JP7183769B2 - Driving support device - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a driving support device that calculates the course of a vehicle and determines whether or not there is a collision between the course of the vehicle and objects around the vehicle.

Japanese Patent Laid-Open No. 2004-100002 discloses a driving support process that determines whether or not there is a possibility of a collision between an object around the own vehicle and the own vehicle, and avoids or mitigates the collision with the object when it is determined that the object will collide with the own vehicle. to the own vehicle is disclosed. When the driving support device determines that there is a possibility of collision between the own vehicle and the object, as driving support processing, the driving support device warns the driver and increases the braking force of the brake.

There is also a driving support device that calculates the course of the own vehicle based on the yaw rate of the own vehicle and determines the possibility of collision between the own vehicle and the object based on the course of the own vehicle and the position of the object. In such a driving assistance device, for example, when it is determined that the position of the object is located on the course of the own vehicle, it is determined that there is a possibility of collision between the own vehicle and the object.

JP 2017-114429 A

In a driving support device that determines the possibility of a collision between the vehicle and an object using the course of the own vehicle based on the yaw rate of the own vehicle, the calculated course of the own vehicle changes as the yaw rate changes. Therefore, when the yaw rate changes greatly while the vehicle is traveling, even if an object is positioned on the currently calculated course of the vehicle, it is conceivable that the object may not be positioned on the actual course of the vehicle. In this case, there are cases where the driving support processing is actually performed for an object with a low collision probability, and there is concern that unnecessary driving support processing will be performed on the own vehicle.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a driving assistance device capable of suppressing unnecessary operation of driving assistance processing for the own vehicle.

In order to solve the above problems, in the present invention, the course of the own vehicle is calculated based on the yaw rate of the own vehicle, and based on the possibility of collision with an object in a target area including the course of the own vehicle, collision with the object is determined. The present invention relates to a driving support device that implements avoidance or mitigation driving support processing. The driving support device includes a reliability calculation unit that calculates a reliability indicating the certainty of the course of the vehicle based on a steering parameter including at least one of a yaw rate change rate, which is the time change rate of the yaw rate, and a steering speed. and a restriction unit that restricts execution of the driving assistance process based on the calculated reliability.

In the above configuration, the reliability indicating the certainty of the course of the vehicle is calculated based on the steering parameter, which is at least one of the rate of change of the yaw rate and the steering speed. Then, the driving support process is restricted according to the calculated reliability. As a result, the driving support processing is restricted according to the certainty of the course of the vehicle, so unnecessary operation of the driving support processing can be suppressed.

The block diagram of a driving assistance device. The figure explaining the operation|movement area set ahead of the own vehicle. The figure explaining the change of a self-vehicle course. The figure explaining an update amount map. The figure explaining the change of the operating condition based on reliability. 4 is a flowchart for explaining the procedure of PCS control; 4 is a timing chart for explaining restrictions on PCS control according to the present embodiment; The figure explaining the update amount map which concerns on a modification. 9 is a flowchart for explaining the procedure of PCS control according to the second embodiment;

(First embodiment)
An embodiment of a driving assistance device will be described below with reference to the drawings. The driving support device according to the present embodiment is mounted on a vehicle, and when it is determined that there is a possibility of collision between the vehicle and an object around the vehicle, the collision between the vehicle and the object is avoided or mitigated. PCS control (pre-crash safety control) is performed on the own vehicle. In the present embodiment, PCS control corresponds to driving support processing.

In FIG. 1, an ECU 10, which is a driving assistance device, is a computer including a CPU, ROM, RAM, I/O, and the like. The ECU 10 implements each function by the CPU executing a program installed in the ROM.

A millimeter wave radar 21 and an image sensor 22 are connected to the ECU 10 as sensor devices for detecting the position of an object positioned in front of the vehicle.

The millimeter wave radar 21, for example, transmits a high frequency signal in the millimeter wave band and receives a reflected wave generated by the millimeter wave being reflected by the object, thereby detecting the position of the object around the vehicle as the first position. do. The millimeter-wave radar 21 is provided at the front end of the own vehicle, and defines an area within a predetermined detection angle as a detection area capable of detecting an object.

The image sensor 22 includes an imaging unit that acquires a captured image in front of the vehicle, and detects the position of an object included in the acquired captured image as a second position. The image sensor 22 is mounted at a predetermined height in the center of the vehicle in the vehicle width direction, and acquires an area extending in a predetermined angle range toward the front of the vehicle as a captured image. For example, the image sensor 22 extracts feature points of an object in the captured image, and uses the extracted feature points to detect the position and shape of the object. The imaging unit is, for example, a monocular camera or a compound eye camera.

Various sensors 23 to 27 are connected to the ECU 10 for detecting the driving state of the own vehicle. The accelerator sensor 23 is provided on an accelerator pedal, and detects whether or not the accelerator pedal is operated by the driver and the amount of operation of the accelerator pedal. The brake sensor 24 is provided on the brake pedal and detects whether or not the brake pedal is operated by the driver and the amount of operation of the brake pedal. The steering sensor 25 detects a steering amount θ associated with steering operation by the driver. A vehicle speed sensor 26 detects the own vehicle speed Vc based on the number of rotations of the wheels. The yaw rate sensor 27 detects a yaw rate ψ that indicates a time change in the orientation of the vehicle when it turns.

An alarm device 31 , a brake device 32 and a seatbelt device 33 are connected to the ECU 10 . The alarm device 31 is a speaker or display installed inside the vehicle, and outputs an alarm sound, an alarm message, or the like according to a control command from the ECU 10 . The braking device 32 applies a braking force to the own vehicle. The seatbelt device 33 is a pretensioner that retracts a seatbelt provided on each seat of the vehicle.

Based on the detection results of the millimeter wave radar 21 and the image sensor 22, the ECU 10 acquires the object position P(i), which is the position of the object around the vehicle. In this embodiment, the ECU 10 determines that the first position of the object detected by the millimeter wave radar 21 and the second position of the object detected by the image sensor 22 are based on the same object. correspond as If the second position exists in the vicinity of the first position, there is a high possibility that the object actually exists at the first position. This state in which the millimeter wave radar 21 and the image sensor 22 can accurately obtain the position of the object is called a fusion state. The ECU 10 obtains, as an object position P(i), a position where an area set with the first position as a reference and an area set with the second position as a reference intersect with respect to the object determined to be in the fusion state.

For each object for which the object position P(i) is obtained, the ECU 10 calculates the relative position of the object with respect to the own vehicle and the relative velocity of the object with respect to the own vehicle.

Next, determination of the possibility of collision between the own vehicle and an object, which is performed by the ECU 10, will be described. The ECU 10 determines whether or not there is a possibility of collision between the vehicle 100 and the object 200 using the vehicle track A, which is the track of the vehicle 100, and the object position P(i). The ECU 10 calculates the turning radius of the vehicle 100 using the vehicle speed Vc detected by the vehicle speed sensor 26 and the yaw rate ψ detected by the yaw rate sensor 27, and uses the calculated turning radius as the vehicle course A. . Since it can be considered that the greater the yaw rate ψ, the greater the change in the direction of the vehicle 100, the ECU 10 calculates the course A of the vehicle so that the greater the yaw rate ψ, the smaller the turning radius.

The ECU 10 determines that there is a possibility of collision between the vehicle 100 and the object 200 when the object position P(i) is located on the course A of the vehicle. In the present embodiment, the course A of the vehicle is calculated linearly.

When the ECU 10 determines that there is a possibility of collision between the vehicle 100 and the object 200, the ECU 10 determines whether or not to operate each device 31-33. Specifically, as shown in FIG. 2, the ECU 10 determines that the object position P(i) of the object 200 determined to have the possibility of colliding with the vehicle 100 is within the operation area B defined in front of the vehicle. , and each device 31-33 is activated when the estimated collision time (hereinafter referred to as TTC) reaches the activation timing associated with each device 31-33.

The operating area B is a virtually defined area in front of the vehicle, and is an area smaller than the detection area of the millimeter wave radar 21 or the image sensor 22, for example. TTC is the estimated time until the vehicle 100 collides with the object 200. In this embodiment, the inter-vehicle distance from the vehicle 100 to the object 200 is divided by the relative speed of the object with respect to the vehicle 100. It is calculated by The operation timing is the timing for starting the operation of each of the devices 31 to 33. When the operation timing is early, the TTC at which the operation of each device 31 to 33 is started becomes larger than when the operation timing is late.

Operation timings are determined for the alarm device 31, the brake device 32, and the seat belt device 33, respectively. In this embodiment, among the operation timings of the devices 31 to 33, the operation timing T1 of the alarm device 31 is set to be the earliest timing.

The ECU 10 activates the alarm device 31 when the object 200 determined to collide with the vehicle 100 approaches the vehicle 100 and the TTC becomes equal to or less than the activation timing T1 of the alarm device 31 . As a result, the warning device 31 notifies the driver of the risk of collision.

After that, the ECU 10 operates the brake device 32 when the TTC becomes equal to or less than the activation timing T2 of the brake device 32 . The operation of the brake device 32 by the ECU 10 includes an automatic brake that operates the brake device 32 when the driver is not stepping on the brake pedal, and a braking force by the brake device 32 when the driver is stepping on the brake pedal. and a brake assist that increases the The actuation timing T2 of the brake device 32 may be provided separately for the brake assist and the automatic brake, or may be the same timing.

In this embodiment, the activation timing of the seatbelt device 33 is set to the same value as the activation timing T2 of the brake device 32 . For example, when the brake device 32 starts operating, the seat belt device 33 performs a preliminary operation for retracting the seat belt.

By the way, when the vehicle course A is calculated based on the yaw rate ψ of the vehicle 100, when the yaw rate ψ of the vehicle 100 changes, the calculated vehicle course A gradually changes over time. change to FIG. 3 is a diagram illustrating, as an example, changes in the course A of the vehicle when the vehicle 100 travels on a curved road that curves to the right. In FIG. 3, the actual travel route of the vehicle 100 is indicated by a solid line, and the vehicle course A calculated at each time is indicated by a broken line.

During a period in which the vehicle travels on the curve entrance side where the road shape changes from straight to curved, the vehicle 100 turns to the right as the driver turns the steering wheel further to the right. The yaw rate ψ increases. During the period in which the vehicle 100 travels in the middle of the curve, the orientation of the vehicle 100 is constant, so the yaw rate ψ is constant. Thereafter, during a period in which the vehicle travels on the curve exit side where the road shape changes from a curved shape to a straight shape, the yaw rate ψ of the vehicle 100 decreases as the driver turns the steering wheel back.

During the period in which the vehicle 100 travels on the curve entrance side, the turning radius of the vehicle course A decreases as the yaw rate ψ increases. In FIG. 3 , the vehicle course A(t1) calculated at time t1 has a larger turning radius than the travel route of the vehicle 100 . Therefore, while vehicle 100 is traveling at the entrance of a curve, there is a concern that PCS control may be actuated for object 200A located radially outside the travel route of vehicle 100 .

During the period in which the vehicle 100 travels on the curve exit side, the turning radius of the vehicle course A decreases as the yaw rate ψ decreases. In FIG. 3 , the vehicle course A(t2) calculated at time t2 has a smaller turning radius than the travel route of the vehicle 100 . Therefore, there is a concern that the PCS control may be actuated for the object 200B positioned radially inward of the travel route of the vehicle 100 while the vehicle is traveling at the exit of the curve.

When the yaw rate ψ changes while the host vehicle 100 is running, the yaw rate change rate C, which is the time change rate of the yaw rate ψ, and the steering speed D, which is the change speed of the steering amount θ, increase. Therefore, the ECU 10 calculates the reliability E of the course A of the vehicle using the yaw rate change rate C and the steering speed D, which are steering parameters. Then, when it is determined that there is a possibility of collision between the vehicle 100 and the object 200, the operation of the PCS control is restricted based on the calculated reliability E. In this embodiment, the ECU 10 corresponds to the reliability calculation unit.

Further, when the vehicle 100 undergoes a turning state change in which at least one of the yaw rate change rate C and the steering speed D increases, the certainty of the vehicle course A decreases. On the other hand, when there is no change in the turning state, the turning state of the vehicle 100 stabilizes, and the certainty of the course A of the vehicle increases. Therefore, in the present embodiment, the reliability E is decreased with the lapse of time during the period when the vehicle 100 is changing its turning state, and during the period when the vehicle 100 is not changing its turning state, the reliability E is decreased. Increase reliability over time.

Specifically, the ECU 10 adds the update amount ΔE calculated using the yaw rate change rate C and the steering speed D to the previous reliability value E(i−1), as shown in the following equation (1). Thus, the current reliability value E(i) is calculated.
E(i) = E(i-1) + ΔE (1)
If the previous reliability value E(i−1) is not calculated, the maximum value max (eg, 100) of the reliability E may be used as the previous reliability value E(i−1).

In this embodiment, the ECU 10 calculates the update amount ΔE used for updating the previous reliability value E(i−1) using the update amount map stored in the ROM. FIG. 4 shows an update amount map, in which the horizontal axis represents the yaw rate change rate C and the vertical axis represents the update amount ΔE. In the update amount map, when the yaw rate change rate C is greater than the reference value SP, the update amount ΔE takes a negative value, and when the yaw rate change rate C is smaller than the reference value SP, the update amount ΔE takes a positive value. The relationship between the yaw rate change rate C and the update amount ΔE is determined so that In this embodiment, the ECU 10 corresponds to an update amount calculation unit.

The update amount map has an up area G1 in which a positive update amount ΔE is defined and a down area G2 in which a negative update amount ΔE is defined with reference value SP as a predetermined yaw rate change rate C as a boundary. . In this embodiment, the reference value SP is defined as the yaw rate change rate C when the vehicle 100 starts to change in turning state. As the yaw rate change rate C increases, the positive update amount ΔE defined for the up region G1 decreases toward the positive side with a limit of zero. On the other hand, the negative update amount ΔE defined for the down region G2 increases on the negative side as the yaw rate change rate C increases. Note that FIG. 4 shows an up region G1 (SP2) and a down region G2 (SP2) when the reference value is "SP2".

The steering speed D changes more easily than the yaw rate change rate C because the steering speed D fluctuates according to the steering operation of the driver. Therefore, when the steering speed D is low, it is more likely that the steering speed D does not reflect changes in the yaw rate ψ of the vehicle 100 than when the steering speed D is high. Therefore, the ECU 10 calculates the update amount ΔE using an update amount map in which the reference value SP is set to a smaller value as the steering speed D increases.

When the steering speed D is higher than the steering speed D assumed by the reference value SP2, the ECU 10 calculates the update amount ΔE using an update amount map set to a value (SP1) where the reference value SP is small. As a result, in the update amount map, the range of the yaw rate change rate C associated with the down region G2 is widened, so that the update amount ΔE tends to become a large value on the negative side. On the other hand, when the steering speed D is equal to or lower than the steering speed D assumed by the reference value SP2, the ECU 10 calculates the update amount ΔE using an update amount map set to a value (SP3) with a large reference value SP. do. As a result, the range of the yaw rate change rate C associated with the down region G2 is narrowed, making it difficult for the update amount Δ to become a large value on the negative side.

In the present embodiment, the ECU 10 adds a positive update amount ΔE to the previous reliability value E(i−1) when the previous reliability value E(i−1) has reached the upper limit value. maintains the current value of reliability E(i) at the upper limit. On the other hand, if the previous reliability value E(i-1) has reached the lower limit and a negative update amount ΔE is added to the previous reliability value E(i-1), the reliability Keep the value E(i) at the lower limit.

The ECU 10 limits the operation of the PCS control according to the calculated reliability E. In this embodiment, the ECU 10 reduces the operating area B, which is the object position condition for operating the devices 31 to 33, and delays the operation timing of the devices 31 to 33, as the operation restrictions of the PCS control. In this embodiment, the ECU 10 corresponds to the restriction unit.

When the reliability E is smaller than the reliability judgment value TH1, the ECU 10 reduces the operation area B in the vehicle width direction with the center in the vehicle width direction as a reference, as shown in FIG. is equal to or greater than the reliability judgment value TH1, the operating area B is not reduced. In this embodiment, when reducing the operating area B in the vehicle width direction, the smaller the reliability E, the larger the amount of reduction in the vehicle width direction. When the operating area B is reduced, the objects 200 subject to the operating conditions for operating the devices 31 to 33 are restricted among the objects 200 in front of the vehicle, so that each device 31 ~33 becomes difficult to operate.

When the reliability E is smaller than the reliability judgment value TH1, the ECU 10 operates the devices 31 to 33 more than when the reliability E is equal to or higher than the reliability judgment value TH1, as shown in FIG. 5(b). delay the timing. In the present embodiment, when the ECU 10 delays the operation timing of each of the devices 31 to 33, the smaller the reliability E, the larger the delay amount of the operation timing. In the example of FIG. 5(b), since the reliability E is smaller than the reliability judgment value TH1, the actuation timing of the brake device 32 is delayed from TTC2 to TTC3. Due to the delay in the operation timing of each device 31-33, each device 31-33 becomes difficult to operate.

Note that the ECU 10 may not use the reliability E to delay the operation timings of the devices 31 to 33 after the devices 31 to 33 have started to operate. This is to prevent the operation of each of the devices 31-33 from being interrupted due to a change in the operation timing after each of the devices 31-33 has been operated.

Next, a series of processing procedures for PCS control will be described with reference to the flowchart of FIG. The process of FIG. 6 is repeatedly performed by the ECU 10 at predetermined control cycles.

In step S11, the steering amount θ obtained by the steering sensor 25, the vehicle speed Vc detected by the vehicle speed sensor 26, and the yaw rate ψ detected by the yaw rate sensor 27 are obtained.

In step S12, the course A of the vehicle is calculated using the vehicle speed Vc and the yaw rate ψ obtained in step S11.

In step S13, the yaw rate change rate C and the steering speed D are used to calculate the update amount ΔE of the reliability E. In this embodiment, the yaw rate change rate C is calculated by dividing the absolute value of the value obtained by subtracting the previous value from the current value of the yaw rate ψ obtained in step S11 by the control cycle. Further, the steering speed D is obtained by dividing the absolute value obtained by subtracting the previous value from the current value of the steering amount θ obtained in step S11 by the control cycle. The current update amount ΔE is calculated by referencing the update amount ΔE corresponding to the calculated combination of the yaw rate change rate C and the steering speed D from the update amount map.

In step S14, the value obtained by adding the update amount ΔE calculated in step S13 to the previous value E(i−1) of the reliability E is calculated as the current value E(i) of the reliability.

In step S15, it is determined whether or not the current reliability value E(i) calculated in step S14 is smaller than the reliability determination value TH1. If it is determined that the current reliability value E(i) is smaller than the reliability determination value TH1, the process proceeds to step S16, and the operation area B is reduced in the vehicle width direction according to the current reliability value E(i). and delays the operation timing of each device 31-33. In this embodiment, when proceeding to step S16, a limit flag F indicating that the PCS control is limited is set to a high state. The limit flag F is in a high state when the PCS control is limited, and is in a low state when the PCS control is not limited.

On the other hand, if it is determined in step S16 that the reliability E is greater than or equal to the reliability determination value TH1, the process proceeds to step S17 without changing the operation area B and the operation timings of the devices 31-33. In this case, the limit flag F is set to the low state.

In step S17, it is determined whether or not there is a possibility that the object will collide with the vehicle using the vehicle path A calculated in step S12 and the object position P(i). If a negative determination is made in step S17, the process of FIG. 6 is terminated. On the other hand, if an affirmative determination is made in step S17, the process advances to step S18 to determine whether the current object position P(i) is within the operation area B or not. When it is determined that the object position P(i) is not within the operation area B, the process of FIG. 6 is once terminated.

If it is determined that the object position P(i) is within the operation area B, the process proceeds to step S19 to determine whether or not the current TTC has passed the operation timing of each device 31-33. If it is determined that the current TTC has not passed the operation timing of each of the devices 31 to 33, the process of FIG. 6 is terminated.

If it is determined in step S19 that the current TTC has passed the operation timing of any of the devices 31 to 33, the process proceeds to step S20. In step S20, the PCS control is performed by activating the devices 31 to 33 whose TTC has reached the activation timing. Then, the process of FIG. 6 is terminated once.

Next, with reference to FIG. 7, changes in the reliability E due to changes in the orientation of the vehicle 100 will be described. FIG. 7(a) shows changes in the yaw rate ψ of the vehicle 100 according to the driver's steering operation, and FIG. 7(b) shows changes in the yaw rate change rate C. FIG. 7(c) shows the transition of the reliability E, and FIG. 7(d) shows the limit flag F. As shown in FIG. Note that in FIG. 7B, the yaw rate change rate C is calculated as the absolute value of the change in the yaw rate ψ.

During the period from time t11 to t13, the yaw rate ψ increases due to changes in the orientation of the vehicle 100 as the driver turns the steering wheel further. Therefore, during the period from time t11 to t13, the negative update amount ΔE is added based on the yaw rate change rate C, so that the reliability E decreases as time elapses. Then, at time t12, the reliability E becomes smaller than the reliability judgment value TH1, so that the limit flag F changes from the low state to the high state, and the PCS control is limited.

Next, during the period from time t13 to t16, the direction of the vehicle 100 is maintained constant by the steering angle being constant by the driver's operation. Since the orientation of the vehicle 100 becomes constant, the yaw rate ψ becomes constant, and after time t13, a positive update amount ΔE is added based on the yaw rate change rate C, so that the reliability increases with the passage of time. E increases. At time t14, the reliability E becomes equal to or greater than the reliability judgment value TH1, so that the restriction flag F changes from high to low, and the restriction on the PCS control is released.

Even after time t14, the orientation of the vehicle 100 is maintained constant, so that the yaw rate change rate C is maintained at zero, so the reliability E continues to increase. At subsequent time t15, the reliability E reaches the maximum value max.

During the period from time t16 to t19, the yaw rate change rate C increases as the yaw rate ψ decreases as the driver returns the steering wheel. By adding the negative update amount ΔE based on the yaw rate change rate C, the reliability E decreases over time. Then, at time t17, the reliability E becomes smaller than the reliability determination value TH1, so that the limit flag F changes from the low state to the high state, and the PCS control is limited.

After that, at time t18, the direction of the vehicle 100 becomes constant as the driver finishes steering the steering wheel back. Therefore, by adding the positive update amount ΔE based on the yaw rate change rate C, the reliability E increases. At time t19, the reliability E becomes equal to or greater than the reliability determination value TH1, so that the restriction flag F changes from high to low, and the restriction on the PCS control is released.

As described above, the present embodiment can provide the following effects.

The ECU 10 calculates a reliability E indicating the likelihood of the course A of the vehicle based on the yaw rate change rate C indicating the time change of the yaw rate ψ and the steering speed D. Based on the calculated reliability E, the implementation of PCS control is restricted. As a result, the PCS control is restricted according to the certainty of the course of the vehicle, so that unnecessary operations of the PCS control can be suppressed.

The ECU 10 reduces the reliability E as time elapses during a period in which a change in the turning state in which the rate of change C of the yaw rate is greater than the reference value SP, The reliability E is increased according to the progress of . This makes it possible to properly calculate the reliability E when the vehicle 100 changes between the straight-ahead state and the turning state.

The ECU 10 calculates the update amount ΔE of the reliability E based on the yaw rate change rate C in a predetermined cycle, and adds the update amount ΔE to the previous value E(i−1) of the reliability to obtain the reliability. The current value E(i) of the degree is calculated. When the yaw rate change rate C is larger than the reference value SP, the update amount ΔE is calculated as a negative value, and when the yaw rate change rate C is smaller than the reference value SP, the update amount ΔE is calculated as a positive value. As a result, the current reliability (i) can be calculated by reflecting the previous reliability E(i−1). A large change from (i-1) can be suppressed. As a result, it is possible to prevent the degree of restriction of the PCS control operation from greatly changing while the vehicle 100 is running.

- The ECU 10 sets the reference value SP to a smaller value as the steering speed D increases. Accordingly, as the steering speed D increases, the update amount ΔE tends to become a negative value, so the reliability E can be calculated more appropriately. As a result, the effect of suppressing unnecessary operations of PCS control can be enhanced.

(Modified example of the first embodiment)
- In the update amount map, the update amount ΔE associated with each of the up region G1 and the down region G2 may be set to a constant value.

FIG. 8 is a diagram showing an update amount map according to this embodiment. In this embodiment, the update amount map also has an up region G1 in which a positive update amount ΔE is defined and a down region G2 in which a negative update amount ΔE is defined. In the up region G1, the same positive update amount ΔE is set regardless of the yaw rate change rate C, and in the down region G2, the same negative update amount ΔE is set regardless of the yaw rate change rate C. is defined.

Also in this embodiment, the ECU 10 calculates the update amount ΔE using an update amount map in which the reference value SP is set to a smaller value as the steering speed D increases. As a result, the update amount ΔE calculated by the ECU 10 tends to become a negative value.

The ECU 10 may use either the yaw rate change rate C or the steering speed D as a steering parameter to set the update amount ΔE. Also in this case, the larger the value of the yaw rate change rate C or the steering speed D used as the steering parameter, the smaller the update amount ΔE is set. The same effects as those of the first embodiment can be obtained in the present embodiment described above.

(Second embodiment)
2nd Embodiment mainly demonstrates a different structure from 1st Embodiment. In addition, the same code|symbol is attached|subjected to the same site|part by 2nd Embodiment and 1st Embodiment, and the description is not repeated.

When self-vehicle 100 meanders, it is highly likely that the driver is operating the steering wheel voluntarily. In addition, since the orientation of the vehicle 100 changes frequently while the vehicle 100 is meandering, there is a high possibility that surrounding objects that are not on the actual course of the vehicle 100 will be subject to collision determination. , unnecessary operation of PCS control is likely to occur. In this embodiment, when the ECU 10 determines that the vehicle 100 is meandering, the ECU 10 further reduces the calculated reliability E, thereby tightening the restrictions on the operation of the PCS control. In this embodiment, the ECU 10 corresponds to a meandering travel determination section and a correction section.

Next, a series of processing procedures for PCS control according to this embodiment will be described using the flowchart of FIG. The process of FIG. 9 is repeatedly performed by the ECU 10 at predetermined control cycles.

After calculating the reliability E in step S14, the process proceeds to step S30 to determine whether or not the vehicle 100 is meandering. In this embodiment, the detection history of the yaw rate ψ detected by the yaw rate sensor 27 is recorded for each control cycle, and the detection history is used to determine whether or not the vehicle 100 is meandering. When the vehicle 100 is traveling straight ahead, the direction of the yaw rate ψ detected in each control cycle does not change significantly to the left or right, so the width of change in the yaw rate ψ to the left or right is equal to or less than the predetermined change width judgment value. . On the other hand, when the vehicle 100 is meandering, the direction of the yaw rate ψ detected in each control cycle changes greatly to the left and right. Therefore, if both the left and right change widths of the yaw rate ψ recorded in the detection history are larger than the change width determination value, it can be determined that the vehicle 100 is in a meandering state. In addition to this, it may be determined whether or not the vehicle 100 is meandering based on a change in the captured image in front of the vehicle captured by the image sensor 22 .

When it is determined in step S30 that the vehicle 100 is meandering, an affirmative determination is made in step S31, and the process proceeds to step S32. In step S32, the current reliability value E(i) calculated in step S15 is corrected to the lower side. In the present embodiment, the current reliability value E(i) is corrected to the lower side by multiplying the current reliability value E(i) by a subtraction coefficient α. The subtraction coefficient α is a value greater than 0 and less than 1.

When proceeding to step S15 via step S32, the current reliability value E(i) becomes smaller than when it is determined that the vehicle 100 is not meandering. This makes it easier for the current reliability value E(i) to become smaller than the reliability judgment value TH1, so that the operation of the PCS control is more likely to be restricted. Further, in step S16, the reduction amount of the operation area B in the vehicle width direction and the delay amount of the operation timing of each of the devices 31 to 33 become larger than when it is determined that the vehicle 100 is not meandering. .

On the other hand, if it is determined in step S30 that the vehicle is not meandering, a negative determination is made in step S31, and the process proceeds to step S15.

In the present embodiment described above, the ECU 10 further reduces the reliability E when determining that the vehicle 100 is meandering. In this case, when the vehicle 100 is meandering, the restriction on the operation of the PCS control is strengthened, so that the unnecessary operation of the PCS control can be preferably suppressed.

(Other embodiments)
Instead of calculating the current reliability value E(i) by updating the previous reliability value E(i−1), the ECU 10 calculates the reliability E using the steering parameter for each control cycle. may be calculated. In this case, the greater the steering parameter, the smaller the reliability E should be.

- The ECU 10 may determine the possibility of collision between the vehicle and the object using the object course A2 calculated using the time change of the object position P(i). Specifically, the ECU 10 acquires the object position P(i) in chronological order, and approximates changes in the acquired object position P(i) to calculate the object course. The ECU 10 may determine that there is a possibility of collision between the vehicle 100 and the object 200 when the calculated vehicle trajectory and the calculated object trajectory intersect.

- The ECU 10 may limit the operation of the PCS control by prohibiting the operation of each of the devices 31 to 33 when the reliability E is smaller than a predetermined value. In this case, if it is determined in step S15 that the current reliability value E(i) is equal to or lower than the operation prohibition determination value that is lower than the reliability determination value TH1, in step S16, the devices 31 to 33 are operated. should be prohibited.

- The controller and method described in the present disclosure can be performed by a dedicated computer provided by configuring a processor and memory programmed to perform one or more functions embodied by a computer program; may be implemented. Alternatively, the controls and techniques described in this disclosure may be implemented by a dedicated computer provided by configuring the processor with one or more dedicated hardware logic circuits. Alternatively, the control units and techniques described in this disclosure can be implemented by a combination of a processor and memory programmed to perform one or more functions and a processor configured by one or more hardware logic circuits. It may also be implemented by one or more dedicated computers configured. The computer program may also be stored as computer-executable instructions on a computer-readable non-transitional tangible recording medium.

Reference Signs List 10: ECU, 31: Alarm device, 32: Brake device, 33: Seatbelt device, 100: Own vehicle, A: Own vehicle course.

Claims (6)

Driving in which the course of the vehicle is calculated based on the yaw rate of the own vehicle, and based on the possibility of collision with an object in a target area including the course of the own vehicle, driving assistance processing is performed to avoid or mitigate collision with the object. A support device (10),
a reliability calculation unit that calculates a reliability indicating the likelihood of the course of the vehicle based on a steering parameter including both a yaw rate change rate, which is the rate of change over time of the yaw rate, and a steering speed;
a limiting unit that limits execution of the driving support process based on the reliability;
with
The reliability calculation unit gradually decreases the reliability with the lapse of time during a period in which a change in turning state occurs in which the steering parameter is greater than a predetermined value, and the change in turning state does not occur. A driving assistance device that gradually increases the reliability in a period according to the passage of time . The reliability calculation unit has an update amount calculation unit that calculates an update amount of the reliability based on the steering parameter, and adds the update amount to the previous value of the reliability in a predetermined cycle. to update the reliability,
The update amount calculation unit calculates the update amount as a negative value during a period when the turning state change occurs, and calculates the update amount as a positive value during a period when the turning state change does not occur. The driving assistance device according to claim 1 . Driving in which the course of the vehicle is calculated based on the yaw rate of the own vehicle, and based on the possibility of collision with an object in a target area including the course of the own vehicle, driving assistance processing is performed to avoid or mitigate collision with the object. A support device (10),
a reliability calculation unit that calculates a reliability indicating the likelihood of the course of the vehicle based on a steering parameter including at least one of a yaw rate change rate, which is the time change rate of the yaw rate, and a steering speed;
a limiting unit that limits execution of the driving support process based on the reliability;
with
The reliability calculation unit
The reliability is decreased with the lapse of time during a period in which a change in turning state in which the steering parameter is greater than a predetermined value occurs, and the reliability is decreased with the lapse of time in a period in which the change in turning state does not occur. increasing the reliability,
An update amount calculation unit for calculating an update amount of the reliability based on the steering parameter is provided, and the reliability is updated by adding the update amount to the previous value of the reliability at a predetermined cycle. and
The update amount calculation unit calculates the update amount as a negative value during a period when the turning state change occurs, and calculates the update amount as a positive value during a period when the turning state change does not occur. Driving assistance device. The update amount calculation unit calculates the update amount as a larger value on the negative side as the steering parameter increases during the period when the turning state change occurs, and calculates the update amount as a larger negative value during the period when the turning state change does not occur. 4. The driving support system according to claim 2 , wherein the smaller the steering parameter is, the larger the positive value of the update amount is calculated. The update amount calculation unit
When it is determined that the turning state change has occurred due to the yaw rate change rate as the steering parameter, the update amount is calculated as a negative value, and it is determined that the turning state change has not occurred due to the yaw rate change rate. when the update amount is calculated as a positive value,
The driving support device according to any one of claims 2 to 4, wherein the predetermined value is set to a smaller value as the steering speed as the steering parameter increases. a meandering travel determination unit that determines whether or not the vehicle is meandering;
and a correction unit that corrects the reliability calculated by the reliability calculation unit to a lower side when the vehicle is determined to be meandering by the meandering travel determination unit. 6. The driving support device according to any one of 5 .

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