to or greater than a predetermined second frequency, the operating characteristics are generated in which the first gain is set in the predetermined scene.

7. The aforementioned driving support device, From the aforementioned operation information, the number of times the accelerator pedal is pressed in the predetermined scene is calculated so that the amount of depression of the accelerator pedal is equal to or greater than the predetermined amount of depression. The driving support method according to any one of claims 1 to 3, wherein if the number of times the foot is pressed is equal to or greater than a predetermined first number, the operating characteristics are generated such that the second gain is set in the predetermined scene.

8. The aforementioned driving support device, From the aforementioned operation information, the number of times the vehicle's speed exceeds a predetermined speed in the predetermined scene is calculated. The driving assistance method according to any one of claims 1 to 3, wherein if the number of times the driving speed is equal to or greater than a predetermined second number, the operating characteristics are generated in which the second gain is set in the predetermined scene.

9. The aforementioned driving support device, From the aforementioned operation information, the number of times in which the time it takes for the driver to complete the driving in the predetermined scene is less than a predetermined time is calculated. The driving support method according to any one of claims 1 to 3, wherein if the number of time occurrences is a predetermined third occurrence or more, the operating characteristics in which the second gain is set in the predetermined scene are generated.

10. The aforementioned driving support device, When generating the aforementioned operating characteristics, the average number of times the amount of depression of the accelerator pedal exceeds a predetermined amount in the predetermined scene is calculated in advance from the operating information. The driving support method according to any one of claims 1 to 3, wherein when the number of times becomes equal to or greater than the average number of times, the operating characteristics are generated in which the second gain is set in the predetermined scene.

11. The aforementioned driving support device, When generating the aforementioned operating characteristics, the average speed of the vehicle's travel speed in the predetermined scene is calculated in advance from the operating information. The driving assistance method according to any one of claims 1 to 3, wherein when the driving speed becomes equal to or greater than the average speed, the operating characteristics are generated in which the second gain is set in the predetermined scene.

12. The aforementioned driving support device, When generating the aforementioned operating characteristics, the average time it takes for the driver to complete the driving in the predetermined scene is calculated in advance from the operating information. The driving support method according to any one of claims 1 to 3, wherein when the aforementioned time falls below the average time, the operating characteristics are generated in which the second gain is set in the predetermined scene.

13. The driving assistance method according to any one of claims 1 to 3, wherein the predetermined scene does not include a scene in which the vehicle decelerates but does not proceed slowly.

14. The driving assistance method according to any one of claims 1 to 3, wherein the predetermined scene does not include a scene in which the vehicle passes through an intersection in which there are no obstacles that would interfere with the detection of traffic participants entering the intersection.

15. The driving assistance method according to any one of claims 1 to 3, wherein the predetermined scene does not include a scene in which the vehicle parks in a parking space where there is a slope on the surrounding road surface, or a scene in which the vehicle parks in a parking space where there is a step on the surrounding area.

16. The driving assistance method according to any one of claims 1 to 3, wherein the predetermined scene does not include a scene in which the vehicle passes a level crossing.

17. The driving assistance method according to any one of claims 1 to 3, wherein the vehicle is provided with a switch for selecting whether or not to perform the setting process of the second gain.

18. The driving assistance method according to any one of claims 1 to 3, wherein the driving assistance device presents the driver with information regarding the operating characteristics.

19. The driving assistance method according to any one of claims 1 to 3, wherein the driving assistance device notifies the driver that the second gain has been set.

20. A driving assistance device comprising a setting unit that sets either a first gain of the reference characteristic or a second gain smaller than the first gain of the reference characteristic, based on the operation characteristics of the vehicle's pedal operation learned in advance from operation information relating to the operation of at least one of the accelerator pedal and brake pedal of the vehicle, if the driving scene of the vehicle is determined to be a predetermined scene in which the vehicle is moving slowly and the amount of pedal depression is less than a predetermined threshold, and if the driving scene of the vehicle is determined to be a predetermined scene in which the vehicle is moving slowly, the setting unit sets either a first gain of the reference characteristic or a second gain smaller than the first gain of the reference characteristic.

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