JP2010202030A - Driving support device and driving support method for vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a driving support device and a driving support method for a vehicle, relieving a sense of incongruity given to a driver by suppressing the abrupt change of a traveling operation support amount. <P>SOLUTION: A base for setting the initial conditions relating to the re-calculation of a target traveling path by a target traveling path calculation part 230 is selectively set by an initial condition setting part 250. The setting of initial conditions is performed by selectively depending on two state amounts, a detected present state value and a predicted state value, according to the circumstances. When any of the calculated values of the target traveling path by the re-calculation may vary largely due to the detection error of the present state, the variation of the calculated values is suppressed by applying, as the initial conditions for calculation, the predicted state values which are not directly affected by the causes of error. Consequently, the sense of congruity which is felt by the driver is reduced by a variation in the operation support amount. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a driving support device for a vehicle and a driving support method for a vehicle that support a driver's driving operation.

  In recent years, an example in which a driving support device that supports a driver's driving operation such as a steering operation or a braking operation is mounted on a vehicle is increasing. As this type of vehicle travel support device, a technique for guiding a vehicle along a target travel locus and coping with changing the target position and recalculating the target locus to increase the error between the target locus and the actual travel locus Proposals already exist (see, for example, Patent Document 1). In the proposal in Patent Document 1, even when it is determined that recalculation of the target trajectory is necessary, the target trajectory is not recalculated when in a specific steering state. Here, the specific steering state is a state where the steering state of the vehicle is switched from steering in the increasing direction to steering in the returning direction in a vehicle in which an error due to a sensor error or a steering delay is likely to increase. When the vehicle is in a specific steering state as described above, the calculation accuracy of the target trajectory is improved by not recalculating the target trajectory.

JP 2004-338635 A

In the proposal of Patent Document 1, when the target destination position is fixed, such as mainly in the case of parking assistance, or when the target position is changed, the frequency of change is not so high. As long as this assumption is true, it is considered that it is reasonably effective.
However, when actually supporting the driving of a vehicle, in many cases, it is required to respond quickly to changes in the circumstances surrounding the vehicle. In order to meet this demand, it is effective to perform recalculation of the target trajectory in a short cycle. Even in this case, it is conceivable that the recalculation of the target locus is stopped as in the prior art only in a situation where a precise target locus is difficult. However, when the recalculation of the target trajectory is stopped, there is a high probability that when the recalculation is restarted, the difference between the target trajectory held so far and the target trajectory obtained as a result of the recalculation becomes large. A large change in the target locus inevitably causes a sudden change in the amount of driving operation support, which may give the driver a great sense of discomfort when recalculation is resumed.
The present invention has been made in view of the above situation, and a vehicle driving support device and a vehicle driving capable of reducing a sense of discomfort given to the driver by suppressing a rapid change in the amount of driving operation support. The purpose is to provide support methods.

  In the vehicle driving support device of the present invention, the target travel route is calculated by sequentially executing recalculation, and when the target travel route is recalculated, it is obtained by the own vehicle state detection unit and the driver operation state detection unit. Based selectively on two state quantities, a current state detection value representing the current state, and a state predicted value obtained by extracting the own vehicle state and the driving operation state corresponding to the current time from the target travel route calculated in the past, The initial conditions used for the current target travel route calculation are set, and the driver's driving operation is supported so that the operation according to the time-series operation procedure corresponding to the target travel route is performed.

  When the target travel route calculation unit repeats recalculation of the target travel route, it is possible to selectively use two state quantities, that is, a current state detection value and a state prediction value, as initial conditions related to the recalculation. For this reason, if there is a possibility that the calculated value of the target travel route in the recalculation may fluctuate significantly due to the detection error of the current state, etc., a predicted state value that is not directly affected by the error factor is calculated. By applying this as the initial condition, it is possible to suppress fluctuations in the calculated value. Thereby, the uncomfortable feeling felt by the driver when the operation support amount varies can be reduced.

It is a schematic diagram for demonstrating the driving assistance apparatus for vehicles as the 1st Embodiment of this invention. It is a functional block diagram corresponding to the apparatus of FIG. It is a flowchart showing the detail of the process in the microprocessor in FIG. It is a figure which shows the scene which detected the obstruction on the front left side of the own vehicle when the own vehicle is traveling on the straight road. It is a figure which shows the example of the coordinate system and physical quantity which were introduced in the scene of FIG. It is a figure which illustrates a tire lateral force function. It is a figure showing the tendency of the risk potential field reflecting the contact risk of an obstacle and a road boundary on a road. It is a flowchart showing the process regarding prediction of a travel route and evaluation of the predicted travel route. It is a figure showing a state when a fixed time passes after a driver | operator starts avoidance operation to the right direction. FIG. 10 is a diagram illustrating calculation results that can occur at a certain time and the next target travel route calculation time in a scene such as FIG. 9. It is a figure which illustrates a mode that the target steering angular velocity command value is vibrating. It is a schematic diagram for demonstrating the driving assistance device for vehicles as the 2nd Embodiment of this invention. It is a functional block diagram corresponding to the apparatus of FIG. It is a flowchart showing the detail of the process in the microprocessor in FIG. It is a figure showing a behavior when the apparatus of 2nd Embodiment encounters the scene of above-mentioned FIG. It is a figure which shows the log | history of the target turning angle calculated in the target driving | running route calculation part in FIG. It is a schematic diagram for demonstrating the driving assistance device for vehicles as the 3rd Embodiment of this invention. It is a functional block diagram corresponding to the apparatus of FIG. It is a figure which shows the condition where the own vehicle approached the curved part of the road. It is a figure for demonstrating the specific operation | movement in the apparatus of 3rd Embodiment. It is a figure for demonstrating the driving assistance characteristic in the apparatus of 3rd Embodiment.

(First embodiment)
FIG. 1 is a schematic diagram for explaining a vehicle driving support apparatus according to a first embodiment of the present invention. In FIG. 1, a camera 1 attached in front of the vehicle interior shoots the road conditions ahead of the host vehicle and detects obstacles, road boundaries, white lines, and the like. In this example, by installing two cameras, not only the direction of the object but also the distance can be detected. On the other hand, a vehicle speed sensor 2 using a rotary encoder or the like attached to the wheel detects a pulse signal generated in proportion to the rotation of the wheel and measures the vehicle speed. In addition, a yaw rate sensor 3 using a crystal resonator or a semiconductor is provided to detect the yaw rate generated in the vehicle. Further, acceleration in a specific direction generated in the vehicle is detected by an acceleration sensor 4 using a piezoelectric element or the like. Here, a configuration is particularly assumed in which acceleration generated in the lateral direction of the vehicle is detected. A steering angle sensor 5 is provided in the steering column to detect the rotation angle of the steering wheel. A steering torque sensor 6 is also provided in the steering column to detect the driver's steering torque. On the other hand, processing of signals detected by various sensors and a target travel route, that is, a time series signal of a target operation amount are calculated by the microprocessor 70, and the assist motor 8 is controlled via the motor controller 9 to obtain the steering assist torque. Add to the steering system.

FIG. 2 is a functional block diagram corresponding to the apparatus of FIG.
In FIG. 2, a sensor group 100 such as a vehicle speed sensor 2, a steering angle sensor 5, a yaw rate sensor 3, an acceleration sensor 4, and a camera 1 is arranged in the vehicle as described above with reference to FIG. These sensor groups embody a vehicle state detection unit, a driver operation detection unit, an obstacle detection unit, and a road boundary detection unit, which are components in the embodiment of the present invention. The microprocessor 70 receives detection signals from the above-described sensor group, and processes these detection signals in an integrated manner to determine the motion state of the host vehicle, the operation state of the driver, the position and motion state of the obstacle, and the road boundary. Get information of each predetermined format to represent.

  In addition to the sensor signal processing described above, the microprocessor 70 determines whether or not to avoid the avoidance support control, calculates the target operation amount when the avoidance support control is activated, and transmits the target value to the actuator control system. Execute the process. The control program stored in the microprocessor 70 has a configuration in which processing units having several functions are combined.

The information collected by the sensor group 100 described above is converted into information in a form developed on the same coordinate system by the sensor signal processing unit 200, and detected and detected by each functional unit of the sensor signal processing unit 200 described below. Prediction processing is performed to obtain each predetermined detection value and prediction value.
The sensor signal processing unit 200 includes a host vehicle state detection unit 210, a driver operation state detection unit 220, an obstacle detection unit 260, an obstacle behavior prediction unit 270, and a road boundary detection unit 280 as the above-described functional units. It is out.

  The own vehicle state detection unit 210 detects the traveling state of the own vehicle. The driver operation state detection unit 220 detects the operation state of the driver. The obstacle detection unit 260 detects an obstacle ahead of the host vehicle. The obstacle behavior prediction unit 270 predicts the behavior of the obstacle up to a predetermined time based on the movement state of the obstacle detected by the obstacle detection unit 260. The road boundary detection unit 280 detects a road boundary on which the vehicle can travel.

  The above is the configuration of the sensor signal processing unit 200. In the driving support activation determination unit 290, the presence / absence of necessity of avoidance support control based on the obstacle information and the driver operation information obtained by the sensor signal processing unit 200 and It is determined whether or not there is an avoidance operation by the driver. In this determination, when it is determined that the necessity of avoidance support control is high and the avoidance operation by the driver is also performed, processing for starting the avoidance support control is performed.

On the other hand, the initial condition setting unit 250 sets initial values of information on the vehicle state and the obstacle state that are the starting points of the travel route when calculating the target travel route.
The target travel route calculation unit 230 calculates a target travel route for the host vehicle to avoid an obstacle on the road based on the information about the state of the host vehicle and the obstacle set by the initial condition setting unit 250 and the road boundary. Execute the process. In this calculation process in the target travel route calculation unit 230, information on time-series operation procedures representing operations necessary for traveling along the target travel route is obtained.

  The time series operation procedure information obtained in this manner is converted into a signal suitable for the driving operation support mode and output via the command value output processing unit 240 as a driving operation support unit for output. This is supplied to the motor controller 9 of the support mechanism 400. Therefore, the steering assist motor 8 can be operated via the motor controller 9 so as to follow the purpose of the driving operation support control, and the driver's avoidance operation can be supported.

  On the other hand, the predicted travel route evaluation unit 310 that evaluates the acquired information evaluates the travel route calculation method based on the time-series operation procedure calculated in the past and the current state detection value based on the current sensor detection information. That is, a process of evaluating how much a preferable travel route is obtained when a time-series operation procedure calculated in the past is applied from the current time is executed. This evaluation result is transmitted to the initial condition setting unit 250 and reflected in the initial condition setting when calculating the target travel route.

Next, details of the processing in the microprocessor 70 will be described with reference to the drawings.
FIG. 3 is a flowchart showing details of processing in the microprocessor 70 in FIG. Here, in order to give concreteness to the description, in the present embodiment, the processing contents will be described assuming the scene shown in FIG. FIG. 4 assumes a scene in which an obstacle is detected on the left side in front of the vehicle while the vehicle is traveling on a straight road.

The microprocessor 70 repeatedly executes a series of processes described below at predetermined time intervals.
In step S301, the signal detected by the sensor group 100 described above is read into the memory of the microprocessor 70, and the motion state of the vehicle and the state of the obstacle are converted into values on a predetermined coordinate system. Although this coordinate system can be determined appropriately, in this embodiment, as shown in FIG. 4, the X axis is set along the road traveling direction, and the Y axis is set in the direction perpendicular to the X axis. Further, the coordinate system is set assuming that the current position of the vehicle is the origin of the X coordinate and the origin of the Y coordinate is located near the center line of the road. By setting the coordinate system as described above, the position of the own vehicle (center point) can be expressed in the form of (X, Y = x, y).

Here, it is considered that the yaw angle θ, the vehicle speed ν, the vehicle slip angle β, the yaw rate γ, and the turning angle δ of the front wheels are important amounts as state quantities representing the motion state of the host vehicle. Among these physical quantities, the vehicle speed ν can be approximated by the wheel speed of the non-driving wheel, so that the measured value of the vehicle speed sensor provided on the non-driving wheel can be used. On the other hand, the yaw rate γ can be obtained from the yaw rate sensor 3. If it is assumed that the road is a straight line, the yaw angle θ of the vehicle can be obtained by estimating the angle formed by the road boundary and the direction in which the vehicle is facing by image processing. Alternatively, it may be calculated by determining an appropriate initial value and integrating the output value of the yaw rate sensor 3. The slip angle β is defined as ν _x for vehicle longitudinal speed and ν _y for lateral speed.

で求めることができる。ν_xをνで近似し、ν_yを車両横加速度を測定するように設置した加速度センサ４の出力を積分することによって求めれば、（１）式からすべり角の近似値を得ることができる。これ以外にも、車輪速、ヨーレート、横加速度等の信号からオブザーバによってより精度良くすべり角を推定する手法も知られているので、そのような手法を用いてすべり角を得てもよい。前輪舵角δは操舵角センサから取得した操舵角θと操舵系のギア比Ｋより

Can be obtained. If ν _x is approximated by ν and ν _y is obtained by integrating the output of the acceleration sensor 4 installed so as to measure the vehicle lateral acceleration, an approximate value of the slip angle can be obtained from the equation (1). In addition to this, since a method of estimating the slip angle with higher accuracy from the signals such as the wheel speed, the yaw rate, and the lateral acceleration is also known, the slip angle may be obtained using such a method. The front wheel steering angle δ is obtained from the steering angle θ acquired from the steering angle sensor and the gear ratio K of the steering system.

という換算式に基づいて得ることができる。

Can be obtained based on the conversion formula.

As described above, all of the state quantities describing the motion state of the vehicle mentioned above can be calculated concrete values by processing the detection signals of the sensors.
When an obstacle is detected, the position coordinates X _p = (x _p , y _p ) of the center point, and the values of the obstacle width σ _y and depth σ _x are acquired by the camera. Calculated by processing information. The depth σ _x may be difficult to measure depending on the shooting direction. In this case, the same value as the width σ _y is set for convenience. If no obstacle is detected, the physical quantity related to the obstacle is not calculated.
Further, the positions of the left end and the right end of the road detected by the road boundary detection by the camera are converted into values on the coordinate system, and Y = Y _L and Y = Y _R are set.

An example of the coordinate system and the physical quantity introduced in the scene of FIG. 4 is shown in FIG.
As described above, the processing in step S301 is to introduce an appropriate coordinate system and calculate information on the own vehicle, the obstacle, and the road boundary as a value on the introduced coordinate system.
In step S302, the process branches depending on the state of the driving support control activation flag. If the driving support control is activated (step S302: Yes), the process proceeds to step S305. On the other hand, if it is not activated (step S302: No), the process proceeds to step S303.

In step S303, it is determined whether or not the driving support control should be started, and the process branches depending on the determination result. As a condition for starting the driving support control, for example, (1) an obstacle that may collide with the own vehicle is detected in front of the own vehicle, and a margin until the collision is below a predetermined level.
(2) The driver has started the avoidance operation.
Two conditions can be set. For condition (1), the time margin for obstacle avoidance can be evaluated by TTC (Time to Collision) between the vehicle and the obstacle defined by the following equation.

That is, when the TTC becomes smaller than a predetermined threshold value TTC _thr (for example, a value of about 3.0 seconds can be set), it is determined that the driving support control is necessary. Regarding condition (2), when the magnitude of the steering angle θ _s is larger than a predetermined threshold value θ _thr, it is determined that an avoidance operation by the driver is being performed. That is,

の２条件が両方とも成立した場合に回避支援制御を起動すると判断して、運転支援起動フラグを立てる処理を行なう。

When both of the two conditions are satisfied, it is determined that the avoidance support control is to be started, and processing for setting a driving support start flag is performed.

If the condition for starting the driving support control described above is not satisfied, the process is terminated as it is, but if the condition is satisfied, the process proceeds to step S304.
In step S304, setting processing related to calculation is performed prior to calculation of the target travel route. In order to explain the details of this process, first, the formulation of the target travel route calculation will be described.
Here, an evaluation function for performing a numerical evaluation on an arbitrary travel route is defined based on obstacle positions, road conditions, etc., and a travel route with the best evaluation function value is calculated as a target travel route. The target travel route is calculated.

Since the travel route of the host vehicle is determined by what operation is applied to the host vehicle, in order to calculate the travel route reflecting the characteristics of the vehicle, the motion of the host vehicle that receives the operation on the host vehicle is input. You need a model to describe.
As a model that describes the motion of a vehicle, a two-wheel model that approximates the motion of a four-wheel vehicle by the motion of a two-wheel vehicle is well known. Assuming that the vehicle speed is constant, the two-wheel model is described by the following differential equation:

However, m, representing I, I _f, each I _r vehicle mass, vehicle yaw inertia moment, distances from the vehicle gravity center to the front axle, the distance to the rear axle from the vehicle gravity center. Y _f and Y _r are functions representing tire lateral force, and are assumed to be functions of a front wheel slip angle β _f and a rear wheel slip angle β _r , respectively. Β _f and β _r can be calculated as follows.

The tire lateral force functions Y _f and Y _r can be expressed by nonlinear functions as shown in FIG. Furthermore, since there is a relationship such as equation (2) between the steering angle δ of the front wheel and the steering angle θ _S of the steering wheel, the relationship between the steering angular velocity ω and the front wheel steering angle is

と表現できる。
以上、（６）〜（１４）式をまとめると、操舵角速度ωを入力とする以下の微分方程式モデルが得られる。

Can be expressed as
As described above, when the equations (6) to (14) are summarized, the following differential equation model using the steering angular velocity ω as an input can be obtained.

任意の走行経路すなわち操舵角の時系列を数値的に評価するために、次式の評価関数を導入する。

In order to numerically evaluate an arbitrary travel route, that is, a time series of steering angles, an evaluation function of the following equation is introduced.

  Here, t is a variable representing the current time, T is a parameter representing the length of the time series to be calculated, and in the case of an obstacle avoidance problem, a series of steps from avoiding the obstacle to returning to the original straight traveling state. Set a value that is long enough to complete the avoidance operation. Ψ is an evaluation formula for evaluating the desirability of the vehicle motion state at time t + T, L is an evaluation formula for evaluating the desirability of the vehicle motion state and the operation amount at each time from time t to t + T, and τ is t Is an integral variable that changes from t to T + T.

The evaluation formulas L and Ψ are configured by combining evaluation terms that reflect the following required items.
(1) Don't get too close to obstacles (2) Don't get too close to road boundaries (3) Make the steering angular velocity as small as possible (4) Bring the vehicle yaw angle at the end of avoidance movement closer to the road traveling direction Request item (1) is It is expressed by a function whose value increases as the distance between the vehicle and the obstacle decreases. Specifically, for example, the following function can be used.

Information on the movement trajectory generated by the obstacle movement trajectory generation unit is assigned to the obstacle positions x _p and y _p .
The request item (2) is expressed by a function that increases as the distance between the vehicle and the road boundary decreases. Specifically, for example, the following function can be used.

However, Δ is a parameter for designating a margin of approach to the road boundary, and an avoidance route that calculates a larger margin of approach to the road boundary is calculated as the value of Δ is larger.
The evaluation formulas L _P and L _R define the risk potential reflecting the contact risk between the obstacle and the road boundary on the road.
FIG. 7 is a diagram in which a function obtained by adding L _P and L _R is plotted on the XY coordinates. The central mountain is the potential formed by the function L _P corresponding to the obstacle, and the mountain on both sides is the potential formed by the function L _P corresponding to the road boundary. The avoidance path is generated as much as possible along the region having a low value of the risk potential field shown in FIG.
The request item (3) is an item introduced to request efficient avoidance by taking an avoidance operation at a steering speed as small as possible. As the evaluation formula, for example, a function of the following formula can be used.

A function obtained by adding appropriate weights to the above three evaluation expressions is configured as an evaluation expression L. That is, if w _P , w _R , and w _S are weights for the essential items (1), (2), and (3), L is

という形で構成することができる。
要請項目（４）は、回避運動後の車両姿勢を立て直すために導入した要請項目である。直線道路においては、時刻ｔ＋Ｔにおける車両ヨー角を評価する関数として、例えば、

Can be configured.
The requirement item (4) is a requirement item introduced for reestablishing the vehicle posture after the avoidance exercise. On a straight road, as a function for evaluating the vehicle yaw angle at time t + T, for example,

という関数を用いることができる。この関数に適当な重みパラメータw_yawをつけて、

Can be used. _{Add an} appropriate weight parameter w _yaw to this function,

とすることで時刻ｔ＋Ｔにおける評価項を構成する。

This constitutes an evaluation term at time t + T.

When the evaluation function is defined as described above, the calculation of the time-series transition mode of the steering angular velocity is formulated as the optimal control problem defined by the control object of the above-described equation (14) and the evaluation function of the equation (15). be able to. Therefore, by solving this optimal control problem, a time-series transition mode of the target steering angular velocity can be obtained. Further, if the equation (14) is integrated according to the time-series transition mode of the obtained steering angular velocity, the target travel route can be obtained. However, since the target travel route calculated here is for assisting the driver's steering operation, it is desirable that the steering angular velocity ω that is an input is within a range that can be operated by a general driver. This request is based on the assumption that the maximum steering angular speed allowable for a general driver is ω _max .

という制約条件を最適制御問題として課すという形で定式化することができる。
以上をまとめると、目標走行経路演算を最適制御問題によって定式化して解く際には、

Can be formulated in the form of imposing the constraint condition as an optimal control problem.
To summarize the above, when formulating and solving the target travel route calculation by the optimal control problem,

Outside 1

In step S304, all setting processes (1), (2), and (3) are performed. Among these, for (1) and (2), specific values can be obtained from the detection information of the sensor as described above. (3) is a design parameter whose value can be set freely. Different values can be set depending on the scenes encountered, and a constant value can be set regardless of the scene. When all the setting processes are completed, the process proceeds to step S309.
In step S309, the optimal control problem defined by the equations (14), (15), and (23) is solved, and the time-series transition mode of the optimal steering angular velocity is calculated. Since there are some known examples of specific algorithms for solving the optimal control problem, detailed description thereof is omitted here.

Outside 2

The above command value vector is written and held in a memory in the microprocessor. Even if the command value vector has already been generated and held in the past calculation cycle, the past command value vector is discarded and overwritten with the latest command value vector.
When the above writing process is completed, the process proceeds to step S310.
In step S310, the command value corresponding to the current time is read from the control command value vector written in the memory in the microprocessor. In order to facilitate the correspondence with the current time, for example, a shift operation is performed on the memory holding the time-series transition of the command value in the microprocessor, and the command value stored at the start address of the memory is always read. Can be considered. In that case, the memory state before executing step S3010 is

となっていた場合には、制御目標値としてω(t₁)が読み出された後、メモリ状態が、

When ω (t ₁ ) is read as the control target value, the memory state is

となるようにシフト操作を行うことになる。以上のような操作を終えた後で、ステップＳ３１１に処理を進める。

The shift operation is performed so that After the above operation is completed, the process proceeds to step S311.

  In step S311, a command value for driving the steering assist motor 18 is calculated based on the steering command value read in step S310. Various methods are conceivable as a control rule for the steering assist torque. For example, a control rule such as the equation (28) that feeds back the deviation between the steering command value and the actual steering state can be used.

Here, T _a ^* represents the target value of the steering assist torque, θ _s represents the current steering angle, and ω represents the current steering angular velocity. In the equation (28), the control law is composed of two terms, ie, the steering angle deviation term and the steering angular velocity deviation term, but it is also conceivable to constitute only one of the terms. If the proportionality constant is K _M between the steering assist torque and the steering assist motor current i _M ,

という関係式があるので、（２９）式から操舵アシストモータ電流指令値を算出した上で、モータコントローラ９に電流指令値を送出して、処理を終了する。

Therefore, after calculating the steering assist motor current command value from the equation (29), the current command value is sent to the motor controller 9 and the process is terminated.

The processing flow in the calculation cycle in which the target travel route is calculated for the first time has been described above. When the target travel route is calculated, the processing in step S305 is performed by branching in step S302 from the next calculation cycle.
In step S305, it is determined whether a condition for updating the target route is satisfied. For example, when the vehicle has traveled behind the obstacle or the obstacle has gone out of the detection range of the sensor, it is determined that there is no need to update the target route any more, and the process proceeds to step S312. Otherwise, the process proceeds to step S306.

In step S306, it is determined whether or not the current time is the time for updating the target route. The target travel route calculation unit 230 calculates the target operation amount in time series, and the cycle of the target travel route calculation unit 230 can be made longer than the control cycle of the driving operation support unit 240. Then, even if the control command value of the driving operation support unit 240 is output, a control cycle in which the target travel route is not calculated occurs. Therefore, the process proceeds to step S312 in such a calculation cycle. If the calculation cycle for calculating the target travel route is underway, the process proceeds to step S307.
In step S307, processing related to the prediction of the travel route and the evaluation of the predicted travel route when the operation is performed based on the time-series transition mode of the command value currently held in the memory of the microprocessor is executed. Step S307 includes the three processes shown in FIG.

Outside 3

  As the evaluation method, a method of calculating the current evaluation function value by using the evaluation function of the formula (15) as it is can be considered, and an evaluation value paying attention to only a part of the evaluation function (for example, a term related to an obstacle) Or another evaluation index such as the minimum value of the distance between the vehicle and the obstacle can be used.

In step S803, a process for calculating an index representing the necessity of correcting the target route from the evaluation index calculated in step S802 is performed. For example, when the minimum value of the distance between the host vehicle and the obstacle is used as the evaluation index, it is assumed that the minimum value of the distance expected for the width of the host vehicle and the obstacle is sufficiently large. If this assumption is met, the purpose of obstacle avoidance is considered even if there is an error between the travel route based on the time-series transition mode of the currently held operation and the initial target travel route. If this happens, it will not be a big problem. In such a case, it is desirable that the target travel route follow the time-series transition mode of the current operation so that the driver does not feel uncomfortable even if the target travel route is recalculated. On the other hand, if the minimum distance expected for the width of the vehicle and the obstacle has decreased to an insufficient size, continue the operation according to the time-series transition mode of the operation currently held. If so, the risk of contact with obstacles will be greater than originally expected. Therefore, in such a case, it is desirable to recalculate the target travel route based on the latest information.
Therefore, an index indicating the necessity of correcting the target route taking a value from 0 to 1 is introduced, and α is calculated as follows based on the minimum value d _min of the distance between the vehicle and the obstacle.

However, d ₀ is a threshold for an appropriate distance. Here, α = 0 is defined as a determination result that the necessity of target travel route correction is low, and α = 1 is defined as a determination result that the necessity of target travel route correction is high. In addition, by making the index continuous,

のように定義することも考えられる。

It is also possible to define as follows.

Outside 4

  The change in the target travel route is transmitted to the driver as a change in the steering assist torque through the steering assist torque control as shown in the equation (28). Therefore, there is a possibility that the driver may feel uncomfortable if the target travel route is renewed without darkness. On the other hand, if the driver travels accurately following the target route that was originally calculated, even if the target travel route is recalculated, there will be a small change accompanying the change in the calculated time interval of the target operation time series over time. Expected to stay. Therefore, since the change in the operation assist torque is also small, it is expected that the possibility of giving the driver a sense of incongruity is small.

Outside 5

  As described above, in the second and subsequent target route calculations, there are two possible target route calculation methods. In step S803, the necessity of correcting the target travel route is evaluated. Therefore, an initial state vector used for target route calculation at time t is set as in equation (32) in order to obtain a target travel route reflecting the evaluation result.

Under the above settings, the process proceeds to step S309, and target route calculation processing is performed.
If the target travel route update condition is not satisfied in step S305 (step S305: No), it is checked in step S312 whether the target operation time series remains in the microprocessor memory. Also, when it is determined in step S306 that it is not the target route update time (step S306: No), in step S312, it is checked whether the target operation time series remains in the microprocessor memory. If the target operation amount remains, the process proceeds to step S310, and the command value recorded at the head address of the memory is read and executed. When the target operation amount does not remain, the process proceeds to step S313, the driving support control activation flag is cleared, and the process ends.

Outside 6

FIG. 9 shows a state at time t ₀ when a certain period of time has elapsed since the apparatus according to the present embodiment was activated in the scene of FIG. 4 and the driver started the avoidance operation in the right direction. The driving support device is instructed to steer at ω _max that is the upper limit value of the target steering angular velocity, and the driver is also performing an operation to increase the steering angular velocity following that. With respect to the previous operation, the target travel route calculation unit 230 calculates a target steering angle time series assuming that the steering angular velocity is gradually lowered and the steering is shifted to the reverse direction. That is, time t ₀ shows a scene where the steering angular acceleration is just reversed.

Figure 10 is in the context, such as in FIG. 9 shows the calculation results can occur at time t ₀ and time t ₁ which is the next target traveling path calculation time. The diagram on the left side of FIG. 10 shows a situation in which the actual vehicle state at time t ₁ is slightly shifted to the left with respect to the target travel route assumed at time t ₀ . Such a deviation is a deviation that can often occur when the driver's steering does not sufficiently follow the target steering or due to the influence of a modeling error of the vehicle.

At this time, the target travel route is recalculated at time t ₁ . In this case, when the target travel route is calculated using the state vector composed of the measured values at time t _1, the steering angular acceleration is increased after the steering in the right direction is strengthened again in order to correct the deviation from the original target travel route. The target steering time series such as reversing is obtained. Therefore, if the driver steers along the target steering at time t ₀ , an error from the steering speed target occurs, so suddenly from the state where almost no auxiliary force has been applied until then. It feels like auxiliary power is generated. On the other hand, if the driver's steering angular acceleration reversal operation is delayed and the assist force begins to be generated, the assist error is lost because the steering error caused by the delay suddenly decreases. feel.

FIG. 11 is a diagram exemplifying a temporal transition of the target steering angular velocity when such a state continues after time t ₁ . In FIG. 11, when the state vector based on the sensor detection value is continuously used, the target steering angular velocity is corrected every time the target travel route is calculated. It shows a state. On the other hand, when the predicted state quantity is used, only the operation time series is extended along with the retroactive evaluation time interval due to the passage of time. Therefore, the steering command value is output as shown in the figure without being affected by a modeling error or the like. Since actual vehicle behavior is affected by modeling errors, the vehicle will travel on a route closer to the obstacle than the originally assumed target route, but a sufficient avoidance margin is maintained between the vehicle and the obstacle. If it exists, it can be said that there is no problem as support for the avoidance operation. Rather, it is expected that the driver will be able to accept the vehicle without a sense of incongruity because the fluctuation of the steering assist torque is small.

  In FIGS. 9 to 11, the description is mainly made assuming that the target travel route correction necessity index of Expression (30) is used. However, the index of Expression (31) can also be used. In that case, it is possible to expect an effect of suppressing the actual travel route from deviating toward an obstacle in exchange for a slight change in steering assist torque. Therefore, the balance between suppression of uncomfortable feeling and securing of avoidance margin can be adjusted by changing the definition of the index of the equation (31).

  In the first embodiment of the present invention described above, when the target travel route calculation unit repeats the recalculation of the target travel route, two initial conditions related to the recalculation are the current condition detection value and the state prediction value. It becomes possible to use the state quantity properly according to the situation. For this reason, if there is a possibility that the calculated value of the target travel route in the recalculation may fluctuate significantly due to the detection error of the current state, etc., a predicted state value that is not directly affected by the error factor is calculated. By applying this as the initial condition, it is possible to suppress fluctuations in the calculated value. Thereby, the uncomfortable feeling felt by the driver when the operation support amount varies can be reduced. In addition, it is possible to prevent the target travel route calculated when the target route calculation using the current state detection value is resumed by continuing the recalculation from changing greatly. For this reason, it is possible to reduce the uncomfortable feeling given to the driver because the operation support amount does not change rapidly.

(Effects of the first embodiment)
(1) In the driving support apparatus as the first embodiment, the own vehicle state detection unit 210 detects the traveling state of the own vehicle, and the driver operation state detection unit 220 detects the operation state of the driver. Further, it is necessary for the target travel route calculation unit 230 to travel along the target travel route along the target travel route on which the host vehicle should travel up to a predetermined time ahead with any host vehicle state and driving operation state as initial conditions. As a time-series operation procedure, recalculation is performed every predetermined calculation cycle. On the other hand, when the target travel route calculation unit 230 recalculates the target travel route, the current state detection value representing the current state obtained by the vehicle state detection unit 210 and the driver operation state detection unit 220 is recalculated. This is one basis for setting initial conditions. In addition, the state prediction value obtained by extracting the own vehicle state and the driving operation state corresponding to the current time from the target travel route calculated in the past calculation cycle is used as another basis for setting the initial condition for the recalculation. Then, based on these two state quantities selectively, the initial condition setting unit 250 sets initial conditions used for the current target travel route calculation by the target travel route calculation unit 230. The driving operation support unit 240 supports the driving operation of the driver so that the operation according to the time-series operation procedure calculated by the target travel route calculation unit 230 is performed.

  In the vehicle driving support device of the above (1), the target travel route calculation unit 230 selectively sets the grounds for initial condition setting related to the recalculation of the target travel route from the initial condition setting unit 250. That is, the initial condition can be set by selectively depending on the two state quantities of the current state detection value and the state prediction value depending on the situation. For this reason, if there is a possibility that the calculated value of the target travel route in the recalculation may fluctuate significantly due to the detection error of the current state, etc., a predicted state value that is not directly affected by the error factor is calculated. By applying this as the initial condition, it is possible to suppress fluctuations in the calculated value. Thereby, the uncomfortable feeling felt by the driver when the operation support amount varies can be reduced. In addition, it is possible to prevent the target travel route calculated when the target route calculation using the current state detection value is resumed by continuing the recalculation from changing greatly. For this reason, it is possible to reduce the uncomfortable feeling given to the driver because the operation support amount does not change rapidly.

(2) In the vehicle driving support device, the obstacle detection unit 260 detects an obstacle ahead of the host vehicle. The initial condition setting unit 250 includes the current state detection value including the obstacle measurement value obtained from the obstacle detection unit 260, and the state prediction value including the obstacle position measured in the past calculation cycle. Based on the two state quantities, initial conditions are set in the previous target travel route calculation unit 230.
In the vehicle driving assistance device of the above (2), avoidance assistance in consideration of obstacles ahead of the host vehicle becomes possible.

(3) In the vehicle driving support apparatus, the obstacle detection unit 260 detects the movement state of the obstacle. The obstacle behavior prediction unit 270 predicts the behavior of the obstacle up to a predetermined time based on the detected motion state.
In the vehicle driving support device of (3) above, it is possible to support effectively avoiding a moving obstacle. In other words, since the initial conditions for calculating the target route including the movement state of the obstacle are set assuming that the vehicle will move, even if the detection accuracy of the movement state of the obstacle changes depending on the situation, the detection accuracy is operational support The influence on the amount can be reduced.

(4) In the vehicle driving support apparatus, the road boundary detection unit 280 detects a road boundary on which the vehicle can travel.
In the vehicle driving support device of (4) above, the target travel route can be calculated so as to be within the detected road boundary, and the driving operation is supported based on the appropriate target travel route even in a situation where the road width is limited. be able to.

(5) In the vehicle driving assistance device, the driving assistance activation determination unit 290 determines the necessity of driving assistance. When the driving support activation determination unit 290 determines that driving support is required, the driving operation support unit 240 performs driving operation support.
In the vehicle driving support device of the above (5), the device acts on the driver's operation only in a scene where driving support is required. For this reason, it is possible to prevent the driver from feeling uncomfortable by intervening in the driver's operation in a situation where assistance is not required.

(6) In the vehicle driving support device, the initial condition setting unit 250 selects either the current state detection value or the state prediction value calculated in the past calculation cycle for each component to initially Set the conditions.
In the vehicle driving support device of (6) above, the state measurement value and the state prediction value are compared for each component of both, and an appropriate value is set as the initial condition. For this reason, the value suitable for the situation given for each signal constituting the state quantity can be selected and applied to the target travel route calculation. Therefore, it is possible to perform optimum processing according to the characteristics of each signal and the performance of the detection section, and it is possible to adaptively reduce the influence of the characteristics of a specific signal and the performance of the detection section on the calculation result of the target path. .

(7) In the vehicle driving support device, the initial condition setting unit 250 is suitable for each component in the two state quantities of the current state detection value and the state prediction value calculated in the past calculation cycle. An initial condition is set by calculating an average value after weighting.
In the vehicle driving support device of the above (7), the initial condition for the target travel route calculation is calculated based on the weighted average of the state measurement value and the state prediction value. As a result, when the two state quantities are switched, the initial condition setting can be continuously changed, and changes in the target travel route and the operation support amount can be made smoother. Therefore, it is possible to perform operation support that is easily accepted by the driver without a sense of incongruity.

(8) In the above-described vehicle driving support device, it is expected when the predicted travel route evaluation unit 310 continues to input time-series operation procedures corresponding to the target travel route calculated in the past calculation cycle after the current time. An evaluation value relating to the validity of the own vehicle travel route is obtained. Then, the initial condition setting unit 250 sets an initial condition that places importance on the current state measurement value as the evaluation value by the predicted travel route evaluation unit 310 is low, and the state calculated in the past calculation cycle as the evaluation value is high Set initial conditions with emphasis on predicted values.

  In the vehicle driving support device of (8) above, while predicting / evaluating the predicted travel route at the current time, it is determined whether the target travel route needs to be recalculated based on the newly detected state quantity. Recalculate the target travel route. As a result, re-calculation of the target route is performed based on the state quantity that is not easily affected by the error factor for deviations from the target route that do not significantly affect the original driving purpose such as obstacle avoidance. . Therefore, the target travel route is less likely to fluctuate, and operation assistance that is natural and understandable for the driver can be performed.

(9) In the vehicle driving support device, the initial condition setting unit 250 is configured to perform an initial operation when the difference between the current state predicted value and the state predicted value calculated in the past calculation cycle is greater than or equal to a predetermined value. The weight of the weighted average calculation in the condition setting is changed step by step from the setting focusing on the state prediction value to the setting focusing on the current state measurement value as time passes thereafter.
In the vehicle driving support device of (9) above, when the error between the state measurement value and the state prediction value becomes large, the initial condition setting is gradually switched to the state measurement value. Thereby, when the deviation from the target travel route becomes large, in the scene where the driver is prompted to return to the original target travel route, the uncomfortable feeling given to the driver due to a sudden change in the operation support amount can be alleviated.

(10) In the vehicle driving support apparatus, the driver operation state detection unit 220 detects a driver's steering operation.
In the vehicle driving support device of the above (10), since the driver's steering operation is detected and the target travel route is calculated, the travel route including the lateral movement of the vehicle is calculated and the vehicle travels accordingly. Operation support can be performed.

(11) In the vehicle driving assistance device, the driver operation state detector 220 detects the driver's accelerator operation and brake operation.
In the vehicle driving support device of the above (11), the driver's accelerator operation and brake operation are detected and the target travel route is calculated. Therefore, the travel route including acceleration / deceleration motion of the vehicle is calculated and followed. It is possible to assist the operation for traveling.

(12) In the vehicle driving support device, the driving operation support unit 240 determines a deviation between the target operation amount calculated by the target travel route calculation unit 230 and the driver operation amount detected by the driver operation state detection unit 220. Based on this, the operation assisting force for the driver's operation is controlled.
In the vehicle driving support device of (12), a deviation between the target operation amount calculated by the target travel route calculation unit 230 and the actual operation amount of the driver is detected, and an operation assisting force according to the deviation is applied. . For this reason, a required operation can be effectively transmitted to the driver depending on the direction and magnitude of the operation assisting force.

(13) In the vehicle driving support apparatus, the driving operation support unit 240 realizes the operation amount calculated by the target travel route calculation unit 230 by automatically controlling the operation system of the own vehicle.
In the vehicle driving support device of (13) above, the target operation amount calculated by the target travel route calculation unit is realized by automatic control. For this reason, the own vehicle can be made to follow a target driving path reliably.

(Second Embodiment)
A second embodiment of the present invention will be described below with reference to FIGS.
FIG. 12 is a schematic diagram for explaining a vehicle driving support apparatus according to a second embodiment of the present invention. FIG. 13 is a functional block diagram corresponding to the apparatus of FIG.
12 and FIG. 13, corresponding parts to those in FIG. 1 and FIG. 2 described above are denoted by the same reference numerals, and the description of each part uses the corresponding parts described above. The sensor group 102 is substantially the same as the sensor group 100 of FIG. 1 except that a brake pressure sensor 12 for measuring a brake pressure generated by a driver's brake operation is added.

  On the other hand, in the second embodiment, a front wheel steering system automatic control system is provided as a driving operation support unit, and the clutch 17, the turning angle sensor 15, the turning assist motor 18, the turning are included as elements related to this system. An angular servo controller 10 is provided. When it is determined that obstacle avoidance assistance is necessary, the clutch 7 is disconnected and the steering wheel and the steering mechanism are separated. Based on the turning angle command from the microprocessor 72, the turning angle servo controller 10 performs servo control of the steering system using the turning angle sensor and the turning motor. Thereby, it is the structure which transfers to the mode which performs automatic control of a vehicle and avoids.

  When the functional block diagram of FIG. 13 is compared with that of FIG. 2, the predicted travel route evaluation unit 310 is replaced with a detection information evaluation unit 320, although it is consistent in many respects. Moreover, the point which the process of the output part is replaced with the process which outputs the command which switches on / off of a clutch, and the process which outputs the target value of a turning angle differs. The detection information evaluation unit 320 evaluates the reliability of information detected by the own vehicle state detection unit 210, the driver operation state detection unit 220, and the obstacle detection unit 260.

Next, details of the processing in the microprocessor 72 will be described with reference to the drawings.
FIG. 14 is a flowchart showing details of processing in the microprocessor 72 in FIG. Since the processing flow itself has many common parts with the first embodiment described with reference to FIG. 3, the specific processing content will be described below with a focus on differences from FIG. Also, in the second embodiment, the description will be made assuming the scene shown in FIG. 4 described above. However, unlike the first embodiment, here, a process assuming that an obstacle is moved will be described.

Step S1401 is almost the same process as that of the first embodiment, but the process of calculating not only the position information of the obstacle but also the speed information is executed on the assumption that the obstacle moves as described above. The speed information can be calculated, for example, by taking the difference between the position detection result at the previous sampling time and the position detection result at the current time.
Here, the speed of the X-axis direction [nu _p ^x obstacles, the speed of the Y-axis direction is denoted by [nu _p ^y.
The processing in steps S1402 and S1403 is the same as the processing in steps S302 and S303 in FIG.

In step S1404, a process for generating a control signal for instructing disconnection of the clutch 17 with the start of the driving support control and transmitting the control signal to the clutch control system is executed.
In step S1405, the setting necessary for target travel route calculation is the same as step S304 in the first embodiment described above, but the formulation of the target travel route calculation is different. The contents are also different. The following description will include the formulation part.

With respect to the vehicle model, the present embodiment is formulated using a two-wheel model, but corrections corresponding to the following two points are added as compared with the first embodiment.
(1) Consider the deceleration behavior accompanying the brake operation by the driver.
(2) A steering angle servo system model is incorporated.
Among these, for (1), the expression (9) is replaced with the following expression (33).

Here, α is a deceleration acting on the vehicle body by the brake. As for α, the deceleration acting on the vehicle body can be estimated from the brake pressure signal detected by the brake pressure sensor, so that it can be treated as a known signal here.
For (2), equation (14) is replaced with equation (34) that approximates the turning angle servo system with a primary system model.

Here, T _s represents a response time constant of the turning angle servo system, and δ _com represents a turning angle command value input to the turning angle servo system. By performing the above replacement, the vehicle model receives the turning angle command value δ _com as an input.

In addition, regarding the turning angle command value δ _com, it is assumed that the maximum turning angle of the turning angle servo system is set to δ _{max and} the input restriction of Expression (36) is imposed.

As the evaluation function, the same evaluation function as the evaluation function (16) in the first embodiment is used. For request items (1), (2), and (4), equations (17), (19), and (21) can be used as they are, respectively. However, since x _p and y _p representing the position of the obstacle in the equation (17) consider the movement of the obstacle,

という予測式と組み合わせた形で組み込まれることになる。
要請項目（３）については、
（３′）転舵角指令値をなるべく小さくする
という要請項目で置き換える。この要請項目は、

Will be incorporated in combination with the prediction formula.
Regarding request item (3),
(3 ′) Replace with a request item to make the steering angle command value as small as possible. This request item is

という評価式で表現することができる。

It can be expressed by the evaluation formula.

Outside 7

Steps S1410 and S1411 are the same as steps S309 and S310 of the first embodiment, except that a time series of turning angle command values is calculated instead of a steering angular velocity command value time series. .
In step S1412, a process of transmitting the turning angle command value to the turning angle servo controller 10 is executed.
Steps S1406 and S1407 are the same as steps S305 and S306 in the first embodiment.
In step S1408, sensor detection information is evaluated.

Outside 8

  However, the detection accuracy and reliability of each sensor are not necessarily the same, so if these information settings are made using only sensor detection information, detection values with low detection accuracy and reliability will affect the target travel route calculation. Is concerned. For example, the information regarding the position and moving speed of an obstacle can be obtained with a relatively high detection value when the vehicle is in a straight traveling state, but the detection accuracy is high when the vehicle is turning with a yaw rate. There is a tendency to decrease. In such a case, an index α representing the reliability of the sensor detection information taking a value from 0 to 1 is introduced, and the reliability index is set as follows according to the yaw rate detection value γ generated in the host vehicle. calculate.

However, γ ₀ is a threshold value for determining the reliability of the detection information. Here, α = 0 is defined as a determination result that the sensor detection information has low reliability, and α = 1 is defined as a determination result that the reliability is high. In addition, by making the index continuous,

のように定義することも考えられる。本実施例では簡単のため、検出したヨーレートの値だけで信頼性評価指標を算出する構成としている。しかし、装置に実装したセンサの検出特性に応じて、例えばカメラの視野角内における障害物の検出位置に応じて信頼性を定義するなど、（４０）、（４１）式とは異なる指標を定義することもできる。また、例えば位置検出情報と速度検出情報とで異なる信頼性評価指標を算出するといった構成をとることもできる。

It is also possible to define as follows. In this embodiment, for simplicity, the reliability evaluation index is calculated only from the detected yaw rate value. However, an index different from the equations (40) and (41) is defined, for example, the reliability is defined according to the detection position of the obstacle within the viewing angle of the camera according to the detection characteristics of the sensor mounted on the apparatus. You can also Further, for example, it is possible to adopt a configuration in which different reliability evaluation indexes are calculated for position detection information and speed detection information.

  In step S1409, as in step S308 of the first embodiment, initial conditions necessary for recalculation of the target travel route are set. In the first embodiment, the processing related to the setting of the state vector of the own vehicle is mainly performed, but in the present embodiment, the processing related to the setting of the position / motion state of the obstacle is executed.

Outside 9

Based on the above settings, the process advances to step S1410 to execute target route calculation processing.
The processes in steps S1413 and S1415 are the same processes as steps S312 and S313 in the first embodiment, respectively. Further, the second embodiment adopts a configuration in which the steering clutch 17 is disengaged during the activation of the driving support control so that the driver's steering angle and the front wheel steering angle of the vehicle can move independently. Then, the clutch 17 is engaged after the driver's steering angle and the front wheel steering angle are restored to the original relationship. In this case, a control routine for returning to the normal operation mode is prepared, and processing for starting the control routine is executed in step S1414.

Outside 10

FIG. 15 is a diagram illustrating the behavior when the apparatus of the second embodiment encounters the scene of FIG. 4 described above. That is, this device is activated at time t ₀ and the driver starts a right avoiding operation, and when the time t ₁ is reached, the arrangement of the own vehicle and the obstacle, the yaw rate of the own vehicle, and the lateral position of the obstacle A history of detection results is shown.

Here, the obstacle is assumed to be stationary. Until the time t ₀ before the avoidance operation starts, the vehicle is in a straight traveling state, so the yaw rate of the host vehicle is almost zero, and the detection result of the lateral position (y coordinate) of the obstacle almost matches the true value. . When the calculation result of the avoidance route is obtained at time t ₀ and the vehicle starts running along the avoidance route and the yaw rate is generated, the error in the detected value of the lateral position of the obstacle gradually increases. Along with this, a recalculation result will be obtained in which the target travel route tends to be gradually corrected to the right from the original target travel route, but the yaw rate generated in the vehicle suddenly increases from around γ _0. The error of the detected value becomes large.

Accordingly, erroneous information that the obstacle is suddenly moving in the right direction is transmitted to the target travel route calculation unit 230, and the target travel route that greatly avoids in the right direction correspondingly. The result of recalculation will be obtained. Therefore, there is a possibility of falling into a vicious circle in which a larger yaw rate is generated.
This makes the driver feel a sense of discomfort equivalent to the fact that the vehicle is following a traveling route in which the vehicle is constantly flowing in the right direction even though the obstacle is stationary.

  FIG. 16 shows a history of the target turning angle calculated by the target travel route calculation unit 230. If the recalculation is continued using the sensor information, an unnatural steering pattern in which the vehicle is steered once to the right and then steered largely to the right and then returned to the steer. On the other hand, when the predicted state vector is used without using sensor information, the target travel route is recalculated on the assumption that the obstacle is almost stationary, so a smooth and stable steering pattern is obtained. It is done.

(Effects of the second embodiment)
In the vehicle driving support device as the second embodiment, the reliability of the information detected by the detection information evaluation unit 320 in the own vehicle state detection unit 210, the driver operation state detection unit 220, and the obstacle detection unit 260. To evaluate. Then, the initial condition setting unit 250 sets an initial condition in which the current state detection value is emphasized as the reliability of the detection information is higher.
With the above configuration, the setting of the state quantity used for the initial condition is changed according to the reliability evaluation of the detection information. For this reason, it is possible to prevent the target travel route from being disturbed by using information with low reliability.

(Third embodiment)
A third embodiment of the present invention will be described below with reference to FIGS.
In the third embodiment, the vehicle is assumed to support the operation of traveling along the road instead of the support of the obstacle avoidance operation as in the first embodiment and the second embodiment described above. A driving support device is configured.

FIG. 17 is a schematic diagram for explaining a vehicle driving support apparatus according to a third embodiment of the present invention. FIG. 18 is a functional block diagram corresponding to the apparatus of FIG.
17 and 18, the corresponding parts to those in FIGS. 1 and 2 described above are denoted by the same reference numerals, and the description of each part uses the above-mentioned reference regarding the corresponding part. In the third embodiment, a GPS signal receiver 13 that receives a positioning signal from an artificial satellite and a map information database 120 that is a recording medium on which road information is recorded are added. Other points are the same as those of the first embodiment shown in FIGS. As will be described later, the processing in the microprocessor 73 is different from that in the microprocessor 70 in the first embodiment of FIG. For example, the position / orientation / road information acquisition unit 283 of the sensor signal processing unit 200 acquires the position and traveling direction of the own vehicle and road information based on information received from the GPS signal receiver 13 and the map information database 120. However, in other respects, there is no apparent difference in this functional block diagram.

  Hereinafter, specific processing contents and operations in the apparatus according to the third embodiment will be described assuming the scene shown in FIG. FIG. 19 shows a situation in which the vehicle is approaching a curved portion of the road. Since the flow of processing in the microprocessor is substantially the same as the contents described in the first embodiment of FIG. 3 described above, FIG. 3 described above is used as a flowchart. However, since the processing contents in each step are different from those in the first embodiment, the specific processing contents will be described below with a focus on differences from FIG.

  In step S301, in addition to the camera and sensor signals, processing related to reception of GPS signals and comparison with the road information database is also performed, and information on the position of the vehicle on the road and the road shape ahead is obtained. Although the coordinate system is also set here, the X-axis and Y-axis are first set as the orthogonal coordinate system in the third embodiment as in the first embodiment described above. In this embodiment, in addition to this, the s coordinate axis and the r coordinate axis orthogonal to the s coordinate axis are set on the center line of the road along the traveling direction as shown in the figure. Since the road traveling direction can be obtained by referring to the data in the road information recording unit, the conversion formula between the X, Y coordinates and the s, r coordinates can be configured as the following formula.

In the process of step S302, in addition to the process similar to the first embodiment, the position / orientation / road information acquisition unit 283 is based on the information received from the GPS signal receiver 13 and the map information database 120. Get the location and direction of travel and road information.
In step S303, driving support activation determination is performed. As driving assistance activation conditions, for example, driving assistance is activated when the curvature of the road that is currently running or the road ahead in the predetermined area is larger than a predetermined value, for the purpose of driving assistance for the road curve portion. You can set conditions such as Alternatively, for the purpose of assisting in a wider scene including the straight portion of the road, it is possible to set conditions such that all the vehicles are supported when the traveling speed of the vehicle is higher than a predetermined value.

  In step S304, a target travel route calculation setting process is executed. Hereinafter, the formulation of the target route calculation in the third embodiment will be described. As the vehicle model, the same model as that of the first embodiment can be used. For the evaluation function, the evaluation term corresponding to the request item (1) is excluded. The evaluation term corresponding to the request item (2) basically follows the equation (18) described above, but in the road curve portion as shown in FIG. 19, the distance from the center of the road is the Y coordinate. Instead, it is expressed in r coordinates. Therefore, the evaluation formula corresponding to the formula (18) is expressed as the following formula.

Here, γ _L and γ _R are the r coordinate values of the left end and the right end of the road, respectively.
By substituting the conversion formula (45), r = hγ (x, y), into the r in the formula (46), the formula L _R (x, y) expressing L _R in the x, y coordinates is obtained. Therefore, this is used as an evaluation formula.
For request item (4), when the vehicle travels along the road centerline at a constant speed and the road traveling direction at the s coordinate value reached is read from the road information database and the value is θ ^* ,

という関数で表現することができる。
以上のような設定変更を行えば、ステップＳ３０９で第１の実施の形態と同様の最適化演算に基づいて道路に沿って走行するための目標走行経路を算出することができる。

It can be expressed by the function
If the setting change as described above is performed, a target travel route for traveling along the road can be calculated in step S309 based on the same optimization calculation as in the first embodiment.

  The processing in the other steps after calculating the target travel route is the same as the processing described above for the first embodiment. However, the scene shown in FIG. 19 reflects the fact that the degree of freedom of the travel route that can be taken is higher than that of the obstacle avoidance scene represented by FIG. Add the process described in. That is, in the initial condition setting in step S308, the initial condition used for the target travel route calculation is calculated according to the equation (32).

Outside 11

Specific operations in the apparatus according to the third embodiment to which the target travel route calculation calculation described above is applied will be described with reference to FIGS.
FIG. 20 shows the vehicle position and target travel route at time t _{0 when the} driving operation support is started, and the vehicle position and target travel route at time t _{A when} the error between the detected state and the predicted state exceeds the allowable level. Here, a situation is considered in which the driver travels while following a route on the right side of the target travel route calculated at time t ₀ . As a result, if the detected travel state matches the predicted state at time t _A and the target travel route A is calculated, the target when the operation based on the time-series operation procedure is performed on the actual vehicle state The travel route is the target travel route B. That is, the route passes through a region near the right end of the road as shown. On the other hand, when the target travel route is calculated using the detection state at time t _A , a corrected target travel route such as the target travel route C is obtained. Although the target travel route B does not greatly deteriorate the evaluation value of the evaluation function, it cannot be said that the target travel route B is an appropriate travel route for use as a target route when assisting the driver's operation. However, if the vehicle is immediately switched to the target travel route C, a step is generated in the steering angle target value as shown in FIG. 21, and thus there is a concern that a step also occurs in the steering assist force and gives the driver a sense of incongruity. Therefore, a calculation method is used in which the initial state vector is gradually brought close to the detected state by the methods shown in the equations (48) and (49).
In the third embodiment described above, since the steering angle target value can be continuously changed as shown in FIG. 21, the driving support control can be continued while suppressing the uncomfortable feeling given to the driver.

(Effects of the third embodiment)
(1) In the vehicle driving support apparatus as the third embodiment, the host vehicle state detection unit 210 detects the traveling state of the host vehicle based on the GPS signal and the information in the map information database.
In the vehicle driving support device of the above (1), it is possible to recognize the traveling state of the host vehicle by looking down over a wide range based on the information of the GPS signal and the map information database, and more appropriate driving support can be performed. become.

(2) In the vehicle driving support device, the target travel route calculation unit 230 performs information that causes the change to be continuously changed when a change occurs in the target travel route obtained by the recalculation, and information on the target travel route. Is calculated.
In the vehicle driving support device of (2), since the target travel route does not discontinuously change, the steering angle target value in driving support can be continuously changed, so that the driver feels uncomfortable. Driving support control can be continued.

(Effect in the embodiment of the present invention)
The effects of the vehicle driving support apparatus according to the embodiment of the present invention described above are listed below in relation to the configuration.
(1) In one embodiment of the present invention, the own vehicle state detection unit 210 detects the traveling state of the own vehicle, and the driver operation state detection unit 220 detects the operation state of the driver. Further, it is necessary for the target travel route calculation unit 230 to travel along the target travel route along the target travel route on which the host vehicle should travel up to a predetermined time ahead with any host vehicle state and driving operation state as initial conditions. As a time-series operation procedure, recalculation is performed every predetermined calculation cycle. On the other hand, when the target travel route calculation unit 230 recalculates the target travel route, the current state detection value representing the current state obtained by the vehicle state detection unit 210 and the driver operation state detection unit 220 is recalculated. This is one basis for setting initial conditions. In addition, the state prediction value obtained by extracting the own vehicle state and the driving operation state corresponding to the current time from the target travel route calculated in the past calculation cycle is used as another basis for setting the initial condition for the recalculation. Then, based on these two state quantities selectively, the initial condition setting unit 250 sets initial conditions used for the current target travel route calculation by the target travel route calculation unit 230. The driving operation support unit 240 supports the driving operation of the driver so that the operation according to the time-series operation procedure calculated by the target travel route calculation unit 230 is performed.

  In the vehicle driving support device of the above (1), the target travel route calculation unit 230 selectively sets the grounds for initial condition setting related to the recalculation of the target travel route from the initial condition setting unit 250. That is, the initial condition can be set by selectively depending on the two state quantities of the current state detection value and the state prediction value depending on the situation. For this reason, if there is a possibility that the calculated value of the target travel route in the recalculation may fluctuate significantly due to the detection error of the current state, etc., a predicted state value that is not directly affected by the error factor is calculated. By applying this as the initial condition, it is possible to suppress fluctuations in the calculated value. Thereby, the uncomfortable feeling felt by the driver when the operation support amount varies can be reduced. In addition, it is possible to prevent the target travel route calculated when the target route calculation using the current state detection value is resumed by continuing the recalculation from changing greatly. For this reason, it is possible to reduce the uncomfortable feeling given to the driver because the operation support amount does not change rapidly.

(2) The vehicle driving support apparatus of (1) further includes an obstacle detection unit 260 that detects an obstacle ahead of the host vehicle, and the initial condition setting unit 250 is an obstacle obtained from the obstacle detection unit 260. The previous target travel route calculation unit 230 is selectively based on two state quantities, that is, the current state detection value including the measurement value and the state prediction value including the obstacle position measured in the past calculation cycle. Set initial conditions for.
In the vehicle driving support device of (2), in addition to the effects of the vehicle driving support device of (1), avoidance support in consideration of obstacles ahead of the host vehicle is possible.

(3) In the vehicle driving support device of (2), the obstacle behavior prediction unit 270 further displays the behavior of the obstacle up to a predetermined time based on the movement state of the obstacle detected by the obstacle detection unit 260. Predict.
In the vehicle driving support device according to (3), in addition to the effect of the vehicle driving support device according to (2), it is possible to support effectively avoiding a moving obstacle. In other words, since the initial conditions for calculating the target route including the movement state of the obstacle are set assuming that the vehicle will move, even if the detection accuracy of the movement state of the obstacle changes depending on the situation, the detection accuracy is operational support The influence on the amount can be reduced.

(4) In the vehicle driving support apparatus of (3), the road boundary detection unit 280 further detects a road boundary on which the host vehicle can travel.
In the vehicle driving support device of (4) above, in addition to the effects of the vehicle driving support device of (3) above, the target travel route can be calculated so as to be within the detected road boundary, and the road width is limited. The driving operation can be supported based on an appropriate target travel route even in a situation where the vehicle is present.

(5) In the vehicle driving assistance device according to any one of (1) to (4), the driving assistance activation determination unit 290 further determines the necessity of driving assistance. When the driving support activation determination unit 290 determines that driving support is required, the driving operation support unit 240 performs driving operation support.
In the vehicle driving support device of the above (5), the device acts on the driver's operation only in a scene where driving support is required. For this reason, it is possible to prevent the driver from feeling uncomfortable by intervening in the driver's operation in a situation where assistance is not required.

(6) In the vehicle driving support device according to any one of the above (1) to (5), the initial condition setting unit 250 further compares the current state detection value and the state prediction value calculated in the past calculation cycle. Either one is selected for each component and initial conditions are set.
In the vehicle driving support device of (6) above, the state measurement value and the state prediction value are compared for each component of both, and an appropriate value is set as the initial condition. For this reason, the value suitable for the situation given for each signal constituting the state quantity can be selected and applied to the target travel route calculation. Therefore, it is possible to perform optimum processing according to the characteristics of each signal and the performance of the detection section, and it is possible to adaptively reduce the influence of the characteristics of a specific signal and the performance of the detection section on the calculation result of the target path. .

(7) In the vehicle driving support device according to any one of (1) to (5), the initial condition setting unit 250 further includes the current state detection value and the state predicted value calculated in a past calculation cycle. The initial condition is set by calculating an average value after giving appropriate weights to the two state quantities for each component.
In the vehicle driving support device of the above (7), the initial condition for the target travel route calculation is calculated based on the weighted average of the state measurement value and the state prediction value. As a result, when the two state quantities are switched, the initial condition setting can be continuously changed, and changes in the target travel route and the operation support amount can be made smoother. Therefore, it is possible to perform operation support that can be easily accepted by the driver without a sense of incongruity.

(8) In the vehicle driving support device according to any one of (6) to (7), the detection information evaluation unit 320 further includes a host vehicle state detection unit 210, a driver operation state detection unit 220, and an obstacle detection. The reliability of the information detected in the unit 260 is evaluated. Then, the initial condition setting unit 250 sets an initial condition in which the current state detection value is emphasized as the reliability of the detection information is higher.
In the vehicle driving support device of (8), the setting of the state quantity used for the initial condition is changed according to the reliability evaluation of the detection information. For this reason, it is possible to prevent the target travel route from being disturbed by using information with low reliability.

(9) In the vehicle driving support device according to any one of (6) to (8), the predicted travel route evaluation unit 310 further performs a time-series operation procedure corresponding to the target travel route calculated in the past calculation cycle. To obtain an evaluation value relating to the validity of the own vehicle travel route that is expected when the input is continued after the current time. Then, the initial condition setting unit 250 sets an initial condition that places importance on the current state measurement value as the evaluation value by the predicted travel route evaluation unit 310 is low, and the state calculated in the past calculation cycle as the evaluation value is high Set initial conditions with emphasis on predicted values.

  In the vehicle driving support device of (9) above, while predicting / evaluating the predicted travel route at the current time, determining the necessity of recalculating the target travel route based on the newly detected state quantity Recalculate the target travel route. As a result, re-calculation of the target route is performed based on the state quantity that is not easily affected by the error factor for deviations from the target route that do not significantly affect the original driving purpose such as obstacle avoidance. . Therefore, the target travel route is less likely to fluctuate, and operation assistance that is natural and understandable for the driver can be performed.

(10) In the vehicle driving support device according to any one of (6) to (9), the initial condition setting unit 250 further includes a divergence between the current state predicted value and the state predicted value calculated in the past calculation cycle. If the value exceeds a specified value, the weighted average calculation weight in the initial condition setting is gradually changed from the setting that emphasizes the predicted state value to the setting that emphasizes the current state measurement value over time. To change.
In the vehicle driving support device of (10) above, when the error between the state measurement value and the state prediction value becomes large, the initial condition setting is gradually switched to the state measurement value. Thereby, when the deviation from the target travel route becomes large, in the scene where the driver is prompted to return to the original target travel route, the uncomfortable feeling given to the driver due to a sudden change in the operation support amount can be alleviated.

(11) In the vehicle driving support device according to any one of (1) to (10), the driver operation state detection unit 220 further detects a steering operation of the driver.
In the vehicle driving support device of the above (11), since the driver's steering operation is detected and the target travel route is calculated, the travel route including the lateral movement of the vehicle is calculated and the vehicle travels accordingly. Operation support can be performed.

(12) In the vehicle driving support device according to any one of the above (1) to (11), the driver operation state detector 220 further detects the driver's accelerator operation and brake operation.
In the vehicle driving support device of the above (12), the driver's accelerator operation and brake operation are detected and the target travel route is calculated, so that the travel route including acceleration / deceleration motion of the vehicle is calculated and followed. It is possible to assist the operation for traveling.

(13) In the vehicle driving support device according to any one of (1) to (12), the driving operation support unit 240 further detects the target operation amount calculated by the target travel route calculation unit 230 and the driver operation state detection. Based on the deviation from the driver operation amount detected by the unit 220, the operation assisting force for the driver's operation is controlled.
In the vehicle driving support device of (13), a deviation between the target operation amount calculated by the target travel route calculation unit 230 and the actual operation amount of the driver is detected, and an operation assisting force according to the deviation is applied. . For this reason, a required operation can be effectively transmitted to the driver depending on the direction and magnitude of the operation assisting force.

(14) In the vehicle driving support device according to any one of the above (1) to (12), the driving operation support unit 240 further automatically sets the operation amount calculated by the target travel route calculation unit 230 to the operation system of the own vehicle. Realized by controlling.
In the vehicle driving support device of (14), the target operation amount calculated by the target travel route calculation unit is realized by automatic control. For this reason, the own vehicle can be made to follow a target driving path reliably.

(15) In the vehicle driving support device according to any one of (1) to (5), the host vehicle state detection unit 210 further detects the traveling state of the host vehicle based on the GPS signal and the information in the map information database. To do.
In the vehicle driving support device of the above (15), it is possible to recognize the traveling state of the host vehicle by looking down over a wide range from the information of the GPS signal and the map information database, and it is possible to perform more appropriate driving support. become.

(16) In the vehicle driving support device according to any one of (1) to (5), the target travel route calculation unit 230 further causes the change to continue when a change occurs in the target travel route obtained by the recalculation. The information about the target travel route is calculated by performing a calculation that is a change in the target.
In the vehicle driving support device of the above (16), since a discontinuous change does not occur in the target travel route, the steering angle target value in driving support can be continuously changed, so that the driver feels uncomfortable. Driving support control can be continued.

1 ………………………… Camera 2 …………………………… Vehicle speed sensor 3 ……………………………… Yaw rate sensor 4 …………………… …………………………………………………………………… Steering angle sensor 6 …………………………… Steering torque sensor 8 …………………………… Steering assist motor 9 …………………………… Motor controller 10 ………………………… Turning angle servo controller 11 ………………………… Brake 12 ………………… ......... Brake pressure sensor 13 ………………………… GPS receiver 15 ………………………… Turning angle sensor 17 ………………………… Clutch 18 …… …………………… Steering motor 70, 72, 73 ………… Microprocessor 100 …………………… Sensor group 200 ……………………… Sensor signal Physical unit 210 …………………… Own vehicle state detection unit 220 …………………… Driver operation state detection unit 230 ………………………… Target travel route calculation unit 240. …………………… Driving operation support unit 250 ………………………… Initial condition setting unit 260 ……………………… Obstacle detection unit 270 ……………………… Obstacle behavior prediction unit 280... ............ road boundary detection unit 290... ……………………… Detection information evaluation unit 400, 402, 403… Driving operation support mechanism

Claims (17)

A vehicle state detection unit for detecting a traveling state of the vehicle;
A driver operation state detector for detecting the operation state of the driver;
Necessary to drive the target travel route along the target travel route at the start of calculation of the target travel route to be traveled by the vehicle or the initial state of the vehicle state and the driving operation state after the start of the calculation. As a simple time-series operation procedure, a target travel route calculation unit that sequentially performs recalculation and calculates,
When the target travel route calculation unit recalculates the target travel route, the current state detection value representing the current state obtained by the host vehicle state detection unit and the driver operation state detection unit, and a past calculation The target travel route calculation unit uses the target travel route calculation unit to calculate the current target travel route based selectively on two state quantities, that is, the own vehicle state corresponding to the current time from the target travel route and the state predicted value obtained by extracting the driving operation state. An initial condition setting section for setting initial conditions;
A driving operation support unit that supports the driving operation of the driver so that the operation according to the time-series operation procedure calculated by the target travel route calculation unit is performed;
A vehicle driving support apparatus comprising: An obstacle detection unit for detecting an obstacle ahead of the host vehicle;
The initial condition setting unit includes two state quantities: a current state detection value including an obstacle measurement value obtained from the obstacle detection unit, and a state prediction value including an obstacle position measured in the past. The vehicle driving support device according to claim 1, wherein an initial condition is set in the target travel route calculation unit based selectively on the vehicle. An obstacle behavior prediction unit for predicting the behavior of future obstacles based on the movement state of the obstacle detected by the obstacle detection unit;
The initial condition setting unit includes the current state detection value including the measured value of the obstacle movement state obtained from the obstacle detection unit, and the obstacle behavior prediction information calculated in the past by the obstacle behavior prediction unit. Selectively setting an initial condition in the target travel route calculation unit based on two state quantities including an obstacle position corresponding to the current time and a state predicted value including a state quantity obtained by extracting an exercise state; The driving support apparatus for a vehicle according to claim 2, wherein the driving support apparatus is for a vehicle. A road boundary detector for detecting a boundary of the road on which the vehicle can travel;
The vehicle driving support device according to any one of claims 1 to 3, wherein the target travel route calculation unit calculates the target travel route so as to be within the detected road boundary. It further comprises a driving support start determination unit for determining the necessity of driving support,
The said driving operation assistance part performs assistance of driving operation, when it determines with the driving assistance starting determination part requiring driving assistance, The driving | operation assistance is performed as described in any one of Claims 1-4 characterized by the above-mentioned. Vehicle driving support device.   6. The initial condition setting unit performs initial condition setting by selecting either one of the current state detection value or the state prediction value calculated in the past for each component. The vehicle driving support device according to any one of the above.   The initial condition setting unit calculates an initial condition by calculating an average value after assigning an appropriate weight to each of the two state quantities of the current state detection value and the state prediction value calculated in the past. The vehicle driving support device according to any one of claims 1 to 5, wherein setting is performed. A detection information evaluation unit for evaluating reliability of information detected in the vehicle state detection unit, driver operation state detection unit, and obstacle detection unit;
8. The vehicle driving support according to claim 6, wherein the initial condition setting unit sets an initial condition in which the current state detection value is emphasized as the reliability of the detection information is higher. apparatus. A predictive travel route evaluation unit that obtains an evaluation value related to the validity of the own vehicle travel route when a time-series operation procedure corresponding to the target travel route calculated in the past is continuously input after the current time;
The initial condition setting unit sets an initial condition in which the current state measurement value is emphasized as the evaluation value by the predicted travel route evaluation unit is low, and the state prediction value calculated in the past is emphasized as the evaluation value is high. The vehicle driving support device according to any one of claims 6 to 8, wherein an initial condition is set.   When the difference between the current state predicted value and the state predicted value calculated in the past is greater than a predetermined value, the initial condition setting unit calculates the weighted average calculation weight in the initial condition setting for the subsequent time. The vehicle driving support device according to any one of claims 6 to 9, wherein the vehicle driving support device is changed in a stepwise manner from a setting that places importance on the predicted state value over time to a setting that places importance on the current state measurement value.   The vehicle driver assistance device according to any one of claims 1 to 10, wherein the driver operation state detector detects a steering operation of the driver.   The vehicle driver assistance apparatus according to any one of claims 1 to 11, wherein the driver operation state detection unit detects an accelerator operation and a brake operation of the driver.   The driving operation support unit is configured to provide an operation assisting force for a driver's operation based on a deviation between the target operation amount calculated by the target travel route calculation unit and the driver operation amount detected by the driver operation state detection unit. The vehicle driving support device according to any one of claims 1 to 12, wherein the vehicle driving support device is controlled.   The driving operation support unit realizes the operation amount calculated by the target travel route calculation unit by automatically controlling an operation system of the own vehicle. Vehicle driving support device.   The vehicle driving support device according to any one of claims 1 to 5, wherein the host vehicle state detection unit detects a driving state of the host vehicle based on information of a GPS signal and a map information database. .   The target travel route calculation unit calculates information on the target travel route by performing an operation in which the change is a continuous change when a change occurs in the target travel route obtained by the recalculation. The vehicle driving support device according to any one of? A vehicle state detection step for detecting a traveling state of the vehicle;
A driver operation state detection step for detecting the operation state of the driver;
Necessary to drive the target travel route along the target travel route at the start of calculation of the target travel route to be traveled by the vehicle or the initial state of the vehicle state and the driving operation state after the start of the calculation. As a time series operation procedure, a target travel route calculation step for calculating by sequentially executing recalculations,
A driving operation support step for supporting the driving operation of the driver so that the operation according to the time-series operation procedure calculated by the target travel route calculating step is performed;
When recalculating the target travel route, from the current state detection value representing the current state obtained in the vehicle state detection step and the driver operation state detection step, and the target travel route calculated in the past calculation cycle The initial conditions used for the current target travel route calculation are set in the target travel route calculation step based selectively on the two state quantities of the own vehicle state corresponding to the current time and the state predicted value obtained by extracting the driving operation state. Initial condition setting step to
A vehicle driving support method comprising:

Images