JP4784007B2 - Vehicle driving support device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a driving support device for a vehicle that automatically maintains the distance between the vehicles.
[0002]
[Prior art]
There is known a constant speed traveling device that causes a vehicle to travel at a set constant speed. Thus, in a constant speed traveling device, an inter-vehicle distance control device that normally decelerates the host vehicle and maintains a safe inter-vehicle distance when the inter-vehicle distance approaches due to deceleration of the preceding vehicle or the like is used in combination.
[0003]
The technology disclosed in Japanese Patent No. 2659224 is an example of such a technology, and this inter-vehicle distance control is canceled when the brake operation is performed in the high-speed traveling mode, and the inter-vehicle distance is achieved during the braking operation in the urban traveling mode. The distance control is stopped, and the inter-vehicle distance control is returned by releasing the brake operation. Accordingly, it is described that it is not necessary to frequently cancel the inter-vehicle distance control and perform the return operation by setting the urban area travel mode particularly in a traffic jam or the like.
[0004]
[Problems to be solved by the invention]
However, especially when the preceding vehicle is accelerating at low speeds or when it is stopped, it is difficult to recognize the inter-vehicle distance more quickly and accurately than during high-speed driving, and the vehicle accelerates even if inter-vehicle distance control is canceled. Since there is a time lag until the vehicle is started, the driver actually operates the accelerator to accelerate, and when starting and stopping repeatedly due to traffic jams, it is necessary to operate the brake and accelerator alternately. Yes, the operation becomes complicated.
[0005]
Therefore, an object of the present invention is to provide a driving support device for a vehicle that can appropriately maintain a distance between vehicles even when starting from a stop or at a low speed.
[0006]
[Means for Solving the Problems]
In order to solve the above-described problem, a driving support device for a vehicle according to the present invention is a driving support device for a vehicle that controls the propulsive force of the host vehicle based on the correspondence relationship between the preceding vehicle and the host vehicle. Brake operation amount detection means for detecting the brake operation amount, vehicle speed detection means for detecting the vehicle speed of the host vehicle, accelerator operation amount detection means for detecting the driver's accelerator operation amount, and this accelerator operation amount detection means When the accelerator operation amount is within a preset range, the inter-vehicle distance control means that automatically maintains the inter-vehicle distance with the preceding vehicle, and the detected vehicle speed is the predetermined speed even in the inter-vehicle distance control setting state. in the following, and the brake operation is changed from the oN to the oFF state is continued is turned off, until the accelerator operation amount range condition in which the inter-vehicle distance control means performs the following distance control are met, the vehicle And control means for increasing by comparing proceeds force during normal vehicle distance control, characterized in that it comprises.
[0007]
In this way, a propulsive force greater than the vehicle creep torque can be applied by turning off the brake operation. Therefore, an appropriate propulsive force is applied quickly until the inter-vehicle distance control functions effectively. You can start and accelerate.
[0008]
When the brake operation is turned on while the propulsive force is being increased , the control means preferably increases the propulsive force gradually by increasing the normal according to the operation state. In this way, acceleration / deceleration can be performed according to the driver's intention.
[0009]
When the brake operation is less than the predetermined time and less than the predetermined amount, it is preferable to continue the propulsive force increase control. In this way, frequent changes in acceleration / deceleration exceeding the driver's intention can be suppressed.
[0010]
It is preferable that steering angle detection means for detecting the steering angle is further provided, and that the control means limits the acceleration or the upper limit value of the acceleration during the propulsive force increase control according to the steering angle. As a result, it is possible to travel along the trajectory intended by the driver when changing lanes or traveling along a curve.
[0011]
It is preferable to further include determination means for determining the ease of slipping of the wheel on the traveling road surface, and the control means preferably controls the propulsive force that is increased during the propulsive force increase control according to the determined slip ease. Thereby, generation | occurrence | production of the acceleration slip in the state where wheels, such as a low micro road, are slippery can be suppressed effectively.
[0013]
When a preceding vehicle is not detected within a predetermined range, it is preferable to prohibit or restrict the propulsive force increase control. Accordingly, it is possible to give priority to the driver's intention, and it is possible to ensure followability when a preceding vehicle newly appears within a predetermined range.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments of the invention will be described in detail with reference to the accompanying drawings. In order to facilitate the understanding of the description, the same reference numerals are given to the same components in the drawings as much as possible, and duplicate descriptions are omitted.
[0016]
FIG. 1 is a block diagram showing a schematic configuration of a vehicle driving support apparatus according to the present invention. The control means of this apparatus comprises an engine ECU 10, a brake ECU 20, and an inter-vehicle distance ECU 30. The engine ECU 10 has a function of communicating information with each of the brake ECU 20 and the inter-vehicle distance ECU 30.
[0017]
The engine ECU 10 receives detection outputs of an accelerator sensor 11 that detects a driver's accelerator operation amount, a vehicle speed sensor 12 that detects a vehicle speed, a shift sensor 13 that detects a shift setting state, and a rain sensor 18 that detects raindrops. In addition, the outputs of the cruise control switch 14 and the inter-vehicle distance setting switch 17 for the driver to set cruise control are input. A throttle control motor 15 that is attached to a throttle (not shown) and adjusts its opening degree and a shift controller 16 that performs automatic shift setting and outputs a predetermined output signal to the display system 40 It is.
[0018]
The brake ECU 20 receives detection outputs of a steering angle sensor 21 that detects the driver's steering operation amount, a yaw rate sensor 22 that detects the yaw rate of the vehicle body, and a brake sensor 23 that detects the driver's brake operation amount. It controls the operation of the brake actuator 24 for controlling the braking force applied to the hydraulic brake attached to each wheel and the lighting of the stop lamp 25.
[0019]
Connected to the inter-vehicle distance ECU 30 is a laser radar sensor 31 for irradiating the front of the vehicle with a pulse laser and detecting the presence of a preceding vehicle and the relative speed based on the time until the reflected light is received.
[0020]
FIG. 2 is a diagram for explaining cruise control by this driving support device. This cruise control is composed of constant speed traveling control that maintains the vehicle speed of the host vehicle at a set speed and inter-vehicle control that maintains the inter-vehicle distance from the preceding vehicle at a safe interval. Here, a case where the set vehicle speed is controlled as Va and the set inter-vehicle distance is controlled as V × ta proportional to the vehicle speed V (hereinafter, the time ta is simply referred to as the set inter-vehicle distance) will be described as an example. This cruise control is performed in a state where the accelerator operation amount detected by the accelerator sensor 11 is within a predetermined range, the set speed is set by the cruise control switch 14, and the inter-vehicle distance (time) is set by the inter-vehicle distance setting. This is done by the switch 17. Note that when raindrops are detected by the rain sensor 18, cruise control is canceled because accurate detection of the preceding vehicle by the laser radar sensor 31 cannot be expected.
[0021]
First, as shown in FIG. 2A, when the inter-vehicle distance ECU 30 determines that the preceding vehicle is not detected by the laser radar sensor 31 within a predetermined range in front of the host vehicle 1, the engine ECU 10 By controlling the shift controller 16 and the throttle control motor 15, the vehicle speed of the host vehicle 1 is maintained at Va.
[0022]
Next, as shown in FIG. 2B, even when the inter-vehicle distance ECU 30 determines that the preceding vehicle 2 exists, the speed Vb is higher than the vehicle speed Va of the own vehicle, and the inter-vehicle distance If a safe inter-vehicle distance is ensured even when La is away from the set distance or is slower, the engine ECU 10 maintains the vehicle speed of the host vehicle 1 as it is.
[0023]
On the other hand, as shown in FIG. 2C, when the inter-vehicle distance ECU 30 is close to or shorter than the set distance, the engine ECU 10 includes the shift controller 16, the throttle control motor 15 and the inter-vehicle distance Lb. By controlling the vehicle, the vehicle speed of the host vehicle is reduced to Vb, so that the inter-vehicle distance is maintained at a safe distance. When the speed reduction or throttle adjustment alone is insufficient, the brake ECU 20 is instructed to reduce the speed, and the brake ECU 20 operates the brake actuator 24 to apply the braking force to reduce the speed, and the stop lamp 25 Turn on to let the following car know that it is braking.
[0024]
As shown in FIG. 2D, when the preceding vehicle 2 moves to another lane during deceleration control or when a safe distance can be secured by acceleration, the engine ECU 10 controls the shift controller 16. By controlling the throttle control motor 15, the vehicle speed of the host vehicle 1 is again accelerated to the set speed Va.
[0025]
During cruise control, it is preferable to alert the driver by displaying information on the current control state on the display system 40 in any state.
[0026]
In the present embodiment, as described below, propulsive force application control for applying a propulsive force when the brake is off is performed.
[0027]
FIG. 3 is a flowchart showing a main process of the control process of the propulsive force application control. This process is performed by the engine ECU 10 and the brake ECU 20 in cooperation, and is repeatedly executed at a predetermined timing from when the ECUs 10 to 30 are operated until the operation is finished.
[0028]
First, in step S1, it is determined whether or not the vehicle speed V of the vehicle 1 is less than a threshold value Vth. If the vehicle speed is equal to or higher than Vth, the following process is skipped and the process ends. On the other hand, when the vehicle speed is less than Vth, the process proceeds to step S2 to determine whether or not the operation from the on state to the off state of the brake has been performed.
[0029]
Specifically, the brake operation amount _θbr detected by the brake sensor 23 continues for a predetermined time step or more until the previous time step, and is equal to or greater than a predetermined threshold θ _{th0. When the value} falls below _th0 , it is determined that the operation from on to off of the brake has been performed.
[0030]
When it is determined that the operation from the on to the off of the brake has been performed, the process proceeds to step S3, and Flag 0 indicating that the applied propulsive force is set is turned on. In step S4, a time change schedule of applied acceleration is set. For example, the acceleration time change schedule is set with reference to the inter-vehicle distance information and the relative speed with the preceding vehicle obtained from the laser radar sensor 31 via the inter-vehicle distance ECU 30. In addition, when the vehicle speed of the own vehicle is not sufficient and the inter-vehicle distance information with the current preceding vehicle cannot be accurately grasped, the acceleration time change schedule may be set with reference to the accumulated inter-vehicle distance information.
[0031]
When the steering angle sensor 21 and the yaw rate sensor 22 detect that the steering or the running state is unstable, it is preferable to change the acceleration time change schedule according to the running state. As a result, it is possible to apply an appropriate acceleration according to the running state, and it is possible to accelerate according to the driver's intention.
[0032]
Furthermore, it is possible to suppress the occurrence of slip at the time of acceleration by determining the slipperiness of the wheel on the running road surface from the previous braking state and controlling the acceleration time change schedule according to the determination result. preferable.
[0033]
The target throttle opening θt is set from the acceleration time change schedule thus set (step S5), and the throttle control motor 15 is controlled to control the target throttle opening (step S6). To get the target driving force and acceleration.
[0034]
FIG. 4 is a diagram for explaining an actual throttle opening control schedule. Here, it is assumed that the brake is turned off at time t ₀ . A time variation curve of the throttle according to the above-mentioned applied propulsive force setting schedule is A, and a time variation curve of the throttle when only the inter-vehicle distance ECU 30 is controlled is B.
[0035]
Since the throttle control by the inter-vehicle distance ECU 30 starts from a time t ₁ after a time has elapsed since the brake was turned off, the driver feels a delay in starting acceleration, and thus feels uncomfortable with the inter-vehicle distance control. According to the present invention, from the point of time when the brake is turned off, the throttle is gradually opened toward the throttle opening degree θx for obtaining the target acceleration to obtain the applied propulsive force, thereby quickly accelerating.
[0036]
In subsequent step S7, it is determined whether or not the applied propulsive force is in an off state. When the imparting propulsive force is set and the determination result is NO, the process proceeds to step S8, where Flag1 that determines whether or not the normal inter-vehicle control is permitted is set to OFF, and the process ends. In this case, the normal inter-vehicle distance control process is skipped.
[0037]
If the determination result in step S2 is NO, that is, if the brake is continuously on or off, or if the brake is changed from off to on, the process proceeds to step S11 and the applied propulsive force The state of Flag0 indicating the setting state is determined.
[0038]
If Flag0 is off, it is determined that the brake is continuously on, and subsequent processing is skipped and the processing ends. On the other hand, if Flag0 is on, the process proceeds to step S12, and it is determined whether or not the accelerator operation is performed based on the detection output of the accelerator sensor 11. When the accelerator operation is performed, the process proceeds to step S20, and the process proceeds to the propulsive force control process shown in FIG. On the other hand, if it is determined that the accelerator operation is not performed, the process proceeds to step S13, where the brake operation amount _θbr is less than the predetermined threshold value _θth , and the operation time _tbr is equal to the predetermined threshold value tbr. It is determined whether it is less than _th .
[0039]
If the condition is met, the brake operation is not performed, or even if the brake operation is performed, the operation is short and the operation amount is small, and the driver does not intend the braking operation. It estimates and transfers to step S14. On the other hand, if the condition is not satisfied, it is estimated that the driver is intentionally performing the braking operation, the process proceeds to step S30, and the process proceeds to the applied propulsion force canceling process shown in FIG.
[0040]
In step S14, it is determined whether the inter-vehicle distance control condition is satisfied. Specifically, it may be determined that the control condition is satisfied when the throttle opening to be set by the inter-vehicle control exceeds the set throttle opening (after time t _{2 in} FIG. 4). Applicable).
[0041]
When the determination result is NO, the process proceeds to step S5 and the propulsive force application control is continued. On the other hand, if the determination result is YES, the process proceeds to step S15, where Flag0 is turned off in order to cancel the propulsive force application control, and Flag1 is set off in order to allow normal inter-vehicle distance control (step S15). S16), the process is terminated. As a result, in FIG. 4, the throttle opening changes from time t _{0 to} time t _{2 as} indicated by the broken line A, and changes from time t ₂ to time according to the solid line B. It becomes possible to smoothly shift to inter-vehicle distance control.
[0042]
After the propulsive force control process at step S20 and the imparted propulsive force release process at step S30 are performed, the process proceeds to step S40, and Flag1 is set to OFF in order to skip the normal inter-vehicle distance control. Exit.
[0043]
Next, details of the propulsive force control process in step S20 will be described with reference to the flowchart shown in FIG. First, in step S21, the throttle opening degree θa calculated from the accelerator operation amount is calculated, while in step S22, the throttle opening degree θb calculated from the set acceleration is calculated. In step S23, the calculated θa and θb are compared. If θa is large, θa is set as the set throttle opening θt (step S24), and Flag0 is turned off in order to cancel the propulsive force application control (step S26). ). On the other hand, when θb is large, θb is set as the set throttle opening degree θt (step S25). In either case, the process thereafter proceeds to step S27, the throttle opening is controlled to the set opening θt, and the process is terminated.
[0044]
In this example, θa and θb are compared and an example of shifting to the driver's accelerator operation when θa becomes large has been described. However, by controlling θt to gradually approach θa, the applied propulsive force can be reduced. You may perform control to reduce gradually.
[0045]
By doing so, it is possible to smoothly shift to acceleration by the accelerator operation, and the driver can perform the switching operation from the brake to the accelerator with a margin, so that drivability is improved. .
[0046]
Next, the details of the imparted driving force canceling process in step S30 will be described with reference to the flowchart shown in FIG. In step S31, the speed at which the throttle is closed is set from the amount of brake operation and the rate of change over time. Specifically, it is preferable to set the throttle closing speed faster as the amount of brake operation is larger and as the rate of time change toward the operating side is larger.
[0047]
Subsequently, in step S32, the throttle opening degree θt is calculated from the set throttle closing speed, and in step S33, the throttle is closed based on this. In step S34, it is determined whether or not the throttle is in a fully closed state. If the throttle is in the fully closed state, Flag0 is turned off (step S35) in order to cancel the propulsive force application control. finish.
[0048]
In addition to the above control, the propulsive force application control may be set not to be performed when the inter-vehicle distance from the preceding vehicle is sufficiently wide. This is because it is presumed that the driver desires to continue the constant speed driving even when the brake is off during the cruise control when the distance between the preceding vehicle and the preceding vehicle is sufficient. The same thing can be said even during high-speed driving, but excessive acceleration may be contrary to the driver's intention. In such a case, there is an effect of preventing deterioration of fuel consumption by prohibiting or restricting acceleration.
[0049]
On the other hand, under conditions where the vehicle speed is low such as traffic jams and the distance between the vehicles is narrow, according to the conventional technology, frequent accelerator and brake operations are required.However, according to the present invention, deceleration and acceleration can be performed only by the brake operation. Since it can be controlled over a wide range, drivability is improved.
[0050]
【The invention's effect】
As described above, according to the present invention, the vehicle speed control performance by the brake operation is improved, and the shift from the brake operation to the accelerator operation can be performed with a margin. As a result, it is possible to prevent a delay in starting at the time of cruise control and suppress deterioration of drivability.
[Brief description of the drawings]
FIG. 1 is a block diagram showing a schematic configuration of a vehicle driving support apparatus according to the present invention.
FIG. 2 is a diagram for explaining control of cruise control.
FIG. 3 is a flowchart showing a control process in the apparatus of FIG. 1;
FIG. 4 is a diagram for explaining a time change schedule of acceleration in the process of FIG. 3;
FIG. 5 is a flowchart showing details of a propulsive force control process in FIG. 3;
6 is a flowchart showing details of an applied propulsion force releasing process in FIG. 3;
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Own vehicle, 2 ... Prior vehicle, 10 ... Engine ECU, 11 ... Accelerator sensor, 12 ... Vehicle speed sensor, 13 ... Shift sensor, 14 ... Cruise control switch, 15 ... Throttle control motor, 16 ... Shift controller, 17 ... Inter-vehicle distance Distance setting switch, 18 ... Rain sensor, 20 ... Brake ECU, 21 ... Steering angle sensor, 22 ... Yaw rate sensor, 23 ... Brake sensor, 24 ... Brake actuator, 25 ... Stop lamp, 30 ... Inter-vehicle distance ECU, 31 ... Laser radar Sensor, 40 ... display system.

Claims (7)

A driving support device for a vehicle that controls the propulsive force of the host vehicle based on the correspondence between the preceding vehicle and the host vehicle,
Brake operation amount detection means for detecting the brake operation amount of the driver;
Vehicle speed detection means for detecting the vehicle speed of the vehicle;
An accelerator operation amount detection means for detecting the driver's accelerator operation amount;
An inter-vehicle distance control means for automatically maintaining the inter-vehicle distance from the preceding vehicle when the accelerator operation amount detected by the accelerator operation amount detection means is within a preset range;
Even in the setting state of the inter-vehicle distance control, the detected vehicle speed is equal to or lower than a predetermined speed, the brake operation is changed from the on state to the off state, and the off state continues, and the inter-vehicle distance control means is Control means for increasing the propulsive force of the vehicle as compared to the normal inter-vehicle distance control until the accelerator operation amount range condition for performing the distance control is satisfied,
A vehicle driving support apparatus comprising: Wherein when the brake operation is turned on when to increase the driving force, according to claim 1, wherein the tapering thrust that is increased than usual in accordance with the operation state Vehicle driving support device. 3. The driving support apparatus for a vehicle according to claim 2 , wherein when the brake operation is less than a predetermined time and less than a predetermined amount, the propulsion force increase control is continued. Further comprising a steering angle detecting means for detecting the steering angle, the control means according to claim 1, characterized in that an upper limit value of the acceleration or acceleration during the propulsion force increase control in accordance with a steering angle Vehicle driving support device. And determining means for determining the ease of slipping of the wheels on the road surface, wherein the control means controls the propulsive force applied during the propulsive force increase control according to the determined slip ease. The driving support apparatus for a vehicle according to claim 1 . It said control means detected driving support apparatus for a vehicle according to claim 1, wherein the tapering thrust that is increased than usual in accordance with the accelerator opening. The vehicle driving support device according to any one of claims 1 to 6 , wherein when the preceding vehicle is not detected within a predetermined range, the control means prohibits or restricts the propulsive force increase control.

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