阅读说明：本技术 车辆控制装置 (Vehicle control device ) 是由 辻完太 石冈淳之 西田大树 于 2020-02-03 设计创作，主要内容包括：本发明提供一种适当地兼顾自动驾驶和介入于该自动驾驶的司机所进行的手动驾驶的车辆控制装置。本发明是实施本车辆的驾驶辅助或自动驾驶的车辆控制装置,具有基于周边的监视结果来设定成为行驶中的车道内的行驶路径的目标位置,基于目标位置来进行转向控制的转向装置。转向装置对转向反力特性进行如下控制：在接受到手动操作进行的转向输入时,在目标位置从成为本车辆所行驶的车道的中央附近的第一基准位置离开的情况下,针对某个舵角的手动操作,使得针对朝向从目标位置指向第一基准位置的第一方向的手动操作的而施加转向反力小于针对朝向与第一方向不同的第二方向的手动操作而施加的转向反力。(The invention provides a vehicle control device which properly combines automatic driving and manual driving performed by a driver involved in the automatic driving. The present invention is a vehicle control device for performing driving assistance or automatic driving of a vehicle, and includes a steering device that sets a target position to be a travel path in a lane during travel based on a surrounding monitoring result and performs steering control based on the target position. The steering device controls the steering reaction force characteristic as follows: when a steering input by a manual operation is received, when a target position is away from a first reference position that is near the center of a lane on which the vehicle is traveling, a steering reaction force applied to the manual operation in a first direction directed from the target position to the first reference position is smaller than a steering reaction force applied to the manual operation in a second direction different from the first direction with respect to a certain steering angle.)

1. A vehicle control device for performing driving assistance or automatic driving of a host vehicle, characterized in that,

the vehicle control device includes:

a setting unit that sets a target position to be a travel route in a lane during travel, based on a surrounding monitoring result; and

a steering control mechanism that performs steering control based on the target position,

the steering control means is capable of receiving a steering input by a manual operation performed by a driver even when steering control is performed based on the target position,

the steering control means generates a predetermined reaction force against the manual operation when the steering input is received,

the steering control mechanism controls the steering reaction force characteristic as follows: when the target position is displaced from a first reference position that is near the center of a lane on which the vehicle is traveling with respect to the width direction of the lane, the steering reaction force applied to a manual operation in a first direction from the target position to the first reference position is smaller than the steering reaction force applied to a manual operation in a second direction different from the first direction with respect to a steering angle when the steering input is received.

2. The vehicle control apparatus according to claim 1,

the steering reaction force characteristic is a characteristic between a steering reaction force and a rudder angle difference that is a difference from a rudder angle based on the target position to a manually-operated rudder angle, and the steering reaction force becomes larger as the rudder angle difference becomes larger.

3. The vehicle control apparatus according to claim 2,

in the steering reaction force characteristic toward the first direction, an increase rate of the steering reaction force applied with respect to the rudder angle difference from the target position to the first reference position is smaller than an increase rate of the steering reaction force applied with respect to the rudder angle difference from exceeding the first reference position.

4. The vehicle control apparatus according to claim 2 or 3,

the steering control means controls the steering reaction force characteristic as follows: the steering reaction force applied to the steering input in the direction away from the target position when approaching an obstacle is made larger than the steering reaction force when not approaching an obstacle based on the surrounding monitoring result.

5. The vehicle control apparatus according to claim 2 or 3,

the setting means performs a first offset control in which the target position is set so as to be apart from an obstacle based on the periphery monitoring, and a second offset control in which the target position is set so as to be apart from the first reference position based on a curvature of a lane in which the vehicle is traveling,

the steering control means controls the steering reaction force characteristic as follows: the rate of increase of the steering reaction force applied to the rudder angle difference in the first direction when the second offset control is performed is made smaller than the rate of increase of the steering reaction force applied to the rudder angle difference in the first direction when the first offset control is performed.

6. The vehicle control apparatus according to any one of claims 1 to 3,

when the steering reaction force is generated by the steering control means, the setting means sets a new target position so as to reduce the deviation from the first reference position when setting the new target position.

Technical Field

The present invention relates to a vehicle control device for performing automatic driving and driving assistance of an automobile, for example.

Background

In automatic driving or driving assistance of a vehicle such as a four-wheel vehicle, a sensor monitors a specific direction or all directions of the vehicle, monitors a state of a driver or a traveling state of the vehicle, and controls automatic driving of the vehicle on an appropriate route and at an appropriate speed or assists driving by the driver based on the monitoring result. Even in a vehicle having such an automatic driving function, the driver is required to actively participate in driving, and such a situation or situation may occur. In such a case, the driver can intervene in driving manually even during automatic driving. Patent document 1 and the like have been proposed as a technique for achieving both of such automatic driving and manual driving by a driver. In patent document 1, the automated driving control state of the vehicle is switched from automated driving to manual driving based on the operation amount of the steering wheel, and a steering reaction force for steering according to the automated driving control state is set according to the steering wheel holding state of the driver.

Disclosure of Invention

Problems to be solved by the invention

In the autonomous driving, a target trajectory on which the vehicle travels is determined, and the vehicle is controlled to travel along the target trajectory. The travel target trajectory is generally mostly along the center of the lane, but a trajectory deviating from the center of the lane may be selected. For example, when there is an obstacle on the shoulder of a road, when passing over a vehicle traveling on an adjacent lane, when turning along a curve, or the like. Such offset driving from the center of the lane is not only for avoiding an obstacle, but may be performed without any problem even when driving in the center of the lane. The purpose of this is, for example, to alleviate the sense of tension and uneasiness of the driver, the fellow passenger, and the like caused by approaching an obstacle or a vehicle, or to improve the comfort during traveling on a curve. The offset driving in such a case is not necessarily required, and there are some drivers who prefer to drive in the center of the lane.

However, in the vehicle under automatic driving, it is not desirable that the driver performs an operation of deviating from the automatically selected travel trajectory, and control for inhibiting the operation may be performed. Therefore, a function of preventing the driver from deviating from the automatic driving is also activated for the operation that can be tolerated.

The present invention has been made in view of the above conventional example, and an object thereof is to provide a vehicle control device that appropriately combines both automatic driving and manual driving by a driver involved in the automatic driving.

Means for solving the problems

In order to achieve the above object, the present invention has the following configurations.

That is, according to one aspect of the present invention, there is provided a vehicle control device for performing driving assistance or automatic driving of a host vehicle,

the vehicle control device includes:

a setting unit that sets a target position to be a travel route in a lane during travel, based on a surrounding monitoring result; and

a steering control mechanism that performs steering control based on the target position,

the steering control means is capable of receiving a steering input by a manual operation performed by a driver even when steering control is performed based on the target position,

the steering control means generates a predetermined reaction force against the manual operation when the steering input is received,

the steering control mechanism controls the steering reaction force characteristic as follows: when the target position is displaced from a first reference position that is near the center of a lane on which the vehicle is traveling with respect to the width direction of the lane, the steering reaction force applied to a manual operation in a first direction from the target position to the first reference position is smaller than the steering reaction force applied to a manual operation in a second direction different from the first direction with respect to a steering angle when the steering input is received.

Effects of the invention

According to the present invention, it is possible to appropriately balance automatic driving and manual driving by a driver involved in the automatic driving.

Drawings

Fig. 1 is a diagram showing a configuration of a vehicle system of an autonomous vehicle according to an embodiment.

Fig. 2 is a functional block diagram of a vehicle control system (control unit).

Fig. 3 is a block diagram of the steering apparatus.

Fig. 4 is a state transition diagram showing transitions in the autonomous driving state according to the first embodiment.

Fig. 5 is a schematic diagram showing switching of the reaction force characteristics at each traveling position in the lane width direction.

Fig. 6 is a diagram showing the distribution (profile) of the reaction force characteristic of the steering wheel.

Fig. 7 is a diagram showing a flowchart of an example of a procedure of switching the distribution of the reaction force characteristics.

Fig. 8 is a diagram showing a flowchart of another example of the step of switching the distribution of the reaction force characteristics.

Description of the reference numerals

2: a control unit; 31: a steering wheel; 21: a steering ECU; 210M: a steering reaction force setting unit; 210E: a reaction motor.

Detailed Description

[ first embodiment ]

● outlines of automatic driving and driving assistance

First, an outline of an example of the automated driving will be described. In automatic driving, generally, a driver sets a destination by a navigation system mounted on a vehicle before traveling, and determines a route to the destination in advance by a server or the navigation system. When the vehicle starts, a vehicle control device (or a driving control device) configured by an ECU or the like included in the vehicle drives the vehicle to a destination along the route. During this period, an appropriate action is determined in accordance with the external environment such as the route and the road condition, the state of the driver (sometimes referred to as the driver), and the like, and the vehicle is caused to travel to perform the action, for example, drive control, steering control, brake control, and the like. These controls are sometimes collectively referred to as running controls.

In autonomous driving, there are several control states (also referred to as autonomous driving control states or simply states) according to an automation rate (or the amount of tasks required for the driver). Generally speaking, the higher the level of the automatic driving control state and thus the higher the level of automation, the lighter the task (i.e., load) required of the driver. For example, in the highest-ranking control state (third control state) in this example, the driver can notice something other than driving. This third control state is performed in a less complicated environment such as a case where the vehicle follows the preceding vehicle due to congestion on an expressway. In the second control state with a low rank, the driver may not hold the steering wheel, but the driver needs to pay attention to the surrounding situation and the like. For example, the second control state may be applied when cruising or the like is performed on a highway or the like with few obstacles. Further, whether the driver is paying attention to the surroundings can be detected by the driver state detection camera 41a (refer to fig. 1), and whether the driver is holding the steering wheel can be detected by the steering wheel holding sensor. The driver state detection camera 41a may recognize the pupils of the driver to determine the direction of observation, or may recognize the face of the driver simply and estimate the direction in which the face is facing as the direction of observation of the driver.

In the first control state of a further lower rank, the driver may not perform the steering wheel operation or the throttle operation, but needs to grasp the steering wheel and pay attention to the driving environment in preparation for the transition (take over) of the driving control from the vehicle to the driver. The zeroth control state, which is further lower in level, is manual driving, but contains automated driving assistance. The first control state is different from the zeroth control state in that the first control state is one of the control states of the automatic driving, and the first control state can be jumped between the first control state and the second control state and the third control state under the control of the vehicle 1 depending on the external environment, the driving state, the driver state, and the like, whereas in the zeroth control state, the first control state is different from the zeroth control state in that the zeroth control state is left as long as the driver does not give an instruction to switch to the automatic driving.

The driving assistance in the above-described zeroth control state is a function of assisting the driving operation performed by the driver as the driving subject by the peripheral monitoring and the partial automation. Examples include LKAS (lane keeping assist function) and ACC (adaptive cruise control). Further, there are an automatic braking function of monitoring only the front and applying a brake when an obstacle is detected, a rear monitoring function of detecting a vehicle diagonally behind to urge the driver's attention, a parking function of parking toward a parking space, and the like. The above-described functions may be functions that can be realized also in the first control state of the automatic driving. Note that LKAS is a function of recognizing a white line on a road or the like to maintain a lane, and ACC is a function of following a preceding vehicle in accordance with the speed of the preceding vehicle.

In addition, in automatic driving, there may be intervention or corrective action by the driver. This is called an override. For example, if the driver performs steering and accelerator operations during automatic driving, the driving operation performed by the driver may be prioritized. In this case, the automatic driving function continues to operate so that automatic driving can be resumed from that point in time even if the driver stops operating. Therefore, even in the override, there is a possibility that there is a variation in the automatic driving control state. In addition, when the driver performs the brake operation, the automatic driving may be cancelled and the vehicle may be shifted to the manual driving (zeroth control state). However, for example, in the case of steering, if the steering angle and the steering speed exceed predetermined threshold values, there is a case where the vehicle is handed over from automatic driving to manual driving.

In the case of switching the automatic driving control state (or automation state), the driver is notified of the situation by sound, display, vibration, or the like. For example, in the case where the automated driving is switched from the above-described first control state to the second control state, the driver is notified that the steering wheel can be released. In the opposite case, the driver is informed to hold the steering wheel. This notification is repeated until the driver's holding of the steering wheel is detected by a steering wheel holding sensor (e.g., sensor 210I of fig. 3). Further, for example, if the steering wheel is not held for a limited time or until the switching limit point of the automatic driving control state, an operation such as stopping the vehicle at a safe place can be performed. Similarly, the switching from the second control state to the third control state is performed, and since the driver is relieved of the monitoring obligation around the driver in the third control state, the driver is notified of a message indicating the content. In the opposite case, the driver is notified to perform the periphery monitoring. This notification is repeated until it is detected by the driver state detection camera 41a that the driver is performing the periphery monitoring. The automated driving is performed substantially as described above, and the configuration and control for realizing the automated driving will be described below.

● structure of vehicle control device

Fig. 1 is a block diagram of a vehicle control device according to an embodiment of the present invention, which controls a vehicle 1. Fig. 1 shows an outline of a vehicle 1 in a plan view and a side view. As an example, the vehicle 1 is a sedan-type four-wheeled passenger vehicle.

The control device of fig. 1 comprises a control unit 2. The control unit 2 includes a plurality of ECUs 20 to 29 that are communicably connected via an in-vehicle network. Each ECU includes a processor typified by a CPU, a storage device such as a semiconductor memory, an interface with an external device, and the like. The storage device stores a program executed by the processor, data used by the processor for processing, and the like. Each ECU may be provided with a plurality of processors, storage devices, interfaces, and the like.

Hereinafter, functions and the like of the ECUs 20 to 29 will be described. The number of ECUs and the functions in charge of the ECUs may be appropriately designed for the vehicle 1, or may be more detailed or integrated than in the present embodiment.

The ECU20 executes control related to automatic driving of the vehicle 1. In the automatic driving, at least one of steering, acceleration, and deceleration of the vehicle 1 is automatically controlled. In the control example described later, both steering and acceleration/deceleration are automatically controlled.

The ECU21 is a steering ECU that controls the steering device 3. The steering device 3 includes a mechanism for steering the front wheels in accordance with a driving operation (steering operation) of a steering wheel (also referred to as a steering wheel) 31 by a driver. The steering device 3 is an electric power steering device, and includes a motor that generates a driving force for assisting a steering operation or automatically steering front wheels, a sensor that detects a steering angle, and the like. When the driving state of the vehicle 1 is the automatic driving, the ECU21 automatically controls the steering device 3 in accordance with an instruction from the ECU20, and controls the traveling direction of the vehicle 1.

The ECU22 and the ECU23 perform control of the detection units 41 to 43 that detect the surrounding conditions of the vehicle and information processing of the detection results. The ambient condition is also referred to as an ambient condition, an external environment, or the like, and information obtained by detecting these is referred to as ambient condition information, external environment information, or the like. The detection means for the surrounding state and the ECU that controls the detection means are also collectively referred to as a surrounding monitoring device, a surrounding monitoring unit, or the like. The detection means 41 is a camera (hereinafter, may be referred to as a camera 41) that captures an image of the front of the vehicle 1, and in the case of the present embodiment, two cameras are provided in the room of the vehicle 1. By analyzing the image captured by the camera 41, the outline of the target object and the lane lines (white lines, etc.) on the road can be extracted. The detection unit 41a is a camera for detecting the state of the driver (hereinafter, sometimes referred to as a driver state detection camera 41a), is provided so as to be able to capture the expression of the driver, and is connected to an ECU (electronic control unit), not shown, for processing image data thereof. As a sensor for detecting the state of the driver, a steering wheel holding sensor, not shown, is provided. This makes it possible to detect whether or not the driver is holding the steering wheel. Including the driver state detection camera 41a and the steering wheel grip sensor 210I, is also referred to as a driver state detection section.

The Detection unit 42 is an optical radar (hereinafter, may be referred to as an optical radar 42) that detects a target object around the vehicle 1 and measures a distance to the target object. In the present embodiment, five optical radars 42 are provided, one at each corner of the front portion of the vehicle 1, one at the center of the rear portion, and one at each side of the rear portion. The detection means 43 is a millimeter wave radar (hereinafter, may be referred to as a radar 43), and detects a target object around the vehicle 1 and measures a distance to the target object. In the present embodiment, five radars 43 are provided, one at the center of the front portion of the vehicle 1, one at each corner portion of the front portion, and one at each corner portion of the rear portion.

The ECU22 controls one of the cameras 41 and the optical radars 42 and performs information processing of detection results. The ECU23 controls the other camera 41 and each radar 43 and performs information processing of the detection results. By providing two sets of devices for detecting the surrounding conditions of the vehicle, the reliability of the detection result can be improved, and by providing different types of detection means such as a camera, an optical radar, and a radar, the surrounding environment (also referred to as a surrounding state) of the vehicle can be analyzed in various ways.

The ECU24 performs control of the gyro sensor 5, the GPS sensor 24b, and the communication device 24c and information processing of the detection result or the communication result. The gyro sensor 5 detects a rotational motion of the vehicle 1. The travel path of the vehicle 1 can be determined based on the detection result of the gyro sensor 5, the wheel speed, and the like. The GPS sensor 24b detects the current position of the vehicle 1. The communication device 24c wirelessly communicates with a server that provides map information and traffic information, and acquires these pieces of information. The ECU24 can access the database 24a of map information constructed in the storage device, and the ECU24 searches for a route from the current position to the destination.

The ECU25 includes a communication device 25a for vehicle-to-vehicle communication. The communication device 25a performs wireless communication with other vehicles in the vicinity, and performs information exchange between the vehicles.

The ECU26 controls the power plant (i.e., the running driving force output device) 6. The power plant 6 is a mechanism that outputs a driving force that rotates the driving wheels of the vehicle 1, and the power plant 6 includes, for example, an engine and a transmission. The ECU26 controls the output of the engine in accordance with the driver's driving operation (accelerator operation or accelerator operation) detected by an operation detection sensor (i.e., an accelerator opening sensor) 7A provided on the accelerator pedal 7A, or switches the transmission gear based on information such as the vehicle speed detected by a vehicle speed sensor 7 c. When the driving state of the vehicle 1 is the automated driving, the ECU26 automatically controls the power unit 6 in accordance with an instruction from the ECU20, and controls acceleration and deceleration of the vehicle 1. Further, the acceleration in each direction, the angular acceleration around each axis, the vehicle speed detected by the vehicle speed sensor 7c, and the like detected by the gyro sensor 5 are information indicating the running state of the vehicle, and these sensors are collectively referred to as a running state monitoring unit. Further, the operation detection sensor 7A of the accelerator pedal 7A and an operation detection sensor (i.e., a brake depression amount sensor) 7B of a brake pedal 7B described later may be included in the traveling state monitoring unit, but in the present example, these are referred to as an operation state detection unit together with a detection unit (not shown) that detects a state of operation with respect to another device.

The ECU27 controls lighting devices (headlights, tail lights, etc.) including the direction indicator 8. In the case of the example of fig. 1, the direction indicator 8 is provided at the front, the door mirror, and the rear of the vehicle 1.

The ECU28 controls the input/output device 9. The input/output device 9 outputs information to the driver and accepts input of information from the driver. The sound output device 91 reports information to the driver by sound. The display device 92 reports information to the driver through display of an image. The display device 92 is disposed on the front surface of the driver's seat, for example, and constitutes an instrument panel or the like. Further, although sound and display are shown here by way of example, information may be reported by vibration or light. Further, a plurality of sounds, displays, vibrations, or lights may be combined to report information. Further, the combination may be different or the reporting method may be different depending on the control state (e.g., the degree of urgency) of the information to be reported. The input device 93 is a switch group that is disposed at a position where the driver can operate and instructs the vehicle 1, and may include a voice input device. The input device 93 is further provided with a cancel switch for manually lowering the level of the automatic driving control state. Further, an automatic driving changeover switch for changing over from manual driving to automatic driving is provided. A driver who wants to lower the level of the automatic driving control state can lower the level by operating the cancel switch. In the present embodiment, regardless of the level of the automatic driving control state, the level can be lowered by the same cancel switch.

The ECU29 controls the brake device 10 and a parking brake (not shown). The brake device 10 is, for example, a disc brake device, is provided to each wheel of the vehicle 1, and decelerates or stops the vehicle 1 by applying resistance to rotation of the wheel. The ECU29 controls the operation of the brake device 10, for example, in accordance with the driving operation (braking operation) of the driver detected by an operation detection sensor 7B provided on the brake pedal 7B. When the driving state of the vehicle 1 is the automatic driving, the ECU29 automatically controls the brake device 10 in accordance with an instruction from the ECU20, and controls deceleration and stop of the vehicle 1. The brake device 10 and the parking brake can also be operated to maintain the stopped state of the vehicle 1. In addition, when the transmission of the power unit 6 includes the parking lock mechanism, the parking lock mechanism may be operated to maintain the stopped state of the vehicle 1.

● vehicle control system

Fig. 2 shows a functional configuration of the control unit 2 in the present embodiment. The control unit 2 is also referred to as a vehicle control system, and each of the functional blocks shown in fig. 2 is realized by execution of a program or the like by each ECU, such as the ECU 20. In fig. 2, a vehicle 1 is mounted with a detection device DD including a camera 41, an optical radar 42, a radar 43, and the like, a navigation device 50, communication devices 24B, 24c, and 25a, a vehicle sensor 60 including a gyro sensor 5, a steering wheel grip sensor, a driver state detection camera 41a, and the like, an accelerator pedal 7A, an accelerator opening sensor 7A, a brake pedal 7B, a brake depression amount sensor 7B, a display device 92, a speaker 91, a switch 93 including an automatic driving changeover switch, a vehicle control system 2, a driving force output device 6, a steering device 3, and a brake device 220. These devices and apparatuses are connected to each other via a multiplex communication line such as a can (controller Area network) communication line, a serial communication line, a wireless communication network, and the like.

The Navigation device 50 includes a gnss (global Navigation Satellite system) receiver, map information (Navigation map), a touch panel display device functioning as a user interface, a speaker, a microphone, and the like. The navigation device 50 determines the position of the own vehicle 1 by the GNSS receiver, and derives a route from the position to a destination designated by the user. The route derived by the navigation device 50 is provided to the target lane determining unit 110 of the vehicle control system 2. Further, the configuration for determining the position of the host vehicle 1 may be provided independently of the navigation device 50.

The communication devices 24b, 24c, and 25a perform wireless communication using, for example, a cellular network, a Wi-Fi network, Bluetooth (registered trademark), dsrc (dedicated Short Range communication), or the like.

The vehicle sensor 60 includes a vehicle speed sensor for detecting a vehicle speed, an acceleration sensor for detecting an acceleration, a yaw rate sensor for detecting an angular velocity about a vertical axis, an orientation sensor for detecting an orientation of the host vehicle 1, and the like. All or a part of them is realized by the gyro sensor 5. A steering wheel grip sensor and a driver state detection camera 41a, which are not shown, may be included in the vehicle sensor 60.

The accelerator pedal 7A is an operation member for receiving an acceleration instruction (or a deceleration instruction based on a return operation) by a driver. The accelerator opening sensor 7A detects a stepping amount of an accelerator pedal 7A, and outputs an accelerator opening signal indicating the stepping amount to the vehicle control system 2. Instead of being output to the vehicle control system 2, the vehicle control system may directly output the vehicle control system to the travel driving force output device 6, the steering device 3, or the brake device 220. The same applies to the configuration of the other driving operation system described below.

The brake pedal 7B is an operation member for receiving a deceleration instruction made by the driver. The brake depression amount sensor 7B detects a depression amount (or a depression force) of the brake pedal 7B, and outputs a brake signal indicating a detection result to the vehicle control system 2.

The display device 92 is, for example, an lcd (liquid Crystal display), an organic el (electroluminescence) display device, or the like, which is attached to each part of the instrument panel, an arbitrary part facing the front passenger seat and the rear seat, or the like. The display device 92 may be a hud (head Up display) that projects an image on a front windshield or other window. The speaker 91 outputs sound.

The running drive force output device 6 outputs a running drive force (torque) for running the vehicle to the drive wheels. The travel driving force output device 6 includes, for example, an engine, a transmission, and an engine ecu (electronic Control unit) that controls the engine. The travel driving force output device 6 may be an electric motor or a hybrid mechanism combining an internal combustion engine and an electric motor.

The brake device 220 is, for example, an electric servo brake device including a caliper, a hydraulic cylinder that transmits hydraulic pressure to the caliper, an electric motor that generates hydraulic pressure in the hydraulic cylinder, and a brake control unit. The brake control unit of the electric servo brake device controls the electric motor based on the information input from the travel control unit 160, and outputs a brake torque corresponding to a brake operation to each wheel. Further, the brake device 220 may include a regenerative brake based on a traveling motor that can be included in the traveling driving force output device 6.

● steering device

Next, the steering device 3 will be explained. The steering device 3 includes, for example, a steering ECU21 and an electric motor. The electric motor changes the orientation of the steering wheel by applying a force to the rack-and-pinion mechanism, for example. The steering ECU21 drives the electric motor based on information input from the vehicle control system 2 or information on the steering angle or the steering torque input, and changes the direction of the steered wheels.

Fig. 3 is a diagram showing an example of the configuration of the steering device 3 according to the present embodiment. The steering device 3 includes, but is not limited to, a steering wheel (also referred to as a steering wheel) 31, a steering shaft 210B, a steering angle sensor 210C, a steering torque sensor 210D, a reaction force motor 210E, an assist motor 210F, a steering mechanism 210G, a steering angle sensor 210H, a steering wheel holding sensor 210I, a steering wheel 210J, and a steering ECU 21. The steering ECU21 includes a steering reaction force setting unit 210M and a storage unit 210N, respectively.

The steering wheel 31 is an example of an operation device that accepts a steering instruction made by a driver. A steering input applied to the steering wheel 31, that is, a steering operation is transmitted to the steering shaft 210B. A steering angle sensor 210C and a steering torque sensor 210D are mounted on the steering shaft 210B. The steering angle sensor 210C detects the angle at which the steering wheel 31 is operated, and outputs the detected angle to the steering ECU 21. The steering torque sensor 210D detects a torque (steering torque) acting on the steering shaft 210B, and outputs the detected torque to the steering ECU 21. That is, the steering torque is a torque that the driver applies to the steering shaft 210B by turning the steering wheel 31. The reaction force motor 210E outputs a steering reaction force to the steering wheel 31 by outputting a torque to the steering shaft 210B under the control of the steering ECU 21. That is, the reaction force motor 210E applies a predetermined steering reaction force for maintaining the steering during the autonomous driving (also referred to as a system steering) to the steering shaft 210B under the control of the steering ECU21 in each of the autonomous driving control states. The steering reaction force acts as a torque that applies resistance to the steering operation of the driver. Therefore, when the driver overrides the system steering, the driver must apply a torque to the steering shaft 210B that exceeds the steering reaction force generated in response to the steering input.

The assist motor 210F assists steering by outputting torque to the steering mechanism 210G under the control of the steering ECU 21. The assist assists not only the operation of the driver at the time of manual driving but also performs steering without the operation of the driver according to the control of the travel control section 160 at the time of automatic driving. The steering mechanism 210G is, for example, a rack and pinion mechanism. The steering angle sensor 210H detects an amount (for example, a rack stroke) indicating an angle (steering angle) at which the steering wheel 210J is driven and controlled by the steering mechanism 210G, and outputs the detected amount to the steering ECU 21. The steering shaft 210B and the steering mechanism 210G may be fixedly coupled or decoupled, or may be coupled via a clutch mechanism or the like.

The steering wheel grip sensor 210I may be a capacitance sensor that is provided at a predetermined position of the rim portion of the steering wheel 31 and detects a change in capacitance caused by the hand of the driver when the driver grips the rim of the steering wheel 31. Alternatively, the pressure sensor may measure a pressure applied to the rim by the driver's grip (hereinafter, also referred to as a grip force). The steering wheel grip sensor 210I outputs the measured gripping force to the steering ECU 21. The steering ECU21 performs the various controls described above in cooperation with the vehicle control system 2.

The steering reaction force setting unit 210M refers to the reaction force distribution information 210P in the storage unit 210N in the steering ECU21, using the difference between the steering angle (override steering angle) detected by the steering angle sensor 210C and the system steering angle (for example, the steering angle determined by the travel control unit 160) acquired from the vehicle control system 2 as an index value of the steering input in the autonomous driving control state. The reaction force distribution information 210P is configured as a reaction force table indicating a correspondence relationship between a steering reaction force and a steering angle difference that overrides a steering angle and a system steering angle, for example. The steering reaction force setting unit 210M reads the steering reaction force corresponding to the steering angle difference from the reaction force table of the reaction force distribution information 210P in the storage unit 210N. The steering ECU21 controls the drive of the reaction force motor 210E so that the steering reaction force of the value read from the storage unit 210N by the steering reaction force setting unit 210M is applied to the steering shaft 210B. In the manual driving control state, reaction force distribution information predetermined for manual driving is prepared, and reaction force is applied based on the reaction force distribution information. As in this example, when the steering shaft 210B is connected to the steering mechanism 210G, the mechanical reaction force from the steering wheel 210J is transmitted to the steering wheel 31, and therefore the reaction force does not have to be applied. However, when the steering shaft is not mechanically connected to the steering mechanism 210G and the steer-by-wire (steer-by-wire) is completed, a reaction force may be generated from a reaction force distribution that simulates a mechanical reaction force in order to give a steering feeling to the driver. In this example, the reaction force is applied so as to have a characteristic according to the automated driving control state of automated driving. The setting of the reaction force will be described again with reference to fig. 3 to 9. The steering angle, torque, steering speed, and the like of the steering are collectively referred to as a steering amount, and the steering amount determined by the travel control unit 160 is sometimes referred to as a system steering amount.

According to the above configuration, the steering reaction force applied to the steering wheel 31 is given in accordance with the difference between the steering angle and the system steering angle, which is generated by the override operation of the steering wheel 31 by the driver in the automated driving control state, and the automated driving control state. In this case, the higher the level of the automatic driving control state, the greater the reaction force. Thus, according to the automatic driving control state, if the level of the automatic driving control state is high, it is difficult to perform override, and if the level of the automatic driving control state is low, it is easy to perform override.

In the automatic steering control state, the steering reaction force setting unit 210M refers to the reaction force distribution information 210P in the storage unit 210N each time the steering ECU21 reads the system steering angle and the override steering angle. The steering reaction force setting unit 210M reads a steering reaction force corresponding to the difference between the system steering angle and the override steering angle, which are read, and the automatic driving control state, and outputs a control signal for applying the steering reaction force to the reaction force motor 210E.

● vehicle control system (continue)

Returning to fig. 2, the vehicle control system 2 includes, for example, a target lane determining unit 110, an automatic driving control unit 120, a travel control unit 160, a human machine interface (hmi) control unit 170, and a storage unit 180. The automated driving control unit 120 includes, for example, an automated driving state control unit 130, a vehicle position recognition unit 140, an external environment recognition unit 142, an action plan generation unit 144, a trajectory generation unit 146, and a switching control unit 150. The target lane determining unit 110, the respective units of the automatic driving control unit 120, the travel control unit 160, and the HMI control unit 170 are partially or entirely realized by executing a program (software) by a processor. Some or all of these may be realized by hardware such as lsi (large Scale integration) or asic (application Specific Integrated circuit), or may be realized by a combination of software and hardware.

The storage unit 180 stores information such as high-precision map information 182 including information on the center of a lane or information on the boundary of a lane, target lane information 184, and action plan information 186. The target lane determining unit 110 divides the route provided by the navigation device 50 into a plurality of sections (for example, every 100[ m ] with respect to the vehicle traveling direction), and determines the target lane for each section with reference to the high-accuracy map information 182. The target lane determining unit 110 determines, for example, to travel in the first lane from the left. For example, when there is a branch position, an entry position, or the like on the route, the target lane determining unit 110 determines the target lane so that the host vehicle 1 can travel on a reasonable travel route for traveling ahead of the branch. The target lane determined by the target lane determining unit 110 is stored in the storage unit 180 as target lane information 184.

The automated driving state control unit 130 determines an automated driving control state of automated driving performed by the automated driving control unit 120 (also referred to as an automated state with a view to an automation rate of each state). The automatic driving control state in the present embodiment includes the following control states. The following is merely an example, and the number of control states of the automatic driving can be arbitrarily determined. Fig. 4 shows a jump diagram of the automatic driving control state.

● jump to autopilot control state

As shown in fig. 4, in the present embodiment, there are the zeroth control state to the third control state as the automatic driving control states, and the automation rate becomes higher in order. In fig. 4, arrows indicate transitions of states. Here, the white arrows indicate transitions of the autonomous driving control state in which the vehicle 1 is the main body, which are caused by autonomous driving by the vehicle control system 2 (particularly, the ECU20) by executing a program, for example. On the other hand, the black arrows indicate transitions in the automatic driving control state that are triggered by the driver's operation. Here, the respective driving control states will be described again.

The zeroth control state is a control state of manual driving, and the zeroth control state is a control state of manual driving required by the driver without driving assistance or the like at all. When the driver explicitly instructs the automated driving in the zeroth control state by, for example, a switch operation, the automated driving control state is transitioned to the first control state or the second control state according to a condition at that time, for example, according to an external environment, vehicle information, or the like. The control unit 2 refers to external environment information, travel state information, and the like to determine which control state to jump to.

The first control state is a state of the lowest automated driving control state in automated driving (the lowest automation rate). When the automatic driving is instructed, for example, in the case where the current position cannot be recognized, and in an environment (for example, a general road or the like) where the second control state cannot be applied even if the current position can be recognized, the automatic driving is started in the first control state. The automated functions implemented in the first control state include LKAS, ACC, etc. When the vehicle is in the first control state, the driver state detection unit may detect whether the driver is monitoring the outside, particularly, the front, and may detect whether the driver is gripping the steering wheel. In this case, the jump is performed if the condition is satisfied. In addition, the monitoring of the driver may be continuously performed during the stay in the first control state. Further, when the automatic driving control state is shifted from a lower level to a higher level, the task requested to the driver is not changed or the task requested to the driver is reduced, and therefore the driver state may not be used as the condition for the shift. Note that the difference between the zeroth control state and the first control state is not limited to the above, and for example, only one of LKAS and ACC may be used in the zeroth control state, and both may be used in the first control state. In addition, there may be a case where the work scene is wider in the first control state than in the LKAS and ACC in the zeroth control state.

The second control state is the above automatic driving control state of the first control state. For example, when an instruction for automatic driving is received in the zeroth control state, and the external environment at this time is a predetermined environment (for example, during driving on a highway), the control device transitions to the second control state. Alternatively, if the external environment is detected as the above-described predetermined environment during automatic driving in the first control state, the vehicle automatically transitions to the second control state. The determination of the external environment can be performed by referring to the current position and map information, in addition to the monitoring result of the peripheral monitoring unit including, for example, a camera. In the second control state, in addition to lane keeping, a function of performing a lane change or the like in accordance with a target object such as a surrounding vehicle is provided. If the condition for maintaining the second control state is lost, the automation state of the vehicle 1 is changed to the first control state by the control unit 2. In the second control state, the driver may not hold the steering wheel (which is called "hands off"), and only ambient monitoring is required of the driver. Therefore, in the second control state, the driver state detection camera 41a monitors whether or not the driver is monitoring the outside, and outputs, for example, a warning if the driver is not monitoring the outside.

The third control state is the above automatic driving control state of the second control state. The controller can jump from the second control state to the third control state, and jump from the zeroth control state and the first control state without jumping from the second control state. The jump to the third control state is not triggered by an instruction from the driver, but is performed by automatic control performed by the control means 2 when it is determined that a certain condition is satisfied. For example, if a state is reached in which the vehicle is following the preceding vehicle at a low speed due to congestion while the vehicle is automatically driven in the second control state, the control state is switched from the second control state to the third control state. The determination in this case is made based on the output of the peripheral monitoring unit such as a camera, the vehicle speed, and the like. When the condition of the second control state is satisfied, for example, when the vehicle is traveling on an expressway, the automatic driving control state is shifted between the second control state and the third control state. In the third control state, the driver does not need to hold the steering wheel nor monitor the surroundings. However, at any time and under any control conditions, there is a possibility that a situation may occur in which the driver must take over driving. Therefore, in order to determine whether the driver can take over driving normally, for example, during automatic driving, it is constantly monitored and detected whether the driver's line of sight is within a predetermined range (e.g., a display portion of a navigation meter). The state of the driver can also be monitored during manual driving.

The automated driving state control unit 130 determines the control state of automated driving based on the operation of the driver for each configuration of the driving operation system, the event determined by the action plan generation unit 144, the travel pattern determined by the trajectory generation unit 146, and the like, and jumps to the determined control state according to the white arrow shown in fig. 4. The HMI control unit 170 is notified of the automatic driving control state. In any control state, it is possible to override the automatic driving by manual driving through operations for the respective configurations of the driving operation system.

The vehicle position recognition unit 140 of the automated driving control unit 120 recognizes the lane (traveling lane) in which the host vehicle 1 is traveling and the relative position of the host vehicle 1 with respect to the traveling lane (or the current traveling route) based on the high-accuracy map information 182, the optical radar 42, the radar 43, the camera 41, the navigation device 50, or information input from the vehicle sensor 60, which are stored in the storage unit 180.

The vehicle position recognition unit 140 recognizes the traveling lane by comparing the pattern of road dividing lines (for example, the arrangement of solid lines and broken lines) recognized from the high-accuracy map information 182 with the pattern of road dividing lines around the vehicle 1 recognized from the image captured by the camera 41, for example. The recognition may be performed by adding a result of processing based on an inertial guidance (inertial guidance) system, if any, of the position of the own vehicle 1 acquired from the navigation device 50. The travel control unit 160 controls the travel driving force output device 6, the steering device 3, and the brake device 220 so that the host vehicle 1 passes through the track generated by the track generation unit 146 at a predetermined timing. The HMI control unit 170 causes the display device 92 to display video and images, and causes the speaker 91 to output audio. The travel control unit 160 determines a steering angle (system steering angle) for performing automated driving in accordance with the action plan information 186, for example, and inputs the steering angle to the steering device 3 to perform steering control. Further, for example, the turning of the lane during traveling can be recognized by the high-accuracy map information 182 and the external world recognition unit 142 described later.

The environment recognition unit 142 recognizes the position, speed, acceleration, and other states of a target object such as a neighboring vehicle based on information input from the camera 41, the optical radar 42, the radar 43, and the like. The environment recognition unit 142 may recognize the position of other objects such as a guardrail, a utility pole, a parked vehicle, and a pedestrian, in addition to the surrounding vehicle.

The action plan generating unit 144 sets a start point of the automated driving and/or a destination of the automated driving. The starting point of the automated driving may be the current position of the host vehicle 1 or a point where an operation for instructing the automated driving is performed. The action plan generating unit 144 generates an action plan in a section between the start point and the destination of the automated driving. Further, the action plan generating unit 144 may generate an action plan for an arbitrary section.

The action plan is composed of a plurality of events that are executed in sequence, for example. Examples of the event include a deceleration event for decelerating the host vehicle 1, an acceleration event for accelerating the host vehicle 1, a lane keeping event for causing the host vehicle 1 to travel without deviating from the travel lane, a lane change event for changing the travel lane, a passing event for causing the host vehicle 1 to pass a preceding vehicle, a branch event for changing the host vehicle 1 to a desired lane at a branch point or for causing the host vehicle 1 to travel without deviating from the current travel lane, an entry event for accelerating and decelerating the host vehicle 1 in an entry lane for entering a trunk, changing the travel lane, and a hand over (hand over) event for shifting from the automatic drive control state to the manual drive control state at a predetermined point of termination of the automatic drive. The action plan generating unit 144 sets a lane change event, a branch event, or an entry event at the place where the target lane is switched, which is determined by the target lane determining unit 110. Information indicating the action plan generated by the action plan generating unit 144 is stored in the storage unit 180 as action plan information 186.

● setting of target driving position

The trajectory generation unit 146 determines a target travel position (or a target position) that is a position of a target point in the lane, determines a trajectory (also referred to as a target trajectory, a target route, or a target travel route) connecting consecutive target travel positions, and stores the trajectory as a part of the action plan information 186, thereby setting the target travel position. As the target position, for example, if there is no target object that needs to be avoided in particular, a position that passes through the center position of the lane in which the vehicle is traveling (this is regarded as the reference position or the first reference position or the point row is regarded as the route, which is also referred to as the first reference route) is selected. If an obstacle exists, a target position avoiding the obstacle is set. In addition, even if the vehicle is not an obstacle in the lane in which the vehicle is traveling, the target position may be set so as to be separated from the vehicle traveling in the adjacent lane in order to reduce psychological burden on the driver and the passenger. Further, in order to reduce the curvature of the traveling position and maintain the comfort, the target position may be set to a position inside the center position of the lane in the curve. The switching control unit 150 switches the automatic driving control state and the manual driving control state to each other based on a signal input from the automatic driving changeover switch 93.

Further, the target position may also be set based on a history of past override operations. For example, in the case where an override operation is performed from the driving route by the autonomous driving toward the center of the lane, the steering is stored. Then, when the target position is set, the memory is referred to, and when the corresponding override operation is performed, the set target position is changed so as to reduce the amount of shift from the center position when the offset travel is performed in which the target position is shifted from the center position of the lane. Alternatively, such a target position may be set from the beginning. Thereby reducing the chance of driver intervention.

Further, the switching control portion 150 switches from the automatic driving (third control state to the first control state) to the manual driving (zeroth control state) based on the operation of the brake pedal 7B. In this example, when the brake operation is performed, the switching control unit 150 switches from the automatic driving control state to the manual driving control state after the suspension time and the warning according to the current automatic control state. In addition, the steering operation and the accelerator operation are override-controlled by manual operation while maintaining automatic driving. Here, by the override control, for example, when the steering operation amount exceeds a predetermined override threshold value, the running control is realized as if switching to the manual driving. Next, the override control will be explained.

● override control

Next, the override control according to the present embodiment, particularly the override control of steering, will be described. Heretofore, the characteristics of the steering control in the automatic driving will be described with reference to fig. 5. Fig. 5 (a) is a diagram illustrating a route maintenance characteristic by the automated driving. The control map is a map showing the characteristics of the intended maintenance route, for example, in the cross-sectional shape of the road. In the control map, the height direction can be interpreted as a map indicating the strength of control for trying to maintain the center of the lane. This figure is not a schematic diagram showing the cross-sectional shape of a real road, but is a schematic diagram for explaining the characteristics by comparing the shape. Although omitted in fig. 5, the control device may have an intermediate control state.

Fig. 5 (a) shows an example of a target position set in the case where there is no target object or the like that needs to be avoided. A driving lane is located between the left white line position and the right white line position, and the target position T coincides with a lane center position C. In this case, a reaction force distribution having a relatively large steering reaction force is set within the range of the respective predetermined widths ML and MR on the left and right sides around the target position T. This makes it difficult to perform override, thereby suppressing misalignment from the target position due to override. A distribution in which the reaction force is weakened is set at a position outside the lane from the positions ML and MR. This does not hinder manual operation for the purpose of significant deviation from the target position. Note that, as shown in fig. 5, when the position of the component in the transverse direction of the road is focused, the position is particularly referred to as a lateral position. In the present embodiment, even in the case of being simply referred to as a position, when a component in the transverse direction of the road is focused in the context, it indicates a lateral position.

Fig. 5 (B) shows an outline of setting of the reaction force distribution during so-called offset running in which the target position is shifted from the lane center position. Note that (B) in fig. 5 is an example of a case where there is no obstacle in the lane during traveling. When an obstacle is present in the lane during travel and the vehicle travels while avoiding the obstacle, the same distribution as in fig. 5 (a) is adopted, except that the center position C and the target position T' are shifted. This is because, in this case, it is dangerous to deviate from the target traveling position by the automated driving. In fig. 5 (B), the position on the left side of the target position T' is set to be difficult to override, as in fig. 5 (a). However, the override operation for returning to the center position is relatively easy by setting a reaction force characteristic smaller than the reaction force on the left side of the target position T 'between the target position T' and the center position C. However, for the override operation of moving to the right side beyond the lane center position C, the same reaction force distribution as that between the target position T and the right predetermined position MR in fig. 5 (a) is applied. Therefore, it is difficult to move rightward from the center position C. Further, when the position is exceeded MR', a reaction force distribution 501 that reduces the reaction force is applied as in fig. 5 (a). However, in this case, when an obstacle is detected on the right side of the right white line position as the lane boundary, the reaction force distribution 502 that generates a larger reaction force may be set.

The characteristics of the steering reaction force (also referred to as "steering reaction force") for realizing such control are shown in fig. 6. In fig. 6 (a), the vertical axis represents a steering reaction force, and the horizontal axis represents a difference (θ m — θ sys) between a system steering angle θ sys for maintaining a target position (particularly, a target lateral position) and a manual steering angle θ m. The curves L1, L2, and L3 each represent a characteristic curve of the steering reaction force (also referred to as a reaction force distribution). For example, when the system steering angle is θ sys, when the driver performs a steering operation, the steering reaction force setting unit 210M increases the steering reaction force in accordance with the curve L3 and the reaction force motor 210E increases the reaction force in accordance with the curve L3 in accordance with an increase in the angle difference θ M — θ sys. The curves L1, L2, and L3 may be discrete values as long as they have characteristics as shown in the figure. The driver must perform the steering operation against the steering reaction force. For example, when the angle difference θ m- θ sys is θ Th, the reaction force F3 is generated if the set reaction force distribution is L3, the reaction force F2 is generated if L2, and the reaction force F1 is generated if L1. In this way, the steering reaction force generated for the same steering angle difference differs depending on the set reaction force distribution.

Fig. 6 (B) shows an example of the transient characteristic. As described later, the reaction force distribution is set based on the current position of the vehicle relative to the target position T and the center position C. That is, the reaction force distribution is switched during traveling. For example, as shown in fig. 6 (a), when the reaction force distribution is switched from L3 to L2 while the steering angle difference θ Th is kept constant, the steering reaction force is changed from F3 to F2, and steering is made to be abrupt. Since this may possibly cause an excessive steering operation, a transient characteristic such as (B) in fig. 6 is given to the change of the reaction force distribution. For example, if the reaction force distribution is changed from L3 to L2 while the steering angle difference θ Th is kept constant, the steering ECU21 continuously changes the generated steering reaction force from F3 to F2 at time t1 as shown in fig. 6 (B). Even when the distribution is changed to another distribution during this period, the steering reaction force generated at the time of switching is continuously changed to the steering reaction force generated in the new distribution according to the transient characteristic.

As described above, the reaction force distribution information 210P stores a table in which the angular difference (θ m — θ sys) between the system steering angle θ sys and the manual steering angle θ m and the steering reaction force are associated with each other for each automatic driving control state as shown in fig. 6 (a), and a table of transient characteristics as shown in fig. 6 (B). The steering reaction force setting unit 210M sets the reaction force distribution according to, for example, the procedure of fig. 7. The transient characteristic may be set to a predetermined transient characteristic as shown in fig. 6 (B). In this way, a steering reaction force corresponding to the rudder angle difference and the set reaction force distribution is applied.

Fig. 7 shows a procedure of setting the reaction force distribution by the steering reaction force setting unit 210M in the present embodiment. Although not shown in fig. 3, the steering reaction force setting unit 210M may refer to the current position on the lane recognized by the vehicle position recognition unit 140 (referred to as the vehicle position in the following description) and the current target position generated by the trajectory generation unit 146. The steps in fig. 7 may be continuously executed by the steering reaction force setting unit 210M as shown in the drawing, or may be executed upon receiving a trigger to switch the reaction force distribution without performing a repetitive cycle. In this case, the trigger may be, for example, a case where the vehicle position moves across each of the left predetermined position ML, the target position T, the center position C, and the right predetermined position MR shown in fig. 5.

In fig. 7, it is first determined whether or not the lane center coincides with the target position (S701). If they match, it is determined whether or not the vehicle position is outside of each of predetermined positions (corresponding to the switching positions of the distributions of MR and ML in fig. 5) on the left and right of the target position (S703). On the outer side, a reaction force distribution L1 is set in which the reaction force generated with respect to the constant steering angle difference is the weakest (S707). On the other hand, when the vehicle is not outside, that is, when the vehicle position is within a predetermined range from the target position, the reaction force distribution L3 is set so that the reaction force generated with respect to the constant rudder angle difference is the strongest (S705). If it is determined in step S701 that the lane center does not coincide with the target position, it is determined whether or not the vehicle position is between the lane center and the target position (S709). When the vehicle is located between the center of the lane and the target position, the center side of the lane is set as the reaction force distribution L2, and the opposite side thereof is set as the reaction force distribution L3 (S711). Referring to fig. 6 (a), for example, when the rudder angle difference in steering from the vehicle position toward the center of the lane is positive, L2 is set as a reaction force distribution with respect to the positive rudder angle difference, and L3 is set as a reaction force distribution with respect to the negative rudder angle difference, which is the opposite side. When the rudder angle difference of the steering from the vehicle position toward the center of the lane is negative, the opposite is true. If it is determined in step S709 that the vehicle position is not between the center of the lane and the target position, the process branches to step S703 and a reaction force distribution corresponding to the vehicle position is set.

By setting the reaction force distribution as described above, for example, as shown in fig. 5 (B), the reaction force generated for the override operation from the target position toward the lane center can be weakened. In step S711, the reaction force distribution L2 may be set. This is because, even if L2 is set, the reaction force distribution is switched according to the positional relationship between the vehicle position and the left predetermined position ML, the target position T, the center position C, the right predetermined position MR, and the like, and therefore, the reaction force distribution can be switched as shown in fig. 5 (B).

[ second embodiment ]

Fig. 8 shows a reaction force distribution setting procedure applied in place of fig. 7. The step of fig. 8 is a step for realizing the reaction force characteristic 502 for the obstacle as described in fig. 5 (B). The description of the portions common to fig. 7 is omitted. When it is determined in step S703 that the vehicle position is outside the left and right predetermined positions MR and ML, it is determined whether an obstacle such as another vehicle is present at a position outside the lane where the vehicle is traveling by a predetermined distance (S801). If no obstacle is present, the reaction force distribution L1 is set (S707). However, if there is an obstacle, the reaction force distribution L2 is set to have a reaction force larger than the reaction force distribution L1 with respect to a constant steering angle (S803). This makes it difficult for the driver to perform an override operation for approaching an obstacle. Further, the determination of the obstacle may be performed based on information acquired from the outside world recognizing unit 142, for example.

● summary of the embodiments

The present embodiment described above is summarized as follows.

(1) According to a first aspect of the present invention, there is provided a vehicle control device for performing driving assistance or automatic driving of a host vehicle, the vehicle control device comprising:

a setting unit that sets a target position to be a travel route in a lane during travel, based on a surrounding monitoring result; and

a steering control mechanism that performs steering control based on the target position,

the steering control means is capable of receiving a steering input by a manual operation performed by a driver even when steering control is performed based on the target position,

the steering control means generates a predetermined reaction force against the manual operation when the steering input is received,

the steering control mechanism controls the steering reaction force characteristic as follows: when the target position is displaced from a first reference position that is near the center of a lane on which the vehicle is traveling with respect to the width direction of the lane, the steering reaction force applied to a manual operation in a first direction from the target position to the first reference position is smaller than the steering reaction force applied to a manual operation in a second direction different from the first direction with respect to a steering angle when the steering input is received.

According to this configuration, when the offset is cancelled toward the center position, the steering reaction force is weakened, so that the ease of intervention by the user can be improved, and the off-road deviation suppression can be improved for erroneous intervention toward the opposite side.

(2) According to a second aspect of the present invention, there is provided the vehicle control device according to (1), wherein the steering reaction force characteristic is a characteristic between a steering reaction force and a rudder angle difference that is a difference between a rudder angle based on the target position and a manually-operated rudder angle, and the steering reaction force becomes larger as the rudder angle difference becomes larger.

According to this configuration, the reaction force characteristic is defined as a slope, and the reaction force characteristic increases and decreases as the rotation angle increases, so that the driver can intuitively understand the reaction force characteristic.

(3) According to a third aspect of the present invention, there is provided the vehicle control device according to (2),

in the steering reaction force characteristic toward the first direction, an increase rate of the steering reaction force applied with respect to the rudder angle difference from the target position to the first reference position is smaller than an increase rate of the steering reaction force applied with respect to the rudder angle difference from exceeding the first reference position.

According to this configuration, when the reaction force is further increased by the center position, the reaction force can be appropriately generated for an excessive intervention operation by the user by coping with a normal reaction force.

(4) According to a fourth aspect of the present invention, there is provided a vehicle control device according to the (2) or (3),

the steering control means controls the steering reaction force characteristic as follows: the steering reaction force applied to the steering input in the direction away from the target position when approaching an obstacle is made larger than the steering reaction force when not approaching an obstacle based on the surrounding monitoring result.

According to this configuration, the approach to the obstacle can be suppressed by increasing the steering reaction force.

(5) According to a fifth aspect of the present invention, there is provided a vehicle control device according to any one of (2) to (4),

the setting means performs a first offset control in which the target position is set so as to be apart from an obstacle based on the periphery monitoring, and a second offset control in which the target position is set so as to be apart from the first reference position based on a curvature of a lane in which the vehicle is traveling,

the steering control means controls the steering reaction force characteristic as follows: the rate of increase of the steering reaction force applied to the rudder angle difference in the first direction when the second offset control is performed is made smaller than the rate of increase of the steering reaction force applied to the rudder angle difference in the first direction when the first offset control is performed.

According to this configuration, the offset cancellation at the time of turning is performed with a low reaction force, and the offset cancellation with respect to the obstacle is performed with a high reaction force, and the risk with respect to the obstacle is expressed by the reaction force characteristic.

(5) According to a sixth aspect of the present invention, there is provided a vehicle control device according to any one of (1) to (5),

when the steering reaction force is generated by the steering control means, the setting means sets a new target position so as to reduce the deviation from the first reference position when setting the new target position.

According to this configuration, when the offset canceling operation is equal to or greater than the predetermined value, the driver's preference can be reflected by canceling the offset next or later or present.