JP6547791B2 - Vehicle driving support device and method thereof - Google Patents

Description

  According to the present invention, for example, in a state where the driver can not drive, a target route to a predetermined target point shifted in the width direction of the vehicle with respect to the longitudinal direction of the vehicle is set, and the set target route is decelerated TECHNICAL FIELD The present invention relates to a driving assistance device for a vehicle that supports driving accompanied by steering until it stops at a target point, and a method therefor.

  2. Description of the Related Art Conventionally, as a driving support device for supporting the driving of a vehicle, one that controls acceleration and deceleration of the vehicle and one that controls steering of the vehicle are known. For example, according to Patent Document 1, when it is detected that the driver has fallen into an inoperable state during traveling, the vehicle is retracted to a shoulder that is shifted in the lateral direction (width direction of the vehicle) with respect to the traveling path. There is disclosed an emergency evacuation system which controls the brake ACT (32) to obtain a predetermined target deceleration and target deceleration gradient so as to stop the vehicle in the parking position. Furthermore, Patent Document 1 also discloses that, by controlling the brake ACT (32), the speed (deceleration) of the vehicle is, for example, gradually (inversely) reduced or reduced at a constant speed. (See paragraph [0038] of Patent Document 1, and FIGS. 3 and 4).

  By the way, during the period from when the vehicle starts turning to the shoulder of the road until it stops, in fact, excessive conditions such as steering cut and turnback will be the majority, so the target route to the target stop point on the road shoulder The followability (trace performance) of the vehicle to the vehicle speed depends on the yaw rate control performance. And the control performance of this yaw rate changes with the magnitude | size of the yaw time constant (response difference of a front wheel and a rear wheel) showing the response characteristic of a vehicle.

  For this reason, if the deceleration (brake) is not properly controlled in the automatic operation with the steering operation and the brake control such as the retraction operation to the road shoulder, the control performance variation of the yaw rate becomes large with the fluctuation of the yaw time constant. In some cases, there is a risk of getting out of the target route.

  However, in the emergency evacuation system of Patent Document 1, the deceleration during the evacuation operation is reduced with a uniform characteristic such as an inverse proportion or a constant speed, and the influence of the fluctuation of the vehicle dynamic characteristic on the following characteristic That is, the effect of the yaw time constant was not considered, and there was room for consideration.

JP, 2009-163434, A

  The present invention has been made in view of such problems, and by enhancing the ability to follow a target route, a driving assistance device for a vehicle capable of automatically driving on the target route without departing from the target route and the same The purpose is to provide a method.

  The present invention includes target route setting means for setting a target route to a predetermined target point shifted in the width direction (lateral direction) of the vehicle with respect to the longitudinal direction (travel direction) of the vehicle, and decelerating the target route In a driving support apparatus for a vehicle performing driving accompanied by steering while traveling while stopping at the target point, deceleration control for controlling the longitudinal deceleration of the vehicle so as to minimize the fluctuation of the vehicle's yaw time constant It is equipped with means.

  According to the above configuration, the followability to the target route can be enhanced by controlling the deceleration in the longitudinal direction of the vehicle so that the fluctuation of the yaw time constant of the vehicle is minimized, and the deviation from the target route does not occur. It is possible to drive automatically on the target route.

  In the present invention, it is more preferable to set the deceleration such that the amount of change in the yaw time constant is 0 (that is, the yaw time constant is constant), but not limited thereto. As long as the deceleration in the traveling direction of the vehicle is set.

According to an aspect of the present invention, the velocity of the vehicle traveling along the target route of the vehicle is v (t), the deceleration is a _x (t), and the lateral direction is added to the vehicle in the lateral direction (width direction of the vehicle). Let acceleration be a _y (t),
The yaw time constant T _r (t) is
T _r (t) = f represented by _{(v (t), a x} (t), a y (t)).
The deceleration control means then evaluates the evaluation function S (t), for example, S = (T _r (t) −T _r (t + Δt)) ²
Of As, defined as the square of the variation of the yaw time constant (rate of change), in which the S sets the deceleration a _{x (t)} so as to minimize.

  According to the above configuration, even if there is no deceleration that makes the change amount of the vehicle's yaw time constant 0 (that is, the yaw time constant is constant), the deceleration that minimizes the fluctuation of the yaw time constant , And can be approximately calculated using a statistical method (e.g., least squares method).

  As an aspect of the present invention, the lateral acceleration for each passing point of a vehicle traveling on the target route is set based on the vehicle speed for each passing point and the curvature at each passing point, and the deceleration control means The deceleration profile setting means sets a deceleration profile relating to the deceleration of each passing point of the vehicle traveling on the target route based on the lateral acceleration for each passing point.

  According to the above configuration, attention is paid to the fact that the yaw time constant fluctuates depending on the vehicle speed, deceleration (longitudinal acceleration), and lateral acceleration for each passing point (passing time) on the target route. Based on the acceleration, it is possible to obtain a deceleration that minimizes the fluctuation of the yaw time constant.

  As an aspect of the present invention, the deceleration control means sets a deceleration profile regarding deceleration for each passing point of a vehicle traveling on the target route based on the lateral acceleration for each passing point. A steering profile setting unit configured to set a steering profile regarding a steering amount (steering angle) of the steering at each passing point of the vehicle traveling on the target route, the steering amount in the steering profile being on the target route In accordance with the lateral acceleration applied to the vehicle traveling at each passing point, the lateral acceleration is set based on at least the steering profile.

  According to the above configuration, the deceleration profile setting means focuses on the fact that the lateral acceleration is interlocked with the steering amount (steering profile) for each passing point of the vehicle traveling on the target route. By setting the steering profile, the lateral acceleration can be set based on the steering profile, and furthermore, the deceleration (deceleration profile) for each passing point of the vehicle traveling on the target route is set based on the lateral acceleration. can do.

  As an aspect of the present invention, the operation control means includes steering profile setting means for setting a steering profile regarding the steering amount of the steering at each passing point of the vehicle traveling on the target route, and the steering amount in the steering profile Is linked to the lateral acceleration applied to each vehicle passing on the target route at each passing point, and the vehicle traveling on the target route has a predetermined relationship between the amount of steering at each passing point and the degree of deceleration Deceleration profile setting means for setting a deceleration profile relating to deceleration at each passing point of the vehicle traveling on the target route based on the steering profile and the predetermined relationship. The

  According to the above configuration, if the steering amount (steering profile) of the steering for each passing point of the vehicle traveling on the target route is set, the passing point of the vehicle traveling on the target route is determined based on the steering profile. A deceleration profile can be set for each deceleration.

  As an aspect of the present invention, the predetermined relationship is a relationship in which the deceleration is gradually increased at least as the magnitude of the steering amount of the steering increases.

  According to the above configuration, it is possible to minimize the fluctuation of the yaw time constant by gradually increasing the deceleration at least as the magnitude of the steering amount of the steering increases. Thus, for example, the vehicle is decelerated at a constant deceleration on a target route to a target point which has a position shifted in the vehicle width direction with respect to the front and rear direction of the vehicle and stopped at the target point. It is possible to improve the followability on the target route.

  As an aspect of the present invention, the steering profile setting means performs a first steering step of steering the steering wheel so as to approach the target point with respect to the longitudinal direction of the vehicle before entering the target point; A second steering step for turning back the steering step notch to the neutral position, and a first steering step for the vehicle to approach parallel to the longitudinal direction of the vehicle before entering the target point on the near side of the target point. The steering profile includes the third steering step for steering in a direction opposite to the steering direction, and the fourth steering step for turning back the incision in the third steering step back to the neutral position.

  According to the above configuration, it is suitable for the target route to the target point which is shifted in the vehicle width direction with respect to the longitudinal direction of the vehicle before steering the first steering step (in other words, before entering the target point) The steering profile can be set.

  As an aspect of the present invention, the deceleration control means is a deceleration profile setting means for setting a deceleration profile related to deceleration for each passing point of the vehicle on the target route so as to stop at the target point, the deceleration profile The setting means includes a first deceleration step for increasing the deceleration during the first steering step, a second deceleration step for maintaining the deceleration constant during the second steering step, and the third steering step. Setting the deceleration profile including a third deceleration step of increasing the deceleration and a fourth deceleration step of maintaining the deceleration constant during the fourth steering step.

  According to the above configuration, according to the steering profile (the amount of steering at each passing point on the target route), the deceleration profile setting unit controls the deceleration by controlling the deceleration as in the first to fourth deceleration steps. The variation of the time constant can be minimized, that is, the followability to the target path can be enhanced.

  As an aspect of the present invention, in the driving support device for supporting the driving of the vehicle according to the state of the occupant, the target point is assumed to be in the evacuation space, and the occupant state acquiring means for acquiring the occupant's state; The vehicle includes a retraction space detecting means for detecting a retraction space for retracting the vehicle when an abnormality occurs in the occupant state.

  According to the above configuration, particularly when an abnormality occurs in the occupant state while the vehicle is traveling, the vehicle can be reliably stopped at the target point even when the vehicle is retracted, and the vehicle can be retracted to a safe place.

  The present invention executes target route setting processing for setting a target route to a predetermined target point shifted in the vehicle width direction with respect to the longitudinal direction of the vehicle, and travels while decelerating on the target route at the target point In a driving assistance method for a vehicle that performs driving with steering that stops, deceleration control processing is performed to control deceleration in the front-rear direction of the vehicle so as to minimize the fluctuation of the yaw time constant of the vehicle.

  According to the above configuration, the followability to the target route can be enhanced by controlling the deceleration in the longitudinal direction of the vehicle so that the fluctuation of the yaw time constant of the vehicle is minimized, and the deviation from the target route does not occur. It is possible to drive automatically on the target route.

  According to the present invention, the followability to the target route can be improved, and the automatic operation on the target route can be performed without departing from the target route.

BRIEF DESCRIPTION OF THE DRAWINGS The block diagram which shows the electric constitution of the vehicle carrying the driving assistance device by embodiment of this invention. The flowchart which shows a part of driving assistance process which the driving assistance device by embodiment of this invention performs. FIG. 3 is a flowchart of driving support processing following FIG. 2; BRIEF DESCRIPTION OF THE DRAWINGS The top view which shows an example of the evacuation space which the vehicle carrying the driving assistance device by embodiment of this invention approachs. FIG. 7 is a diagram showing lateral acceleration and longitudinal acceleration corresponding to each point on the target route. It is a flowchart which shows the steering step of the vehicle which drive | works on a target path | route, Comprising: The conceptual diagram of a steering profile. The flowchart which shows the deceleration profile determination processing which determines the deceleration of the vehicle which drive | works on a target path | route. The conceptual diagram which shows the mode of a change of a yaw time constant according to the deceleration degree and lateral acceleration for every predetermined vehicle speed. FIG. 7 is a diagram showing each time change of the vehicle speed and the yaw time constant in the case of decelerating at a constant deceleration up to the target point and in the case of decelerating so that the change of the yaw time constant is minimized. The graph which shows the comparison result of the trace error maximum value in the case where it decelerates with fixed deceleration to a target point by fixed deceleration, and when decelerating so that the change of a yaw time constant may become the minimum, and a yaw time constant change integrated value. FIG. 7 is a diagram showing a relationship between lateral acceleration and longitudinal acceleration of a vehicle traveling on a target route. FIG. 16 is a diagram showing each time change of the vehicle speed and the yaw time constant in the case of decelerating at a constant deceleration up to the target point and in the case of decelerating so as to minimize the change of the yaw time constant in another embodiment.

Hereinafter, embodiments of the present invention will be described in detail.
Hereinafter, a driving support apparatus according to an embodiment of the present invention will be described with reference to the attached drawings.
First, a vehicle equipped with a driving assistance apparatus according to an embodiment of the present invention will be described with reference to FIG.

As shown in FIG. 1, the code | symbol 2 is a driving assistance device code | symbol by this embodiment, and the code | symbol 1 shows the vehicle carrying the driving assistance device 2 by this embodiment.
The vehicle 1 is an external camera 3 for photographing the front of the vehicle 1, an occupant state sensor 4 for detecting the state of an occupant in the vehicle compartment, and evacuating the vehicle 1 from the traffic lane Rm (see FIG. 4A) in an emergency. The map database 5, which stores information on the position and shape of the evacuation space S (for example, an emergency parking zone, a shelter, etc.) (see FIG. 4 (a)), and the GPS 8 (Global Positioning System) A vehicle speed sensor 7 and an acceleration sensor 8 for detecting an acceleration in the traveling direction of the vehicle 1 are provided. The image data taken by the camera 3 outside the vehicle, the information on the evacuation space S acquired from the map database 5, the position information acquired by the GPS 8, and the detection data detected by each sensor are output to the ECU 20 (driving support device 2) Be done.

  The ECU 20 is an occupant state acquisition unit 21 that acquires the state of the occupant of the vehicle 1, a retraction space detection unit 22 that detects a retraction space S that retracts the vehicle 1, and retraction that determines the vehicle 1 entering the retraction space S Space entry possibility determination unit 23, target route setting unit 24 for setting a save route R (see FIG. 4A) as a target route, and the vehicle 1 from the entrance Ps of the save space S (see FIG. 4) save space A steering profile setting unit 25 for setting a steering profile for stopping at the target point Pd of S (see the same figure), decelerates the vehicle 1 from the entrance Ps of the evacuation space S, and sets the target point Pd in the evacuation space S A deceleration profile setting unit 26 for setting a deceleration profile for stopping the vehicle, and controlling the engine 10 and the brake 11 of the vehicle 1 according to the deceleration profile It includes a deceleration control unit 27, and a steering torque controller 28 which controls the electric power steering 12 of the vehicle 1 in accordance with the steering profile.

  21 to 28 include a CPU, various programs interpreted and executed on the CPU (including a basic control program such as an OS, and an application program activated on the OS to realize a specific function), programs, and various data. And a computer having an internal memory such as a ROM or a RAM for storing data.

  Next, as shown in FIG. 4A, a predetermined target point Pd in the evacuation space S shifted in the lateral direction (y direction) with respect to the traveling direction (x direction) of the vehicle 1 traveling on the traveling lane Rm When stopping the vehicle 1 while decelerating the vehicle 1 along the target route (evacuation route R), the driving support process executed by the driving support device 2 of the present embodiment will be described in order from the background art as the premise.

  In order to prevent traffic accidents, automatic driving technology is actively studied. In order to prevent accidents using automatic driving technology, it is possible to travel safely without colliding with obstacles including other vehicles in general traffic flow, and correct the vehicle to a safe place which does not disturb the traffic of other vehicles. You need to stop it. Therefore, a target tracking performance with high accuracy is required as compared with an ADAS device that functions as a driver assistance, such as a conventional anti-slip device.

  So far, while the technology to generate the target route has been studied as a field of information science such as graph search and dynamic programming, the technology to trace the target route (trajectory and vehicle speed) with high accuracy is the dynamics of the vehicle. And research on control technology, and the current state is that research on both technologies has been carried out separately.

  However, in practice, the vehicle 1 is moved along a target route (for example, a target route including a trajectory that describes a sigmoid curve (S-shaped curve)) to a predetermined target point Pd laterally shifted with respect to the travel lane Rm. When traveling, the target of the variation of the dynamic characteristic of the vehicle 1 is, for example, the variation of the lateral acceleration applied to the vehicle 1 (the acceleration applied in the direction orthogonal to the traveling direction of the vehicle 1 traveling along the target route in plan view) In order to influence the ability to follow the route (R), the inventors considered the deceleration (deceleration profile) of the vehicle 1 up to the target point Pd in consideration of such fluctuation of the dynamic characteristics of the vehicle 1 .

  Driving conditions in the real environment, including traveling along a target route (R) to a predetermined target point Pd laterally shifted with respect to the traffic lane Rm, include acceleration and deceleration of the vehicle 1, steering cut and turnback It is important to improve the control performance of the yaw time constant (yaw rate) in the transient region, since the transient state such as is the majority.

なお、Ｋ_ｆ，Ｋ_ｒは、それぞれ前輪、後輪の等価コーナリングスティフネスであり、共に荷重移動によって変化し、車両の特性によって定まる係数である。Ａはスタビリティファクタ（ステアリング特性、すなわち、車両がアンダステアかオーバーステアかによって変わる定数）、ｍは車体質量、Ｉはヨー慣性モーメント、Ｖは車速、ｌは前輪と後輪との前後方向の距離、ｌ_ｆ，ｌ_ｆは車体重心位置からそれぞれ前輪、後輪までの前後方向の距離を示す。 Specifically, the yaw rate transfer function γ in the two-wheel model is represented by [Equation 1], and the transient response is determined by the yaw time constant T _r , the natural frequency ω _n and the damping ratio φ as shown in [Equation 1] . Since the vehicle speed can be regarded as almost steady for the transient region (~ 0.5 Hz) of lateral motion, parameter changes such as natural frequency ω _n , damping ratio φ, and yaw time constant _Tr are accompanied by the coefficient _Kf and the coefficient It results from the fluctuation of K _r . As for the parameter structure of the yaw rate transfer function γ, the natural frequency ω _n and the damping ratio φ are, as is apparent from the following [Equation 2] and [Equation 3], the coefficient K _f and the coefficient K _r are sums and products As the yaw time constant T _r contains only the coefficient K _r , as is apparent from [Equation 4], the yaw time constant T _r is likely to be affected by the back and forth movement. It can be said.

K _f and K _r are equivalent cornering stiffnesses of the front and rear wheels, respectively, and they are coefficients which change depending on the load movement and are determined by the characteristics of the vehicle. A is a stability factor (steering characteristics, that is, a constant that changes depending on whether the vehicle is understeer or oversteer), m is a body mass, I is a yaw moment of inertia, V is a vehicle speed, and l is a distance between front and rear wheels , L _f and l _f indicate the distances in the front-rear direction from the vehicle center of gravity position to the front wheels and the rear wheels, respectively.

Therefore, as described above, the inventors pay attention to the fact that the yaw time constant T _r is easily influenced by the back and forth motion, and the longitudinal acceleration (target of the vehicle) is performed as the driving support processing executed by the driving support device 2 of the present embodiment. The acceleration in the traveling direction of the vehicle 1 traveling along the route R, that is, the deceleration a _x (longitudinal acceleration) is set such that the amount of change of the yaw time constant T _r is minimized.

Next, it will be described taking an example in which a target route to draw a sigmoid curve for setting algorithm deceleration a _x the amount of change in the yaw time constant is the minimum vehicle travels while decelerating.

First, focusing on [Equation 4], of the parameters constituting the yaw time constant T _r , the vehicle body mass m and the distances l and l _f are structural parameters of the vehicle body and are invariant during traveling of the vehicle on the target route. On the other hand, the vehicle speed V changes because it travels while decelerating on the target route, and the coefficient K _r changes due to the load movement when the vehicle travels on the target route that draws a sigmoid curve.

で表される。ここでヨー時定数Ｔ_ｒ（ｔ）のΔｔ［ｓ］後の変化量の２乗で定義される評価関数Ｓ（ｔ）は、統計的手法（例えば最小二乗法）に基づいて、

で表される。この［数６］を用いて評価関数Ｓ（ｔ）が最小となるように目標経路上の車両１の通過地点ごとのａ_ｘ（ｔ）を設定し、減速度プロファイルを生成する。
次に、図２、図３のフローチャートを用いて、本実施形態の運転支援装置２が実行する運転支援処理について説明する。
まず、図２、図３の運転支援処理は、ドライバの状態に応じて車両１の運転を支援する処理であり、例えば車両１のイグニッションスイッチがＯＮにされた後に実行される。 Then, assuming that the vehicle speed is v (t), the deceleration is a _x (t), and the lateral acceleration is a _y (t), the yaw time constant T _r (t) is v (t) other than [Equation 4] , A _x (t), a _y (t) functions, ie

Is represented by Here, the evaluation function S (t) defined by the square of the variation after Δt [s] of the yaw time constant T _r (t) is based on a statistical method (for example, the least squares method).

Is represented by The [6] to set the a _{x (t)} the evaluation function S (t) is per pass position of the vehicle 1 on the target path so as to minimize is used to generate a deceleration profile.
Next, driving support processing executed by the driving support device 2 of the present embodiment will be described using the flowcharts of FIG. 2 and FIG. 3.
First, the driving support process of FIGS. 2 and 3 is a process of supporting the driving of the vehicle 1 according to the state of the driver, and is executed, for example, after the ignition switch of the vehicle 1 is turned on.

As shown in FIG. 2, when the driving support process is started, the ECU 20 reads output values of various sensors mounted on the vehicle 1 in step S1.
Subsequently, in step S2, the occupant state acquisition unit 21 determines whether or not there is an abnormality in the state of the driver based on the output value of the occupant state sensor 4 read in step S1. For example, the occupant state sensor 4 may be a blink detection camera for detecting blinks of the driver, an infrared sensor for detecting body surface temperature or pulse wave of the driver, load balance or body surface pulse wave according to the posture of the driver. A seat sensor or the like to be detected can be used, and the occupant state acquisition unit 21 determines whether or not there is an abnormality in the state of the driver based on the data output from the occupant state sensor 4.

  In the present embodiment, “there is an abnormality in the state of the driver” means that it is a difficult state for the driver to drive the vehicle 1. For example, when the body surface temperature of the driver is outside the predetermined range or when the pulse wave number of the driver is outside the predetermined range, the occupant state acquisition unit 21 determines that the driver state is abnormal.

  As a result, when there is no abnormality in the state of the driver, the process returns to step S1. Thereafter, steps S1 and S2 are repeated until it is determined in step S2 that there is an abnormality in the state of the driver.

  On the other hand, when there is an abnormality in the state of the driver, the process proceeds to step S3, and the ECU 20 switches the driving operation of the vehicle 1 to the automatic driving. That is, the ECU 20 automatically performs acceleration / deceleration and steering of the vehicle 1 instead of the driver.

  Next, in step S4, the evacuation space detection unit 22 is evacuation closest to the current position in the traveling direction of the vehicle 1 based on the data read from the external camera 3 or the GPS 8 in step S1 or the data acquired from the map database 5. Space S is detected. The evacuation space S is a space in which the vehicle 1 can be evacuated from the traveling lane Rm as shown in FIG. 4A, and for example, an emergency parking zone or a shelter can be used.

In the following step S5, the evacuation space approach possibility determination unit 23 detects the distance from the current traveling position of the vehicle 1 to the entrance Ps (see FIG. 4A) of the evacuation space S detected in step S4 by the vehicle speed sensor 7. It is determined whether to enter the evacuation space S based on the current vehicle speed of the vehicle 1 and the imaging data of the evacuation space S imaged by the external camera 3 or the like. Specifically, whether or not the vehicle 1 can be safely decelerated to a speed V ₀ or lower that can enter the evacuation space S by the time the vehicle 1 reaches the entrance Ps of the evacuation space S from the current traveling position It is determined whether the vehicle 1 can enter the evacuation space S based on whether the other vehicle 1 is stopped in the evacuation space S or not.

  When it is determined by the evacuation space approach possibility determination unit 23 that the vehicle 1 can not approach the evacuation space S (step 5: No), the process returns to the front of step 4 and the vehicle 1 can enter next The processes in steps 4 and 5 are repeated until the save space S is determined.

On the other hand, when it is determined by the evacuation space approach possibility determination unit 23 that the vehicle 1 can approach the evacuation space S (step 5: Yes), the vehicle 1 is reached by the time the vehicle 1 reaches the entrance Ps of the evacuation space S The acceleration / deceleration control unit 27 controls the brake 11 and the engine 10 of the vehicle 1 so as to reduce the speed 1 to a speed V _{0 that} can enter the evacuation space S (step 6).

Next, in step 7 shown in FIG. 3, the target route setting unit 24 sets the target point Pd of the vehicle 1 in the evacuation space S and the entrance Ps of the evacuation space S as shown in FIG. And the target point Pd are connected to draw a sigmoid curve to set an evacuation route R as a target route of the vehicle 1. Specifically, as shown in FIG. 4A, the save space detection unit 22 sets the save route R based on the data read from the external camera 3 or the GPS 8 in step S1, or the data acquired from the map database 5. Information such as the length L _x (longitudinal distance) in the direction (x direction) in which the traveling lane Rm extends or the length L _y (lateral distance) in the direction (y direction) orthogonal to the traveling lane Rm is acquired. As information on the evacuation route R, for example, the length L of the evacuation route R, the curvature ρ of each point, coordinate information, and the like are determined.

  Next, in step 8, the steering profile setting unit 25 reads information such as the length L of the evacuation route R detected by the target route setting unit 24 and the curvature ρ of each point of the evacuation route R, and these evacuation routes R The steering profile (steering direction and steering amount for each passing point of the vehicle 1 traveling on the retreat route R) is set based on the information related to.

Specifically, the steering profile setting unit 25 sets the evacuation route R based on the shape of each point of the evacuation route R (the inclination of each point of the evacuation route R, the magnitude of the curvature, the presence of an inflection point, etc.) for convenience. As shown in FIG. 5A along the direction in which the traveling lane Rm of the retraction route R extends, a steering profile configured of a plurality of steering steps set for each section where the retraction route R is divided is set. For example, when the retraction route R draws a sigmoid curve as in this example, the steering profile setting unit 25 segments the retraction route R as shown by a waveform L _xy shown in FIG. 5A representing the retraction route R. The four sections D1 to D4 are divided, and a steering profile consisting of four steering steps corresponding to each of these sections is set.

  In addition, the front-back distance which shows the horizontal axis of the diagram of Fig.5 (a) shows the distance of the component parallel to the direction (x direction) in which the travel lane Rm extends among retraction | saving path R, The horizontal distance which similarly shows a vertical axis Represents the distance of the component in the direction (y direction) orthogonal to the direction in which the traveling lane Rm extends in the retraction route R.

  FIG. 6 is a conceptual view of a steering profile including steering steps set for each section of the retraction route R which draws a sigmoid curve.

  As shown in FIG. 6, the steering profile setting unit 25 sets the electric power at a predetermined steering amount so as to approach the target point Pd with respect to the traveling direction of the traveling lane Rm corresponding to the section D1 of the retraction route R. In the first steering step (step 81) for cutting the steering 12 and the second steering step (step 82) for returning the cut of the electric power steering 12 in the first steering step to the neutral position corresponding to the section D2 of the retraction route R Then, on the near side of the vehicle 1 reaching the target point Pd corresponding to the section D3 of the evacuation route R, the steering direction of the first steering step is set to a predetermined direction opposite to the traveling direction of the road. The third steering step (step 83) for cutting the electric power steering 12 by the steering amount and the electric power at the third steering step corresponding to the section D4 of the retraction route R Fourth steering returning off cuts word steering 12 to the neutral position (step 84) to set the steering profile running in this order, the process proceeds to step 9 in FIG.

  The steering profile setting unit 25 may change the content of each steering step that configures the steering profile, as appropriate, in accordance with the shape of the retraction route R.

For example, in the second steering step corresponding to the section D2, after turning the electric power steering 12 in the first steering step back to the neutral position, before performing the electric steering of the electric power steering 12 in the third steering step, A time may be provided to maintain the electric power steering 12 at the neutral position (steering amount is zero). In the fourth steering step corresponding to the section D4, the electric power steering 12 is moved to the neutral position (steering) until the target point Pd is reached after the cut of the electric power steering 12 in the third steering step is turned back to the neutral position. A time may be provided to maintain the quantity 0).
The steering speed for each steering step and the time for maintaining the electric power steering 12 in the neutral position are on the retraction route R until automatic driving is performed based on various profiles (step 10 in FIG. 3). It sets suitably based on the vehicle speed in each passing point of vehicles 1 and the longitudinal acceleration of vehicles 1, etc.

Subsequently, in step 9 in FIG. 3, the deceleration profile setting unit 26 performs deceleration profile setting processing.
Specifically, as in step 91 shown in FIG. 7, the deceleration profile setting unit 26 sets the vehicle speed V ₀ at the entrance Ps of the evacuation space S that can enter the evacuation space S (the vehicle 1 traveling on the evacuation route R Based on the initial velocity V ₀ ), the length L of the evacuation path R set in step 7 and the curvature ρ, an initial deceleration a _{x 0} is set.

Specifically, the vehicle 1 located at the entrance Ps of the evacuation space S is, for example, decelerated on the evacuation path R from the initial speed V ₀ ′ (see FIG. 9B) at a constant deceleration a _xc and at the target point Pd. When the vehicle stops (see the waveform L _VC in FIG. 9B), the constant deceleration is represented by a _xc = V ₀ ' ² / 2L. In this example, the initial speed V ₀ (see FIG. 9B) is set with a margin more than when stopping at the target point Pd while decelerating at a constant deceleration a _xc , and at the initial stage at the entrance Ps of the evacuation space S the deceleration _{a x0,} for example, the constant deceleration _{a xc,} set to about half (in this example less than half) a value of ^{_{a x0 = V 0 2 / 4L}} (≒ 1/2 · a xc) ing.
The initial deceleration _ax0 is not limited to about half the constant deceleration _axc but may be set to another value, but is preferably set to a value equal to or less than the constant deceleration _axc .

で表される。 Here, assuming that the vehicle speed, the longitudinal acceleration, and the curvature of the target trajectory after time t [s] from the entrance Ps of the save space S are v (t), a _x (t), ρ (t), (t + Δt ) [S] after the vehicle speed and lateral acceleration,

Is represented by

Then, in step 92 in FIG. 7, the deceleration profile setting unit 26 determines the vehicle speed v (t) after t [s] from the entrance Ps of the save space S based on the deceleration a _x (t) and [Equation 7]. The vehicle speed v (t + Δt) after (t + Δt) [s] is set, and the vehicle speed v (t + Δt) calculated in step 92 in the subsequent step 93, the curvature ρ (t + Δt) calculated in step 7 in FIG. And, based on [Equation 8], the lateral acceleration a _y (t + Δt) of the vehicle 1 after (t + Δt) [s] is set, and in the subsequent step 94, the lateral acceleration a of the vehicle 1 calculated in step 93 The deceleration a _x (t + Δt) (front-rear acceleration) of the vehicle 1 at which the yaw time constant between Δt [s] is minimum based on _y (t + Δt) and the above-mentioned [Equation 5] and [Equation 6] Set

The deceleration profile setting unit 26 repeatedly executes the processing of such steps 92 to 94 until the deceleration a _x (t) of the vehicle 1 traveling from the entrance Ps of the evacuation space S to the target point Pd is set ( Step 95: No) When the deceleration a _x (t) of the vehicle 1 to the target point Pd is determined, the deceleration a _x (t) is set as a deceleration profile (step 95: Yes), Go to step 10 of

  Here, regarding the processing of steps 92 to 94 in FIG. 7 described above, three cycles after the first Δt [s], after 2 Δt [s] and after 3 Δt [s] from the entrance Ps of the save space S A more specific description will be given using FIG.

FIG. 8 is a diagram conceptually showing the variation of the yaw time constant expressed based on [Equation 5] and [Equation 6], and FIGS. 8 (a), (b) and (c). Is an area obtained by dividing the magnitude of the variation of the yaw time constant, which varies according to the deceleration a _x and the lateral acceleration a _y , when the vehicle speed is set to V ₁ , V ₂ and V ₃ respectively. Shows a conceptual diagram for each.

Here, the vehicle speeds V ₁ , V ₂ and V ₃ are vehicle speeds v (Δt) after 2 Δt [s] after Δt [s] of the vehicle 1 which has passed the entrance Ps of the save space S at V ₀ [s] The vehicle speed v (2Δt) after the vehicle speed v (3Δt) after 3 Δt [s] is shown. The area in FIG. 8 _{S n} is n-1 <S ≦ n (area _{S 0} is S = 0, the area _{S 1} is 0 <S ≦ 1, region _{S 2} is 1 <S ≦ 2, area _{S 3} is It shows notionally 2 <S <= 3, ...).

First, in step 92 in FIG. 7, based on the initial deceleration a _x0 (= V ² / 4L) set in step 91 as the vehicle speed at the entrance Ps of the evacuation space S, and [Equation 7], from the entrance Ps The vehicle speed V ₁ after Δt (s) is calculated. That is, as shown in FIG. 8A, V ₁ : v (Δt) = V ₀ + a _{x 0} Δt. In step 93 in FIG. 7, the lateral acceleration a _y1 of the vehicle 1 after Δt (s) from the entrance Ps of the evacuation space S is calculated based on V ₁ and [Equation 8]. That is, a _y1 : a _y (Δt) = ρ (Δt) · v (Δt) ² . In step 94 in FIG. 7, as shown in FIG. 8A, when a _y (t) = a _y1 , the evaluation function S (t) defined by the square of the change amount of the yaw time constant is the most Identify _ax1 that becomes smaller. Specifically, in combination with a _y1 , a _x1 that belongs to the area 0 in FIG. 8A is specified.

Returning to step 92 in FIG. 7, on the basis of _{a x1} and [Expression 7] identified in step 94, it calculates the vehicle speed _{V 2} after 2? T (s). That is, as shown in FIG. 8B, V ₂ : v (2Δt) = V ₀ + a _{x 1} · 2Δt. At step 93 in FIG. 7, the lateral acceleration a _y2 of the vehicle 1 after 2 Δt (s) is calculated based on V ₂ and [Equation 8]. That is, a _y2 : a _y (2Δt) = ρ (2Δt) · v (2Δt) ² . In step 94 in FIG. 7, as shown in FIG. 8B, when a _y (t) = a _y 2, the evaluation function S (t) defined by the square of the change amount of the yaw time constant is the most Identify _ax2 that becomes smaller.

Specifically, it is preferable to identify a _x2 as belonging to an area 0 in Fig. 8 (b) in the combination with a _y2, as shown in FIG. 8 (b), the area S _{0 (i.e.} yaw when when the variation constants 0) become a _y2 and a combination of _x2 is not present, as the amount of change in the yaw time constant is minimized, most among the region S ₁ in FIG. 8 (b) Based on a point close to S ₀ (see P ₂ in FIG. 8B), set a _{x 2} .

Returning to step 92 in FIG. 7, the processes of steps 92 and 93 are performed based on a _{x 2} and [Equation 7] and [Equation 8] specified in step 94 in the same manner as described above, and 3Δt (s) Lateral acceleration a _y3 of the vehicle 1 is calculated. That is, a _y3 : a _y (3Δt) = ρ (3Δt) · v (3Δt) ² . Then, in step 94 in FIG. 7, as shown in FIG. 8 _(c), when a y (t) _{= a y3,} small evaluation function S, which is defined by the square of the yaw time constant (t) is most Identify such a _x3 .

And by repeating the processing of steps 92 to 94 in FIG. 7 until the vehicle 1 reaches the target point Pd also after Δ 4 t [s], the lateral acceleration a from the entrance Ps of the evacuation space S to the target point Pd _{While being} able to specify _y (t), it is possible to set the deceleration a _x (t).

Specifically, the lateral acceleration applied to the vehicle 1 from the entrance Ps of the evacuation space S to the target point Pd has a waveform _Lay as shown in FIG. 5B, and the deceleration (longitudinal acceleration) applied to the vehicle 1 as well. Becomes a waveform L _ax as shown in FIG. 5 (b). The waveform L _ax shown in FIG. 5 (b) displays the deceleration profile.

  The processing up to step 9 in FIG. 3 described above is executed until the vehicle 1 reaches the entrance Ps of the evacuation space S (the initial position of the evacuation route R), and before the vehicle 1 actually travels on the evacuation route R In addition, a steering profile and a deceleration profile to be used when traveling are set in advance.

  When the vehicle 1 eventually reaches the entrance Ps of the evacuation space S, as shown in step 10 in FIG. 3, based on the steering profile set in step 8 described above and the deceleration profile set in step 9 described above The automatic driving is performed so that the vehicle 1 stops at the time when the vehicle 1 reaches the target point Pd in the evacuation space S while decelerating along the evacuation path R (step 11).

Here, the waveform L _Ic in FIG. 9 (a) is such that the vehicle 1 stops at the target point Pd while decelerating at a constant deceleration a _xc on the retraction route R with the vehicle speed at the entrance Ps substantially V ₀ '. The relationship between the variation of the yaw time constant and time is shown, and the waveform _Lvc in FIG. 9B shows the relationship between vehicle speed and time under the same conditions.

On the other hand, the waveform L _I in the diagram of FIG. 9A indicates the vehicle speed at the entrance Ps as V ₀ and the deceleration a _x at which the fluctuation of the yaw time constant becomes minimum according to the above-described driving support processing. The relationship between the variation of the yaw time constant and the time until the vehicle stops at the target point Pd while decelerating is shown, and the waveform L _vc in the diagram of FIG. 9 (b) is the vehicle speed and time under the same conditions. Show the relationship.
Sections X in FIGS. 9A and 9B correspond to the time during which the vehicle 1 travels along the evacuation route R from the entrance Ps to the target point Pd.

As shown in section X of FIG. 9 (a), (hereinafter also referred to as "the case of those examples.") On the retraction path R when the change amount of the yaw time constant is decelerated at a rate of a _x that minimize the It can be seen that the amount of change in the yaw time constant is smaller than when decelerating at a constant deceleration _axc on the retraction path R (hereinafter, also referred to as "the case of the conventional example").

Specifically, as is apparent from comparison of the two waveforms L _I and L _IC shown in the section X of FIG. 9A, the case of the present example (waveform L _I ) is better than the case of the conventional example (waveform L _IC ) Also, the difference between the maximum value and the minimum value of the yaw time constant is small.

  Then, by performing the driving support process as in this example, as shown in FIG. 10, compared with the case of the conventional example, the yaw time constant until the vehicle 1 traveling on the retreat route R reaches the target position The integrated value of the variation could be reduced by 11%.

  By the way, the followability (trace performance) of the vehicle 1 traveling on the retreat route R depends on the control performance of the yaw rate. And, the control performance of the yaw rate changes with the magnitude of the yaw time constant representing the response characteristic of the vehicle.

  Therefore, as shown in FIG. 10, the vehicle 1 traveling on the evacuation route R as compared with the conventional example by performing the driving support process to reduce the change amount of the yaw time constant as in this example. Could reduce the integrated value of the yaw rate control error by 11% until it reached the target position.

Furthermore, in step 10 in FIG. 3, the acceleration / deceleration control unit 27 controls the brake 11 and the engine 10 according to the deceleration profile based on the waveform L _ax as shown in FIG. The vehicle 1 can be decelerated at a deceleration that minimizes the amount (that is, a deceleration that results in the waveform L _ax shown in FIG. 5 (b)), whereby the trace to the evacuation route R is made more than in the conventional example. It is possible to enhance sex.

  Specifically, as shown in FIG. 10, in the case of this example, the tracing error with respect to the evacuation route R of the vehicle 1 traveling on the evacuation route R is reduced by 8% at the maximum value compared to the case of the conventional example. It was possible.

  The driving support apparatus 2 according to the present embodiment described above has a predetermined target shifted in the lateral direction (y direction in FIG. 4A) with respect to the direction of the traveling lane Rm (x direction in FIG. 4A). A vehicle 1 including a target route setting unit 24 (target route setting means) for setting a retreat route R up to a point Pd, traveling while decelerating on the retreat route R and stopping at the target point Pd; In the driving support apparatus 2, the deceleration profile setting unit 26 (deceleration control means) for controlling the deceleration in the traveling direction of the vehicle 1 so as to minimize the fluctuation of the yaw time constant of the vehicle 1 (see FIG. 1, step 9 of FIG. 3, FIG. 5 (b), FIG. 9 (a), (b) reference).

  According to the above configuration, by controlling the deceleration in the traveling direction of the vehicle 1 so that the fluctuation of the yaw time constant of the vehicle 1 is minimized, the followability to the retraction route R can be enhanced. Automatic operation can be performed to reach the target point Pd without departing.

The driving support device 2 according to the present embodiment adds the speed of the vehicle 1 traveling along the retreat route R of the vehicle 1 v (t), the deceleration a _x (t), and the lateral direction with respect to the vehicle 1 Assuming that the lateral acceleration is a _y (t), the yaw time constant T _r (t) is expressed by the above [Equation 5], and the deceleration profile setting unit 26 changes the yaw time constant based on the above [Equation 6] The deceleration a _x (t) is set so as to minimize the evaluation function S (t) defined by the square of the quantity.

  According to the above configuration, even if there is no deceleration at which the amount of change in the yaw time constant of the vehicle 1 becomes 0 (that is, the yaw time constant becomes constant), the deceleration with the smallest variation in the yaw time constant Can be approximately calculated using a statistical method (for example, the least squares method) (see FIG. 8B).

  The driving support device 2 according to the present embodiment uses the lateral acceleration at each passing point of the vehicle 1 traveling on the evacuation route R, the vehicle speed at each passing point, and the curvature at each passing point, as in [Equation 8]. Based on the lateral acceleration for each passing point, the deceleration profile setting unit 26 sets the deceleration based on the lateral acceleration, and the deceleration related to the deceleration for each passing point of the vehicle 1 traveling on the retraction route R is set. The profile is set (see step 9 in FIG. 3).

  According to the above configuration, attention is paid to the fact that the yaw time constant fluctuates depending on the vehicle speed, deceleration (longitudinal acceleration), and lateral acceleration for each passing point (time) on the save route R (see 5), and based on the vehicle speed and the lateral acceleration, the deceleration at which the fluctuation of the yaw time constant becomes minimum can be determined (see steps 91 to 94 in FIG. 7 and FIGS. 8A and 8B).

Next, a modified example (corresponding to claim 4) of the driving support process executed by the driving support device 2 of the present embodiment will be described.
As a premise of the modification of the driving support process, the lateral acceleration _ay and the steering amount (steering profile) at each passing point of the vehicle 1 traveling on the retreat route R generally interlocks with each other. Specifically, the steering amount per pass position of the vehicle 1 traveling on the retraction path R, the characteristic indicated by the lateral acceleration a _y, that is, the same characteristics as the waveform L _ay shown in the diagram of FIG. 5 (b).

Therefore, the inventors pay attention to this point, and in the above-described driving support processing, the deceleration profile setting unit 26 determines the lateral acceleration based on [Equation 8] in the step 93 in FIG. In step 94 in FIG. 7, the deceleration a _x (t), ie, the deceleration profile is set based on the lateral acceleration so that the variation of the yaw time constant is minimized. In a modification of the driving support processing here, the deceleration profile setting unit 26 is based on the steering amount (steering profile) that exhibits the same characteristics as the lateral acceleration (that is, the same waveform as the waveform _Lay in FIG. 5B). , A deceleration ( _x ) at which the variation of the yaw time constant becomes minimum, that is, the deceleration profile is set.

  According to the above configuration, since the lateral acceleration can be set (estimated) using the steering profile that is necessarily required in the driving support processing, as shown in step 93 in FIG. If the steering profile can be set in step 8 in FIG. 3 without separately calculating, the steering amount determined according to the steering profile can be used as a parameter indicating the lateral acceleration.

Specifically, in step 94 in FIG. 7, the parameter indicating the lateral acceleration specified (estimated) from the steering amount is taken as the lateral acceleration calculated in step 93, and using this, in the same manner as described above The deceleration a _x (t), that is, the deceleration profile can be set on the basis of [Equation 6].

Furthermore we, 5 (b) and the lateral acceleration waveform _{L ay} shown in (lateral acceleration waveform _{L ay} the steering amount waveform _{(L ay} showing the same characteristics)), also FIG. 5 (b) before and shown in It focused on the fact that a certain relationship is established with the acceleration waveform L _ax .

For example, as shown by waveforms L _ax and L _ay in FIG. 5B, in sections D1 and D3 in FIG. 5B, steering is performed so as to cut the required steering amount from the neutral position of the electric power steering 12. With the execution of the first and third steering steps (see the sections D1 and D3 of the waveform _Lay in FIG. 5 (b)) and the sections D1 and D3 of the waveform L _ax in FIG. 5 (b). In addition, it was found that gradually increasing the deceleration leads to minimizing the fluctuation of the yaw time constant.

  As described above, the lateral acceleration (steering amount) and the longitudinal acceleration (deceleration) have the relationship shown in the diagram of FIG. FIG. 11 shows the relationship between lateral acceleration (steering amount) and longitudinal acceleration (deceleration) applied to the vehicle 1 while decelerating under the deceleration of the present example from the entrance Ps of the evacuation space S to the target point Pd. Arrows d1, d2, d3 and d4 in FIG. 11 indicate the first steering step corresponding to section D1, the second steering step corresponding to section D2, and the third steering step corresponding to section D3, section D4. The variation of the lateral acceleration and the longitudinal acceleration accompanying execution of a corresponding 4th steering step is shown.

That is, when the retraction route R draws a predetermined sigmoid curve, the relationship between such steering amount and longitudinal acceleration (deceleration) may be, for example, the waveform _Laxy in FIG. If the correspondence relationship between the waveform L _ax and the waveform L _ay as shown is known in advance, if the steering profile (see the waveform L _ay in FIG. 5 (b)) is determined in step 8 in FIG. Based on the above, it is possible to directly determine the deceleration profile (see the waveform L _ax in FIG. 5B) that minimizes the amount of change in the yaw time constant.

Therefore, as another modification (corresponding to claims 5 to 8) of the driving support processing, the deceleration profile setting unit 26 decelerates during the first steering step corresponding to the section D1 (step 81 in FIG. 6). Between the second steering step corresponding to the section D2 (step 82 in FIG. 6) and the first decelerating step (waveform L _ax , L _ay in FIG. 5 (b), see arrow d1 in FIG. 11) , A second deceleration step for keeping the deceleration constant (see waveforms L _ax , L _ay in FIG. 5B, arrow d 2 in FIG. 11), and a third steering step corresponding to the section D 3 (in FIG. 6). Step 83), the third deceleration step for increasing the deceleration (waveform L _ax , L _ay in FIG. 5 (b), see arrow d 3 in FIG. 11), and the fourth steering step corresponding to the section D 4 ( Step 84 in FIG. 6, keep the deceleration constant 4 reduction step and setting the deceleration profile having a (waveform _L ax in FIG 5 _{(b), L ay,} see arrow d4 in Fig. 11).

That is, as described above, the steering amount (steering profile) at each passing point of the vehicle 1 traveling on the retreat route R is the lateral acceleration a _y at each passing point (the waveform _Lay in FIG. 5B). The deceleration profile setting unit 26 indicates a steering profile based on the relationship between the lateral acceleration (steering amount) and the longitudinal acceleration (deceleration) (see the waveform L _{axy in} FIG. 11). if deterministic waveform L _ay in FIG 5 (b), it is possible to set the waveform L _{a x} in FIG. 5 (b) showing the deceleration profile based.

  According to the above configuration, if a steering profile that is absolutely necessary in the driving support processing can be set (see step 8 in FIG. 3), the deceleration profile can also be set directly using this steering profile.

Thus, the evacuation route R is divided into steering steps according to the steering amount and the steering direction, and in each steering step, the deceleration step has a relation to minimize the fluctuation of the yaw time constant. By correlating (waveform L _ax , L _ay in FIG. 5B, waveform L _{axy in} FIG. 11), if the steering profile is set, the followability to the retraction route R is based on the steering profile. It is possible to set up a deceleration profile that can be enhanced.

The relationship between the lateral acceleration (steering amount) and the longitudinal acceleration (deceleration) as shown by the waveforms L _ax and L _ay in FIG. 5B and the waveform L _axy in FIG. And the like, and can be made into a database according to the shape of the evacuation route R and can be used for driving support processing in actual traveling.

The present invention is not limited to the configuration of the above-described embodiment, and can be formed in various embodiments.
For example, the deceleration a of the vehicle is set so that the amount of change in the yaw time constant _Tr is minimized over the entire evacuation route R as shown in FIG. 4A from the entrance Ps of the evacuation space S to the target point Pd. _{Although the} example which performs driving support processing of this embodiment which sets _x (longitudinal acceleration) was explained, not only this but driving support processing of this embodiment mentioned above is performed only in at least one section in evacuation route R Embodiments may be employed.

  By the way, in the situation where the driving support process of the present embodiment described above involves the steering of the vehicle 1 (load movement in the lateral direction), the evacuation route R is when the vehicle speed is Vth (for example, about 10 km / h) or more. The effect of trace performance improvement can be exhibited more. Therefore, when the vehicle 1 travels at such a vehicle speed higher than Vth, it is preferable to execute the above-described driving support process of the present embodiment.

  For example, it is assumed that a save route R as shown in FIG. Specifically, when a point on the near side in the x direction with respect to the target point Pd in the evacuation space S is set as the pre-stop target passing point Ppred, the evacuation route R starts from the entrance Ps of the evacuation space S to the pre-stop target passage point An evacuation route R ′ connecting the sigmoid curve up to Ppred and an evacuation route R ′ ′ linearly drawing along the x direction from the pre-stop target passing point Ppred to the target point Pd are configured in series.

  When the vehicle 1 travels along the evacuation route R as shown in FIG. 4B, the vehicle 1 travels while decelerating along the evacuation route R 'from the entrance Ps of the evacuation space S, and the vehicle passes the pre-stop target passing point Ppred Vth. It passes by at the vehicle speed of this, and it shall stop at target point Pd by driving | running | working while decelerating evacuation path | route R ''.

In such a case, when the vehicle 1 travels while decelerating the evacuation route R ′ in FIG. 4B from Vo (the entrance Ps) to Vth (the target passage point before stopping Ppred), FIG. As shown in each section X in (b) and (b), the driving support according to the above-described embodiment, in which the deceleration a _x (longitudinal acceleration) of the vehicle is set so as to minimize the amount of change in the yaw time constant _Tr Processing shall be performed.

  On the other hand, when the vehicle 1 travels on the retreat route R ′ ′ in FIG. 4B at a vehicle speed equal to or less than Vth, the driving support processing of the embodiment described above is not performed, and FIGS. As shown in each section Y, the driving support processing is executed so as to uniformly decelerate from the vehicle speed Vth at a constant speed and stop at the target point Pd.

  As described above, the evacuation route R ′ is one of the entire evacuation route R by executing the driving support process of the present embodiment described above only when the vehicle 1 travels the evacuation route R ′ traveling at a vehicle speed of at least Vth. Even in the section, excellent trace performance can be exhibited in the save route R ′.

  In another embodiment, for example, in the above-described embodiment, the deceleration profile is set before entering the retreat route R (see steps 9 and 10 in FIG. 3), but the present invention is not limited thereto. While traveling on the retreat route R, the current lateral acceleration of the vehicle 1 is obtained from the output signal of the acceleration sensor 8, and the deceleration at which the change in the yaw time constant is minimized is obtained based on the lateral acceleration detected in this real time. You may employ | adopt the structure set sequentially in the middle of driving | running | working.

1 ... Vehicle 2 ... Driving support device 21 of vehicle ... Occupant state acquisition unit (Occupant state acquisition means)
12: Electric power steering (steering)
22 ... Evacuation space detection unit (evacuation space detection means)
24 Target route setting unit (target route setting means)
25: Steering profile setting unit (steering profile setting means)
26 ... Deceleration profile setting unit (deceleration profile setting means, deceleration control means)
S7 ... Target route setting processing (step 7 in FIG. 3)
S9 ... deceleration control process (step 9 in FIG. 3)
S ... evacuation space R ... evacuation route (target route)
Pd ... Target point ... ... Curvature

Claims (10)

A target route setting means for setting a target route to a predetermined target point shifted in the width direction of the vehicle with respect to the longitudinal direction of the vehicle is provided, and the vehicle travels while decelerating on the target route and stops at the target point In a driving support device of a vehicle that performs driving involving
A driving support apparatus for a vehicle, comprising a deceleration control unit that controls deceleration of the vehicle in the front-rear direction so as to minimize fluctuation of a yaw time constant of the vehicle. Assuming that the velocity of the vehicle traveling along the target route of the vehicle is v (t), the deceleration is a _x (t), and the lateral acceleration applied to the vehicle is a _y (t),
The yaw time constant T _r (t) is
T _r (t) = f (v (t), a _x (t), a _y (t))
Assuming that the amount of change in the yaw time constant is S,
The said deceleration control means evaluates evaluation function S (t),
S = (T _r (t) −T _r (t + Δt)) ²
The driving assistance of the vehicle according to claim 1, wherein the deceleration a _x (t) is set so as to minimize this S by defining as a square of the amount of change (rate of change) of the yaw time constant. apparatus. The lateral acceleration at each passing point of the vehicle traveling on the target route is set based on the vehicle speed at each passing point and the curvature at each passing point.
The deceleration control means is a deceleration profile setting means for setting a deceleration profile related to deceleration for each passing point of a vehicle traveling on the target route based on the lateral acceleration for each passing point. Or the driving assistance device of the vehicle as described in 2. The deceleration control means is deceleration profile setting means for setting a deceleration profile related to deceleration for each passing point of a vehicle traveling on the target route based on the lateral acceleration for each passing point,
A steering profile setting unit configured to set a steering profile related to a steering amount of steering for each passing point of a vehicle traveling on the target route;
The steering amount in the steering profile is interlocked with a lateral acceleration applied to a vehicle traveling on the target route at each passing point.
The driving assistance device for a vehicle according to claim 1, wherein the lateral acceleration is set based on at least the steering profile. The operation control means
A steering profile setting unit configured to set a steering profile related to a steering amount of steering for each passing point of a vehicle traveling on the target route;
The steering amount in the steering profile is interlocked with a lateral acceleration applied to a vehicle traveling on the target route at each passing point.
The vehicle traveling on the target route has a predetermined relationship between the amount of steering and the degree of deceleration for each passing point,
The deceleration control means may be set as a deceleration profile setting means for setting a deceleration profile regarding deceleration for each passing point of a vehicle traveling on the target route based on the steering profile and the predetermined relationship. The driving assistance device for a vehicle according to claim 1. The vehicle driving support device according to claim 5, wherein the predetermined relationship is a relationship in which the deceleration is gradually increased at least as the magnitude of the steering amount of steering increases. The steering profile setting means
A first steering step of steering the steering wheel so as to approach the target point with respect to the longitudinal direction of the vehicle before entering the target point;
A second steering step for turning back the notch of the first steering step to a neutral position;
And a third steering step of steering the vehicle in a direction opposite to the steering direction of the first steering step so that the vehicle approaches parallel to the longitudinal direction of the vehicle before entering the target point on the near side of the target point ,
The driving support device for a vehicle according to claim 6, wherein the steering profile having the fourth steering step of turning back the notch of the third steering step to a neutral position is set. The deceleration control means is a deceleration profile setting means for setting a deceleration profile related to deceleration for each passing point of the vehicle on the target route so as to stop at the target point,
The deceleration profile setting means
A first deceleration step for increasing the deceleration during the first steering step;
A second deceleration step for maintaining the deceleration constant during the second steering step;
A third deceleration step for increasing the deceleration during the third steering step;
8. The driving support device for a vehicle according to claim 7, wherein the deceleration profile is set including a fourth deceleration step for keeping the deceleration constant during the fourth steering step. In a driving support device that supports driving of a vehicle according to the condition of an occupant,
The target point shall be in the evacuation space,
Occupant state acquisition means for acquiring the state of the occupant;
9. The driving assistance device for a vehicle according to any one of claims 1 to 8 , further comprising evacuation space detection means for detecting a evacuation space for evacuating the vehicle when an abnormality occurs in a passenger state while the vehicle is traveling. A target route setting process for setting a target route to a predetermined target point shifted in the width direction of the vehicle with respect to the front-rear direction of the vehicle is executed, and the vehicle travels while decelerating on the target route and stops at the target point. In a driving support method of a vehicle that performs driving involving steering,
A driving support method for a vehicle, which executes a deceleration control process for controlling deceleration of the vehicle in the front-rear direction so as to minimize fluctuation of a yaw time constant of the vehicle.

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