JP2020062990A - Parking assisting method and parking assisting device - Google Patents

Abstract

To reduce discomfort of an occupant to a speed of an own vehicle during parking assist.SOLUTION: A parking assisting method sets a parking route to a target parking position (S1), and assists parking of an own vehicle on the basis of the set parking route. Brain activity of an occupant is measured, and discomfort of the occupant to a speed change when the own vehicle travels along the parking route is detected on the basis of the brain activity (S6:Y). When a speed profile can be changed so as not to further deteriorate ride comfort (S8:Y), the speed profile for the own vehicle travelling along the parking route is changed (S9).SELECTED DRAWING: Figure 9

Description

  The present invention relates to a parking assistance method and a parking assistance device.

  In Patent Document 1, the target position of the vehicle at each time is set by the moving distance from the start point position to the end point position, the required time, and the physical quantity related to the movement of the vehicle, and the deviation between the target position and the actual position is set. A parking assistance system is described which controls a drive mechanism and a braking mechanism of a vehicle so as to be small.

JP, 2016-120896, A

The control device described in Patent Document 1 performs parking assist control based on a predetermined speed profile. For this reason, the occupant sometimes feels uncomfortable, for example, the movement of the vehicle traveling along the parking route is sluggish or the movement is suddenly felt.
It is an object of the present invention to reduce an occupant's uncomfortable feeling with respect to the speed of a host vehicle during parking assistance.

  According to an aspect of the present invention, there is provided a parking assistance method of setting a parking route to a target parking position and assisting the parking of the own vehicle based on the parking route. In the parking assistance method, the occupant's brain activity is measured, and the occupant's sense of discomfort due to speed changes when the vehicle is driven along the parking route is detected based on the brain activity. Change the speed profile along which the vehicle travels along.

ADVANTAGE OF THE INVENTION According to this invention, the occupant's uncomfortable feeling with respect to the speed of the own vehicle during parking assistance can be reduced.
The objects and advantages of the invention will be realized and attained by means of the elements and combinations pointed out in the appended claims. It should be understood that both the foregoing general description and the following detailed description are merely examples and explanations, and do not limit the present invention as claimed.

It is a block diagram which shows an example of the parking assistance apparatus which concerns on embodiment of this invention. It is a schematic diagram of an example of electrode arrangement of a living body information sensor. It is an explanatory view of an example of a speed profile set up by a profile setting part. It is a graph which shows an example of the waveform of an electroencephalogram. 6 is a graph for explaining an example of processing for detecting a feeling of strangeness. 8 is a graph for explaining another example of the process of detecting a feeling of strangeness. It is explanatory drawing of the example of a change of the speed profile which makes a speed change large. It is explanatory drawing of the example of a change of the speed profile which makes speed change small. It is explanatory drawing of the example of a change of the speed profile according to the intensity | strength of discomfort. It is a flowchart of an example of the parking assistance method. It is a flowchart of another example of the parking assistance method. It is a flow chart of an example of profile setting processing according to a surrounding environment.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
(Constitution)
The parking assistance device according to the embodiment of the present invention is mounted on, for example, a vehicle (hereinafter, the vehicle on which the parking assistance device according to the embodiment of the present invention is mounted is referred to as “own vehicle”).

Please refer to FIG. The parking assistance device 1 according to the embodiment of the present invention includes a surrounding sensor 2, a vehicle sensor 3, a biological information sensor (for example, a brain wave sensor) 4, an input device 5, a controller 6, and an actuator 7.
The controller 6, the ambient sensor 2, the vehicle sensor 3, the biological information sensor 4, and the actuator 7 can send and receive data and signals by wire or wirelessly using a controller area network (CAN) bus or the like.

  The surrounding sensor 2 is a sensor that detects the surrounding environment (surrounding condition) of the vehicle. The ambient sensor 2 can be composed of, for example, a camera, a radar, a communication device, or the like. A CCD camera or the like can be used as the camera, and may be a monocular camera or a stereo camera. The camera captures an image of the surrounding environment of the own vehicle, and the relative position between the obstacle and the own vehicle from the captured image, the distance between the obstacle and the own vehicle, the white line that divides the parking frame such as a parking lot, the curb, etc. The data of the surrounding environment of the vehicle is detected, and the data of the detected surrounding environment is output to the controller 6. The obstacles include vehicles other than the own vehicle (other vehicles), pedestrians, walls, columns, and the like.

  As the radar, for example, a millimeter wave radar, a laser radar, a laser range finder (LRF) or the like can be used. The radar detects data of the surrounding environment of the own vehicle including the relative position of the obstacle and the own vehicle, the distance between the obstacle and the own vehicle, and the relative speed of the obstacle and the own vehicle, and detects the detected surrounding environment. The data is output to the controller 6.

  The communication device receives the data of the surrounding environment such as the parking area and the parking area of the garage by performing the inter-vehicle communication between the own vehicle and the other vehicle or the road-vehicle communication between the own vehicle and the roadside device. Then, the received environment data is output to the controller 6. The type and number of the ambient sensors 2 are not particularly limited.

  The vehicle sensor 3 is a sensor that detects the current position of the host vehicle and the traveling state of the host vehicle. The vehicle sensor 3 can be composed of a global positioning system (GNSS) receiver, a vehicle speed sensor, an acceleration sensor, an angular velocity sensor, and the like. The GNSS receiver is a global positioning system (GPS) receiver or the like, receives radio waves from a plurality of navigation satellites to acquire the current position of the own vehicle, and outputs the acquired current position of the own vehicle to the controller 6. The controller 6 can collate the current position of the vehicle acquired by the GNSS receiver with the map data stored in the storage device of the controller 6 to acquire the current position of the vehicle on the map data.

  The vehicle speed sensor detects the wheel speed of the host vehicle, detects the vehicle speed from the detected wheel speed, and outputs the detected vehicle speed to the controller 6. The acceleration sensor detects the acceleration of the host vehicle in the front-rear direction and the vehicle width direction and outputs the detected acceleration to the controller 6. The angular velocity sensor detects the angular velocity of the host vehicle and outputs the detected angular velocity to the controller 6. The type and number of vehicle sensors 3 are not particularly limited.

The biological information sensor 4 measures the brain activity of an occupant (for example, a driver). The biological information sensor 4 is, for example, an electroencephalogram sensor, has a plurality of electrodes, and the plurality of electrodes are attached to the head of the occupant.
Please refer to FIG. For example, the plurality of electrodes of the biological information sensor 4 may be arranged on the occupant's crowns Fz, Fcz, Cz, and CPz related to the cognitive function according to the International 10-20 law. Note that the number and attachment positions of the plurality of electrodes are not particularly limited.

  Further, the method of attaching the plurality of electrodes of the biological information sensor 4 to the head is not particularly limited, but may be composed of, for example, a wearable electrode cap or band provided with the plurality of electrodes. The biological information sensor 4 detects data of the electroencephalogram (brain activity) of the occupant and outputs the detected electroencephalogram data to the controller 6.

  Please refer to FIG. The input device 5 receives an instruction from the occupant and outputs instruction information of the occupant to the controller 6. As the input device 5, for example, a voice input device such as a microphone, a lever, a switch, a touch panel, or the like can be used.

The controller 6 is a processing circuit such as an electronic control unit (ECU) that performs arithmetic logic operation of processing required for the operation performed by the parking assistance device according to the embodiment of the present invention. For example, a processor, a storage device, and an input / output interface. May be provided.
The processor may correspond to a microprocessor equivalent to an arithmetic and logic unit (ALU), a control circuit (control unit), a central processing unit (CPU) including various registers, and the like.

  The storage device built in or attached to the controller 6 includes a semiconductor memory, a disk medium, or the like, and may include a storage medium such as a register, a cache memory, and a ROM and a RAM used as a main storage device. For example, the processor may execute a program (parking assistance program) that is stored in advance in the storage device and indicates a series of processes necessary for the operation of the parking assistance device according to the embodiment of the present invention.

The controller 6 functionally or physically implements logical blocks such as the parking position detection unit 11, the parking route setting unit 12, the profile setting unit 13, the discomfort detection unit 14, the profile changing unit 15, the vehicle control unit 16, and the learning unit 17. Prepared as a hardware resource.
These logic blocks may be functionally configured by a general-purpose semiconductor integrated circuit and software, or physically configured by a programmable logic device (PLD) such as a field programmable gate array (FPGA). May be.

In addition, the parking position detection unit 11, the parking route setting unit 12, the profile setting unit 13, the discomfort detection unit 14, the profile changing unit 15, the vehicle control unit 16, the learning unit 17, and the like that configure the controller 6 are a single piece of hardware. Or may be configured by separate hardware.
For example, the controller 6 can be configured by a car navigation system such as an in-vehicle infotainment (IVI) system and a driving support system such as an advanced driving support system (ADAS).

The controller 6 sets a parking route leading to the target parking position and a speed profile that causes the vehicle to travel along the parking route, and assists parking of the vehicle based on the parking route and the speed profile. For example, the controller 6 controls the actuator 7 so that the host vehicle travels along the parking route according to the speed profile.
At this time, the controller 6 detects, based on the occupant's brain activity measured by the biometric information sensor 4, an occupant's discomfort with respect to a change in speed when the vehicle travels along the parking route. When the uncomfortable feeling of the occupant is detected, the controller 6 changes the speed profile.

  The actuator 7 controls the traveling of the own vehicle according to the control signal from the controller 6. The actuator 7 can be configured by an accelerator actuator, a brake actuator, or a steering actuator. The accelerator actuator is composed of, for example, a throttle valve and controls the accelerator opening of the host vehicle.

  The brake actuator is composed of, for example, a hydraulic circuit, and controls the braking operation of the brake of the host vehicle. The steering actuator is composed of, for example, a motor capable of transmitting torque to the steering shaft, and controls the steering amount of the steering shaft. The number and type of actuators 7 are not limited and can be used as appropriate.

Next, each function of the parking position detection unit 11, the parking route setting unit 12, the profile setting unit 13, the discomfort detection unit 14, the profile changing unit 15, the vehicle control unit 16, and the learning unit 17 of the controller 6 will be described.
The parking position detection unit 11 detects, as the target parking position, an area where the vehicle can be parked, such as a parking lot or a garage, based on the surrounding environment detected by the surrounding sensor 2.

The parking route setting unit 12 calculates a parking route from the initial position such as the current position of the own vehicle to the target parking position set by the parking position detecting unit 11 based on the surrounding environment detected by the surrounding sensor 2. To do.
The profile setting unit 13 sets an initial value of a speed profile that causes the vehicle to travel along the parking route set by the parking route setting unit 12. The velocity profile only needs to set at least the acceleration.

  The profile setting unit 13 sets an initial value of the target arrival time required for the host vehicle to reach the target parking position from the initial position according to the target distance from the initial position to the target parking position. The initial value of the target arrival time set by the profile setting unit 13 is referred to as “initial target arrival time to0”.

The profile setting unit 13 displays the time change of the position (distance), speed, acceleration, jerk (jerk, jerk) of the vehicle traveling from the initial position to the target parking position during the initial target arrival time to0. The time functions of the position (distance), speed, acceleration, and jerk of the host vehicle at each time are set so that the waveforms shown in the first to fourth stages of No. 3 are obtained.
The profile shown in FIG. 3 shows an example in which the target distance is normalized to 1 m and the target arrival time is normalized to 1 second.

For example, the time functions X (t), V (t), A (t), and J (t) of the position, speed, acceleration, and jerk of the host vehicle can be set as follows.
The position X (t) of the host vehicle can be set as a 7th-order polynomial function of time t as in the following expression (1). As a result, the velocity V (t), the acceleration A (t), and the jerk J (t) are the first-order differentials of the position X (t) with respect to the time t, as in the following equations (2) to (4). It can be set as a second derivative and a third derivative. In Expressions (1) to (4), c _{0 to} c ₇ are coefficients (constants).

Equations (1) to (4) are polynomial functions of degree 7 or less with respect to time t, and these equations include eight coefficients c _{0 to} c ₇ . The coefficients c _{0 to} c ₇ can be obtained by giving eight different constraint conditions (boundary conditions) according to the equations (1) to (4), whereby each function X (t), V (t). ), A (t), and J (t) can be set.

The constraint condition may be, for example, the use of position (distance), velocity, acceleration, and jerk at two different times. For example, it may be the position (distance), speed, acceleration, and jerk at the start time t _s and the end time t _e of the period for controlling the travel of the own vehicle.
Now, the position at the start time _{t s} (distance) X _(t s), the speed V _(t s), and acceleration A _(t s), and jerk J _{(t s),} the position at the end time _{t e} ( distance) X _(t e), the speed V _(t e), the acceleration a _(t e), and the jerk is represented J 8 pieces of expression for the _{(t e)} a matrix equation, the following equation (5) is obtained To be

Then, when the coefficients c _{0 to} c ₇ are obtained using the inverse matrix of the matrix in Expression (5), the position function X (t) is given by the following Expression (6).

In the above formula _{(6), x s = X} (t s), x e = X (t e), v s = V (t s), v e = V (t e), a s = A (t s ), A _e = A (t _e ), j _s = J (t _s ), j _e = J (t _e ).
Please refer to FIG. The profile setting unit 13 calculates the function X (t) based on the state of the host vehicle at the initial position and the target parking position, the target distance, and the initial target arrival time to0 as shown in the first stage of FIG. as the change in position of a vehicle, variables _x s in the above equation _{(6), x e, v} s, v e, a s, a e, j s, sets the _{j e,} and _{t e.}

Specifically, the profile setting unit 13 sets x _s = 0, x _e = target distance, v _s = v _e = a _s = a _e = j _s = j _e = 0, and t _e = to 0. , Obtain a time function X (t) of the position of the host vehicle.
The profile setting unit 13 sets the velocity profile by first-order differentiating the obtained function X (t) with respect to time t to obtain a velocity function V (t).

  Please refer to FIG. The vehicle control unit 16 controls the actuator 7 so that the own vehicle moves along the parking route set by the parking route setting unit 12 and parks at the target parking position according to the speed profile set by the profile setting unit 13. Output a control signal for For example, the vehicle control unit 16 may automatically control all of acceleration, steering, and braking, or may automatically control only steering and perform acceleration and braking manually.

The uncomfortableness detection unit 14 detects an uncomfortable feeling of the occupant with respect to a change in speed when the vehicle travels along the parking route, based on the occupant's brain activity measured by the biological information sensor 4.
For example, the uncomfortable feeling detection unit 14 detects the uncomfortable feeling generated during the period when the vehicle starts from the stopped state, as the uncomfortable feeling due to the speed change (for example, acceleration or jerk) of the vehicle during this period.

Here, the operation from the state where the own vehicle stops at the initial position to the start of traveling until the vehicle stops at the target parking position is referred to as “all parking operation”. For example, the discomfort detection unit 14 determines, as a period in which the host vehicle starts from the stopped state, when α% of all parking operations are completed from the parking start time (that is, the time when the vehicle starts traveling from the stopped state at the initial position). The sense of discomfort of the occupant during the period is detected.
The “time point when α% of all parking operations are completed” may be, for example, the time when α% of the initial target arrival time to0 has elapsed or the time when the vehicle travels α% of the target distance. The threshold value α may be, for example, about 25%.

Please refer to FIG. The discomfort detection unit 14 performs frequency analysis on the data of the occupant's electroencephalogram detected by the biological information sensor 4, and detects an event-related potential (ERP) that indicates a brain reaction that appears as a result of thought or recognition. The occurrence of discomfort for the occupant is detected.
For example, the occupant's electroencephalogram pattern when the occupant feels uncomfortable is stored in advance in the storage device of the controller 6, and the occupant's occupant is determined based on the degree of coincidence between the stored electroencephalogram pattern and the electroencephalogram pattern detected by the biological information sensor 4. The presence / absence of discomfort may be determined.

  For example, as shown in FIG. 4, the uncomfortableness detecting unit 14 detects N pieces of EEG signals at a predetermined time T1 (for example, 500 milliseconds) from time t1 to time t2 after the start of the turning operation of the vehicle along the parking route. , PN are extracted to generate a brain wave feature vector P = (p1, p2, ..., PN). As the feature amount, for example, a value sampled at regular intervals can be used.

  Please refer to FIG. 5A. The feature space map 20 is obtained by plotting the generated feature vector on the N-dimensional space. The hatched circular plot point P1 indicates a feature vector when the occupant does not feel uncomfortable, and the unhatched round plot point P2 indicates a feature vector when the occupant feels uncomfortable. .

The feature vector P1 when the occupant does not feel uncomfortable tends to concentrate in a certain area in the feature space. The feature vector P2 when the occupant feels uncomfortable also tends to concentrate in a certain area.
In the example of FIG. 5A, the feature vector P1 when the occupant does not feel discomfort is concentrated in the relatively upper left region D1, and the feature vector P2 when the occupant feels discomfort is relatively lower right. Are concentrated in the area D2.

The feature vector P1 can be obtained by plotting the feature vector P1 when the occupant does not feel uncomfortable and the feature vector P2 when the occupant feels in the feature space to create the feature space map 20. The discrimination area D1 and the discrimination area D2 that the feature vector P2 can take can be defined.
The discomfort detection unit 14 calculates a discrimination rate Rd1 in which it is determined that the current brain wave feature vector of the occupant exists in the determination area D1 and a determination rate Rd2 in which it is determined that the occupant's current brain wave characteristic vector exists in the determination area D2.

The discomfort detection unit 14 determines that the occupant does not feel discomfort when the discrimination rate Rd1 is larger than the discrimination rate Rd2. On the contrary, when the discrimination rate Rd2 is larger than the discrimination rate Rd1, the discomfort detection unit 14 determines that the occupant feels discomfort.
Further, for example, the discomfort detection unit 14 determines that the occupant feels a sense of discomfort when the ratio (Rd2 / Rd1) of the discrimination rates is equal to or higher than a predetermined threshold, and the ratio (Rd2 / Rd1) is less than the predetermined threshold. If it is, it may be determined that the occupant does not feel uncomfortable.
The discomfort detection unit 14 may detect the strength of the discomfort felt by the occupant based on the ratio (Rd2 / Rd1) of the discrimination rates. For example, the discomfort detection unit 14 may detect a stronger discomfort as the ratio (Rd2 / Rd1) is larger.

Further, by creating the feature space map 20, it is possible to define the discrimination plane 21 that divides the range that the feature vector P1 can take from the range that the feature vector P2 can take. The discriminant plane 21 can be defined using, for example, a linear discriminant method.
In the example of FIG. 5A, if the current characteristic vector of the occupant's electroencephalogram is located above the discrimination plane 21, the discomfort detection unit 14 determines that the occupant does not feel discomfort, and determines that the occupant is below the discrimination plane 21. If it is located, the discomfort detection unit 14 may determine that the occupant feels discomfort.

Please refer to FIG. 5B. The discomfort detection unit 14 calculates a distance Dc between the feature vector P of the current electroencephalogram of the occupant and the center of gravity C1 of the discrimination region D1, and a distance De between the feature vector P and the center of gravity C2 of the discrimination region D2. Good. The discomfort detection unit 14 determines that the occupant feels a sense of discomfort when the distance ratio (De / Dc) is greater than or equal to a predetermined threshold value, and determines that the distance ratio (De / Dc) is less than the predetermined threshold value. It may be determined that the occupant does not feel uncomfortable.
The discomfort detection unit 14 may detect the intensity of discomfort felt by the occupant based on the distance ratio (De / Dc). For example, the discomfort detection unit 14 may detect a stronger discomfort as the distance ratio (De / Dc) is larger.

When an uncomfortable feeling is detected during the period in which the host vehicle starts from the stopped state (for example, the period from the start of parking to the time when α% of all parking operations is completed), the profile changing unit 15 causes the profile setting unit to The speed profile set by 13 is changed. When the discomfort is not detected during the period when the host vehicle starts from the stopped state, the profile changing unit 15 maintains the current speed profile.
The vehicle control unit 16 controls the speed of the own vehicle according to the speed profile changed by the profile changing unit 15.

When the profile setting unit 13 sets a relatively slow speed profile, the profile changing unit 15 determines that the speed change of the host vehicle is small during the period when the host vehicle starts from the stopped state, and Determine if you feel something is wrong.
For example, in the speed profile set by the profile setting unit 13, the change in speed is relatively small during the period when the host vehicle starts from the stopped state (for example, the maximum value of acceleration or the maximum value of jerk is relatively small). In addition, when an uncomfortable feeling is detected for a relatively small speed change (for example, acceleration or jerk) smaller than the first predetermined value, it is determined that the occupant feels a strange feeling for the small speed change.

When it is determined that the occupant feels uncomfortable with the small speed change, the profile changing unit 15 causes the speed change to be larger (for example, the maximum acceleration value or the jerk maximum value may be increased). To) change the speed profile. The speed profile may simply set the acceleration / deceleration and the allowable speed range. It is possible to control the speed of the host vehicle within a permissible speed range with respect to the stop position.
For example, the profile changing unit 15 increases the speed change of the speed profile by changing the target arrival time.

Please refer to FIG. The solid curve in the second stage of FIG. 6 shows the speed profile set by the profile setting unit 13, and the broken curve shows the speed profile changed so that the speed change becomes larger.
The first stage of FIG. 6 shows the time change of the position of the host vehicle when acceleration / deceleration is performed according to the speed profile of the second stage of FIG. 6, and the third and fourth stages of FIG. The change in jerk over time is shown. The solid line curve shows the time change before the profile change, and the broken line curve shows the time change after the profile change.

For example, the profile changing unit 15 may change the speed profile after the change start time tst so that the speed change increases by reducing the target arrival time from the initial target arrival time to0 to to1.
The change start time tst may be, for example, a time at which α% of all parking operations are completed, or a time at which a feeling of strangeness is detected.

The profile changing unit 15 calculates the position x _s , the speed v _s , the acceleration a _s , and the jerk j _s at the start time t _s of the above formula (6) as the position, the speed, the acceleration, and the jerk at the change start time tst. change in the position x _e at the end time t _e, changed to the difference position (the distance) is subtracted from the target distance at change start time tst, the end time t _e, the change start time tst and the target arrival time to1 The speed profile after the change start time tst is calculated by changing the difference to the difference.

  At this time, the profile changing unit 15 may determine whether or not the speed profile can be changed so that the riding comfort is not deteriorated. For example, the profile changing unit 15 may determine whether or not the following conditions (A) to (D) are satisfied even if the target arrival time is changed by a predetermined changing step Δt.

(A) The number of inflection points of the changed speed profile is equal to the number of inflection points of the speed profile set by the profile setting unit 13.
(B) Do not pass the target position.
(C) The target arrival time after change does not exceed the range determined by the system.
(D) The smoothness of the velocity profile is not impaired (for example, jerk is not discontinuous).

The range in which the target arrival time can be changed while the speed profile after the change start time tst generated by the above equation (6) satisfies the conditions (A) to (D) changes depending on the change start time tst. This is because as the change start time tst is delayed, there is less room to change the speed profile, and the range in which the target arrival time can be changed is narrowed.
For example, the following Table 1 shows a range in which the target distance can be changed without changing the riding comfort (that is, satisfying the conditions (A) to (D)) while keeping the target arrival time.

The constant β is set within a condition defined by the system, for example, a range that does not exceed the upper limits of velocity, acceleration, and jerk.
Similar to Table 1, the range in which the target arrival time can be changed without impairing the riding comfort (that is, the conditions (A) to (D) are satisfied) while the target distance remains unchanged can be determined according to the change start time tst. .
The profile changing unit 15 determines that the speed profile can be changed so that the riding comfort is not deteriorated when the change amount of the target arrival time does not exceed the allowable range set according to the change start time tst. On the contrary, when the allowable range is exceeded, it is determined that the speed profile cannot be changed so that the riding comfort is not deteriorated.

The profile changing unit 15 changes the speed profile when the speed profile can be changed so that the riding comfort is not deteriorated, and does not change the speed profile when the speed profile cannot be changed so that the riding comfort is not deteriorated. Maintain speed profile.
The speed profile may be changed by limiting the amount of change in the target arrival time to the extent that the allowable range defined according to the change start time tst is not exceeded.

On the other hand, when the profile setting unit 13 sets a relatively fast speed profile, the profile changing unit 15 has a large change in the speed of the own vehicle during the period when the own vehicle starts from the stopped state. To determine whether the occupant feels uncomfortable.
For example, in the speed profile set by the profile setting unit 13, the change in speed is relatively large during the period when the host vehicle starts from the stopped state (for example, the maximum value of acceleration and the maximum value of jerk are relatively large). In addition, when an uncomfortable feeling is detected for a relatively large speed change (e.g., acceleration or jerk) equal to or greater than the second predetermined value, it is determined that the occupant feels uncomfortable due to the large speed change.

When it is determined that the occupant feels a sense of discomfort due to the large speed change, the profile changing unit 15 reduces the speed change (for example, decreases the maximum acceleration value or the maximum jerk value). To) change the speed profile.
For example, the profile changing unit 15 reduces the speed change of the speed profile by changing the target arrival time.

Please refer to FIG. The solid curve in the second row of FIG. 7 shows the speed profile set by the profile setting unit 13, and the broken curve shows the speed profile changed so that the speed change becomes smaller.
The first stage of FIG. 7 shows the time change of the position of the host vehicle when acceleration / deceleration is performed according to the speed profile of the second stage of FIG. 7, and the third and fourth stages of FIG. The change in jerk over time is shown. The solid line curve shows the time change before the profile change, and the broken line curve shows the time change after the profile change.

For example, the profile changing unit 15 may change the speed profile after the change start time tst so as to reduce the speed change by extending the target arrival time from the initial target arrival time to0 to to2.
The method for changing the profile is the same as when the discomfort for the small speed change is detected.

The profile changing unit 15 may determine whether or not the speed profile can be changed so that the riding comfort is not deteriorated. The profile changing unit 15 changes the speed profile when the speed profile can be changed so that the riding comfort is not deteriorated, and does not change the speed profile when the speed profile cannot be changed so that the riding comfort is not deteriorated. Maintain speed profile.
The profile changing unit 15 may change the speed profile by limiting the change amount of the target arrival time to the extent that the allowable range defined according to the change start time tst is not exceeded.

  The profile changing unit 15 may change the degree of changing the speed profile according to the detected strength of discomfort. For example, the velocity profile may be changed more when the sense of discomfort is stronger and smaller when the sense of discomfort is weaker.

Please refer to FIG. The second stage of FIG. 8 shows an example of changing the speed profile so that the speed change becomes smaller when the discomfort for the large speed change is detected. The solid line curve indicates the initial value of the speed profile set by the profile setting unit 13, the broken line indicates the speed profile obtained by extending the target arrival time by 1.2 times, and the dashed-dotted line indicates the target arrival time by 1.4 times. Figure 6 shows an extended velocity profile.
The first stage of FIG. 8 shows the time change of the position of the host vehicle when acceleration / deceleration is performed according to each of the speed profiles of the second stage of FIG. 8, and the third stage and the fourth stage of FIG. The time change of acceleration and jerk is shown.

For example, when the sense of discomfort is stronger, the profile changing unit 15 changes the speed profile after the change start time tst to the speed profile of the alternate long and short dash line in which the extension amount of the target arrival time is larger, and the sense of discomfort is detected. If is weaker, the extension amount of the target arrival time may be changed to a velocity profile with a smaller broken line.
Even when an uncomfortable feeling due to a small speed change is detected, the shortening amount of the target arrival time may be changed in accordance with the detected strength of the uncomfortable feeling. For example, when the sense of discomfort is stronger, the reduction amount of the target arrival time may be made larger, and when the sense of discomfort is weaker, the reduction amount of the target arrival time may be made smaller.

Please refer to FIG. The learning unit 17 associates the discomfort data detected by the discomfort detection unit 14 (for example, discomfort for a small speed change or discomfort for a large speed change) with the speed profile when the discomfort is detected. Then, the speed profile desired by the occupant is learned by storing it for each occupant.
When setting the initial value of the speed profile, the profile setting unit 13 changes the magnitude of the speed change of the speed profile based on the learning result by the learning unit 17.

For example, when an uncomfortable feeling for a small speed change is detected, the profile setting unit 13 shortens the initial target arrival time to0 of the speed profile stored in association with the uncomfortable feeling data, thereby further reducing the speed change. May set a large speed profile.
By repeating learning of discomfort data for a small speed change and shortening the initial target arrival time to0, it is possible to learn the lower limit of the speed change at which the occupant does not feel discomfort.

On the other hand, when a sense of discomfort due to a large speed change is detected, the profile setting unit 13 extends the initial target arrival time to0 of the speed profile stored in association with the discomfort data to further increase the speed. A velocity profile with a small change may be set.
By repeating the learning of the discomfort data for a large speed change and the extension of the initial target arrival time to0, the upper limit of the speed change at which the occupant does not feel the discomfort can be learned.

Further, the learning unit 17 may store data of the surrounding environment of the own vehicle when the discomfort is detected. By storing the data of the surrounding environment, the learning unit 17 learns the speed profile of the occupant, which is different depending on the surrounding environment.
The parameters of the surrounding environment include, for example, a target parking position and a target parking posture relative to the parking start position, forward parking or backward parking, a switching position and posture, a safety margin, and an arrangement of surrounding obstacles. May be included.

The occupant may select, for example, by operating the input device 5, the parameter of the environment data to be learned by the learning unit 17.
The profile setting unit 13 detects the surrounding environment of the parameter selected by the occupant from the surrounding environment data detected by the surrounding sensor 2. The profile setting unit 13 reads the uncomfortable data learned in association with the detected surrounding environment.
The profile setting unit 13 sets an initial value of the speed profile based on the read out discomfort data and the speed profile stored in association with the discomfort data.

(motion)
Next, the operation of the parking assistance device 1 will be described with reference to FIGS. 9, 10, and 11. FIG. 9 is a flowchart illustrating the operation of the parking assistance device 1 when the profile setting unit 13 sets a relatively slow speed profile.
In step S1, the parking position detector 11 detects the target parking position based on the surrounding environment detected by the surrounding sensor 2. The parking route setting unit 12 calculates a parking route from the initial position to the target parking position based on the surrounding environment detected by the surrounding sensor 2.

  In step S2, the profile setting unit 13 performs profile setting processing. In the profile setting process, the profile setting unit 13 sets the initial target arrival time to0 according to the target distance from the initial position to the target parking position. The profile setting unit 13 generates an initial value of a speed profile that causes the host vehicle to travel from the initial position to the target parking position during the initial target arrival time to0. In the example of FIG. 9, the parking position detection unit 11 generates a relatively slow speed profile in order to determine the lower limit of the speed change at which the occupant feels uncomfortable.

In step S3, the vehicle control unit 16 starts parking of the own vehicle so that the own vehicle moves along the parking route set by the parking route setting unit 12 according to the speed profile set by the profile setting unit 13.
In step S4, the profile changing unit 15 determines whether or not α% of all parking operations have been completed. When α% of all parking operations are completed (step S4: Y), the process proceeds to step S12. When α% of all parking operations are not completed (step S4: N), the process proceeds to step S5.

  In step S5, the profile changing unit 15 determines whether the speed change of the host vehicle is less than the first predetermined value. When the speed change of the host vehicle is less than the first predetermined value (step S5: Y), the process proceeds to step S6. When the speed change of the host vehicle is not less than the first predetermined value (step S5: N), the process proceeds to step S11.

  In step S6, the profile changing unit 15 determines whether or not the uncomfortable feeling detecting unit 14 detects the uncomfortable feeling of the occupant. When the discomfort is detected (step S6: Y), the process proceeds to step S7. If no discomfort is detected (step S6: N), the process proceeds to step S11.

  In step S7, the profile changing unit 15 determines whether the maximum speed and the maximum acceleration in the current speed profile are the upper limit values. When the maximum velocity and the maximum acceleration are the upper limit values (step S7: Y), the process proceeds to step S11. When the maximum velocity and the maximum acceleration are not the upper limit values (step S7: N), the process proceeds to step S8.

  In step S8, the profile changing unit 15 determines whether or not the speed profile can be changed so that the riding comfort is not deteriorated. When the speed profile can be changed so that the riding comfort is not deteriorated (step S8: Y), the process proceeds to step S9. When the speed profile cannot be changed so that the riding comfort is not deteriorated (step S8: N), the process proceeds to step S11.

In step S9, the profile changing unit 15 changes the speed profile so as to increase the speed change (for example, increase the maximum acceleration or the maximum jerk). For example, the profile changing unit 15 shortens the target arrival time and regenerates the speed profile after the change start time tst.
In step S10, the learning unit 17 learns the discomfort data detected by the discomfort detection unit 14 and the speed profile when the discomfort is detected. The learning unit 17 may also learn the data of the surrounding environment of the own vehicle when the discomfort is detected. After that, the process returns to step S4.

In step S11, the profile changing unit 15 maintains the current speed profile without changing the speed profile. After that, the process returns to step S4.
After α% of all the parking operations are completed (step S4: Y), the vehicle control unit 16 executes the remaining parking operations according to the speed profile set or changed immediately before in step S12. The process ends when the entire parking operation is completed.

FIG. 10 is a flowchart illustrating the operation of the parking assistance device 1 when the profile setting unit 13 sets a relatively fast speed profile.
In step S21, the parking position detector 11 calculates the parking route from the initial position to the target parking position.
In step S22, the profile setting unit 13 performs profile setting processing. In the example of FIG. 10, the parking position detection unit 11 generates a relatively fast speed profile in order to determine the upper limit of the speed change at which the occupant feels uncomfortable.

In step S23, the vehicle control unit 16 starts parking the own vehicle.
In step S24, the profile changing unit 15 determines whether or not α% of all parking operations have been completed. When α% of all parking operations are completed (step S24: Y), the process proceeds to step S32. If α% of all parking operations are not completed (step S24: N), the process proceeds to step S25.

  In step S25, the profile changing unit 15 determines whether or not the speed change of the host vehicle is equal to or more than the second predetermined value. When the speed change of the host vehicle is equal to or larger than the second predetermined value (step S25: Y), the process proceeds to step S26. If the speed change of the host vehicle is not equal to or more than the second predetermined value (step S25: N), the process proceeds to step S31.

  In step S26, the profile changing unit 15 determines whether or not the discomfort detection unit 14 detects the discomfort of the occupant. When the discomfort is detected (step S26: Y), the process proceeds to step S27. If no discomfort is detected (step S26: N), the process proceeds to step S31.

  In step S27, the profile changing unit 15 determines whether the maximum speed and the maximum acceleration in the current speed profile are the lower limit values. When the maximum velocity and the maximum acceleration are the lower limit values (step S27: Y), the process proceeds to step S31. When the maximum velocity and the maximum acceleration are not the lower limit values (step S27: N), the process proceeds to step S28.

  In step S28, the profile changing unit 15 determines whether or not the speed profile can be changed so that the riding comfort is not deteriorated. When the speed profile can be changed so that the riding comfort is not deteriorated (step S28: Y), the process proceeds to step S29. When the speed profile cannot be changed so that the riding comfort is not deteriorated (step S28: N), the process proceeds to step S31.

In step S29, the profile changing unit 15 changes the velocity profile so as to reduce the velocity change (for example, reduce the maximum acceleration or the maximum jerk). For example, the profile changing unit 15 extends the target arrival time and regenerates the speed profile after the change start time tst.
In step S30, the learning unit 17 learns the discomfort data detected by the discomfort detection unit 14 and the speed profile when the discomfort is detected. The learning unit 17 may also learn the data of the surrounding environment of the own vehicle when the discomfort is detected. After that, the process returns to step S24.

In step S31, the profile changing unit 15 maintains the current speed profile without changing the speed profile. After that, the process returns to step S24.
After α% of all the parking operations are completed (step S24: Y), the vehicle control unit 16 executes the remaining parking operations according to the speed profile set or changed immediately before in step S32. The process ends when the entire parking operation is completed.

FIG. 11 is a flowchart of an example of the profile setting process (step S2 of FIG. 9, step S22 of FIG. 10) by the profile setting unit 13 when the learning unit 17 is learning the data of the surrounding environment. The profile setting unit 13 sets the initial value of the speed profile according to the surrounding environment.
In step S41, the learning unit 17 receives the parameters of the surrounding environment selected by the occupant. The occupant may select the parameter of the surrounding environment by operating the input device 5, for example. The received parameters are used to select the surrounding environment stored in the learning unit 17 when the discomfort is detected.

In step S42, the profile setting unit 13 detects the surrounding environment of the parameter selected by the occupant from the surrounding environment data detected by the surrounding sensor 2.
In step S43, the profile setting unit 13 reads the uncomfortable data learned in association with the detected surrounding environment.

In step S43, the profile setting unit 13 sets the initial value of the speed profile based on the read out discomfort data and the speed profile stored in association with the discomfort data.
Specifically, the profile setting unit 13 determines whether the occupant feels a sense of discomfort for a small speed change or a large speed change based on the sensed discomfort data learned in association with the detected surrounding environment. To determine if the occupant felt uncomfortable.

When the occupant feels a sense of discomfort due to a small speed change, the profile setting unit 13 shortens the initial target arrival time to0 of the speed profile stored in association with the discomfort data to further improve the speed change. Sets a large speed profile.
When the occupant feels a sense of discomfort due to a large speed change, the profile setting unit 13 extends the initial target arrival time to0 of the speed profile stored in association with the discomfort data to further increase the speed change. Sets a small speed profile.

(Effects of the embodiment)
(1) The parking route setting unit 12 sets a parking route to reach the target parking position, and the vehicle control unit 16 supports parking of the own vehicle based on the parking route. The biological information sensor 4 measures the brain activity of the occupant. The uncomfortableness detecting unit 14 detects an uncomfortable feeling of an occupant with respect to a change in speed when the vehicle travels along the parking route based on brain activity. When an uncomfortable feeling is detected, the profile changing unit 15 changes the speed profile that causes the host vehicle to travel along the parking route.
Therefore, the speed profile can be changed based on the occupant's brain activity measured by the biometric information sensor 4 so that the occupant's discomfort with respect to the speed of the own vehicle during parking assistance is reduced. As a result, it is possible to approach the speed change of the vehicle preferred by the occupant during the operation of the parking assistance device 1 without additional operation by the occupant.

(2) The profile changing unit 15 changes the speed profile based on the occupant's discomfort with respect to the acceleration during the period when the vehicle starts from the stopped state.
As a result, immediately after starting the vehicle, the speed change of the vehicle preferred by the occupant can be approximated, and the frequency with which the occupant feels uncomfortable decreases. In addition, the period in which the occupant feels uncomfortable is shortened.

  (3) When an uncomfortable feeling that the occupant feels due to a small speed change is detected, the profile changing unit 15 changes the speed profile so that the speed change becomes larger. Accordingly, when the occupant feels that the speed change is small, the speed change can be increased so as to be the speed change of the vehicle preferred by the occupant.

  (4) When an uncomfortable feeling that the occupant feels due to a large speed change is detected, the profile changing unit 15 changes the speed profile so that the speed change becomes smaller. Accordingly, when the occupant feels that the speed change is large, the speed change can be reduced so that the speed change of the vehicle is preferred by the occupant.

(5) The learning unit 17 stores the detected discomfort data. The profile setting unit 13 sets a speed profile that causes the vehicle to travel along the parking route, based on the stored uncomfortable data.
As a result, each time the parking assistance device 1 is used, the initial value of the speed profile set by the profile setting unit 13 can be brought closer to the occupant's preference, so that the occupant feels no discomfort after the second time in the same parking scene. it can.

(6) The learning unit 17 stores the data of the surrounding environment of the vehicle when the occupant's discomfort is detected, and the profile setting unit 13 stores the data of the stored surrounding environment and the stored discomfort data. Set the speed profile to drive your vehicle.
As a result, since a speed profile suitable for the surrounding environment can be set, it is possible to reduce the occurrence of discomfort in a more complicated environment.

  DESCRIPTION OF SYMBOLS 1 ... Parking assistance device, 2 ... Surrounding sensor, 3 ... Vehicle sensor, 4 ... Biological information sensor, 5 ... Input device, 6 ... Controller, 7 ... Actuator, 11 ... Parking position detection part, 12 ... Parking path setting part, 13 ... profile setting section, 14 ... discomfort detection section, 15 ... profile changing section, 16 ... vehicle control section, 17 ... learning section

Claims (7)

A parking assistance method for setting a parking route to a target parking position, and assisting the parking of a vehicle based on the parking route,
Measure the occupant's brain activity,
Detecting an uncomfortable feeling of the occupant with respect to a speed change when traveling the own vehicle along the parking route based on the brain activity,
When the discomfort is detected, the speed profile that causes the vehicle to travel along the parking route is changed,
A parking assistance method characterized in that   The parking assistance method according to claim 1, wherein the speed profile is changed based on a feeling of discomfort of the occupant with respect to acceleration during a period in which the vehicle starts from a stopped state.   The parking assistance method according to claim 1, wherein, when a sense of discomfort felt by the occupant with respect to the small speed change is detected, the speed profile is changed so as to increase the speed change. .   4. The speed profile is changed so that the speed change becomes smaller when an uncomfortable feeling that the occupant feels due to the large speed change is detected. Parking assistance method described in paragraph. Storing the detected discomfort data,
The parking assistance method according to any one of claims 1 to 4, wherein a speed profile for causing the vehicle to travel along the parking route is set based on the stored uncomfortable data. Stores data of the surrounding environment of the own vehicle when the discomfort of the occupant is detected,
The parking assistance method according to claim 5, wherein a speed profile for causing the vehicle to travel is set based on the stored data of the surrounding environment and the stored data of discomfort. A parking assistance device that sets a parking route to a target parking position, and assists parking of a vehicle based on the parking route,
A sensor that measures the brain activity of the occupant,
Based on the brain activity measured by the sensor, the sense of discomfort of the occupant with respect to the speed change when the vehicle is traveling along the parking route is detected, and when the sense of discomfort is detected, along the parking route A controller that changes the speed profile that causes the vehicle to travel.
A parking assistance device comprising:

Images