Driving assistance control device and method and driving assistance system for a vehicle

Abstract

Driving assistance control device (100) for a vehicle, comprising: an acquiring unit (103) that acquires a detected driving state of the vehicle and a detected driving environment of the vehicle, and a control unit (101, P1) that, when a turning radius of a travel trajectory of the vehicle is equal to or smaller than a predetermined radius threshold, causes a driving assistance unit (31) to perform collision avoidance assistance using a reduced activation area obtained by reducing a reference activation area as an activation area of ​​the collision avoidance assistance, and when it is determined that the vehicle is making a constant turn, causes the driving assistance unit (31) to perform the collision avoidance assistance using the driving state of the vehicle and the driving environment of the vehicle and the reference activation area, even if the turning radius of the travel trajectory is equal to or smaller than the radius threshold.

Description

Technical area

[0001] The present invention relates to a technique for controlling a driving assistance system in a vehicle to suppress or avoid a collision with a target object. State of the art

[0002] A technique for defining an activation area based on the length or height of a target object is known. A driving assistance system for suppressing or avoiding a collision with the target object is activated in response to the target object entering or entering the activation area (e.g., JP 2016 - 164 031 A).

[0003] When a self-driven vehicle is driving with steering operations, it is often difficult to determine the driving trajectory of the self-driven vehicle, such as the direction of movement of the self-driven vehicle, and it is also difficult to distinguish a target object likely to collide with the self-driven vehicle from detected objects. Performing driving assistance with respect to a non-target object under circumstances where it is not easy to distinguish the target object may cause passengers of the self-driven vehicle, including a driver of the self-driven vehicle, to feel discomfort or anxiety. While it is necessary to avoid performing such unnecessary driving assistance, it is desirable to perform appropriate driving assistance under the condition that unnecessary driving assistance can be avoided.

[0004] Further prior art is known from DE 10 2014 018 621 A1 and DE 10 2015 202 736 A1.

[0005] The object of the invention is to carry out suitable driving assistance while driving the own vehicle with steering operations.

[0006] This object is achieved by the subject matter having the features according to the independent claims. Advantageous embodiments are the subject matter of the dependent claims.

[0007] The present invention can be carried out according to the aspects described below.

[0008] According to a first aspect, a driving assistance control device for a vehicle is provided. The driving assistance control device for a vehicle according to the first aspect comprises: an acquisition unit that acquires a detected driving state of the vehicle and a detected driving environment of the vehicle; and a control unit that, when a turning radius of a driving trajectory of the vehicle is equal to or smaller than a predetermined radius threshold, causes a driving assistance unit to perform collision avoidance assistance using a reduced activation area obtained by reducing a reference activation area as an activation area of ​​the collision avoidance assistance; and when it is determined that the vehicle is traveling at a constant curve, causes the driving assistance unit to:to perform the collision avoidance assistance using the driving state of the vehicle and the driving environment of the vehicle and the reference activation area, even if the curve radius of the driving trajectory is equal to or smaller than the radius threshold.

[0009] According to the driving assistance control device for the vehicle according to the first aspect, it is possible to perform appropriate driving assistance while the subject vehicle is driving with steering operations.

[0010] According to a second aspect, a driving assistance system is provided. The driving assistance system according to the second aspect includes: the driving assistance control device according to the first aspect, a detection unit that detects the driving state and the driving environment, and the driving assistance unit that performs collision avoidance assistance under an instruction from the control unit.

[0011] According to the driving assistance system according to the second aspect, it is possible to perform appropriate driving assistance while the host vehicle is driving with steering operations.

[0012] According to a third aspect, a driving assistance control method for a vehicle is provided. The driving assistance control method for a vehicle according to the third aspect includes: acquiring a detected driving state of the vehicle and a detected driving environment of the vehicle when a turning radius of a driving trajectory of the vehicle is equal to or less than a predetermined radius threshold; setting an activation area of ​​a collision avoidance assist to a reduced activation area obtained by reducing a reference activation area, and when determining whether the vehicle is making a constant turn; performing collision avoidance assist processing using the driving state of the vehicle and the driving environment of the vehicle and the reference activation area, even if the turning radius of the driving trajectory is equal to or less than the radius threshold.

[0013] According to the driving assistance control method for the vehicle according to the third aspect, it is possible to perform appropriate driving assistance while the host vehicle is traveling with steering operations. The present invention can also be implemented as a driving assistance control program for a vehicle or as a computer-readable recording medium that records the program. Short description of the characters Fig. 1 shows a schematic diagram of a vehicle equipped with a driving assistance control device according to a first embodiment, Fig. 2 shows a functional block diagram of the driving assistance control device according to the first embodiment, Fig. 3 is a flowchart showing driving assistance processing performed by the driving assistance control device according to the first embodiment, Fig. 4 shows a representation of turning situations of vehicles on a winding road, Fig. 5 shows a representation of a turning situation of a vehicle on a straight road, Fig. 6 shows a representation of a reference activation area and a reduced activation area, and Fig. 7 is a diagram showing an example of changes in a steering rate when the reduced activation area is turned on / off during driving assistance control processing performed according to the first embodiment. Description of embodiments

[0014] Hereinafter, some embodiments of a driving assistance control apparatus for a vehicle, a driving assistance system for a vehicle, and a driving assistance control method for a vehicle according to the present embodiment will be described. First embodiment

[0015] As in Fig. As shown in Figure 1, a driving assistance control device 100 for a vehicle according to a first embodiment is installed and used in a vehicle 500. The driving assistance control device 100 includes at least a control unit and an Erlang unit. A driving assistance system 10 includes, in addition to the driving assistance control device 100, a radar ECU 21, a camera ECU 22, a rotation angle sensor 23, a wheel speed sensor 24, a yaw rate sensor 25, a position sensor 26, and a driving assistance device 31. The vehicle 500 includes wheels 501, brake devices 502, brake lines 503, a steering wheel 504, a windshield 510, a front bumper 520, and a rear bumper 521.The radar ECU 21 is connected to millimeter radars 211 that emit radio waves and uses reflected waves from an object acquired by the millimeter radars 211 to generate and output detection signals indicating the object through reflection points. The camera ECU 22 is connected to a monocular camera 221 and uses an image acquired by the camera 221 and a prepared shape pattern of the object to generate and output a detection signal indicating the object through the image. Each of the ECUs 21 and 22 is a microprocessor that includes a processing unit, a storage unit, and an input / output unit. Detection units that detect the reflected waves can be laser radars (lidars) or ultrasonic wave detection units that emit sound waves and detect reflected waves, instead of the millimeter radars 211.The image pickup unit that captures images of the target object may be a stereo camera or a multi-camera formed by two or more cameras instead of the monocular camera 221. Additionally, a rear camera or a side camera may be provided.

[0016] The braking devices 502 are provided in the corresponding wheels 501. The braking devices 502 are, for example, disc brakes or drum brakes, which apply braking to the corresponding wheels 501 by a braking force dependent on a brake fluid pressure supplied via the brake lines 503 in response to the driver's operation of the brake pedal, thereby implementing braking of the vehicle 500. The brake lines 503 include a brake piston and a brake fluid line that generate brake fluid pressure in response to a brake pedal operation. Instead of a brake fluid line, the brake lines 503 may be a control signal line configured to activate an actuator provided in each of the braking devices 502.

[0017] The steering wheel 504 is connected to the front wheels 501 via a steering device 42, which includes a handlebar, a steering mechanism, and a steering axle. The steering device 42 may be provided with a steering force assist device for reducing steering forces.

[0018] The driving assistance device 31, which is a driving assistance unit, is provided together with the brake lines 503 and includes a brake assist device capable of controlling fluid pressure by an actuator, such as an electric motor, independently of a brake pedal operation, a steering assist device capable of driving the steering device 42 by an actuator, such as an electric motor, and an output control device that controls the outputs of the internal combustion engine and the electric motor, which are motive power sources for driving. The driving assistance device 31 performs brake assistance, steering assistance, and collision avoidance assistance in response to detection results by the millimeter radars 211 and the camera 221.

[0019] As in Fig. As shown in Figure 2, the driving assistance control device 100 includes a central processing unit (CPU) 101 as a control unit, a memory 102, an input / output interface 103 as an Erlang unit, and a bus 104. The CPU 101, the memory 102, and the input / output interface 103 are connected together via the bus 104 in a manner capable of bidirectional communication. The memory 102 includes a memory that stores a driving assistance program P1 for performing driving assistance in a non-volatile and read-only manner, for example, a ROM, and a memory that is readable and writable by the CPU 101, for example, a RAM. The memory 102 further includes a map information storage area 102a for storing map information MI that can be used in a navigation system.The CPU 101 loads the driving assistance program P1 in the memory 102 into the readable / writable memory and executes it therein to set an activation area of ​​a collision avoidance assist to a reference activation area or a reduced activation area obtained by reducing the reference activation area, and controls the driving assistance device 31 to implement a function of the control unit for performing collision avoidance assist processing. The CPU 101 may be a single CPU, a plurality of CPUs executing different programs, or a multi-core CPU capable of executing a plurality of programs simultaneously.

[0020] The input / output interface 103 is connected to the radar ECU 21, the camera ECU 22, the rotation angle sensor 23, the wheel speed sensor 24, the yaw rate sensor 25, the position sensor 26, and the driving assistance device 31 via their respective control signal lines. The input / output interface 103 receives detection signals from the radar ECU 21, the camera ECU 22, the rotation angle sensor 23, the wheel speed sensor 24, the yaw rate sensor 25, and the position sensor 26. The input / output interface 103 outputs control signals indicating an operating state of the vehicle, such as a braking level or a steering level, to the driving assistance device 31. Thus, the input / output interface 103 serves as an acquisition unit that acquires a driving state of the host vehicle and a driving environment around the host vehicle, which are detected by various sensors.The radar ECU 21 and the millimeter radars 211, and the camera ECU 22 and the monocular camera 221 serve as a driving environment detecting device 20A. The rotation angle sensor 23, the wheel speed sensor 24, the yaw rate sensor 25, and the position sensor 26 serve as a driving state detecting device 20B.

[0021] The millimeter radars 211 are sensors that emit millimeter waves and receive reflected waves from an object to detect a distance, relative speed, and angle of the object. In the present embodiment, the millimeter radars 211 are arranged at the center and on both sides of the front bumper 520 and on both sides of the rear bumper 521. Unprocessed detection signals output from the millimeter radars 211 are processed by the radar ECU 21 and input to the driving assistance control device 100 as detection signals formed from dots or dotted lines indicating one or more representative positions of the object. The radar ECU 21 may alternatively be provided so that signals indicating unprocessed received waves are input as detection signals from the millimeter radars 211 to the driving assistance control device 100.In the case of using unprocessed reception signals as detection signals, the driving assistance control device 100 performs signal processing to determine a position and a distance of the object.

[0022] The camera 221 is an imaging device including an imaging element such as a CCD, and is a sensor that detects external shape information of a target object by receiving visible light and outputs a detection signal as image data. The image data output from the camera 221 is subjected to feature point extraction processing by the camera ECU 22, and a pattern indicated by the extracted feature points is compared with a prepared reference pattern indicating an external shape of a target object to be discriminated, i.e., a vehicle. If the extracted pattern and the reference pattern match or are similar, a frame image showing the discriminated target object is generated. On the other hand, if the extracted pattern and the reference pattern do not match or are similar, i.e., if these patterns are not analogous, no frame image is generated.When the image data shows a plurality of target objects, the camera ECU 22 generates a plurality of frame images showing the corresponding discriminated target objects and inputs them as a detection signal to the driving assistance control device 100. Each frame image is represented by pixel data including position information, i.e., coordinate information, of the discriminated target object. The number of frame images that can be present in the detection signal depends on the bandwidth between the camera ECU 22 and the driving assistance control device 100. Instead of providing the camera ECU 22 separately, unprocessed image data through the camera 221 can be input to the driving assistance control device 100 as a detection signal. In this case, the driving assistance control device 100 can perform target discrimination using an external shape pattern of the target object to be discriminated.In the present embodiment, the camera 221 is arranged at the upper center of the windshield 510. The pixel data output from the camera 221 is monochrome pixel data or color pixel data. When it is desired that a target object to be distinguished is an object other than a vehicle, for example, a traffic light or a traffic sign such as a lane or a stop line, the camera ECU 22 may prepare an external shape pattern of the desired target object and output frame images representing the desired target object as a detection signal. In this case, an appropriate frame image can be selectively used in the subsequent processing by the driving assistance control device 100. The same applies to the case where a rear camera is provided.

[0023] The rotation angle sensor 23 is a torque sensor that detects the amount of rotation of the handlebar, i.e., a steering torque caused by steering the steering wheel 504, and detects the steering angle of the steering wheel 504. In the present embodiment, the rotation angle sensor 23 is provided in the handlebar connected between the steering wheel 504 and the steering mechanism. A detection signal output from the rotation angle sensor 23 indicates a voltage value proportional to the amount of rotation.

[0024] The wheel speed sensors 24 are sensors that detect the rotational speeds of the wheels 501 and are provided on the corresponding wheels 501. Detection signals output from the wheel speed sensors 24 are pulse waves that output the voltage value proportional to the wheel speed or an interval corresponding to the wheel speed. Using the detection signals from the wheel speed sensors 24 makes it possible to obtain information about a vehicle speed, a travel distance, and the like.

[0025] The yaw rate sensor 25 is a sensor that detects the rotational angular velocity of the vehicle 500. The yaw rate sensor 25 is located, for example, at the center of the vehicle. A detection signal output by the yaw rate sensor 25 outputs a voltage value proportional to the rotational direction and the angular velocity. The detected voltage value can indicate a lane change or a turn of the vehicle 500.

[0026] Position sensor 26 is a sensor that receives signals from satellites and base stations and determines the location of the host vehicle, such as a global navigation satellite system (GNSS) receiver or a mobile communications transceiver. The host vehicle's location is treated as information about the host vehicle's current location.

[0027] A driving assistance processing performed by the driving assistance control device 100 according to the first embodiment will be described. The processing routine shown in Fig. 3 is repeatedly performed at predetermined time intervals from startup to shutdown of the vehicle's control system, or from powering on to powering off the start switch. The driving assistance processing in the present embodiment includes, for example, brake assist processing and steering assist processing. The brake assist processing includes sudden braking and slow braking to avoid a collision with a target vehicle. The steering assist processing includes steering to avoid a collision with a target vehicle and steering to prohibit lane departure.

[0028] The CPU 101 acquires the driving environment from the driving environment acquisition device 20A and acquires the driving state from the driving state acquisition device 20B via the input / output interface 103 as the acquisition unit (in step S100). The driving environment means the states and conditions of the surroundings of the own vehicle, that is, the outside world, which includes, for example, information about the positions, speeds, shapes, and states of objects in front of and behind the vehicle and on the right and left sides thereof. The objects include, for example, other vehicles, roads, road markings, and traffic signs. The driving state of the vehicle is information about the own vehicle, which includes, for example, the speed of the vehicle 500, the direction of the vehicle 500, and the rotation angular velocity of the vehicle 500.

[0029] The CPU 101 obtains an estimated turning radius R (m) of the travel trajectory of the host vehicle (in step S110). The travel trajectory includes an expected trajectory in which the vehicle is expected to travel and a driving lane of the host vehicle. The estimated turning radius R refers to a turning radius of the expected trajectory or the driving lane, which is a steering radius of the vehicle M3, which is associated with a steering operation of the vehicle M3, as shown in Fig. 4. In the Fig. In the example shown in Figure 4, a vehicle M1 is about to enter a curved road from a straight road along a trajectory TL1, and a vehicle M2 is traveling on the curved road in a travel trajectory TL2. In the example shown in Fig. In the example shown in Figure 5, the vehicle M3 travels meandering in a travel trajectory TL3 on a straight road. The estimated curve radius R is determined using information present in at least one of the units, driving state and driving environment, and is determined, for example, by R = v / ω, where v is the speed of the host vehicle (m / s) and ω is the rotational angular velocity of the host vehicle (rad / s). The estimated curve radius R may be calculated in step S110 or may be repeatedly calculated at predetermined time intervals, regardless of the Fig. 3. Furthermore, the estimated curve radius R can be calculated by combining the own vehicle location obtained by the position sensor 26 and the road shape information included in the map information MI, by the steering angle of the steering wheel 504, by image processing of images captured by the camera 221, or by matching processing of the own vehicle location determined by the position sensor 26 and the captured images.

[0030] The CPU 101 determines whether the obtained estimated curve radius R is equal to or smaller than a predetermined determination curve radius Rr, that is, R ≤ Rr (in step S120). The determination curve radius Rr is a small curve radius at which driving assistance can be performed even against an object that is not a target object of the driving assistance. The determination curve radius Rr is a curve radius of a curved road in which guardrails, walls, curbs, and markers ahead on the road sides exist in a reference activation area in front of the vehicle 500, which is set as an activation area of ​​collision avoidance assistance. When traveling along the road, the vehicle 500 cannot actually travel toward these guardrails, walls, curbs, and markers ahead on the road sides.However, at a time when the turning radius is acquired, distances between the vehicle 500 and these objects may be so short that it is determined that there is a possibility of collision, and unnecessary collision avoidance assistance may then be performed. Therefore, when the estimated turning radius R is equal to or smaller than the predetermined determination turning radius Rr, a reduced activation area DA2 may be used instead of a reference activation area DA1 defined by straight lines extending from both lateral ends of the subject vehicle, as shown in FIG. Fig. 6, spread forward. The reduced activation area DA2 is obtained by reducing, in the width direction or the lateral direction of the vehicle 500, the reference activation area DA1, which is set under the assumption that the vehicle is traveling straight. The amount of reduction may increase with a decrease in the estimated turning radius R, and may be decreased not only in the width direction of the vehicle 500 but also in a direction perpendicular to the width direction.

[0031] In the present embodiment, even if the estimated turning radius R is equal to or smaller than the predetermined determination turning radius Rr when the host vehicle is making a constant turn, the reference activation area DA1 is set as the activation area to increase the occurrence of a determination to perform collision avoidance assistance. That the host vehicle is making a constant turn means that the estimated turning radius R is substantially constant and the lane makes a substantially fixed arc. Whenever the host vehicle is making a constant turn, it is determined by the steering rate and changes in the steering rate over time, as described later.If it is determined that R ≤ Rr ("Yes" branch in step S120), the CPU 101 then determines whether a curve radius flag F indicating whether it has been determined that the estimated curve radius R is equal to or smaller than the predetermined determination curve radius Rr is set to 0. That is, the CPU 101 determines whether it is determined for the first time that R ≤ Rr. If it is determined that F = 0 ("Yes" branch in step S130), the CPU 101 sets the reduced activation area DA2 as the activation area (in step S132), sets the curve radius flag F to 1, and proceeds to step S180. That is, if it is determined that R ≤ Rr, the CPU 101 sets the reduced activation area DA2 as the activation area for the first time.

[0032] If it is not determined that F = 0 ("No" branch in step S130), the CPU 101 then determines whether the steering rate V (deg / sec) is equal to a predetermined determination steering rate Vr (deg / sec) (in step S140). Specifically, if the reduced activation area DA2 is already set as the activation area, the CPU 101 subsequently sets the reference activation area DA1 as the activation area when the host vehicle is making a constant turn. The steering rate V may be, for example, the rotation angular velocity of the vehicle 500 detected by the yaw rate sensor 25 or the rotation angular velocity of the steering wheel 504 detected by the rotation angle sensor 23. The steering rate V becomes a positive or a negative value in a left-right direction with respect to the neutral position of the steering wheel 504. In the present embodiment, this means the absolute value of the steering angle V, i.e.the magnitude of the steering rate V, and it is determined whether 0 ≤ the steering rate V ≤ the target steering rate Vr. The steering rate V is used to determine whether the steering operation of the vehicle 500 is large or small. Instead of the steering rate V, the steering angle can be used. This is because, in general, the vehicle frequently performs a large turning action with unstable turning behavior when the steering angle is large.

[0033] If it is not determined that the steering rate V ≤ the determination steering rate Vr (“No” branch in step S140), the CPU 101 goes to step S132. The case where the steering rate V ≤ the determination steering rate Vr does not stop may, for example, be in a driving state of the vehicle M1 which, as shown in Fig. 4, is about to enter a winding road from a straight road or of the vehicle M3, which is on a straight road, as in Fig. 5, meandering may occur. When the steering rate V is high, the turning action of the vehicle M1 or M3 fluctuates with a high degree of turning as shown in the travel trajectory TL1 and RTL3, so that the vehicles M1 and M3 cannot be said to be making a constant turn. Therefore, the reduced activation area DA2 is set as the activation area in order to reduce or avoid unnecessary collision avoidance assistance being performed against an object on the road side as a target object. In addition, when the reference activation area DA1 is currently set as the activation area and the steering rate V ≤ the determination steering rate Vr continues, the reduced activation area DA2 is set as the activation area.For example, when the driver performs an abrupt steering operation during a constant curve, the activation area is changed from the reference activation area DA1 to the reduced activation area DA2.

[0034] If it is determined that the steering rate V ≤ the determination steering rate Vr (“Yes” branch in step S140), the CPU 101 then determines whether the steering rate V is stable (in step S150). The case where the steering rate V is stable may occur in the driving state of the vehicle M2 traveling in the traveling trajectory TL2 on a curved road as shown in Fig. 4. Whether the steering rate V is stable can be determined, for example, by determining whether the magnitude of the steering rate V is equal to or smaller than a stability determination speed Str or a stability determination rate, ie whether 0 ≤ the steering rate V ≤ Str, as in Fig. 7, over a determination period tr. The stability determination speed Str can be said to be a varying threshold or a determination steering rate for determining that the steering rate V is stable. In the present embodiment, the stability determination speed Str ≤ the determination steering rate Vr. Since the steering rate V being stable is the same as the steering angle being substantially constant, it can be determined that the steering rate V is stable when the steering angle is within a predetermined range of variation over the determination period tr. Even if the turning trajectory is generally constant, a small correction is generally made for the steering angle. When the change in the steering rate V or the steering angle over time is within a range of small corrections, it can be determined that the turning action of the vehicle M2 is stable.The steering rate V used in determining whether the steering rate V is stable may be the steering rate or the rotation angular velocity output by one of the rotation angle sensor 23 and the yaw rate sensor 25. From the standpoint of better estimation of the driver's steering operation, it is desirable to use the steering angle of the steering wheel 504 operated by the driver.

[0035] If it is determined that the steering rate V is stable ("Yes" branch in step S150), the CPU 101 proceeds to step S170 to set the reference activation area DA1 as the activation area. That is, if the steering rate V is equal to or less than the determination steering rate Vr and the steering rate V is stable, the CPU 101 determines that the vehicle 500 is making a constant turn and sets the reference activation area DA1 as the activation area, even if the estimated turning radius R is equal to or less than the determination turning radius Rr.

[0036] If it is determined that the steering rate V is unstable ("No" branch in step S150), the CPU 101 proceeds to step S160 to set the same activation area as before to maintain the current activation area. That is, in the present embodiment, the CPU 101 determines whether to set the reduced activation area DA2 using the determination steering rate Vr, and determines whether to maintain or change the activation area using the stability determination speed Str. The stability determination speed Str can be said to be a determination steering rate for determining whether the steering rate V is stable.A difference between the determination steering rate Vr and the stability determination speed Str, which are set to different values, causes a hysteresis or deadband to suppress frequent switching between the reference activation area DA1 and the reduced activation area DA2. Note that Vr = Str.

[0037] If it is not determined that R ≤ Rr ("No" branch in step S120), the CPU 101 sets the curve radius flag F to zero (in step S125) and sets the reference activation area as the activation area (in step S170). That is, the estimated curve radius R is larger than the determination curve radius Rr, and there is a low probability that unnecessary driving assistance against an object on the road side will be performed, and thus the reference activation area DA1 is set as the activation area.

[0038] The CPU 101 performs collision avoidance assistance processing using the currently set activation area (in step S180) and then terminates this processing routine. In the collision avoidance assistance processing, the CPU 101 identifies the object as a target of collision avoidance assistance in the activation area using the driving environment information, and uses the relationship of a position and a relative speed between the identified object and the host vehicle obtained from the driving state information and the driving environment information to perform driving assistance processing to calculate a control command value for performing at least one of the assistances: brake assistance, which includes sudden braking with a high braking level for collision avoidance, and steering assistance, which includes sudden steering with a large steering angle or a high steering rate.The CPU 101 transmits the calculated control command value to the driving assistance device 31 to perform collision avoidance assistance as a driving assistance.

[0039] According to the driving assistance control device 100 in the first embodiment, as shown in Fig.7, the activation area is reduced to the reduced activation area DA2 when the estimated turning radius R is equal to or smaller than the determination turning radius Rr and the vehicle is not making a constant turn, that is, when V > Vr and V > Str stops. Thereafter, when V ≤ Vr stops and V ≤ Str continues to stop for the determination period tr, it is determined that the vehicle is making a constant turn, and the reduction of the activation area is canceled or reset to set the reference activation area DA1. Even if V > Str stops thereafter, it is continuously determined that the vehicle is making a constant turn, and the reference activation area DA1 is maintained as the activation area until V > Vr stops. Then, when V > Vr stops, it is no longer determined that the vehicle is making a constant turn, and the activation area is reduced to the reduced activation area DA2.The determination period tr may take a fixed value or a variable value depending on the speed or a steering angle of the vehicle 500, provided that the period is sufficient to determine the stability of the turning behavior of the vehicle 500. In the case where the determination period tr takes a variable value, the determination period tr may be set to increase as the speed of the vehicle 500 increases or as the steering angle of the vehicle 500 increases. This is because the vehicle 500 exhibits a relatively steep turning behavior under these conditions, and thus a long-term determination is desirable for estimating stability.

[0040] According to the driving assistance control device 100 in the first embodiment, as described above, when the vehicle makes a constant turn, even if the estimated turning radius R is equal to or smaller than the determination turning radius Rr, the driving assistance processing can be performed using the reference activation area DA1 instead of the reduced activation area DA2. This makes it possible to perform collision avoidance assistance with respect to a wider range of objects while suppressing implementation of unnecessary collision avoidance assistance without reducing the activation area, even if the vehicle 500 makes a turn on a curved road or the like.Consequently, it is possible to increase the occurrence of performing collision avoidance assistance during turning of the vehicle 500 and to reduce or avoid a collision or contact between the subject vehicle and the target object by implementing collision avoidance assistance during turning of the vehicle. Other embodiments

[0041] (1) In the driving assistance control device 100 according to the first embodiment, it is determined that the vehicle 500 is making a constant turn, and the reference activation area DA1 is set as the activation area when the steering rate V ≤ the determination steering rate Vr continues and the steering rate V is stable. In an alternative embodiment, it may be determined that the vehicle 500 is making a constant turn when the steering rate V ≤ the determination steering rate Vr continues without determining that the steering rate V is stable. This is because when the steering rate V is equal to or less than the determination steering rate Vr, the behavior of the vehicle 500 is relatively stable, and thus it can be determined that the vehicle 500 is making a constant turn. In this case, using a small value of the determination steering rate Vr while using only the steering rate V makes it possible to more appropriately determine that the vehicle 500 is making a constant turn.

[0042] (2) In the previous embodiment, the control unit is implemented in software by the CPU 101 executing the driving assistance program P1. In an alternative embodiment, the control unit may be implemented in hardware by a pre-programmed integrated circuit or a discrete circuit.

[0043] The present embodiment has been described above based on the embodiments and modifications. However, the embodiments of the present invention described above are provided to make the present invention easy to understand and should not be interpreted as limiting the present invention. The present invention can be modified or improved without departing from the spirit of the present invention or the scope of the claims, and the present invention has its equivalent embodiments. The technical features of the embodiments and modifications corresponding to the technical features of the modes described in the summary of the invention section can be replaced or appropriately combined to solve the same or all of the problems described above or to obtain some or all of the advantageous effects described above.In addition, the technical features may be appropriately deleted as long as they are not described herein as essential.

[0044] For example, the driving assistance control device for a vehicle according to the first aspect described above can be set as Example 1. The driving assistance control device according to Example 1, in which the control unit determines whether the vehicle is making a constant turn using a steering rate as the driving state, can be set as Example 2. The driving assistance control device for a vehicle according to Example 2, in which the control unit determines that the vehicle is making a constant turn when the steering rate is equal to or less than a predetermined speed threshold, can be set as Example 3.The driving assistance control device according to Example 2, in which the control unit determines that the vehicle is making a constant turn when the steering rate is equal to or less than the predetermined speed threshold and a variation in the steering rate is equal to or less than a predetermined variation threshold, can be set as Example 4. The driving assistance control device for a vehicle according to any one of Examples 1 to 4, in which the reduced activation area is smaller than the reference activation area in a width dimension of the vehicle, can be set as Example 5.

Claims

[1] Driving assistance control device (100) for a vehicle, comprising: an acquiring unit (103) that acquires a detected driving state of the vehicle and a detected driving environment of the vehicle, and a control unit (101, P1) that, when a turning radius of a travel trajectory of the vehicle is equal to or smaller than a predetermined radius threshold, causes a driving assistance unit (31) to perform collision avoidance assistance using a reduced activation area obtained by reducing a reference activation area as an activation area of ​​the collision avoidance assistance, and when it is determined that the vehicle is making a constant turn, causes the driving assistance unit (31) to perform the collision avoidance assistance using the driving state of the vehicle and the driving environment of the vehicle and the reference activation area, even if the turning radius of the travel trajectory is equal to or smaller than the radius threshold. [2] The driving assistance control device (100) according to claim 1, wherein the control unit (101, P1) determines whether the vehicle is making a constant turn using a steering rate as the driving state. [3] The driving assistance control device (100) according to claim 2, wherein the control unit (101, P1) determines that the vehicle is making a constant turn when the steering rate is equal to or less than a predetermined speed threshold. [4] The driving assistance control device (100) according to claim 2, wherein the control unit (101, P1) determines that the vehicle is making a constant turn when the steering rate is equal to or less than the predetermined speed threshold and a variation in the steering rate is equal to or less than a predetermined variation threshold. [5] The driving assistance control device (100) according to any one of claims 1 to 4, wherein the reduced activation area is smaller than the reference activation area in a width dimension of the vehicle. [6] Driver assistance system (10) comprising: the driving assistance control device (100) according to one of claims 1 to 5, a detection unit that detects the driving condition and the driving environment, and the driving assistance unit (31) which performs the collision avoidance assistance under an instruction from the control unit (101, P1). [7] Driving assistance control method for a vehicle comprising: Obtaining a recorded driving state of the vehicle and a recorded driving environment of the vehicle, if a curve radius of a travel trajectory of the vehicle is equal to or smaller than a predetermined radius threshold, setting an activation area of ​​a collision avoidance assistance to a reduced activation area obtained by reducing a reference activation area, and when it is determined that the vehicle is making a constant turn, performing collision avoidance assistance processing using the driving state of the vehicle and the driving environment of the vehicle and the reference activation area, even if the turning radius of the driving trajectory is equal to or smaller than the radius threshold.

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