JP2021088324A - Travel assist method and travel assist device - Google Patents

Abstract

To provide a travel assist method capable of extending an assist in precise accordance with a travel situation.SOLUTION: A travel assist method uses controllers (on-vehicle control unit 3 and VDC-TCS controller 6) which determine whether or not to start VDC control on the basis of comparison of a drive wheel slip rate of an own RWD vehicle with a TCS control start threshold. The on-vehicle control unit 3 and the VDC-TCS controller 6 execute the following first and second steps. In the first step, whether the own vehicle is traveling at an entrance or an exit of a corner is determined on the basis of a surrounding situation detected through a sensor detecting a surrounding situation of the own vehicle. In the second step, the TCS control start threshold is set on the basis of a determination result of whether the own vehicle is traveling at the entrance or the exit of the corner.SELECTED DRAWING: Figure 1

Description

The present disclosure relates to a driving support method and a driving support device.

Conventionally, a traveling support method for controlling the driving force and braking force of a vehicle has been known. Further, in such a traveling support method, there is known that the control for stabilizing the behavior of the vehicle is changed according to the road surface condition (see, for example, Patent Document 1). In this prior art, an oversteer (OS) threshold or an understeer (US) threshold is set according to the road surface friction coefficient, and a deviation signal between a target yaw rate and an actual yaw rate and an oversteer (OS) threshold or understeer (OS) threshold value or understeer (OS) threshold value or understeer threshold value Based on the US) threshold, the control intervention to stabilize the behavior is determined.

Japanese Unexamined Patent Publication No. 2008-105439

However, in the above-mentioned conventional technique, if the road surface friction coefficient is common, a certain intervention judgment is made regardless of the driving situation, so that in some cases, the driving support may not be appropriate according to the driving situation. It was.

The present disclosure has been made by paying attention to the above problems, and an object of the present disclosure is to provide a driving support method and a driving support device capable of providing appropriate driving support according to a driving situation.

The traveling support method of the present disclosure is a traveling support method using a controller that determines whether or not to start TCS control based on a comparison between a value indicating the behavior of the front-wheel drive own vehicle and a TCS control start threshold value. Then, the controller determines whether the traveling of the own vehicle is a corner entrance traveling or a corner exit traveling, and based on the determination result of whether the driving is the corner entrance traveling or the corner exit traveling, the TCS control is performed. Set the start threshold.

The driving support method and the driving support device of the present disclosure can provide appropriate driving support according to the driving situation.

It is an overall system block diagram which shows the structure of the system of the self-driving vehicle to which the running support method and the running support device of Embodiment 1 are applied. It is a block diagram which shows the structure of the VDC / TCS controller of the self-driving vehicle. It is a block block diagram which shows the control block of the automatic driving controller and the vehicle motion controller of the automatic driving vehicle. It is a block diagram which shows the structure of the traveling state determination part of the automatic driving controller. It is a block diagram which shows the structure of the running state analysis part and the turning strength calculation part of the running state determination part of the automatic driving controller. It is a flowchart which shows the flow of the conversion process from each reference value to the turning strength by the turning strength calculation part of the running state determination part. The threshold characteristic diagram showing the relationship between the US suppression VDC control threshold and the OS suppression VDC control start threshold when calculating the control start threshold in the control start threshold calculation unit of the VDC / TCS controller, and the curve entrance strength and curve exit strength. is there. The threshold characteristic diagram showing the relationship between the TCS control threshold of RWD and the TCS control start threshold of FWD when calculating the control start threshold in the control start threshold calculation unit of the VDC / TCS controller, and the curve entrance strength and curve exit strength. is there. 6 is a time chart showing an operation example of VDC control between an autonomous driving vehicle to which the first embodiment is applied and a comparative example. It is a time chart which shows the operation example of the TCS control of the rear wheel drive self-driving vehicle and the comparative example to which Embodiment 1 was applied. It is a time chart which shows the operation example of the TCS control of the front-wheel drive self-driving vehicle to which the first embodiment is applied, and the comparative example. It is a flowchart which shows the flow of the process of setting the VDC control start threshold value in the control start threshold value calculation part of the self-driving vehicle to which the travel support method of Embodiment 2 and the travel support device are applied. It is a flowchart which shows the flow of the process of setting the TCS control start threshold value in the front wheel drive vehicle (FWD) in the control start threshold value calculation unit of the self-driving vehicle to which the travel support method and the travel support device of Embodiment 2 are applied. It is a flowchart which shows the flow of the process of setting the TCS control start threshold value in a rear wheel drive vehicle (RWD) in the control start threshold value calculation unit of the self-driving vehicle to which the travel support method and the travel support device of Embodiment 2 are applied. FIG. 5 is a block configuration diagram showing a control block of an automatic driving controller and a vehicle motion controller of an automatic driving vehicle to which the traveling support method and the traveling support device of the third embodiment are applied.

Hereinafter, a vehicle control method and a mode for implementing the vehicle control device according to the present disclosure will be described with reference to the drawings.

(Embodiment 1)
First, a travel support device that executes the travel support method of the first embodiment will be described.
The driving support device that executes the driving support method of the first embodiment generates a target locus when the automatic driving mode is selected, and automatically controls the vehicle motion by the speed and the steering angle so as to travel along the generated target locus. It is applied to the driving vehicle AD.

Hereinafter, the configuration of the autonomous driving vehicle AD will be described separately for [overall system configuration] and [autonomous driving controller control block configuration]. Further, the configurations of the VDC / TCS controller, the running state determination unit, and the control start threshold value determination unit are changed to [VDC / TCS controller configuration], [Running state determination unit configuration], [Running state analysis unit, and turning strength calculation unit]. Configuration], [Conversion processing flow of processing of turning strength conversion unit], and [Control start threshold value calculation unit and control start threshold value calculation procedure] will be described separately.

[Overall system configuration (Fig. 1)]
As shown in FIG. 1, the autonomous driving vehicle AD to which the vehicle control device of the first embodiment is applied includes an in-vehicle sensor 1, a navigation device 2, an in-vehicle control unit 3, an actuator 4, an HMI module 5, and the like. It is equipped with a VDC / TCS controller 6. "HMI" is an abbreviation for "Human Machine Interface". "VDC" is an abbreviation for "Vehicle Dynamics Control". "TCS" is an abbreviation for "traction control system".

The in-vehicle sensor 1 is various sensors mounted on the own vehicle in order to recognize the surrounding environment such as objects around the own vehicle and the shape of the traveling path, the position of the own vehicle, the state of the own vehicle, and the like. The in-vehicle sensor 1 has an external sensor 11, a GPS receiver 12, and an internal sensor 13.

The external sensor 11 is provided toward the vicinity of the own vehicle, and is a sensor that detects a stationary object, a moving object, a traveling path shape, or the like around the own vehicle. As the external sensor 11, for example, a camera, a radar, a rider, a sonar, or the like is used.

Radar is an abbreviation for Radio Detection and Ranging. Rider is "Lidar", which stands for Light Detection and Ranging. Sonar is "Sonar", which stands for Sound Navigation and Ranging. Further, in the external sensor 11, for example, a sensor fusion may be performed in which a camera and a radar or a camera and a rider are combined and necessary information is acquired by fusing the detection information.

The GPS receiver 12 is a device that receives signals from three or more GPS satellites by the GNSS antenna 12a and acquires position data (latitude and longitude) indicating the position of the own vehicle. "GNSS" is an abbreviation for "Global Navigation Satellite System", and "GPS" is an abbreviation for "Global Positioning System". Further, when the signal reception by the GPS receiver 12 is poor, the function of the GPS receiver 12 may be complemented by using the internal sensor 13 or the odometer (vehicle movement amount measuring device).

The internal sensor 13 is a detection device that detects own vehicle information such as speed, acceleration, and attitude data of the own vehicle. For example, it has a 6-axis inertial measurement unit (IMU) and can detect the moving direction, direction, and rotation of the own vehicle. Further, the moving distance, the moving speed, and the like can be calculated based on the detection result of the internal sensor 13. The 6-axis inertial sensor is realized by combining an acceleration sensor capable of detecting acceleration in three directions of front-back, left-right, and up-down, and a gyro sensor capable of detecting the speed of rotation in these three directions. The internal sensor 13 can include a sensor that acquires necessary information such as a wheel speed sensor, a yaw rate sensor, and an accelerator operation amount sensor.

Further, in the in-vehicle sensor 1, necessary information may be acquired from the outside by performing wireless communication with an external data communication device (not shown). That is, when the external data communication device is, for example, a data communication device mounted on another vehicle, vehicle-to-vehicle communication is performed between the own vehicle and the other vehicle. Through this vehicle-to-vehicle communication, necessary information can be obtained from various information held by other vehicles. Further, when the external data communication device is, for example, a data communication device provided in the infrastructure equipment, infrastructure communication is performed between the own vehicle and the infrastructure equipment. Through this infrastructure communication, necessary information can be obtained from the information held by the infrastructure equipment. As a result, for example, it is possible to supplement the map data required when there is insufficient information or changed information in the high-precision map data possessed by the automatic driving controller 31. It is also possible to acquire traffic information such as traffic congestion information and driving regulation information on the route on which the vehicle is scheduled to travel.

The navigation device 2 is a device that incorporates facility information data and guides the route on which the vehicle travels to the destination. The navigation device 2 may include high-precision map data including position information of lanes on the travel path. In the navigation device 2, when the destination is input, a guide route from the current location (or an arbitrarily set departure point) of the own vehicle to the destination is generated. The generated guidance route information is combined with the high-precision map data and displayed on the display of the HMI module 5. As the destination, the one set by the occupant of the vehicle in the vehicle may be used, or the destination set by the user by the user terminal (for example, a mobile phone or a smartphone) may be set by the user via wireless communication. You may use the received destination. Further, the guide route may be calculated by a navigation device using a controller provided in the own vehicle, or may be calculated by a navigation device using a controller outside the vehicle.

The in-vehicle control unit 3 includes a CPU and a memory, and receives various detection information detected by the in-vehicle sensor 1, guidance route information generated by the navigation device 2, and driver input information appropriately input as needed. Integrated processing. The in-vehicle control unit 3 is a controller that controls vehicle motion by hierarchical processing. Note that "hierarchical processing" is to calculate the final output information by sequentially (hierarchically) executing a plurality of processes on the input information, and the output value output in the upper layer process. (Calculated value) is the input value in the lower layer processing. Note that the hierarchical processing in which the above-mentioned plurality of processes are executed in order (hierarchically) to calculate the final output information is an example, and if the result of the processing in the upper layer is not necessarily required, a different layer is used. But it is possible to process in parallel (simultaneously).

The in-vehicle control unit 3 includes an automatic driving controller 31 that generates a target locus and a target speed profile, and a vehicle motion controller 32 that calculates a command value for controlling vehicle motion based on the generated target locus and the target speed profile. And have. Here, the automatic driving controller 31 that performs the calculation in the first control cycle performs the processing of the upper layer, and the vehicle motion controller 32 that performs the calculation in the second control cycle shorter than the first control cycle performs the processing of the lower layer. Do.

The automatic driving controller 31 generates a target trajectory and a target speed profile by hierarchical processing based on input information from the vehicle-mounted sensor 1 and the navigation device 2, high-precision map data, and the like. Here, the "target locus" is a travel locus that is a target when the vehicle is automatically driven, and is, for example, a locus in which the vehicle travels within the lane width or in a travelable area around the vehicle. Includes trajectories for traveling on the road and trajectories for avoiding obstacles. The generated target trajectory and target speed profile information is output to the vehicle motion controller 32. The generated target trajectory information may be combined with the high-precision map data and displayed on the display of the HMI module 5.

In the vehicle motion controller 32, a control command for driving the own vehicle based on the information of the target trajectory and the target speed profile from the automatic driving controller 31 or the input information by the driver operation (hereinafter referred to as "driver input"). Calculate the value. The calculated control command value is output to the actuator 4. The vehicle motion controller 32 arbitrates the traveling mode depending on the presence or absence of driver input, and calculates a control command value according to the arbitration result (automatic driving driving mode or manual driving driving mode).

The actuator 4 includes a control actuator for traveling straight / turning / stopping the own vehicle, and includes a speed control actuator 41 and a steering control actuator 42. The running includes acceleration running / constant speed running / deceleration running.

The speed control actuator 41 controls the drive torque or braking torque output to the drive wheels (each wheel) based on the speed control command value input from the vehicle-mounted control unit 3, and includes the TCS actuator 41a and the VDC actuator 41b. Is done.

The TCS actuator 41a is an actuator that controls the driving force applied to the wheels connected to the driving source of the own vehicle. The drive source of the own vehicle is, for example, an engine in the case of an engine vehicle, an engine and a motor / generator in the case of a hybrid vehicle, and a motor / generator in the case of an electric vehicle. Further, as the TCS actuator 41a, an actuator that controls the output of the drive source or the drive source itself can be used.

The VDC actuator 41b is a well-known actuator that can independently control the braking torque of the wheels connected to the braking device of the own vehicle. As the VDC actuator 41b, one having a pressure source such as a hydraulic pump, an electric pump or an accumulator, and a control valve capable of supplying and discharging pressure to the wheel cylinders of each wheel can be used. Further, when a motor / generator is provided as a drive source, the motor / generator can be used as the VDC actuator 41b to control the regenerative braking force thereof.

The steering control actuator 42 controls the steering angle of the steering wheels based on the steering control command value input from the vehicle-mounted control unit 3. As the steering control actuator 42, a steering motor or the like provided in the steering force transmission system of the steering system is used.

The HMI module 5 is an interface for transmitting each other's intentions and information between the occupant including the driver of the own vehicle and the vehicle-mounted control unit 3. The HMI module 5 includes, for example, a head-up display or meter display that displays image information based on the automatic driving control status to the occupant, a speaker that outputs an announcement sound, a lamp that warns the occupant by lighting or blinking, and an operation button that the occupant performs an input operation. And touch panel.

[Control block configuration of automatic driving controller (Fig. 3)]
Next, the configuration of the automatic operation controller 31 will be described.
As shown in FIG. 3, the automatic driving controller 31 includes a high-precision map data storage unit 311, a self-position estimation unit 312, and a driving environment recognition unit as information acquisition processing units necessary for generating a target speed profile. It includes a 313 and a surrounding object recognition unit 314. Further, the automatic driving controller 31 includes a traveling lane planning unit 315, an operation determining unit 316, a traveling area setting unit 317, and a target trajectory generating unit 318 as hierarchical processing units for generating a target trajectory and a target speed profile. I have.

The high-precision map data storage unit 311 stores high-precision three-dimensional map data (hereinafter referred to as "HD map") in which three-dimensional position information (longitude, latitude, height) of a stationary object existing outside the vehicle is set. It is an in-vehicle memory. Stationary objects with high-precision map data include, for example, pedestrian crossings, stop lines, various signs, branch points, road signs, traffic lights, utility poles, buildings, signboards, center lines of roads and lanes, lane markings, shoulder lines, and running. It includes various factors such as the connection between the road and the road. The high-precision map data storage unit 311 does not necessarily have to include all the elements of the above-mentioned stationary object.

The self-position estimation unit 312 inputs sensor information from the in-vehicle sensor 1 and HD map information from the high-precision map data storage unit 311, matches the input sensor information with the HD map information, and displays it on the high-precision map. Estimate the current location (self-position) of your vehicle. Then, the self-position estimation unit 312 outputs the self-position information to the traveling environment recognition unit 313.

The driving environment recognition unit 313 includes sensor information from the in-vehicle sensor 1, guidance route information from the navigation device 2, HD map information from the high-precision map data storage unit 311, self-position information from the self-position estimation unit 312, and surrounding objects. The surrounding object recognition information from the recognition unit 314 is input. Then, these input information and the ever-changing dynamic information of the own vehicle driving environment are integrated to recognize the own vehicle driving environment. Here, the "dynamic information" is, for example, quasi-static data (traffic regulation information, etc.), quasi-dynamic data (accident information, traffic jam information, etc.), and dynamic data (peripheral moving vehicle information, pedestrian information, etc.). Etc.) are combined. The driving environment recognition unit 313 outputs the driving environment recognition information to the operation determination unit 316.

The surrounding object recognition unit 314 inputs the sensor information from the vehicle-mounted sensor 1 and recognizes the surrounding object of the own vehicle by detecting or predicting the position, attribute, and behavior of the object existing around the own vehicle. Then, the surrounding object recognition unit 314 outputs the surrounding object recognition information to the traveling environment recognition unit 313 and the traveling area setting unit 317.

The traveling lane planning unit 315 inputs the guidance route information from the navigation device 2 and the HD map information from the high-precision map data storage unit 311, and the traveling lane in which the own vehicle should travel on the guidance route to the destination ( Hereinafter referred to as "target lane"). The target lane information is output from the traveling lane planning unit 315 to the operation determination unit 316 of the next layer.

The operation determination unit 316 inputs the driving environment recognition information from the driving environment recognition unit 313 and the target lane information from the driving lane planning unit 315, and extracts the events encountered by the own vehicle when traveling along the target lane. , Determine the behavior of your vehicle for those events. Here, the "movement of the own vehicle" refers to the movement of the own vehicle required to drive along the target lane such as starting, stopping, accelerating, decelerating, and turning left or right. The own vehicle operation determination information is output from the operation determination unit 316 to the traveling area setting unit 317 of the next layer.

The traveling area setting unit 317 inputs HD map information from the high-precision map data storage unit 311, own vehicle operation determination information from the operation determination unit 316, and surrounding object recognition information from the surrounding object recognition unit 314. Then, the motion information of the own vehicle and the recognition information of surrounding objects are collated, and a travelable area in which the own vehicle can be driven along the target lane is set. Here, the "travelable area" is set so as to avoid interference or contact with the area when, for example, an object such as a parked convoy exists or a construction section exists around the own vehicle. Area. The travelable area information is output from the travel area setting unit 317 to the target trajectory generation unit 318 of the next layer.

The target locus generation unit 318 inputs the travelable area information from the travel area setting unit 317, and travels within the travelable area from the current position of the own vehicle to an arbitrarily set target position as a constraint condition. , Generate a target trajectory including lane change.

Based on the target locus generated by the target locus generation unit 318, the vehicle motion controller 32 calculates a control command value for traveling the own vehicle and outputs it to the actuator 4.

In the first embodiment, the vehicle motion controller 32 determines the traveling state, which is one element for determining the control threshold value of the VDC / TCS controller 6, based on the target trajectory generated by the target trajectory generating unit 318. A determination unit 700 is provided. Hereinafter, the VDC / TCS controller 6 and the traveling state determination unit 700 will be described.

The VDC / TCS controller 6 performs VDC control and TCS control, which are controls of the braking force and driving force of the own vehicle, independently of the automatic driving. At the time of automatic driving, the control by the VDC / TCS controller 6 is prioritized and intervened with respect to the control of the vehicle motion controller 32. Further, even during manual operation, the driver's operation is intervened by the control of the VDC / TCS controller 6.

In VDC control, the VDC / TCS controller 6 uses the VDC actuator 41b and the TCS actuator 41a to control the braking force and the driving force so as to stabilize the vehicle posture and the vehicle behavior. Further, in the TCS control, the VDC / TCS controller 6 uses the TCS actuator 41a and the VDC actuator 41b to control the driving force and the braking force so as to stabilize the driving wheels.

More specifically, the VDC / TCS controller 6 has US suppression VDC control for suppressing the understeer (hereinafter referred to as US) state of the own vehicle and oversteer (hereinafter referred to as OS) of the own vehicle as VDC control. The OS suppression VDC control that suppresses the state is executed. The US state and OS state of the own vehicle are determined based on the deviation between the target yaw rate and the actual yaw rate. Specifically, if the actual yaw rate is lower than the target yaw rate, it can be determined to be in the US state, and conversely, if the actual yaw rate is higher than the target yaw rate, it can be determined to be in the OS state.

The US suppression VDC control is a control for suppressing the US state by giving a moment in the OS direction to the own vehicle when it is detected that the vehicle posture is in the US state equal to or higher than a predetermined value. The application of the yaw moment in the OS direction to the own vehicle can be executed by reducing the driving force to the driving wheels and applying the braking force to the rear wheels inside the corner, or both. Further, when the own vehicle has a driving force distribution mechanism, the yaw moment in the OS direction can be applied by making the driving force distribution of the turning outer ring larger than the driving force distribution of the turning inner ring. Alternatively, when the own vehicle has a drive source such as an in-wheel motor that can independently apply a driving force, the driving force of the turning outer ring is made larger than the driving force of the turning inner ring, so that the OS A directional yaw moment can be applied.

The OS suppression VDC control is a control for suppressing the OS state by giving a moment in the US direction to the own vehicle when it is detected that the vehicle posture is in the OS state equal to or higher than a predetermined value. The application of the yaw moment in the US direction to the own vehicle can be executed by reducing the driving force to the driving wheels and applying the braking force to the front wheels on the outside of the corner, or both. Further, when the own vehicle has a driving force distribution mechanism, the yaw moment in the US direction can be applied by making the driving force distribution of the turning inner ring larger than the driving force distribution of the turning outer ring. Alternatively, when the own vehicle has a drive source such as an in-wheel motor that can independently apply a driving force, the driving force of the turning inner ring is made larger than the driving force of the turning outer ring to be US. A directional yaw moment can be applied.

Further, in the TCS control by the VDC / TCS controller 6, when the road surface friction coefficient is low or the driving force is excessive and the driving wheels slip, the driving force of the driving source is lowered or the driving wheels are driven. The amount of slip is reduced by applying a braking force to the controller. The road surface friction coefficient can be estimated based on the wheel speed and the acceleration of the vehicle body.

[Configuration of VDC / TCS controller (Fig. 2)]
The outline of the configuration of the VDC / TCS controller 6 that performs the VDC control and the TCS control as described above will be described with reference to FIG.

The VDC / TCS controller 6 includes a target yaw rate calculation unit 61, an actual yaw rate calculation unit 62, a yaw rate deviation calculation unit 63, a drive wheel slip ratio calculation unit 64, and a control start threshold value calculation unit 65. Further, the VDC / TCS controller 6 includes a US suppression VDC control command unit 66, an OS suppression VDC control command unit 67, and a TCS control command unit 68 as control command output units.

The target yaw rate calculation unit 61 calculates the target yaw rate, which is the ideal vehicle behavior, based on the vehicle body speed and the steering angle obtained from the vehicle speed sensor and the steering angle sensor included in the internal sensor. Further, the actual yaw rate calculation unit 62 calculates the actual yaw rate actually generated in the own vehicle based on the signal from the yaw rate sensor included in the internal sensor. The yaw rate deviation calculation unit 63 calculates the deviation between the target yaw rate and the actual yaw rate.

The drive wheel slip ratio calculation unit 64 calculates the slip ratio of the drive wheels, and calculates the slip ratio of the drive wheels based on the driven wheel speed and the drive wheel speed obtained by the wheel speed sensor.

The control start threshold value calculation unit 65 calculates the US suppression VDC control start threshold value, the OS suppression VDC control start threshold value, and the TCS control start threshold value.

The US suppression VDC control start threshold value is used to determine whether or not to start US suppression VDC control. The OS suppression VDC control start threshold value is used to determine whether or not to start OS suppression VDC control. The TCS control start threshold value is used to determine whether or not to perform TCS control.

Further, the control start threshold value calculation unit 65 sets the OS suppression VDC control start threshold value, the US suppression VDC control start threshold value, and the TCS control start threshold value with the vehicle speed (including each wheel speed) and the road surface friction coefficient obtained from the in-vehicle sensor 1. It is calculated based on the turning strength obtained from the traveling state determination unit 700. The details of the turning strength will be described later.

The US suppression VDC control command unit 66 inputs the yaw rate deviation and the US suppression VDC control start threshold value. Then, when the yaw rate deviation on the US side exceeds the US suppression VDC control start threshold value, the US suppression VDC control command unit 66 increases the actual yaw rate of the own vehicle toward the VDC actuator 41b toward the target yaw rate to the US. Execute control to suppress the state. The yaw rate deviation on the US side is a deviation that occurs when the actual yaw rate is lower than the target yaw rate in the US state.

The OS suppression VDC control command unit 67 inputs the yaw rate deviation and the OS suppression VDC control start threshold value. Then, when the yaw rate deviation on the OS side exceeds the OS suppression VDC control start threshold value, the OS suppression VDC control command unit 67 lowers the actual yaw rate of the own vehicle toward the VDC actuator 41b toward the target yaw rate. Execute control to suppress the OS state. The yaw rate deviation on the OS side is a deviation that occurs in an OS state in which the actual yaw rate exceeds the target yaw rate.

The TCS control command unit 68 inputs the drive wheel slip ratio and the TCS control start threshold value. Then, when the drive wheel slip ratio exceeds the TCS control start threshold value, the TCS control command unit 68 executes TCS control that suppresses the slip ratio of the drive wheels within a predetermined slip ratio.

As described above, the control start threshold value calculation unit 65 calculates the US suppression VDC control start threshold value, the OS suppression VDC control start threshold value, and the TCS control start threshold value based on the vehicle speed, the road surface friction coefficient, and the turning strength.
The traveling state determination unit 700 inputs the sensor information from the vehicle-mounted sensor 1 and the target locus information from the target locus generation unit 318, and calculates the turning strength as a value indicating the traveling condition in the target locus of the own vehicle. Then, using this turning strength, the control start threshold value calculation unit 65 of the VDC / TCS controller 6 described above calculates each control start threshold value.

[Structure of running state determination unit (Fig. 4)]
Hereinafter, the configuration of the traveling state determination unit 700 will be described with reference to FIGS. 4, 5, and 6.
First, the overall configuration of the traveling state determination unit 700 will be described with reference to FIG.
The traveling state determination unit 700 calculates the traveling condition on the target locus as the turning strength based on the aggregate of the curvatures of the target locus, and the curvature calculation unit 710, the curvature information analysis unit 720, and the traveling condition analysis unit 730. And a turning strength calculation unit 740.

The curvature calculation unit 710 sets calculation points Pn on the target locus at predetermined intervals, and calculates the curvature of each calculation point Pn.

The curvature information analysis unit 720 analyzes the curvature of each calculation point Pn. This analysis includes the maximum, average and deviation of left and right curvature, and skewness. Here, the skewness refers to the variation in the distribution of curvature. This skewness is used to determine whether the running state of a predetermined section of the target trajectory is a steady state or a transient state. The details will be described later, but the steady state of the running state refers to straight running or steady circular running, and in that case, the distribution of curvature is a normal distribution within a predetermined width (deviation). That is, the average value is close to the median value of the distribution, the deviation is relatively small, and the skewness is small.

On the other hand, in transient states other than straight running and steady circular running, that is, in the corner entrance running state, corner exit running state, and indefinite turning running state, the curvature distribution is non-normal distribution, or even if it is normal distribution, the skewness Becomes larger. In addition, the non-normal distribution has a difference between the mean value and the median value, or has a plurality of peaks. A normal distribution with a large skewness is a distribution in which the deviation (width) is wider than a predetermined width.

The traveling condition analysis unit 730 analyzes the traveling condition on the target locus based on the curvature analysis information (maximum value, average value, deviation, skewness) along the target locus and the input from the vehicle-mounted sensor 1. Then, as an analysis of this traveling state, it is determined whether it is a steady state or a transient state other than that. The running state in the steady state includes straight running and steady circular running. On the other hand, the traveling state in the transient state includes corner entrance traveling, corner exit traveling, and indefinite turning traveling.

Then, the turning strength calculation unit 740 calculates the turning strength along the target locus based on the reference value calculated by the traveling condition analysis unit 730. Here, the turning strength is calculated by calculating the corner inlet strength, the corner exit strength, the corner indefinite strength, the steady circular strength, and the linear strength, which indicate the traveling state on the target trajectory, as a value at which the total value thereof is “1”.

The corner entrance strength indicates the degree to which the running state is like corner entrance running, and the corner exit strength indicates the degree to which the running state is like corner exit running. Further, the steady circular strength indicates the degree to which the running state is like a steady circular running, the linear strength indicates the degree to which the running state is like a straight running, and the corner indefinite strength indicates the degree to which the running state is neither of the above. Indicates the degree of indefinite turning driving.

Therefore, for example, when a certain traveling section on the target trajectory is a straight road, the values of the straight line strength become large, and the values of the corner entrance strength, the corner exit strength, the corner indefinite strength, and the steady circle strength become small.

Even if it is a straight road, the target trajectory is not always a perfect straight line. For example, even on a straight road, the target locus may move left and right on the traveling lane due to a change in the width of the traveling lane. Therefore, the distribution of curvature in the straight running state is a normal distribution with a small skewness having a certain narrow width (variance: deviation) with "0" as the average value, the median value, and the mode value.

Also, in the case of steady turning, since the curvature is substantially constant, the median value, average value, and mode value deviate from "0", but the width (variance: deviation) is suppressed to some extent. It has a normal distribution with small skewness.

On the other hand, at the corner entrance, the transition from a straight section whose curvature is close to "0" to a curved section where the curvature increases in one direction on the left and right, so the distribution of values with high curvature increases from the distribution of values with low curvature. The distribution is rising to the right.

On the other hand, at the corner exit, since the section where the curvature is higher than "0" goes to the section where the curvature is "0", the distribution of the values with a high curvature is followed by the distribution of the values with a low curvature. It becomes.

When the left and right corners are continuous, the value of curvature "0" increases in the section near the middle part between the corners, but the curvature before and after that is a large value, so the width (deviation) of the distribution. Spreads and the skewness increases. In this way, a section having a wide distribution width (deviation) can be distinguished from straight running (steady state) even if it has a normal distribution, and is included in the transient region.

Then, the corner indefinite intensity indicates that it is an interval of the distribution of curvature other than the above. Specifically, the distribution of curvature is not a normal distribution, and the width of the distribution is widened, and the distribution has a plurality of peaks and valleys.

[Structure of running state analysis unit and turning strength calculation unit (Fig. 5)]
Next, the configurations of the traveling condition analysis unit 730 and the turning strength calculation unit 740 will be described with reference to the block diagram of FIG.

The traveling condition analysis unit 730 includes a reference curvature calculation unit 731, a curvature increase / decrease extraction unit 732, a skewness dimensionalization unit 733, and a curvature component conversion unit 734.

The reference curvature calculation unit 731 is a reference curvature used when determining the traveling situation, and is a reference value used for normalization (non-dimensionalization) when analyzing the curvature aggregate of the target locus. Calculate the curvature RhoRef. This reference curvature RhoRef is calculated from the current vehicle speed V, the maximum lateral acceleration (road surface friction coefficient) GyMaxTraj, and the preset base gain K _PTC using the following equation (1).
RhoRef = (K _PTC・ GyMaxTraj ・ g) / V ² ... (1)

The curvature increase / decrease extraction unit 732 extracts the increase / decrease in curvature as the curvature increase RhoEntry and the curvature decrease RhoExit from the curvature of the forward gazing point, which is the position ahead of the current position in the target locus, and the curvature with the current position.

Here, the curvature increase RhoEntry is calculated as a value indicating the probability (possibility) of being a corner entrance, and the higher this value is, the higher the probability of being a corner entrance is. On the other hand, the curvature reduction RhoExit is calculated as a value indicating the probability (possibility) of the corner exit, and the higher this value, the higher the probability of the corner exit.

As described above, since the curvature increasing RhoEntry and the curvature decreasing RhoExit are contradictory to each other, the higher the value of one of them, the lower the value of the other.

The skewness dimensionalization unit 733 uses the standard deviation Rho of curvature, the maximum left and right curvature RhoMax / Min, and the skewness Skewness, and the skewness is separately curved from the following equations (2), (3), and (4). Convert to. Then, the dimensionalized skewness RhoSQN is obtained from the skewnesses of the curvatures of the left and right sides.
RhoSQN _L = 3 · RhoStd · | sign (RhoMax) | · max (Skewness, 0) ... (2)
RhoSQN _R = 3 · RhoStd · | sign (RhoMin) | · min (Skewness, 0) ... (3)
RhoSQN = RhoSQN _L + RhoSQN _R ... (4)

The curvature component conversion unit 734 calculates a non-dimensional reference value by dividing the curvature increase RhoEntry, the curvature decrease RhoExit, the average RhoAve, the standard deviation RhoStd, and the dimensional skewness RhoSQN by the reference curvature RhoRef. As a result, the curvature increase reference value NormRhoEntry, the curvature decrease reference value NormRhoExit, the average reference value NormRhoAve, the standard deviation reference value NormRhoStd, and the dimensionalized skewness reference value NormRhoSQN are calculated. Each reference value obtained by dividing by the reference curvature RhoRef to make it dimensionless is calculated as a value of 1 when the value is the same as the reference curvature RhoRef.

The turning strength calculation unit 740 converts the curvature increase reference value NormRhoEntry, the curvature decrease reference value NormRhoExit, the average reference value NormRhoAve, the standard deviation reference value NormRhoStd, and the dimensionalized skewness reference value NormRhoSQN into turning strengths, respectively.

[Conversion processing flow of processing of turning strength conversion unit]
FIG. 6 shows the flow of conversion processing from each reference value to the turning strength by the turning strength calculation unit 740.
In step S11, transient components and stationary components are extracted. As described above, if the curvature distribution is non-normal, or even if it is a normal distribution, the deviation is large and the distribution varies widely, that is, the width of the distribution is greater than or equal to a predetermined value. , In a transient state.

Therefore, the transient component (FactorTRA) and the stationary component (FactorSTA) are obtained by the following equations (5) and (6). As shown in the following formula (6), the transient component Factor TRA and the stationary component Factor STA have a relationship of "1" in total.
FactorTRA = max (NormRhoSQN, NormRhoStd) ... (5)
FactorSTA = 1-FactorTRA ... (6)

In steps S12 and S13, the transient component is converted into a corner inlet strength KappaCorEntry, a corner exit strength KappaCorExit, and a corner indefinite strength KappaCorUndef.

In step S12, among the transient components, the components that are not determined to be the corner inlet and the corner exit are processed as indefinite turns according to the following equation (7).
NormRhoUndef =
1- (NormRhoEntry + NormRhoExit) ... (7)

In step S13, the transient component is converted into intensity. That is, the corner inlet strength KappaCorEntry, the corner exit strength KappaCorExit, and the corner indefinite strength KappaCorUndef are calculated by the following equations (8), (9), and (10).
KappaCorEntry = FactorTRA x NormRhoEntry ... (8)
KappaCorExit = FactorTRA x NormRhoExit ... (9)
KappaCorUndef =
FactorTRA x NormRhoUndef ... (10)

In steps S14 and S15, the steady-state component is converted into the steady-state circular strength KappaCircle and the linear strength KappaStright.

First, in step S14, a linear component and a stationary circular component are calculated from the stationary component. That is, if the mean curvature (NormRhoAve) is zero (the turning radius is infinite), it is determined as a straight line. As shown in the following formula (11), the linear component NormStright and the steady-state circular component NormCircle have a relationship of "1" in total.
NormStright = 1-NormCircle ... (11)

In step S15, the steady-state circular component NormCircle and the linear component NormStright, which are the steady-state components, are converted into the steady-state circular strength KappaCircle and the linear strength KappaStright, respectively, by the following equations (12) and (13).
KappaCircle = FocusSTA x NormCircle ... (12)
KappaStright =
FocusSTA x NormStright ・ ・ ・ (13)

The corner inlet strength KappaCorEntry, the corner exit strength KappaCorExit, the corner indefinite strength KappaCorUndef, the steady-state circular strength KappaCircle, and the linear strength KappaStright are "1" in total. Further, in the following description, when the above five strengths are collectively referred to, they are simply referred to as strength Kappa.

Then, each intensity Kappa calculated by the turning intensity calculation unit 740 is output to the control start threshold value calculation unit 65 of the VDC / TCS controller 6.

[Control start threshold calculation unit and control start threshold calculation procedure]
As described above, in the VDC / TCS controller 6, the control start threshold value calculation unit 65 calculates the US suppression VDC control threshold value, the OS suppression VDC control threshold value, and the TCS control threshold value as the control start threshold value based on the turning strength. The calculation of the control start threshold value according to the turning strength in the control start threshold value calculation unit 65 will be described below.

The control start threshold value calculation unit 65 sets the control start threshold value based on the maximum value of each strength Kappa of the turning strength. The control start threshold is a standard value (conventional threshold) set in advance according to the road friction coefficient and the vehicle speed, and a control start promotion value that is relatively easy to start control (shallow) than this standard value. , It is possible to set a control start limit value that is (deeper) more difficult to control intervention than the standard value. The above-mentioned standard value, intervention promotion value, and control start limit value are calculated for each of the US suppression VDC control threshold value, the OS suppression VDC control threshold value, and the TCS control threshold value.

Further, the control start threshold value calculation unit 65 calculates the control start threshold value based on the intensity of the maximum value of each intensity Kappa. As described above, each intensity Kappa is calculated as a value that totals "1". Therefore, as the value of a certain intensity of each intensity Kappa increases, the value of the other intensity decreases. For example, when the target locus is on a straight road, the value of the straight line strength is high and the other values are low. Therefore, each strength Kappa has a maximum value according to the traveling situation. Therefore, the control start threshold value calculation unit 65 calculates the control start threshold value based on the intensity of the maximum value of each intensity Kappa.

Specifically, when the maximum value of each intensity is the maximum value other than the curve entrance intensity and the curve exit intensity, the control start threshold value calculation unit 65 sets the control start / entry threshold value as a standard value.

On the other hand, when either the curve entrance strength or the curve exit strength is the maximum value, the control start threshold value calculation unit 65 sets the control start threshold value to either the control promotion threshold value or the control limit threshold value.

The setting of the US suppression VDC control threshold value, the OS suppression VDC control threshold value, and the TCS control threshold value, which are the control start threshold values based on the curve entrance strength and the curve exit strength, will be described below.

First, the US suppression VDC control threshold value and the OS suppression VDC control start threshold value will be described. FIG. 7 is a threshold characteristic diagram showing the relationship between the US suppression VDC control threshold value and the OS suppression VDC control start threshold value, and the curve entrance strength and the curve exit strength.

As shown in FIG. 7, the OS suppression VDC control start threshold value is set to a value larger (difficult to start) as the corner inlet strength is higher and smaller (easier to start) as the corner inlet strength is lower, depending on the corner inlet strength. .. Further, since the corner inlet strength has a relationship that one increases in inverse proportion to the corner outlet strength and the other decreases, the OS suppression VDC control start threshold value increases as the corner outlet strength decreases according to the corner exit strength ( (It is difficult to start), and the higher the corner exit strength, the smaller (easier to start) the value.

On the other hand, the US suppression VDC control start threshold value is set to be larger (difficult to start) as the corner outlet strength is higher and smaller (easier to start) as the corner outlet strength is lower, depending on the corner outlet strength. Further, the corner outlet strength is inversely proportional to the corner inlet strength, and when one increases, the other decreases. Therefore, the US suppression VDC control start threshold value decreases as the corner inlet strength increases according to the corner inlet strength. (Easy to start), the lower the corner entrance strength, the larger (difficult to start) the value.

As described above, the control start threshold value calculation unit 65 is set based on the maximum value of the turning intensity. Therefore, when the corner inlet strength is the maximum value in each strength Kappa, the OS suppression VDC control value is set to a value higher than the standard value (difficult to start), while the US suppression VDC control value is set to a value higher than the standard value. Set to a low (easy to start) value. Further, in this case, the OS suppression VDC control start threshold value is set by multiplying the standard value by a coefficient larger than 1 according to the corner entrance strength, and the standard value of the US suppression VDC control start threshold value is set according to the corner entrance strength. Multiply by a coefficient less than 1 to set. The coefficient may be set by associating the horizontal axis of FIG. 7 with the coefficient, for example. For example, in the case of the corner entrance strength at the intersection of the OS suppression VDC control start threshold value and the US suppression VDC control start threshold value, the coefficient is set to "1", and the coefficient is determined according to the magnitude of the difference from the value at this intersection. Can be done.

When the corner exit strength is the maximum value among the strengths of Kappa, the US suppression VDC control threshold value is set to a value larger than the standard value, while the OS suppression VDC control threshold value is set to a value smaller than the standard value. .. In this case as well, the standard value of the US suppression VDC control value is multiplied by a coefficient larger than 1 according to the corner exit strength, and the OS suppression VDC control threshold value is multiplied by a coefficient smaller than 1 according to the corner exit strength. ..

Therefore, the VDC / TCS controller 6 sets the OS suppression VDC control start threshold value for suppressing the OS state of the own vehicle to the steady state when the vehicle is traveling at the corner entrance (for example, when the corner entrance strength is KCEntry shown in FIG. 7). The control start limit value, which is a value that is more difficult to execute than, is used. On the other hand, the US suppression VDC control start threshold value for suppressing the US state of the own vehicle is a control start promotion value which is a value that is easier to execute than the steady state.

That is, at the corner entrance, it is easier to suppress the tendency of the own vehicle to move toward the outside of the turning circle than in the case of the standard value, and it is easier to drive the vehicle along the turning circle. Further, when traveling at the corner entrance, it is made easier to turn by allowing the own vehicle to have an OS tendency, that is, a tendency toward the inside of the turning circle.

Further, the VDC / TCS controller 6 sets the US suppression VDC control start threshold value for suppressing the US state of the own vehicle to the steady state when the vehicle is traveling at the corner exit (for example, when the corner exit strength is KCExit1 shown in FIG. 7). The control start limit value is set to a value that is more difficult to execute than. On the other hand, the OS suppression VDC control start threshold value for suppressing the OS state of the own vehicle is a control start promotion value which is a value that is easier to execute than the steady state.

That is, when traveling at the corner exit, the own vehicle is allowed to tend to be in the US, so that smooth acceleration is possible. In addition, when driving at the corner exit, it suppresses the tendency of the own vehicle to become OS, and suppresses the own vehicle from facing the inside of the turn, so that the vehicle does not easily collapse from the posture facing the direction of travel of the road and becomes a turning circle. Make it easier to drive along.

Next, the setting of the TCS control start threshold value will be described.
The TCS control start threshold value differs depending on whether the vehicle is front-wheel drive (hereinafter referred to as FWD) or rear-wheel drive (hereinafter referred to as RWD). Therefore, the VDC / TCS controller 6 is shared by the FWD vehicle and the RWD vehicle, and the method of setting the TCS control threshold value in the control start threshold value calculation unit 65 is set in advance according to the FWD vehicle and the RWD vehicle. ..

<For FWD vehicles>
First, a case where the own vehicle is an FWD vehicle will be described as an example.
The TCS control start threshold value is the standard value and the shallowest value that is smaller than the standard value and is the easiest to start, depending on the magnitude of the corner entrance strength when the corner entrance strength is the maximum value among each strength Kappa. The stronger the corner entrance strength, the closer to the shallowest value. Specifically, the value is obtained by multiplying the standard value by a coefficient smaller than "1" according to the corner entrance strength. The corner entrance strength used here is a value equal to or higher than the corner entrance strength at the intersection of the TCS control start threshold value of the FWD and the TCS start threshold value of the RWD in FIG.

On the other hand, when the corner exit intensity is the maximum value in each intensity Kappa, the TCS control start threshold value is set between the standard value and the deepest value which is larger than the standard value and difficult to start control. The higher the strength, the closer to the deepest value. Specifically, the value is obtained by multiplying the standard value by a coefficient larger than "1" according to the corner outlet strength. The corner exit strength used here is a value equal to or higher than the corner exit strength at the intersection of the TCS control start threshold value of the FWD and the TCS start threshold value of the RWD in FIG. Further, as shown in FIG. 8, the TCS control start threshold value for FWD may be continuously changed between the deepest value and the shallowest value according to either the corner inlet strength or the corner exit strength. Good.

The standard value may be a preset value or a value corresponding to the estimated road surface friction coefficient.

Therefore, in the case of an FWD vehicle, when traveling at the corner entrance, it is easy to start TCS control and a turning force is secured. As a result, when traveling at the corner entrance, the own vehicle can be more reliably traveled along the target trajectory.

On the other hand, in the FWD vehicle, when traveling at the corner exit, it is difficult to intervene by TCS control, the own vehicle is allowed to tend to understeer, and the direction facing the direction of travel at the corner exit, which is the steering direction of the front wheels. It is possible to easily secure the driving force to. This enables smooth acceleration after turning.

<For RWD vehicles>
When the own vehicle is an RWD vehicle and the corner entrance strength is the maximum value in each strength Kappa, the TCS control start threshold value is set to the standard value and larger than the standard value according to the magnitude of the corner entrance strength. The stronger the corner entrance strength, the closer to the deepest value, which is the value that is the most difficult to start. Specifically, the value is obtained by multiplying the standard value by a coefficient larger than "1" according to the corner entrance strength. The corner entrance strength used here is a value equal to or higher than the corner entrance strength at the intersection of the TCS control start threshold value of the FWD and the TCS start threshold value of the RWD in FIG.

On the other hand, when the corner exit strength is the maximum value in each strength Kappa, the TCS control start threshold value is set between the standard value and the shallowest value which is smaller than the standard value and is the easiest value to start. The higher the corner exit strength, the closer to the shallowest value. Specifically, the value is obtained by multiplying the standard value by a coefficient smaller than "1" according to the corner entrance strength. The corner exit strength used here is a value equal to or higher than the corner exit strength at the intersection of the TCS control start threshold value of the FWD and the TCS start threshold value of the RWD in FIG. Further, as shown in FIG. 8, the TCS control start threshold value for RWD may be continuously changed between the deepest value and the shallowest value according to either the corner inlet strength or the corner outlet strength. Good.

Therefore, in the case of an RWD vehicle, it is difficult to start TCS control when traveling at the corner entrance, allowing the OS to tend to occur, and it is easy to drive the own vehicle from the corner entrance toward the middle corner along the target trajectory. can do.

On the other hand, in RWD vehicles, it is easy to start TCS control when driving at the corner exit, suppresses the own vehicle from becoming OS-prone due to excessive driving force, and is positive in the direction of travel at the corner exit, which is the steering direction of the front wheels. Propulsive force in the opposite direction can be secured. This enables smooth acceleration after turning.

(Operation example of the first embodiment)
First, an example in which control intervention by VDC control is performed during automatic operation control will be described.
FIG. 9 shows an execution example of VDC control during each running of an automatic driving vehicle AD equipped with a running support device that executes the running support method of the first embodiment and a comparative example that does not carry out the running support method of the present disclosure. Is shown. In the comparative example, standard values are always used as the OS suppression VDC control start threshold value and the US suppression VDC control start threshold value.

In the figure, the running state determination result by the running state determination unit 700 is shown in the second stage from the top. This running state is based on the maximum value of each strength Kappa calculated by the turning strength calculation unit 740. The determination results are in the order of steady circle running (Circle), indefinite turning running (CornerUndefined), corner exit running (CornerExit), corner entrance running (CornerEntry), and steady circle running (Circle).

The third row from the top shows the time zone in which the control intervention by VDC control was performed in the comparative example. In this comparative example, OS suppression VDC control (OS1) is executed during indefinite turning (CornerUndefined). After that, the US suppression VDC control (US1) is executed when the corner exit travels (Corner Exit), and the second US suppression VDC control (US1) is executed when the corner exit travels (Corner Entry). Then, the second OS suppression VDC control is executed during steady circle running (Circle).

On the other hand, the fourth row from the top shows the execution time zone of the control intervention of VDC control according to the first embodiment. In the first embodiment, the US suppression VDC control (US1) is not executed when the vehicle exits the corner (CornerExit). That is, in the first embodiment, in the case of the RWD vehicle, the US suppression VDC control start threshold value is set to the control limit threshold value at the corner exit. For this reason, it becomes difficult to start the US suppression VDC control, the US state is allowed to some extent, the own vehicle is made to face the traveling direction of the corner exit, and smooth acceleration is possible.

Further, in the case of the first embodiment, the US suppression VDC control (US2b) is started at the start timing (t1) earlier than the start timing (t01) of the comparative example at the time of the subsequent corner entry traveling (CornerEntry). There is. That is, in the first embodiment, the US suppression VDC control start threshold value is set to the control promotion value at the corner entrance to facilitate the start of the US suppression VDC control. Therefore, it is possible to prevent the own vehicle from entering the US state in which the vehicle moves outside the turning circle of the target locus at an early stage, and to reliably travel along the target locus.

Further, although not shown, in the first embodiment, regarding the OS suppression VDC control, when the own vehicle tends to be OS when traveling at the corner exit (Corner Exit), the OS is suppressed earlier than the comparative example. Perform VDC control.

Therefore, at the corner exit, it is possible to surely suppress that the OS tendency of the own vehicle becomes strong and deviates from the target trajectory.

On the other hand, when traveling at the corner entrance (CornerEntry), even if the own vehicle tends to be OS, it is more difficult to execute the OS suppression VDC control than in the comparative example. Therefore, when traveling at the corner entrance, it is possible to secure the turning force of the own vehicle and surely prevent the vehicle from deviating to the outside of the target trajectory.

Next, an example in which control intervention by TCS control is performed during automatic driving control will be described.
FIG. 10 shows an execution example of TCS control during traveling by the automatic driving vehicle AD of the RWD equipped with the traveling support device that executes the traveling support method of the first embodiment.

Similar to FIG. 9, the third stage from the top shows an operation example of the comparative example, and the fourth stage from the top shows an operation example of the first embodiment. Further, the comparative example is an example in which only the standard value is used as the TCS control start threshold value.

In the case of the comparative example, the first TCS control (TCS1) is executed when the corner entry travels (CornerEntry), and the second TCS control (TCS2) is executed during the subsequent steady circle travel (Circle).

On the other hand, in the case of the first embodiment applied to the RWD vehicle, the TCS control is not executed because the control limit value is used as the TCS control start threshold value at the time of corner entry traveling (CornerEntry). In this case, it is possible to secure a turning force when traveling at the corner entrance to enable traveling along the target trajectory, and to suppress a decrease in acceleration due to TCS control.

Although not shown, in the case of an RWD vehicle, since the control promotion value is used as the TCS control start threshold value when traveling at the corner exit (CornerEntry), the own vehicle tends to be OS due to excessive driving force when traveling at the corner exit. It can be suppressed. Therefore, it is possible to prevent the own vehicle from deviating from the target trajectory due to excessive OS tendency.

FIG. 11 shows an execution example of TCS control during traveling by the automatic driving vehicle AD of the FWD equipped with the traveling support device that executes the traveling support method of the first embodiment.
In FIG. 11, similarly to FIGS. 9 and 10, the third stage from the top shows an operation example of the comparative example, and the fourth stage from the top shows an operation example of the first embodiment. Further, the comparative example is an example in which only the standard value is used as the TCS control start threshold value.

In the case of the comparative example, the first TCS control (TCS1) is executed at the time of corner entry travel (CornerEntry), and the second TCS control (TCS1) is executed at the time of corner exit travel (CornerExit) after the subsequent steady circular travel state (Circle). TCS2) is being executed.

On the other hand, in the case of the first embodiment applied to the FWD vehicle, since the control promotion value is used as the TCS control start threshold value when traveling at the corner entrance (CornerEntry), the TCS control (TCS1) is executed at an earlier timing than the comparative example. To do. In this case, it is possible to reliably suppress the loss of the turning force (front wheel lateral force) due to the generation of an excessive driving force when traveling at the corner entrance.

On the other hand, the TCS control (TCS2) is not executed during the subsequent corner exit. That is, in the case of an FWD vehicle, since the control limit threshold value is used as the TCS control start threshold value at the corner exit, it is possible to secure the driving force of the front wheels and perform smooth acceleration along the target trajectory.

(Effect of Embodiment 1)
(1) Does the traveling support method of the first embodiment start TCS control, which is drive control of the own vehicle by the TCS system, based on the comparison between the drive wheel slip ratio of the own vehicle of the RWD and the TCS control start threshold value? This is a driving support method using a controller for determining whether or not the vehicle is used. The TCS system includes a VDC / TCS controller 6, an in-vehicle sensor 1 for inputting information, and a speed control actuator 41. Further, the controller includes an in-vehicle control unit 3 and a VDC / TCS controller 6.

Then, the controller (vehicle-mounted control unit 3 and VDC / TCS controller 6) executes the following first and second steps.
In the first step, it is determined whether the traveling of the own vehicle is a corner entrance traveling or a corner exit traveling based on the surrounding conditions detected by the sensor that detects the surrounding condition of the own vehicle.
In the second step, the TCS control start threshold value is set based on the determination result of whether the vehicle is traveling at the corner entrance or the corner exit. In the first embodiment, the surrounding condition refers to information for calculating a target locus, and includes map data capable of specifying a traveling route of the vehicle and information such as vehicles and obstacles around the own vehicle. Further, the detection of the surrounding condition is not limited to the one that calculates the target route because it is sufficient that at least the corner entrance and the exit on the traveling route of the own vehicle can be specified. Anything that can detect the presence or absence of a corner in the traveling direction of the own vehicle is sufficient.

Therefore, it is possible to set an appropriate TCS control start threshold value at the time of traveling at the corner entrance and at the time of traveling at the corner exit, and to perform TCS control as an appropriate traveling support according to the traveling situation.

(2) In the driving support method of the first embodiment, the controllers (vehicle-mounted control unit 3 and VDC / TCS controller 6) calculate a target trajectory for driving the own vehicle based on the surrounding conditions, and based on the target trajectory. It executes automatic driving control that controls the running of the own vehicle. The TCS control is executed by intervening in the automatic driving control of the own vehicle, and the TCS control start threshold value is set when the running of the own vehicle is automatically controlled based on the target trajectory.

That is, during the automatic driving control, the target track, which is the trajectory on which the own vehicle will travel, can be calculated in advance. Therefore, it is possible to determine in advance the characteristics of the vehicle according to the driving situation of the own vehicle based on the target trajectory on which the own vehicle is going to travel, and then execute appropriate driving support according to the driving situation to be driven from now on. it can.

In addition, during the implementation of automatic driving control, it is desirable to drive accurately according to road conditions such as lane keeping. In the present embodiment, during automatic driving control, a TCS control start threshold value is determined so that driving can be performed accurately according to the driving situation, and TCS control as appropriate driving support control according to the driving situation is performed to perform automatic driving. Control can be continued stably.

(3) In the driving support method of the first embodiment, the controller (vehicle-mounted control unit 3 and VDC / TCS controller 6) sets the TCS control start threshold value when traveling at the corner entrance to the TCS control starting threshold value used when traveling at the corner exit. Is also set to a value that makes it difficult to start TCS control.

Therefore, in the RWD vehicle, when traveling at the corner entrance, the start of TCS control is suppressed as compared with when traveling at the corner exit, and the own vehicle is allowed to tend to be OS due to the driving force of the rear wheels. This makes it easier for the own vehicle to turn, allows the vehicle to travel along the turning circle from the corner entrance, and makes it more reliable to travel along the target trajectory while maintaining the speed during automatic driving.

In the first embodiment, the TCS start threshold value is set to a value that makes it more difficult to start TCS control than the standard value used in the steady state when traveling at the corner entrance, and the turning performance and the acceleration property are ensured even when compared with the steady state. , Ensure running along the turning circle while maintaining speed.
On the other hand, when traveling at the corner exit, the OS tendency is suppressed as compared with when traveling at the corner entrance, and traveling along the turning circle at the corner exit is ensured.

(4) In the driving support method of the first embodiment, the controller (vehicle-mounted control unit 3 and VDC / TCS controller 6) sets the TCS control start threshold value to the TCS control more than the standard value used in the steady state when traveling at the corner exit. Set it to a value that is easy to start.

Therefore, when traveling at the corner exit, it is easy to start TCS control, it is possible to surely suppress the own vehicle from becoming an OS tendency at the corner exit, and it is possible to maintain a posture facing the road direction after exiting the corner. .. As a result, during automatic driving, traveling along the target trajectory is made more reliable.

(5) In the traveling support method of the first embodiment, the controller (vehicle-mounted control unit 3 and VDC / TCS controller 6) determines the corner entrance traveling as follows. First, the corner entrance strength KappaCorEntry, which indicates the strength of the corner entrance, is calculated based on the curvature of the target locus, and the corner entrance running is determined based on the corner entrance strength KappaCorEntry. Specifically, when the maximum value of each strength Kappa calculated as the turning strength is the corner entrance strength KappaCorEntry, it is determined to be the corner entrance.
Therefore, the corner entrance and the corner exit can be determined with high accuracy.

(6) In the traveling support method of the first embodiment, the controller (vehicle-mounted control unit 3 and VDC / TCS controller 6) determines the corner exit traveling as follows. First, the corner exit strength KappaCorExit indicating the strength of the corner exit strength is calculated based on the curvature of the target locus, and the corner exit running is determined based on the corner exit strength KappaCorExit. Specifically, when the corner exit strength KappaCorExit is the maximum value among the respective strength Kappa calculated as the turning strength, it is determined to be the corner exit.
Therefore, the corner exit can be determined with high accuracy.

(7) In the traveling support method of the first embodiment, the turning strength calculation unit 740 calculates the corner inlet strength KappaCorEntry and the corner exit strength KappaCorExit as values in which one becomes larger and the other becomes relatively smaller.
Further, the control start threshold value calculation unit 65 sets the TCS control start threshold value as a start limit threshold value (deepest value) at which TCS control is most difficult to start and a start propulsion threshold value (shallowest value) at which TCS control is most likely to start. Between, it is continuously changed according to the corner inlet strength and the corner outlet strength.

Therefore, by continuously setting the TCS control start threshold value corresponding to the magnitude of the corner inlet strength and the corner exit strength, the TCS control can be started smoothly. That is, when traveling at the corner entrance or at the corner exit, the vehicle posture changes from moment to moment by gradually strengthening the turning or gradually weakening the turning from the straight running state or the steady turning state up to that point. Therefore, the TCS control start threshold value can be changed from moment to moment to an appropriate value according to the vehicle posture that changes from moment to moment. As a result, the TCS control start timing can be optimized with high accuracy.

(8) The traveling support device of the first embodiment determines whether or not to start TCS control by the TCS system based on the comparison between the drive wheel slip ratio of the RWD own vehicle and the TCS control start threshold value. It is a traveling support device having a TCS controller 6.

Further, the automatic driving controller 31 of the vehicle-mounted control unit 3 as a controller includes a target locus generation unit 318 and a traveling state determination unit 700. The target locus generation unit 318 calculates a target locus for traveling the own vehicle based on the surrounding conditions. The traveling state determination unit 700 determines whether the traveling of the own vehicle on the calculated target trajectory is the corner entrance traveling or the corner exit traveling.
The VDC / TCS controller 6 as a controller includes a control start threshold value calculation unit 65 that sets a TCS control start threshold value based on a determination result of corner entrance travel or corner exit travel.

Therefore, it is possible to set an appropriate TCS control start threshold value at the time of traveling at the corner entrance and at the time of traveling at the corner exit, and to perform TCSC control as driving support according to the driving situation accurately.

(Other embodiments)
The traveling support device of another embodiment will be described below. In describing the other embodiments, common reference numerals will be given to the configurations common to the embodiments, and the description thereof will be omitted.

(Embodiment 2)
In the second embodiment, the method of setting each control start threshold value is different from that of the first embodiment.
That is, in the first embodiment, each control start threshold value is continuously set according to the magnitude of the corresponding intensity, but in the second embodiment, the predetermined control propulsion is performed according to the magnitude of the corresponding intensity. The threshold value, the predetermined control limit threshold value, and the standard value are selectively switched.

FIG. 12 shows a flow of processing for setting the VDC control start threshold value in the second embodiment.
In step S101, it is determined whether or not the corner entrance strength exceeds the preset threshold value change set value (CV1), and if it exceeds, the process proceeds to step S102, and if it does not exceed, the process proceeds to step S103. The threshold value change setting value (CV1) used in step S101 is arbitrarily set in the value of the corner entrance strength when the OS suppression VDC control start threshold value is within the control start limit value in FIG. 7, for example. A value (eg, KCEntry1 in FIG. 7) can be used.

In step S102, the US suppression VDC control start threshold is set to a control promotion value smaller (shallow) than the standard value, while the OS suppression VDC control start threshold is set to a preset control limit larger (deeper) than the standard value. Set to a value.

In step S103, it is determined whether or not the corner exit strength exceeds the preset threshold value change set value (CV2), and if it exceeds, the process proceeds to step S104, and if it does not exceed, the process proceeds to step S105. The threshold value change setting value (CV2) used in step S103 is, for example, arbitrarily set in the value of the corner exit intensity when the US suppression VDC control start threshold value is within the control start limit value in FIG. 7. Values (eg, KCExit in FIG. 7) can be used.

In step S104, the US suppression VDC control start threshold is set to a preset control limit value larger (deeper) than the standard value, while the OS suppression VDC control start threshold is set to a control promotion smaller (shallow) than the standard value. Set to a value. In step S105, the US suppression VDC control start threshold value and the OS suppression VDC control start threshold value are set to standard values.

Next, FIG. 13 shows the flow of processing for setting the TCS control threshold value in the case of an FWD vehicle.
In step S201, it is determined whether or not the corner entrance strength exceeds the preset threshold value change set value (CV1), and if it exceeds, the process proceeds to step S202, and if it does not exceed, the process proceeds to step S203. The threshold value change setting value (CV1) used in step S201 is, for example, a preset value in the value of the corner entrance strength when the TCS control start threshold value of the FWD is within the range of the control start promotion value in FIG. Is.

In step S202, the TCS control start threshold value is set to a control promotion value (THS) smaller (shallow) than the standard value. In step S203, it is determined whether or not the corner exit strength exceeds the preset threshold value change set value (CV2), and if it exceeds, the process proceeds to step S204, and if it does not exceed, the process proceeds to step S205. The threshold value change setting value (CV2) used in step S203 is, for example, a preset value in the value of the corner entrance strength when the TCS control start threshold value of the FWD is within the control start limit value in FIG. Is.

In step S204, the TCS control start threshold value is set to a preset control limit value (THL) larger (deeper) than the standard value. In step S205, the TCS control start threshold value is set to a standard value.

Next, FIG. 14 shows the flow of processing for setting the TCS control threshold value in the case of an RWD vehicle.
In step S301, it is determined whether or not the corner entrance strength exceeds the preset threshold value change set value (CV1), and if it exceeds, the process proceeds to step S302, and if it does not exceed, the process proceeds to step S303. The threshold value change setting value (CV2) used in step S301 is, for example, a preset value in the value of the corner entrance strength when the TCS control start threshold value of the RWD is within the control start limit value in FIG. Is.

In step S302, the TCS control start threshold value is set to a control limit value (THL) larger (deeper) than the standard value. In step S303, it is determined whether or not the corner exit strength exceeds the preset threshold value change set value (CV2), and if it exceeds, the process proceeds to step S304, and if it does not exceed, the process proceeds to step S305. The threshold value change setting value (CV2) used in step S303 is, for example, a preset value in the value of the corner exit intensity when the TCS control start threshold value of the RWD is within the range of the control start promotion value in FIG. Is.

In step S304, the TCS control start threshold value is set to a preset control promotion value (THS) smaller (shallow) than the standard value. In step S305, the TCS control start threshold value is set to a standard value.

(2-1) In the traveling support method of the second embodiment, the turning strength calculation unit 740 calculates the corner inlet strength KappaCorEntry and the corner exit strength KappaCorExit as values in which one becomes larger and the other becomes relatively smaller.
Further, the control start threshold value calculation unit 65 controls the TCS control start threshold value to make it easier to start the TCS control than the standard value used in the steady state when the corner exit strength is higher than the preset threshold value change setting value. Set as a limit value. Further, when the corner entrance strength is higher than the preset threshold value change set value, the control promotion value is set so that it is difficult to start the TCS control than the standard value used in the steady state.

Therefore, when driving at the corner entrance, it is more difficult to start TCS control than during steady driving, and while ensuring the driving force of the rear wheels, allowing the own vehicle to become OS-prone due to a decrease in lateral force, the speed is increased. It is possible to drive along the corner entrance on the target trajectory while maintaining the above.

In addition, when traveling at the corner exit, it is easier to start TCS control, secure the driving force of the rear wheels, suppress the spin tendency due to the generation of excessive driving force, and make it into the corner. It makes it possible to run along the road more reliably.
Even in the second embodiment, the effect of the above (5) is exhibited.

(Embodiment 3)
The third embodiment is a modification of the first embodiment, and as shown in FIG. 15, the vehicle motion controller 32 includes a VDC / TCS control unit 300. That is, in the first embodiment, the example in which the own vehicle is provided with the existing VDC system is shown, but in the third embodiment, the VDC control and the TCS control are executed by the vehicle motion controller 32 without using the existing VDC system. To do.

The VDC / TCS control unit 300 executes the same control as the VDC / TCS controller 6 shown in the first embodiment. That is, the VDC / TCS control unit 300 sets the VDC control start threshold value and the TCS control start threshold value to values according to the traveling state based on the vehicle speed, the road surface friction coefficient, etc. obtained from the in-vehicle sensor 1 and the turning strength. However, it is possible to provide appropriate driving support.

Therefore, even in the third embodiment, the effects described in (1) to (11) above can be obtained.

The traveling support method and the traveling support device of the present disclosure have been described based on the embodiment, but the specific configuration is not limited to this embodiment, and the gist of each claim in the claims is described. Design changes and additions are permissible as long as they do not deviate.

In the first embodiment, in the first embodiment, an example of determining whether the vehicle is traveling at the corner entrance or the corner exit is determined based on the turning strength obtained from the curvature of the target locus. Not limited. For example, it may be determined whether the traveling state of the own vehicle is corner entrance traveling or corner exit traveling based on the map data and the position of the own vehicle by the GPS function. Such a determination can be used when applied to a vehicle that does not calculate a target trajectory without performing automatic driving control. Further, in this case, it is preferable to determine immediately before the corner entrance travel and the corner exit travel, and appropriately set the VDC control start threshold value at the corner entrance travel and the corner exit travel.

Further, in the embodiment, in obtaining the corner inlet strength and the corner exit strength, the turning strength is calculated as a value in which the total value of the respective strengths is "1", but the present invention is not limited to this, and the point is the curvature. It may be possible to determine whether it is a corner entrance or a corner exit based on. As described above, in the distribution of curvature, the section where the curvature increases indicates the corner entrance, and the section where the curvature decreases indicates the corner exit. Therefore, the corner inlet strength and the corner exit strength may be calculated from the increasing tendency and decreasing tendency of such a distribution. Further, in the first embodiment, when setting each control start threshold value, an example of setting based on either the corner inlet strength or the corner exit strength is shown, but the corner inlet and the corner exit which are the reference of this setting are shown. The strength can be replaced. For example, although the example in which the corner inlet strength is used when setting the OS suppression VDC control start threshold value to the control start limit value is shown, it is also possible to set the OS suppression VDC control start threshold value based on the corner exit strength. Similarly, in steps S101, S201, and S301 of the second embodiment, instead of determining whether the corner inlet strength is larger than the threshold change set value, it is determined whether the corner exit strength is smaller than the threshold change set value. It is also possible. The same can be said for steps S103, S203, and S303.
Further, in the embodiment, the slip ratio is shown as a value indicating the behavior of the own vehicle to be compared with the TCS control start threshold value, but the slip ratio is not limited to this, and a value in consideration of the skid angle may be used.

Further, in the second embodiment, only one type of threshold value change setting value to be compared with the corner entrance strength is shown, but the present invention is not limited to this, and a plurality of steps of threshold value change setting value may be used. The same applies to the threshold value change setting value to be compared with the corner exit strength. When the threshold value change setting value of a plurality of stages is used, the VDC control start threshold value can also be set stepwise according to the magnitude of the threshold value change setting value.

Further, in the second embodiment, the TCS control start threshold value is set based on each of the corner inlet strength and the corner exit strength, but the present invention is not limited to this, and the TCS control start threshold value may be set based on either one. ..

Further, in the embodiment, the VDC / TCS controller is shown as the configuration for executing the TCS control, but the configuration for executing the VDC control and the configuration for executing the TCS control may be separately configured.

1 In-vehicle sensor 2 Navigation device 3 In-vehicle control unit (controller)
4 Actuator 6 VDC / TCS controller (TCS system)
11 External sensor 12 GPS receiver 13 Internal sensor 41 Speed control actuator 41a TCS actuator (TCS system)
41b VDC actuator (TCS system)
61 Target yaw rate calculation unit 62 Actual yaw rate calculation unit 63 Yorate deviation calculation unit 64 Drive wheel slip ratio calculation unit 65 Control start threshold value calculation unit 66 US suppression VDC control command unit 67 OS suppression VDC control command unit 68 TCS control command unit 318 Target locus Generation unit 700 Running state determination unit 740 Turning strength calculation unit AD Self-driving vehicle KappaCorEntry Corner entrance strength KappaCorExit Corner exit strength

Claims (9)

Traveling using a controller that determines whether or not to start TCS control, which is the drive control of the own vehicle, by the TCS system based on the comparison between the value indicating the behavior of the own vehicle driven by the rear wheels and the TCS control start threshold value. It ’s a support method,
The controller
Based on the surrounding conditions detected by the sensor that detects the surrounding conditions of the own vehicle, it is determined whether the traveling of the own vehicle is corner entrance traveling or corner exit traveling.
A traveling support method for setting the TCS control start threshold value based on a determination result of traveling at the corner entrance or traveling at the corner exit. In the driving support method according to claim 1,
The controller
A target locus for driving the own vehicle is calculated based on the surrounding conditions, and the target locus is calculated.
Controlling the running of the own vehicle based on the target trajectory,
The TCS control is executed by intervening in the control of the running of the own vehicle, and the setting of the TCS control start threshold value is performed when the running of the own vehicle is controlled based on the target locus. Driving support method. In the driving support method according to claim 1 or 2.
In setting the TCS control start threshold value, the controller sets the TCS control start threshold value to a value that makes it more difficult to start the TCS control than the value used when the corner exit travels. Driving support method. In the driving support method according to any one of claims 1 to 3.
The controller sets the TCS control start threshold value, and when traveling at the corner exit, the controller sets the TCS control start threshold value to a value that makes it easier to start the TCS control than a value used in a steady state. .. In the driving support method according to any one of claims 1 to 4.
The controller
In determining the driving at the corner entrance
Based on the curvature of the target locus for driving the own vehicle calculated based on the surrounding conditions, the corner entrance strength indicating the strength of the corner entrance is calculated.
A traveling support method for determining the corner entrance traveling based on the corner entrance strength. In the driving support method according to claim 5,
The controller
In determining the driving at the corner exit
Based on the curvature of the target locus for driving the own vehicle calculated based on the surrounding conditions, the corner exit strength indicating the strength of the corner exit characteristic is calculated.
A traveling support method for determining the corner exit traveling based on the corner exit strength. In the driving support method according to claim 6,
The controller
The corner inlet strength and the corner outlet strength are calculated as values in which one becomes larger and the other becomes relatively smaller.
In setting the TCS control start threshold,
Among the TCS control start threshold values used when the corner exit strength is relatively high or the corner inlet strength is low, the start limit threshold value that makes it easier to start the TCS control and the start limit threshold value.
Between the start propulsion threshold that makes it most difficult to start the TCS control among the TCS start thresholds, which is used when the corner outlet strength is relatively low and the corner inlet strength is high.
A traveling support method that continuously changes according to the magnitude of at least one of the corner inlet strength and the corner exit strength. In the driving support method according to claim 6,
The controller
The corner inlet strength and the corner outlet strength are calculated as values in which one becomes larger and the other becomes relatively smaller.
In setting the TCS control start threshold,
When the corner exit strength is higher than the preset threshold value change setting value or the corner entrance strength is lower than the preset threshold value change setting value, the TCS control is started more than the standard value used in steady state. Set the value to make it easier
When the corner inlet strength is higher than the preset threshold value change setting value or the corner exit strength is lower than the preset threshold value change setting value, the TCS control is started more than the standard value used in steady state. A driving support method that makes it difficult to make a value. Traveling using a controller that determines whether or not to start TCS control, which is the drive control of the own vehicle, by the TCS system based on the comparison between the value indicating the behavior of the own vehicle driven by the rear wheels and the TCS control start threshold value. It ’s a support device,
The controller
Based on the surrounding conditions detected by the sensor that detects the surrounding conditions of the own vehicle, the traveling state determination unit that determines whether the traveling of the own vehicle is corner entrance traveling or corner exit traveling, and
A TCS control start threshold value setting unit that sets the TCS control start threshold value based on a determination result of whether the vehicle is traveling at the corner entrance or the corner exit.
A driving support device equipped with.

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