JP5163346B2 - Vehicle braking / driving control device and automatic driving control method - Google Patents

Description

  The present invention relates to a braking / driving control apparatus and an automatic driving control method for a vehicle that automatically controls the own vehicle according to the intention of the driver.

As a technique for automatic operation control, for example, there is a technique described in Patent Document 1. This automatic driving control controls the vehicle speed based on the set vehicle speed when there is no preceding vehicle. On the other hand, if there is a preceding vehicle, the vehicle speed of the host vehicle is controlled so as to follow the preceding vehicle. Further, the curve approach speed of the preceding vehicle and the distance to the preceding vehicle are stored. Then, when the host vehicle reaches the stored point, the speed of the host vehicle is controlled so that the vehicle enters the curve at a speed equal to or lower than the stored speed of the preceding vehicle.
Patent Document 2 discloses a driving assistance technique for assisting a vehicle to pass a curve.
JP 2007-168788 A JP 2007-106170 A

In an automatic driving state, in a driving state where the front is a curve, there is a case where control is performed to decelerate the vehicle so as to achieve an approach speed that can pass through the curve. In some cases, the automatic operation control release condition is satisfied during such control. At this time, when the road surface is downhill, the host vehicle is accelerated as it is, although it is preferable to decelerate the host vehicle toward the curve. In response to this acceleration, the driver who has left the vehicle to drive needs to decelerate by, for example, performing a brake operation. Such a situation where the vehicle accelerates before the curve gives the driver a sense of incongruity. In particular, when the automatic driving is canceled without depending on the driver's will, the driver feels uncomfortable.
The present invention has been made paying attention to the above points, and it is an object of the present invention to alleviate the driver's uncomfortable feeling according to the traveling situation even if the automatic driving cancellation condition is satisfied.

  In order to solve the above-described problems, the present invention includes an automatic driving control for performing acceleration / deceleration control of the host vehicle and controlling the host vehicle at a target vehicle speed at which the vehicle can travel at least before entering the curve. Even if the release condition of the automatic driving control is satisfied, if it is estimated that the deceleration state of the host vehicle is not maintained until the curve, the deceleration control is maintained.

According to the present invention, the deceleration state is maintained even if the automatic driving control is canceled under a situation where the host vehicle is estimated to be accelerated. Accordingly, it is possible to suppress acceleration of the host vehicle in a situation where deceleration is necessary.
As a result, even if the automatic driving cancellation condition is satisfied, the driver does not feel uncomfortable according to the driving situation, or the uncomfortable feeling can be reduced.

Next, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a schematic configuration diagram showing a vehicle according to the present embodiment. FIG. 2 is a block diagram showing the configuration of the braking / driving controller 50.
(Constitution)
The vehicle of the present embodiment is, for example, a rear wheel drive vehicle (for example, an AT vehicle, a vehicle equipped with a convex). The braking device is configured to be able to independently control the left and right braking forces (braking fluid pressure) for both the front and rear wheels. In addition, the braking force control apparatus of this embodiment does not necessarily assume such a vehicle configuration.

  In FIG. 1, reference numeral 1 denotes a brake pedal. Reference numeral 2 denotes a booster connected to the brake pedal 1. Reference numeral 3 denotes a master cylinder. Reference numeral 4 denotes a reservoir. Reference numerals 10 and 20 indicate left and right front wheels, and reference numerals 30 and 40 indicate left and right rear wheels, respectively. Each wheel is provided with a brake unit. Each brake unit includes brake disks 11, 21, 31, 41 and wheel cylinders 12, 22, 32, 42. The wheel cylinders 12, 22, 32, and 42 frictionally clamp the brake disc by supplying hydraulic pressure to give a braking force (braking force) for each wheel. And each wheel is braked individually by supplying hydraulic pressure from the pressure control unit 5 to the wheel cylinder of each brake unit. The pressure control unit 5 includes an actuator for each hydraulic pressure supply system (each channel) on the front, rear, left, and right. The actuator includes a proportional solenoid valve that can control each wheel cylinder hydraulic pressure to an arbitrary braking hydraulic pressure. The pressure control unit 5 adjusts the hydraulic pressure from the master cylinder 3 based on the input signal from the braking / driving controller 50, and controls the brake hydraulic pressure supplied to the wheel cylinders 12, 22, 32, 42 of each wheel.

  The drive torque control controller 60 includes an engine control unit, a throttle control unit, and a transmission control unit, and controls the drive torque of the drive wheels. The engine control unit controls the fuel injection amount of the engine 6. The throttle control unit controls the throttle opening by the throttle control device 7. The transmission control unit controls the transmission 8. The drive torque controller 60 operates in response to a command from the braking / driving controller 50 and outputs information related to driving such as the driving torque Tw on the wheel shaft to the braking / driving controller 50.

The acceleration sensor 53 detects the longitudinal and lateral acceleration values Xg ^* and Yg ^* of the vehicle. The detected signal is output to the braking / driving controller 50.
The yaw rate sensor 54 detects the yaw rate φ generated in the vehicle. The detected signal is output to the braking / driving controller 50.
Wheel speed sensors (not shown) 13, 23, 33, 43 installed on the wheels detect the wheel speed Vwi of each wheel. The detected signal is output to the braking / driving controller 50.
The master cylinder hydraulic pressure sensor 55 detects the master cylinder hydraulic pressure Pm. By this detection, the operation amount of the brake pedal 1 can be detected. The detected signal is output to the braking / driving controller 50.

The accelerator opening sensor 56 detects the accelerator opening Acc of the accelerator pedal 57. By this detection, the operation amount of the accelerator pedal 57 can be detected. The detected signal is output to the braking / driving controller 50.
The steering angle sensor 52 detects the steering angle δ of the handle 9. The detected signal is output to the braking / driving controller 50.
Further, a millimeter wave radar 58 is mounted as an external recognition sensor for detecting the preceding vehicle. The millimeter wave radar 58 outputs a detection signal to the millimeter wave radar controller 90. The millimeter wave radar controller 90 calculates the inter-vehicle distance Lx to the preceding vehicle based on the detection signal from the millimeter-wave radar 58, and outputs the calculated inter-vehicle distance Lx to the braking / driving controller 50.

Further, a steering switch SW is installed on the handle 9 or in the vicinity thereof. The steering switch SW is an operator operated by the driver, and performs an instruction for setting / releasing automatic driving, a setting instruction for a set inter-vehicle distance state Acc_LMS_state, and a setting instruction for a set vehicle speed Vset. A signal generated by operating the steering switch SW is input to the braking / driving controller 50.
Here, the automatic driving control of the present embodiment performs a follow-up control to the preceding vehicle and a vehicle speed control for controlling the speed of the host vehicle to a target speed capable of traveling on the curve before entering the curve. The set inter-vehicle distance state Acc_LMS_state represents a set value of the inter-vehicle distance. For example, three modes are provided: a relatively close inter-vehicle distance, a normal inter-vehicle distance, and a relatively far inter-vehicle distance.

  A navigation system 70 is also provided. The navigation system 70 periodically acquires the position of the host vehicle by GPS or the like, and searches the front road information of the host vehicle as node information from the acquired host vehicle position and map information. Then, the navigation system 70 outputs the searched node information (node point Nj, position, score, etc.) to the braking / driving controller 50. If the navigation system 70 has a function capable of acquiring gradient information, the gradient information is also output to the braking / driving controller 50.

  A warning monitor 80 is provided in front of the driver's seat. The monitor 80 has a built-in speaker for generating sound and buzzer sound. The warning monitor 80 is a device that presents a warning to the driver when a signal indicating that at least a forward curve that activates automatic deceleration control is detected is input. The warning is not limited to voice. A warning may be presented by light or vibration to the handle 9.

As described above, the braking / driving controller 50 includes automatic operation control that performs acceleration / deceleration control so as not to exceed the curve approach speed by controlling the target vehicle speed at which the vehicle can travel along the curve at least before entering the curve. However, in the present embodiment, the driving support device is not installed. “Before entering a curve” indicates, for example, a curve existing up to 100 m ahead.
As shown in FIG. 2, the braking / driving controller 50 includes an automatic operation control unit 50A, a target vehicle speed selection unit 50B, a vehicle speed servo calculation unit 50C, and a wheel torque distribution control calculation unit 50D. The automatic operation control unit 50A includes a curve target vehicle speed calculation unit 50Aa, a follow-up target vehicle speed calculation unit 50Ab, and a control state determination unit 50Ac.

The automatic driving control unit 50A calculates a target vehicle speed command value and a control state for automatic driving control, and outputs them to the target vehicle speed selecting unit 50B.
The curve target vehicle speed calculation unit 50Aa calculates a target vehicle speed command value capable of traveling on a curve ahead.
The follow-up target vehicle speed calculation unit 50Ab calculates a target vehicle speed command value for follow-up control with respect to the preceding vehicle.
The control state determination unit 50Ac determines a control state of automatic driving control.
The target vehicle speed selection unit 50B selects a target vehicle speed command value for controlling the vehicle with reference to the control state.
In addition, the vehicle speed servo calculation unit 50C calculates a target acceleration / deceleration for achieving the target vehicle speed command value selected by the target vehicle speed selection unit 50B.
The wheel torque distribution control calculation unit 50D distributes the torque based on the target acceleration / deceleration calculated by the vehicle speed servo calculation unit 50C to the engine torque and the brake torque.

The processing of the braking / driving controller 50 will be described with reference to FIG. The braking / driving controller 50 operates every predetermined sampling period.
First, in step S100, various data from each sensor and controller are read. Specifically, each wheel speed Vwi (i = 1 to 4), accelerator opening Acc, lateral acceleration value Yg ^* , and setting information from the steering switch SW are acquired. Also, the node point information (Xj, Yj, Lj) from the navigation system 70 to the own vehicle position (X, Y) and each node point Nj (j = 1 to n, n is an integer) in front of the own vehicle along the travel path. ) To get.

Here, (Xj, Yj) is an XY coordinate of the node point Nj. Lj is distance information from the vehicle position (X, Y) to the position (Xj, Yj) of the node point Nj. Further, each node point Nj (j = 1 to n) is located farther from the host vehicle along the travel path, as the node point Nj having a larger value of the subscript j.
Subsequently, in step S200, the host vehicle speed V is calculated.
During normal travel, the host vehicle speed V is calculated as an average value of the wheel speeds Vw1 and Vw2 of the front wheels (non-driven wheels) by the following equation (1).
V = (Vw1 + Vw2) / 2 (1)
However, when a control system using vehicle speed such as ABS control is operating, information on the own vehicle speed (estimated vehicle speed) used in such a system is acquired and set as the own vehicle speed V.

Next, in step S300, the turning radius Rj at each node point Nj is calculated based on the node information.
Here, there are several methods for calculating the turning radius itself. For example, the turning radius Rj may be calculated based on a commonly used three-point method.
Further, instead of calculating the turning radius Rj at each node point Nj, interpolation points may be created at equal intervals so as to pass through each node point Nj, and the turning radius at the interpolation point may be calculated.

Next, in step S400, a target vehicle speed for automatic driving at each node point Nj is calculated. Specifically, based on the turning radius Rj of each node point Nj obtained previously and a predetermined lateral acceleration Yg ^* , the following formula (2) is used to calculate the target vehicle speed Vrac _j for automatic driving control at each node point Nj. Is calculated.
Vrac _j ² = Yg ^* × | Rj | (2)
That is, Vrac _j = √ (Yg ^* × | Rj |).
Here, for example, 0.3 G is set as the predetermined lateral acceleration Yg ^* . Alternatively, the predetermined lateral acceleration Yg ^* may be a lateral acceleration set by the driver.

As can be seen from the above equation (2), the larger the turning radius Rj, the larger the target vehicle speed Vracc _{j for} automatic operation control.
Here, in the process of step S300, when calculating the turning radius at the interpolation point, the target vehicle speed at the interpolation point may be calculated. In this case, in the following processing, the interpolation point is regarded as a node point, or the processing is performed by calculating the target vehicle speed at each node point Nj from the target vehicle speed at the interpolation point.

Next, in step S500, a target deceleration at each node point Nj is calculated. That is, the target deceleration Xgsacc _j for automatic operation control at each node point Nj is calculated by the following equation (3). In this calculation, the host vehicle speed V obtained earlier, the target vehicle speed Vrac _{j at} each node point Nj, and the distance Lj from the current position to each node point Nj are used.
Xgsacc _j = (V ² −Vrac _j ² ) / (2 × Lj)
= (V ² −Yg ^* × | Rj |) / (2 × Lj) (3)
Here, the target deceleration Xgsaccj is negative on the deceleration side.

The target deceleration Xgsacc _j is a value calculated from the own vehicle speed V, the target vehicle speed Vrac _j, and the distance Lj from the current position to each node point Nj. Accordingly, as the target vehicle speed Vracc _j is small, the more the turning radius Rj is small, or as the distance Lj is small, the target deceleration Xgsacc _j becomes smaller.
In the above description, the target deceleration Xgsacc _j of each node point Nj is calculated using the distance Lj to each node point Nj. Instead, the target deceleration at each interpolation point may be calculated using distances to the interpolation points set at equal intervals.

Next, in step S600, a target deceleration to be controlled is detected from the target deceleration Xgsacc _j at each node point Nj. That is, the minimum value of the target deceleration Xgsacc _j (the value with the largest absolute value of the deceleration) is detected by the following equation (4). Specifically, the minimum value Xgsacc_min of the target deceleration Xgsacc _j of the automatic operation control at each node point Nj calculated in the above step is calculated.
Xgsacc_min = min (Xgsacc _j ) (4)

Next, in step S700, the target vehicle speed command value Vrrac in the automatic operation control state is calculated from the minimum value Xgsacc_min of the target deceleration by using the following equation (5) with the deceleration change limiter Xg_min as a limit.
Vrracc = f (Xgsacc_min, Xg_min) × t
(5)
The above f (Xgsacc_min, Xg_min) is a function for performing a select high, and selects a larger value (a value having a smaller absolute value).
Here, t represents a sampling time. The above equation (5) is obtained by time integration by multiplying by t.
Further, for example, −0.01 G is set as the change amount limiter Xg_min.

Next, in step S800, a target vehicle speed command value Vgacc for follow-up control for the preceding vehicle is calculated.
For example, the target vehicle speed command value Vgacc for the preceding vehicle is calculated based on the parameters shown in the following formula.
Vgacc = f (Lx, V, Acc_LMS_state, Vset)
here,
V: own vehicle speed Lx: inter-vehicle distance sent from the millimeter wave radar Acc_LMS_state: set inter-vehicle distance state, that is, the magnitude of the target inter-vehicle distance from the preceding vehicle Vset: the set vehicle speed set by the driver.

The above function performs the following calculation, for example.
When no preceding vehicle exists ahead of the host vehicle by a distance that can be measured, the target vehicle speed command value Vgacc is set as the set vehicle speed Vset.
When a preceding vehicle exists ahead of the host vehicle by a distance that can be measured, the vehicle speed for following the preceding vehicle is calculated and used as the target vehicle speed command value Vgacc. For example, based on the distance to the preceding vehicle and the relative speed, a speed for maintaining the inter-vehicle distance set in the set inter-vehicle distance state Acc_LMS_state based on the distance to the preceding vehicle is calculated and used as the target vehicle speed command value Vgacc. The relative speed can be obtained from changes in the host vehicle speed and the inter-vehicle distance. When the inter-vehicle distance is within the target inter-vehicle distance range, the speed of the preceding vehicle is set as the target vehicle speed command value Vgacc. When the inter-vehicle distance is larger than the target inter-vehicle distance range, a value obtained by adding a predetermined increment value corresponding to the relative speed to the speed of the preceding vehicle is set as the target vehicle speed command value Vgacc. Conversely, when the inter-vehicle distance is smaller than the target inter-vehicle distance range, a value obtained by adding a predetermined decrement value corresponding to the relative speed to the speed of the preceding vehicle is set as the target vehicle speed command value Vgacc.

Next, in step S900, the control state for the curve is determined. That is, a control state determination unit 50Ac described later is activated to set / update the state variable state.
Here, the meaning of the value of the state variable state is as follows.
state = 0: automatic operation control state release state state = 1: normal automatic operation state state = 2: normal deceleration state after normal automatic operation is released In step S900, the normal automatic operation state is started. When it is detected that the transition to the deceleration maintaining state is detected (when the state is updated from “1” to “2”), the distance Lx from the transition position to the control target curve is stored as the distance Ldj. The control target curve is a node position curve corresponding to the minimum value Xgsacc_min of the target deceleration Xgsacc _j .

Next, in step S1000, an actual target vehicle speed command value Vrr is selected based on the value of the state variable state.
That is, in the deceleration maintaining state (state = 2), the target vehicle speed command value Vrracc in the automatic driving control state for the curve is set as the target vehicle speed command value Vrr as in the following equation.
Vrr = Vrracc
In the case of the automatic driving control state (state = 1), a smaller value is selected from the target vehicle speed command value Vgacc for the preceding vehicle and the set vehicle speed and the target vehicle speed command value Vrrac for the automatic driving control state as in the following equation. Select, that is, select low, and set the smaller side as the target vehicle speed command value Vrr.
Vrr = min (Vgacc, Vrracc)

In the deceleration release state (state = 0), the host vehicle speed V is set to the target vehicle speed command value Vrr as shown in the following equation in order to release the automatic operation control.
Vrr = V
Next, in step S1100, it is determined whether or not an alarm is activated.
In the release state (state = 0), the alarm is not activated (flg_wow = 0).
In other control states (state = 1, 2), an alarm is activated (flg_wow = 1).
Here, when the accelerator opening degree Acc is activated, the alarm is deactivated (flg_wow = 0), and the driver's driving is prioritized.

Next, in step S1200, a control operation determination is performed.
In the release state (state = 0), the control is set to non-operation flg_control = 0.
In the case of other control states (state = 1, 2), the control is set to operation flg_control = 1.
Here, when the accelerator opening degree Acc is activated, the deceleration control is set to non-actuated flg_control = 0, and the driver's driving is prioritized.
Next, in step S1300, a control amount for achieving the target vehicle speed command value Vrr calculated in step S1000 is calculated.

Here, the control amount is calculated by calculating the target acceleration / deceleration in the vehicle speed servo calculation unit 50C in order to achieve the vehicle speed command value calculated in step S1000 when the deceleration control operation flag flg_control is "1". . Then, according to the target acceleration / deceleration calculated by the vehicle speed servo calculation unit 50C, the wheel torque distribution control calculation unit 50D performs torque distribution to the engine torque and the brake torque, respectively. Then, a throttle opening command value for achieving the allocated engine torque and a brake fluid pressure command value for achieving the brake torque are output.
Here, the engine torque includes braking force by engine braking.
In the deceleration maintaining state, only deceleration control is performed in principle.

Next, in step S1400, the throttle opening command value is output to the drive torque control controller, and the brake fluid pressure command value is output to the pressure control unit. When an alarm operation is required based on flg_wow (flg_ww = 1), a command to that effect is output to the monitor 80 that outputs a warning. Here, the alarm may be, for example, sound, HUD, voice utterance from the navigation system 70, navigation screen display, or meter display.
When the above process is completed, the process returns.

Next, the process of step S900 (control state determination for the curve) will be described with reference to FIG.
First, in step S910, it is determined whether or not the current state is a normal automatic driving state. In the normal automatic operation state, the process proceeds to step S930. On the other hand, if it is not the normal automatic operation state, the process proceeds to step S920.
This determination is made based on the value of the previous state variable state.
That is, in step S910, it is determined whether or not state = 1. If state = 1, the process proceeds to step S930. On the other hand, if the state is not 1, the process proceeds to step S920.

In step S920, it is determined whether or not the current state is a deceleration control cancellation state. If it is determined that the deceleration control cancellation state is present, the process proceeds to step S991. That is, when state = 0, it is determined that the deceleration control is released. The deceleration control release state is a state in which the normal automatic operation state is released and deceleration control is not maintained.
On the other hand, if it is determined that the deceleration control is not canceled, the process proceeds to step S960. In this case, the control state variable state is “2”.
That is, the decision branching process in steps S910 and S920 branches to step S920, step S930, and step S960 depending on the value of the previous state variable state.

In step S930, it is determined whether a condition for canceling automatic driving is satisfied. If it is determined that the automatic driving release condition is not satisfied, that is, if the automatic driving state is continued, the process proceeds to step S991. On the other hand, when the automatic driving state cancellation condition is satisfied, the process proceeds to step S940.
In step S940, it is determined whether or not the automatic driving state cancellation condition is determined by the driver's will. In the case of release by the driver's will, the process proceeds to step S992. On the other hand, when it is not cancellation | release by a driver | operator's will, it transfers to step S950. In step S940, the cancellation condition may not be determined, and the process may unconditionally move to step S950.

Here, the release by the will of the driver includes the following. That is, there is a case where the driver performs a brake operation or selects automatic driving cancellation by SW operation. Moreover, there are the following as cancellations not depending on the driver's will. That is, this is a case where information necessary for tracking control becomes undetectable due to contamination of the detection sensor, sunlight, or the like.
In step S950, it is determined whether or not it can be estimated that deceleration is not maintained until the curve ahead, that is, whether or not deceleration is necessary. If it can be estimated that the deceleration is not maintained, the process proceeds to step S960. On the other hand, when it cannot be estimated that the deceleration is not maintained, the process proceeds to step S992.
Here, it is estimated that the deceleration is not maintained when the traveling road surface is a downhill.

The determination as to whether or not it can be estimated that the deceleration is not maintained is performed, for example, as follows.
When the target vehicle speed command value previous value Vrrfz1 is compared with the host vehicle speed V and the host vehicle speed V is equal to or higher than the target vehicle speed command value previous value Vrrfz1, ).
(1) When Vrrfz1 ≦ V Rd = ON
(2) Otherwise Rd = Off
In the above determination, the determination may be made in consideration of the delay that appears in the vehicle by the engine characteristics and the brake characteristics.
Further, when the navigation system 70 outputs the gradient information to the braking / driving controller 50, the presence / absence of the downward gradient may be determined in consideration of whether the road gradient to the curve is a downhill or not.

In step S960, it is determined whether or not the vehicle has passed the deceleration maintenance state target curve.
The position of the node point (referred to as a control target node point) at which the target deceleration of the automatic driving control becomes the minimum value Xgsacc_min is the position of the deceleration maintenance state target curve. Then, it is determined whether or not the node point position has been passed. And when it determines with having passed the deceleration maintenance state object curve, it transfers to step S992. On the other hand, if it is determined that the vehicle has not yet passed through the deceleration maintenance state target curve, the process proceeds to step S970.

An example of the specific determination method is shown.
When transitioning from the automatic control state to the deceleration maintaining state, the distance Lx from the host vehicle to the control target node point at the time of transition is stored as the distance Ldj. Further, the distance Lt is calculated by integrating the moving distance of the automobile every control cycle from the transition time. The distance Lt is a total distance from the base point to the current position of the host vehicle with the position of the host vehicle at the time of the transition as a base point.
Then, the reference distance Ldj is compared with the distance Lt sequentially added from the transition point to determine whether or not the vehicle has passed the deceleration maintenance state target curve.
That is, when Ldj ≦ Lt, it is determined that it has passed. On the contrary, when Ldj> Lt, it is determined that it has not passed. The determination may be made based on whether or not the control target node point has been passed.

In step S970, it is determined whether or not there is a curve to be subjected to the deceleration maintenance state. That is, it is determined whether the road surface ahead is in a curve state enough to keep the deceleration maintained. If it is determined that there is a curve that is targeted for the deceleration maintenance state, the process proceeds to step S980. On the other hand, if the curve is not the deceleration maintenance target, the process proceeds to step S991.
It is determined as follows whether there is a curve to be subjected to the deceleration maintenance state.

When the value of the minimum value Xgsacc_min of the target deceleration that is the deceleration at the node point as the deceleration maintenance state target curve position is equal to or less than the predetermined deceleration, the curve is determined to be the deceleration maintenance state target. For example, −0.15G is set as the predetermined deceleration. You may determine by turning curvature being less than predetermined.
In step S980, it is determined whether or not the brake switch is ON by a driver's operation (depressing the brake pedal 1). If the brake switch is ON, it is determined that the deceleration maintaining state is cancelled, and the process proceeds to step S992. On the other hand, when the brake switch is not ON (the brake switch is OFF), the process proceeds to step S993.

The control state is determined by the above processing.
In step S991, the automatic operation state is set. Return by assigning "1" to the state variable state.
In step S992, the automatic operation is canceled and “0” is substituted into the state variable state to return.
In step S993, the state is returned by substituting “2” into the state variable state as the deceleration maintaining state after the normal automatic operation is canceled.
When an automatic driving ON signal is input by a signal from the steering SW, the state is set to “1”.

Here, Step S300 to Step S700 constitute a curve target vehicle speed calculation unit 50Aa. Step S800 constitutes the follow-up target vehicle speed calculation unit 50Ab. Step S900 constitutes the control state determination unit 50Ac. Step S1000 constitutes the target vehicle speed selection unit 50B.
Further, the automatic driving control unit 50A and the target vehicle speed selecting unit 50B constitute automatic driving control means. Step S950 constitutes deceleration maintenance estimation means. Step S993 (control state determination unit 50Ac) and step S1000 (target vehicle speed selection unit 50B) constitute deceleration control maintaining means.

(Operation)
It is assumed that the automatic driving state is set according to the driver's setting.
In this automatic operation state, the following processing is performed periodically.
Based on the navigation information, a target curve position (a travel path position having the smallest turning radius in front of the vehicle) is specified, and a target vehicle speed command value Vracc that can pass through the control target curve is calculated (step S700).
Further, a target vehicle speed command value Vgacc for traveling following the preceding vehicle is calculated (step S800).
Then, one of the two target vehicle speed command values (the smaller command value side in this embodiment) is selected as a target vehicle speed command value for normal automatic driving.
Further, the control state is periodically determined (step S9).

  At this time, deceleration control is continued under a predetermined condition even if the automatic driving cancellation condition is satisfied. That is, when the traveling path having the smallest turning radius in front of the vehicle is a curve to be controlled, automatic driving control is not canceled under a predetermined condition. That is, the deceleration control with the target vehicle speed command value Vracc that can pass through the control target curve as the target vehicle speed is maintained. The predetermined condition is a case where it can be estimated that deceleration is not maintained, such as a situation where the host vehicle accelerates to the target curve. For example, it is a case where it is a downhill to a curve.

If the vehicle is traveling on a downhill before the curve, the deceleration control is normally performed so that the target speed can pass through the curve in the automatic driving state.
In this state, if the automatic driving is canceled by satisfying the automatic driving cancellation condition due to a sensor error, etc., the vehicle moves to the acceleration state as it is, and braking by the driver who recognizes that deceleration is required by an alarm or the like, for example. Operation is required. That is, an unnecessary acceleration state may occur and give the driver a feeling of strangeness.

On the other hand, in the present embodiment, the deceleration control is maintained when deceleration traveling is necessary even when the automatic driving cancellation condition is satisfied. This suppresses the occurrence of an unnecessary acceleration state in front of the curve and suppresses the driver from feeling uncomfortable.
This time chart is shown in FIG. The scene shown in FIG. 5 is assumed to travel on a gentle downhill downhill toward a forward curve. In FIG. 5, the symbol A indicates the transition of the vehicle speed in the present embodiment. On the other hand, symbol B is a transition of the vehicle speed when the automatic driving is canceled under the automatic driving cancellation condition.

However, when the automatic driving is canceled at the driver's will, the driver's intention is respected and the automatic driving state is canceled without maintaining the deceleration control.
The deceleration control is canceled when the target curve position is passed. Also, when the brake pedal 1 is depressed during the deceleration control or when the accelerator pedal 57 is depressed, the deceleration control is canceled with respect to the driver's braking.
Further, when the driver turns on the automatic driving switch again during the deceleration control, the normal automatic driving control state is restored.

(Effect of this embodiment)
(1) A deceleration maintenance estimation unit and a deceleration control maintenance unit are provided.
Thus, even if the condition for canceling the control by the automatic driving control means is satisfied, if it is estimated that the deceleration state of the host vehicle is not maintained until the next curve, the deceleration control is maintained.
Therefore, it is possible to suppress acceleration of the host vehicle in a situation where deceleration is necessary. As a result, it is possible to prevent or alleviate the driver's uncomfortable feeling according to the driving situation when the automatic driving is released.

(2) At this time, the deceleration control is maintained with the target vehicle speed that can be traveled on the curve calculated by the automatic operation control as the target value.
As a result, it is possible to decelerate to an approach speed capable of traveling along the curve when entering the curve.
(3) The deceleration maintaining estimation means determines that the deceleration is necessary when the traveling path of the host vehicle is determined to be a downhill.
When the automatic operation is canceled on the downhill, the deceleration state is not maintained, for example, the acceleration state is established. On the other hand, in this embodiment, even if the conditions for canceling automatic driving on a downhill are satisfied, it is possible to suppress acceleration of the host vehicle. As a result, it is possible to prevent or alleviate the driver's uncomfortable feeling according to the driving situation when the automatic driving is released.

(4) The deceleration maintenance estimation means determines whether or not a deceleration is necessary only when a release condition that does not depend on the driver's will is satisfied among the release conditions of the vehicle control by the automatic driving control means.
That is, the deceleration control is maintained only when automatic driving is canceled under conditions that do not depend on the driver's will.
As a result, unnecessary acceleration before the curve can be suppressed only when the driver feels more uncomfortable. Further, when automatic driving is canceled at the driver's will, the driver's will can be respected.
(5) The deceleration control maintaining means cancels the deceleration control when detecting the driver's intention to accelerate.
As a result, the vehicle can be changed to a state in which the vehicle can be operated according to the driver's intention.

(6) If the deceleration control maintaining means determines that the host vehicle has passed the curve to be controlled, it cancels the deceleration control.
If it passes through the curve to be controlled, it can be assumed that the driver wants to accelerate. On the other hand, in this embodiment, since deceleration control is cancelled | released, after passing a curve, reflection to the vehicle of acceleration operation by a driver | operator can be implement | achieved at an early stage.
(7) When the driver requests the operation of the automatic operation control means during the deceleration control by the deceleration control maintaining means, the automatic control means shifts the control from the control by the deceleration control maintaining means to the normal automatic operation control. To do.
This makes it possible to shift to normal automatic operation.
(Modification)
(1) The deceleration control by the deceleration control maintaining means may be canceled when the vehicle speed reaches the target vehicle speed at the target curve position.

(Second Embodiment)
Next, a second embodiment will be described with reference to the drawings. In addition, about the apparatus similar to the said embodiment, the same code | symbol is attached | subjected and demonstrated.
The basic configuration such as the vehicle configuration of the present embodiment is the same as that of the first embodiment.
This embodiment is an example in the case of a vehicle provided with driving support control in addition to the above-described automatic driving control as braking / driving control of the vehicle.
That is, in this embodiment, driving support control for limiting the vehicle speed to the target speed at which the vehicle speed can travel along the curve is added to the automatic driving control for controlling the vehicle speed to the target speed at which the vehicle can travel along the curve.

Here, in the above-mentioned automatic driving control, the control of the speed of the own vehicle is left to the vehicle at the driver's will.
On the other hand, the driving support control is premised on that the driver travels by operating the vehicle state (braking and acceleration). When it is determined that there is a possibility that the vehicle cannot run on the curve, the system intervenes to reduce the speed of the vehicle and assist the driver in driving the vehicle on the curve.
For this reason, the driving support by the driving support control operates when the automatic driving control is released.

In addition, the driving assistance is in a vehicle state different from the driver's operation. For this reason, in the driving support control, the target vehicle speed for the curve is set higher in order to reduce the system intervention compared to the automatic driving control. Also, in order to delay the timing at which the system operates, the control is not performed until just before the curve by lowering the predetermined value of the target deceleration.
As shown in FIG. 6, the braking / driving controller 50 of the present embodiment includes a driving assistance target vehicle speed calculation unit 50 </ b> E. Other configurations are the same as those in the first embodiment (see FIG. 2).
The driving assistance target vehicle speed calculation unit 50E calculates a target vehicle speed for limiting the vehicle speed so as not to exceed the curve approach speed. The calculated target vehicle speed is output to the target vehicle speed selection unit 50B.

Next, processing of the braking / driving controller 50 in the present embodiment will be described with reference to the drawings.
Steps S100 to S300 are the same as those in the first embodiment, and a description thereof will be omitted.
In step S400, as in the first embodiment, the target vehicle speed command value Vraccr _j for automatic driving control at each node point Nj is calculated by the following equation.
Vraccr _j ² = Ygacc ^* × | Rj | (2-1)
Next, in step S450, a target vehicle speed for driving support control at each node point Nj is calculated.

Specifically, based on the turning radius Rj and lateral acceleration Yg * of each node point Nj, the target vehicle speed Vrspt _j for driving support control at each node point Nj is calculated by the following equation (2-2).
Vrspt _j ² = Ygspt ^* × | Rj | (2-2)
Here, a certain predetermined value is set as the lateral acceleration Yg ^* . However, the lateral acceleration Ygspt for driving support control ^*, lateral acceleration Ygacc of automatic operation control ^* rather than set to a large value. For example, to set the lateral acceleration Ygacc automatic operation control ^* to 0.3 G, to set the lateral acceleration Ygspt driving support device ^* to 0.5G. The set lateral acceleration set by the driver may be used.

According to the equation (2-1) and the equation (2-2), the larger the turning radius Rj, the larger the target vehicle speed, Vrspt _j and Vracc _j .
In this step, the target vehicle speed is set for each node point Nj. However, as described in step S300, interpolation points are created at equal intervals so as to pass through each node point Nj. The target vehicle speed at may be calculated.

Next, in step S500, as in the first embodiment, a target deceleration for automatic operation control at each node point Nj is calculated.
Xgsacc _j = (V ² −Vrac _j ² ) / (2 × Lj)
= (V ² −Yg ^* × | Rj |) / (2 × Lj) (3-1)
Next, in step S550, the target deceleration of the driving support control at each node point Nj is calculated as in the first embodiment.
Specifically, the target deceleration Xgsspt _j of the driving support control at each node point Nj is calculated by the following equation (3-2). At this time, the host vehicle speed V, the target vehicle speed at each node point Nj, and the distance Lj from the current position to each node point Nj are used.
Xgsspt _j = (V ² −Vrspt _j ² ) / (2 × Lj)
= (V ² −Yg ^* × | Rj |) / (2 × Lj) (3-2)

Here, the target decelerations Xgsspt _j and Xgsacc _j are negative on the deceleration side. Thus, the target decelerations Xgsspt _j and Xgsacc _j are values calculated from the host vehicle speed V, the target vehicle speeds Vracc _j and Vrspt _j, and the distance Lj from the current position to each node point Nj. And, specifically, as the target vehicle speed Vracc _j, Vrspt _j is small, the more the turning radius Rj is small, or the distance the more Lj is small, the target deceleration Xgsspt _j, Xgsacc _j becomes smaller.
Here, in this step, the target deceleration of each node point Nj was calculated using the distance L to each node point Nj. Instead, the target deceleration at each interpolation point may be calculated using distances to the interpolation points set at equal intervals.

Next, in step S600, the target deceleration Xgsacc _j of the node point Nj to be controlled is detected from the target deceleration of the automatic operation control at each node point Nj.
Xgsacc_min = min (Xgsacc _j ) (4-1)
Next, in step S650, the target deceleration of the node point Nj to be controlled is detected from the target deceleration of the driving support control at each node point Nj.
That is, the minimum value of the target deceleration Xgsspt _j is detected by the following equation (4-2). That is, the minimum value Xgsspt_min of the target deceleration Xgsspt _j for driving support control is calculated.
Xgsspt_min = min (Xgsspt _j ) (4-2)

Next, in step S700, as in the first embodiment, the target vehicle speed command value in the automatic driving control state is set from the minimum value Xgsacc_min of the target deceleration in the automatic driving control state to the upper limit of the change amount limiter of the deceleration. Vrracc is calculated.
Vrracc = f (Xgsacc_min, change amount limiter) × t
... (5-1)
The change amount limiter is set to, for example, -0.01G.
Next, in step S750, from the minimum value Xgsspt_min of the target deceleration of the driving support control, the target vehicle speed command value of the driving support control is set to the upper limit of the change amount limiter of the deceleration as shown in the following equation (5-1). Vrrspt is calculated.
Vrrspt = f (Xgsspt_min, change amount limiter) × t
... (5-2)
The function f () is a function that performs select high.
Here, t represents the sampling time. The change amount limiter is set to, for example, -0.01G.

Next, in step S800, a target vehicle speed command value Vgacc for follow-up control for the preceding vehicle is calculated. The processing is the same as in the first embodiment.
Next, in step S900, the control state for the curve is determined. The basic process is the same as that of the first embodiment as shown in FIG.
However, it differs from the process of the first embodiment (FIG. 4) in the following points. That is, it is an example when the process of step S940 is not performed. Moreover, the process of step S985 is added between step S980 and step S992.

In step S985, it is determined whether or not the host vehicle speed V is higher than a target vehicle speed command value for driving support control. If the host vehicle speed is higher than the target vehicle speed command value for driving support control, the process proceeds to step S993 as continuing deceleration control.
On the other hand, when the host vehicle speed is equal to or lower than the target vehicle speed command value of the driving support control, the process proceeds to step S992 to cancel the deceleration, that is, cancel the automatic driving control.
Other processes in step S900 are the same as those in the first embodiment.
Next, in step S1000, an actual target vehicle speed command value Vrr is selected based on the value of the state variable state.

That is, in the deceleration maintaining state (state = 2), the target vehicle speed command value Vrrspt of the driving support control is used as the target vehicle speed command instead of the target vehicle speed command value Vrracc in the automatic driving control state for the curve as in the following equation. Let it be the value Vrr.
Vrr = Vrrspt
In the case of the automatic driving control state (state = 1), a smaller value is selected from the target vehicle speed command value Vgacc for the preceding vehicle and the set vehicle speed and the target vehicle speed command value Vrrac for the automatic driving control state as in the following equation. The target vehicle speed command value Vrr is used.
Vrr = min (Vgacc, Vrracc)

Further, in the deceleration release state (state = 0), the target vehicle speed command value is set to the target vehicle speed command value Vrrspt of the driving support control as in the following equation.
Vrr = Vrrspt
However, when the host vehicle speed V is lower than the target vehicle speed command value Vrrspt of the driving support control, the host vehicle speed V is set as the target vehicle speed command value so as not to intervene in the driving support control.
Vrr = V

Next, in step S1100, an alarm activation start determination is performed.
When the release state (state = 0) and Xgsspt_min is a predetermined value, for example, −0.01 G or less, an alarm is activated (flg_how = 1).
In the case of other control states (state = 1, 2), an alarm is activated (flg_wow = 1).
In this way, the intervention start of the system is reduced by lowering the predetermined value of the alarm start determination in the case of the deceleration release state in which the driving support control is activated (state = 0) than in the case of the automatic driving control (state = 1). Can do.
Here, when the accelerator opening degree Acc is activated, the alarm is deactivated (flg_wow = 0), and the driver's driving is prioritized.

Next, in step S1200, a deceleration control operation determination is performed.
In the release state (state = 0), when Xgsspt_min is a predetermined value, for example, −0.015 G or less, the deceleration control is set to operation flg_control = 1.
In other control states (state = 1, 2), the deceleration control is set to operation flg_control = 1.
In this way, the intervention of the system is reduced by lowering the predetermined value of the deceleration control operation in the case of the deceleration release state in which the driving support control is activated (state = 0) than in the case of the automatic driving control (state = 1). Can do.

Here, when the accelerator opening degree Acc is activated, the deceleration control is set to non-actuated flg_control = 0, and the driver's driving is prioritized.
Since subsequent steps S1300 to S1400 are the same as those in the first embodiment, description thereof will be omitted.
Here, the driving assistance target vehicle speed calculation unit 50E, the target vehicle speed selection unit 50B, and steps S450, S550, S650, and S750 constitute driving assistance control means. The target vehicle speed command value Vrrspt for driving support becomes the second target speed.

(Operation)
It is assumed that the automatic driving state is set according to the driver's setting.
In this automatic operation state, the following processing is performed periodically.
Based on the navigation information, a target curve position (a travel path position having the smallest turning radius in front of the vehicle) is specified, and a target vehicle speed command value Vracc that can pass through the control target curve is calculated (step S700).
Further, a target vehicle speed command value Vgacc for traveling following the preceding vehicle is calculated (step S800).
Then, one of the two target vehicle speed command values (small command value side in the present embodiment) is set as a target vehicle speed command value for normal automatic driving.
Further, the control state is periodically determined (step S900).

Further, a target vehicle speed command value for driving support is also periodically calculated (step S750).
At this time, the deceleration control is continued under a predetermined condition even if the automatic driving cancellation condition is satisfied. That is, when the traveling path having the smallest turning radius in front of the vehicle is a curve to be controlled, automatic driving control is not canceled under a predetermined condition. That is, the deceleration control with the target vehicle speed command value Vracc that can pass through the control target curve as the target vehicle speed is maintained. The predetermined condition is a case where it can be estimated that deceleration is not maintained, such as acceleration of the host vehicle to the target curve. For example, it is a case where it is a downhill to a curve.

For example, if the vehicle is traveling on a downhill before a curve, the automatic driving state is normally controlled to reduce to a target speed that can pass the curve.
In this state, if the automatic driving is canceled by satisfying the automatic driving cancellation condition due to a sensor error or the like, the vehicle shifts to the acceleration state as it is. After that, the driving assistance is activated, and the vehicle behavior becomes such that the brake is decelerated again.
That is, an unnecessary acceleration state may occur and give the driver a feeling of strangeness.

On the other hand, in this embodiment, if deceleration traveling is necessary even if the automatic driving release condition is satisfied, the deceleration control is maintained. Therefore, the occurrence of an unnecessary acceleration state in front of the curve is suppressed, and the driver feels uncomfortable.
However, in the present embodiment, unlike the first embodiment, the target vehicle speed of the driving support control is used as the target vehicle speed of the deceleration control.
Thereafter, even when the deceleration control state is shifted to the driving support control state, the target value of the deceleration control is set as the target vehicle speed of the driving support control, so that the shift can be smoothly performed.
Other operations are the same as those in the first embodiment.

(Effect of 2nd Embodiment)
(1) Basic effects are the same as those in the first embodiment.
(2) A driving support control means is provided together with the automatic driving control means. In this case, the deceleration maintaining control means uses the curve approach speed that is the target vehicle speed of the driving support control means as the target value.
Even when switching from the deceleration control to the driving support control, the target vehicle speed of the control is the same, so it is possible to eliminate the uncomfortable feeling when the control is switched.
In addition, it is not necessarily the division to switch.

1 is a schematic configuration diagram of a vehicle according to a first embodiment based on the present invention. It is a figure explaining the structure of the braking / driving controller which concerns on 1st Embodiment based on this invention. It is a figure explaining the process of the braking / driving controller which concerns on 1st Embodiment based on this invention. It is a figure explaining the process of the control determination which concerns on 1st Embodiment based on this invention. It is a figure explaining the operation example which concerns on 1st Embodiment based on this invention. It is a figure explaining the structure of the braking / driving controller which concerns on 2nd Embodiment based on this invention. It is a figure explaining the process of the braking / driving controller which concerns on 2nd Embodiment based on this invention. It is a figure explaining the process of the control determination which concerns on 2nd Embodiment based on this invention.

Explanation of symbols

5 pressure control unit 6 engine 50 braking / driving controller 50A automatic operation control unit 50Aa curve target vehicle speed calculation unit 50Ab tracking target vehicle speed calculation unit 50Ac control state determination unit 50B target vehicle speed selection unit 50C vehicle speed servo calculation unit 50D wheel torque distribution control calculation Unit 50E target vehicle speed calculation unit 60 for driving support driving torque controller 70 navigation system Lx inter-vehicle distance Nj node point Rj turning radius state state variable V own vehicle speed Vrr final target vehicle speed command value Vgacc following target vehicle speed command value Vrracc curve Target vehicle speed command value Vrrspt Target vehicle speed command value for driving support

Claims (9)

In a braking / driving control device for a vehicle having an automatic driving control means for performing acceleration / deceleration control of the host vehicle and controlling the target vehicle speed at least so that the host vehicle can travel the curve before entering the curve,
When a release condition for releasing vehicle control by the automatic driving control means is satisfied, the vehicle is provided with deceleration maintenance estimation means for determining whether or not the deceleration state of the host vehicle is not maintained until the curve,
The automatic driving control means includes a deceleration control maintaining means for maintaining deceleration control until before entering the curve when the deceleration maintenance estimating means determines that the deceleration is required.   2. The braking / driving control device for a vehicle according to claim 1, wherein the deceleration control maintaining means performs deceleration control using a target vehicle speed capable of traveling on the curve as a target value. Apart from the above automatic operation control means,
Driving that limits the vehicle speed of the host vehicle by calculating a second target vehicle speed that does not exceed the curve entry speed that can pass through the curve when passing through the curve, and performing deceleration control at the second target vehicle speed In a braking / driving control device for a vehicle comprising support control means,
2. The braking / driving control device for a vehicle according to claim 1, wherein the deceleration maintaining control means performs deceleration control at the second target vehicle speed.   The braking / driving control device for a vehicle according to any one of claims 1 to 3, wherein the deceleration maintaining estimation means determines that the vehicle needs to be decelerated when the traveling path of the host vehicle is determined to be a downhill. .   The deceleration maintaining estimation means determines whether or not the vehicle is in a deceleration-necessary state only when a release condition that does not depend on the driver's will is satisfied among the vehicle control release conditions by the automatic driving control means. The braking / driving control device for a vehicle according to any one of claims 1 to 4.   The braking / driving control device for a vehicle according to any one of claims 1 to 5, wherein the deceleration control maintaining means is released when the driver's intention to accelerate is detected.   The braking / driving control device for a vehicle according to any one of claims 1 to 6, wherein the deceleration control maintaining means is canceled when it is determined that the host vehicle has passed the curve.   When the driver requests the operation of the automatic driving control means during the deceleration control by the deceleration control maintaining means, the automatic control means shifts the control from the control by the deceleration control maintaining means to the normal automatic driving control. The braking / driving control device for a vehicle according to any one of claims 1 to 7.   A state where the deceleration state of the host vehicle is not maintained up to the above curve even if the release condition of the automatic driving control that controls the host vehicle at the target vehicle speed that can drive the curve at least before entering the curve is satisfied by performing acceleration / deceleration control of the host vehicle When it is estimated that the vehicle is decelerated, the vehicle deceleration control is maintained.

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